Heat cycle
The waste heat recovering operation mode (a Rankine cycle) is started and operated for a predetermined period of time T1 (s) (S430 to S450). In the case where the difference (P2−P1) between the upstream pressure P1 and the downstream pressure P2 of the liquid pump is higher than the predetermined pressure P, the waste heat recovering operation mode is continued. In the case where the difference (P2−P1) is not more than the predetermined pressure P, after the air conditioning mode is started (S480 to S500), the waste heat recovering operation mode is started again (S430 to S450). Due to the foregoing, it is possible to provide a heat cycle, which is provided with a refrigerating cycle and a Rankine cycle which are changeable each other, in which an incomplete start at the time of Rankine cycle can be reduced and a deterioration of the cycle efficiency can be reduced.
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1. Field of the Invention
The present invention relates to Rankine cycle in which power is obtained from heat energy given to a refrigerant.
2. Description of the Related Art
Conventionally, a heat cycle device referred to as a refrigerating cycle device has been known, and a heat cycle device referred to as Rankine cycle device has also been known. According to the refrigerating cycle device, when refrigerant is compressed being given power so as to transfer heat, a high or a low temperature can be provided. According to Rankine cycle device, power can be obtained from heat energy given to refrigerant. For example, a Rankine cycle device is disclosed in Japanese Granted Patent Publication No. 3356449 and of Japanese Unexamined Utility Model Publication No. 63-92021. These Rankine cycle device can be used as an electric power generating device in which waste heat is recovered so as to generate electric power. Alternatively, this Rankine cycle device can be used as an automotive power generating device in which waste heat of an internal combustion engine of an automobile is recovered so as to generate automotive power.
In Japanese Patent Application No. 2003-390893, the present inventors proposed an air conditioner (refrigerating cycle) for vehicle use having Rankine cycle for recovering heat energy from waste heat exhausted from an engine mounted on a vehicle. This air conditioner for vehicle use will be referred to as an example of the prior application.
This example of the prior application will be explained below by referring to
Further, this prior application includes a liquid-phase pipe 31 for connecting the pipe composing the refrigerating cycle with the vapor generator 30; and a liquid pump 32, which is arranged in the liquid-phase pipe 31, for moving the liquid-phase refrigerant to the vapor generator 30. The prior application further includes: components to compose a Rankine cycle device to provide a waste heat recovery operation mode (Rankine cycle operation) in which the refrigerant is made to flow in the order of the liquid pump 32→the vapor generator 30→the reversible rotary machine 10→the radiator 11.
Due to the foregoing, at the time of the air conditioning operation mode, the vehicle room can be air-conditioned, and at the time of the waste heat recovering operation mode, the waste heat exhausted from the engine 20 can be recovered by the reversible rotary machine 10 in the form of power.
However, in the example of the prior application, the following cases may occur. In the case where a quantity of the refrigerant staying the gas-liquid separator 12 is small on the basis of a state of operation of the air conditioner (the refrigerating cycle) for vehicle use or in the case where the liquid-phase refrigerant inside the liquid pump 32 is evaporated by a rise in the temperature inside the liquid pump 32, bubbles of the gas-phase refrigerant may enter into the inside of the liquid pump 32, and the liquid-phase refrigerant can not be moved to the vapor generator 30 even when the liquid pump 32 is operated. Due to the foregoing, there is a possibility that it becomes impossible to normally operate the waste heat recovering operation mode (Rankine cycle).
Even in the case where the liquid pump 32 can move the liquid-phase refrigerant to the vapor generator 30, the operation efficiency of the liquid pump 32 is lowered by the bubbles of the gas-phase refrigerant mixed into the liquid pump 32. In other words, a quantity of the refrigerant to be conveyed is decreased with respect to the power consumption of the pump. That is, a quantity of the refrigerant to be supplied to the vapor generator 30 is decreased, and there is a possibility that the efficiency of a Rankine cycle may be lowered.
One object of the present invention is to reduce the possibility of the occurrence of an incomplete start of a Rankine cycle device.
Another object of the present invention is to reduce the possibility of the deterioration of the efficiency of a Rankine cycle device.
Still another object of the present invention is to make it possible to stably operate a Rankine cycle device by utilizing the function of a refrigerating cycle device in the heat cycle device which can be used for both the Rankine cycle device and the refrigerating cycle device.
SUMMARY OF THE INVENTIONIn order to accomplish the above objects, the present invention employs the following technical means.
The invention described in aspect 1 employs a heat cycle device comprising: a rotary fluid machine (10, 10b, 10c) for mutually converting between fluid energy of refrigerant and mechanical rotary energy; a condenser (11) for condensing the refrigerant supplied from the rotary fluid machine (10, 10b, 10c); a Rankine cycle system (10, 11, 30, 32, 300) including a fluid pump (32, 300) for moving the refrigerant supplied from the condenser (11) and also including a vapor generator (30) for heating the refrigerant, which has been moved by the fluid pump, by the heat of a heat generating body (20); a refrigerating cycle system (10, 11, 13, 14) including an evaporator (14) for evaporating the refrigerant supplied from the condenser (11); and a control unit (40) for conducting a refrigerant condensing operation in which the refrigerant in the refrigerating cycle system (10, 11, 13, 14) is compressed by the rotary fluid machine (10, 10b, 10c) at the time of operating the Rankine cycle system (10, 11, 30, 32, 300) and the compressed refrigerant is condensed by the condenser (11).
According to this invention, when a Rankine cycle system is operated, the refrigerant in the refrigerating cycle system is compressed by the rotary fluid machine and condensed by the condenser. Therefore, the liquid-phase refrigerant can be supplied to a Rankine cycle system. As a result, it is possible to suppress the occurrence of an incomplete start of a Rankine cycle system. Further, it is possible to suppress the deterioration of the efficiency during the operation.
The invention described in aspect 2 employs a heat cycle device according to aspect 1, the control unit (40) including: a judging means for judging whether or not the Rankine cycle system (10, 11, 30, 32, 300) is normally operated after the operation of the Rankine cycle system (10, 11, 30, 32, 300) was started; and a control means for continuing the operation of the Rankine cycle system (10, 11, 30, 32, 300) in the case where it is judged that the Rankine cycle system (10, 11, 30, 32, 300) is normally operated, and for conducting the refrigerant condensing operation in the case where it is judged that the Rankine cycle system (10, 11, 30, 32, 300) is not normally operated.
According to this invention, when it is judged that the Rankine cycle system is not normally operated, the refrigerant condensing operation is executed. Therefore, the liquid-phase refrigerant can be supplied to the Rankine cycle system. Accordingly, it is possible to suppress the occurrence of an abnormal state caused by lack of the liquid-phase refrigerant.
According to one embodiment of the present invention, the refrigerant condensing operation can be executed when the operation of the Rankine cycle system is temporarily stopped. According to another embodiment of the present invention, the refrigerant condensing operation can be executed simultaneously while the operation of the Rankine cycle system is being continued.
The invention described in aspect 3 employs a heat cycle device according to aspect 2, further comprising: an upstream refrigerant pressure sensor (42) for measuring pressure of the refrigerant, arranged in an upstream side portion of the refrigerant flow of the fluid pump (32, 300); and a downstream refrigerant pressure sensor (43) for measuring pressure of the refrigerant, arranged in a downstream side portion of the refrigerant flow of the fluid pump (32, 300), wherein the judging means judges that the Rankine cycle (10, 11, 30, 32, 300) is normally operated at the time of operating the Rankine cycle system (10, 11, 30, 32, 300) in the case where a difference (P2−P1) between the detected pressure (P2) of the downstream refrigerant pressure sensor (43) and the detected pressure (P1) of the upstream refrigerant pressure sensor (42) is larger than the predetermined pressure (P), and the judging means judges that the Rankine cycle (10, 11, 30, 32, 300) is not normally operated at the time of operating the Rankine cycle system (10, 11, 30, 32, 300) in the case where the difference (P2−P1) between the detected pressure (P2) of the downstream refrigerant pressure sensor (43) and the detected pressure (P1) of the upstream refrigerant pressure sensor (42) is not more than the predetermined pressure (P).
According to this invention, it is possible to appropriately judge an abnormality of the Rankine cycle system caused by a lack of the liquid-phase refrigerant.
The invention described in aspect 4 employs a heat cycle device according to aspect 2, wherein the judging means judges that the Rankine cycle system (10, 11, 30, 32, 300) is normally operated in the case where a work-load of the liquid pump (32, 300) is heavier than a predetermined work-load at the time of operating the Rankine cycle system (10, 11, 30, 32, 300), and the judging means judges that the Rankine cycle system (10, 11, 30, 32, 300) is not normally operated in the case where the work-load of the liquid pump (32, 300) is not more than the predetermined work-load at the time of operating the Rankine cycle system (10, 11, 30, 32, 300).
According to this invention, it is possible to appropriately judge an abnormality of the Rankine cycle system caused by a lack of the liquid-phase refrigerant.
The invention described in aspect 5 employs a heat cycle device according to aspect 4, wherein the liquid pump is an electric liquid pump (32), and the work-load is represented by electric power consumed by the electric liquid pump (32).
According to this invention, it is possible to judge an abnormality of the Rankine cycle system by a simple structure.
The invention described in aspect 6 employs a heat cycle device according to one of aspects 1 to 5, further comprising an air blowing means (14a) for blowing air, the temperature of which is adjusted by the refrigerating cycle system (10, 11, 13, 14), wherein the control unit (40) conducts the refrigerant condensing operation under the condition that the air blowing means (14a) is not operated.
According to this invention, the refrigerant condensing operation can be provided when the cooling device or the refrigerating device in the refrigerating cycle system is operated, and a state in which the blast means is not operated is provided by the means for providing the operation in which the liquid-phase refrigerant is increased. As a result, the liquid-phase refrigerant can be positively supplied.
The invention described in aspect 7 employs a heat cycle device according to one of aspects 1 to 6, further comprising a sensor (46, 47) for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump (32, 300), wherein the control unit (40) determines the time, which has passed from the start of the refrigerant condensing operation to when the physical value measured by the sensor (46, 47) shows that the refrigerant inside the refrigerant pump (32) is in the supercooled state, to be the continuation time for continuing the refrigerant condensing operation.
According to this invention, it is possible to suppress an excessive refrigerant condensing operation.
The invention described in aspect 8 employs a heat cycle device according to one of aspects 1 to 6, wherein the condenser (11) is a heat exchanger for condensing the refrigerant by exchanging heat between the outside air and the refrigerant, the heat cycle device further comprising: an outside air temperature sensor (45) for measuring the temperature of the outside air; and a sensor (46, 47) for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump (32, 300), wherein the control unit (40) determines a target temperature at which the refrigerant inside the refrigerant pump (32) is in the supercooled state according to the outside air temperature measured by the outside air temperature sensor (45), and further the control unit (40) determines the time, which has passed from the start of the refrigerant condensing operation to when the physical value measured by the sensor (46, 47) becomes the target temperature, to be the continuation time for continuing the refrigerant condensing operation.
According to this invention, it is possible to suppress an excessive refrigerant condensing operation.
The invention described in aspect 9 employs a heat cycle device according to aspect 7 or 8, wherein the sensor is a temperature sensor (46) for measuring the temperature of the housing of the refrigerant pump.
According to this invention, it is possible to provide a simple structure of the heat cycle device.
The invention described in aspect 10 employs a heat cycle device according to aspect 7 or 8, wherein the sensor is a temperature sensor (47) for measuring the temperature of air immediately after heat was exchanged with the refrigerant in the evaporator (14).
According to this invention, it is possible to provide a simple structure of the heat cycle device.
The invention described in aspect 11 employs a heat cycle device according to one of aspects 1 to 6, wherein the condenser (11) is a heat exchanger for condensing the refrigerant by exchanging heat between the outside air and the refrigerant, further comprising an outside air temperature sensor (45) for measuring the outside air temperature, wherein the control unit (40) includes a continuation time setting means for determining the continuation time (T21), in which the refrigerant condensing operation is continued, according to the temperature measured by the outside air temperature sensor (45).
According to this invention, it is possible to suppress an excessive refrigerant condensing operation.
The invention described in aspect 12 employs a heat cycle device according to one of aspects 1 to 11, wherein the rotary fluid machine is a reversible rotary machine (10) capable of being reversibly operated as an expansion machine for obtaining power when the refrigerant is expanded, or operated as a compressor for compressing the refrigerant when power is supplied to the compressor.
According to this invention, when the rotary fluid machine, which can reversibly function as an expansion machine or a compressor, is used, the refrigerant condensing operation can be executed when the rotary fluid machine functions as a compressor at the time of operating the Rankine cycle system.
The invention described in aspect 13 employs a heat cycle device according to aspect 12, wherein the control unit (40) conducts the refrigerant condensing operation by operating the rotary fluid machine as a compressor before the rotary fluid machine is operated as an expansion machine and the operation of the Rankine cycle system (10, 11, 30, 32, 300) is started.
According to this invention, when the rotary fluid machine is made to function reversibly, the refrigerant condensing operation can be realized before the operation of the Rankine cycle system is started.
The invention described in aspect 14 employs a heat cycle device according to aspect 12 or 13, wherein the reversible rotary machine (10) is integrated with the fluid pump (32, 300) into one body, and the fluid pump (32, 300) is arranged so that it can be cooled by the gas-phase refrigerant sucked into the reversible rotary machine (10) at the time of operating the refrigerating cycle system (10, 11, 13, 14).
According to this invention, the temperature of the liquid pump can be decreased when the refrigerating cycle system is operated.
The invention described in aspect 15 employs a heat cycle device according to one of aspects 1 to 11, wherein the rotary fluid machine includes an expansion machine (10c) for expanding the refrigerant to obtain power and a compressor (10b) for compressing the refrigerant when power is supplied to the compressor.
According to this invention, when both the expansion machine and the compressor are provided, the refrigerant condensing operation can be executed by using the compressor function at the time of operating Rankine cycle system.
The invention described in aspect 16 employs a heat cycle device according to aspect 15, wherein the control unit (40) conducts the refrigerant condensing operation by operating the compressor (10b) before the expansion machine (10c) is operated and the operation of the Rankine cycle system (10, 11, 30, 32, 300) is started.
According to this invention, it is possible to realize the refrigerant condensing operation before the operation of Rankine cycle system is conducted.
The invention described in aspect 17 employs a heat cycle device according to aspect 15, wherein the control unit (40) conducts the refrigerant condensing operation by operating the compressor (10b) simultaneously when the expansion machine (10c) is operated and the operation of the Rankine cycle system (10, 11, 30, 32, 300) is started.
According to this invention, at the time of starting the Rankine cycle system, the refrigerant condensing operation can be realized. The refrigerant condensing operation can be executed in parallel with the operation of the Rankine cycle system.
The invention described in aspect 18 employs a heat cycle device comprising: a Rankine cycle system (10, 11, 30, 32, 300) including a fluid pump (32, 300) for moving refrigerant and also including a vapor generator (30) for heating the refrigerant, which has been moved by the fluid pump, by the heat of a heat generating body (20); a refrigerating cycle system (10, 11, 13, 14) including an evaporator (14) for evaporating the refrigerant; and a control unit (40) for conducting the cooling operation for cooling the fluid pump by operating the refrigerating cycle system (10, 11, 13, 14) at the time of operating the Rankine cycle system (10, 11, 30, 32, 300).
According to this invention, when the Rankine cycle system is operated, the liquid pump can be cooled. Therefore, it is possible to prevent the occurrence of a problem caused by the gas-phase refrigerant.
The invention described in aspect 19 employs a heat cycle device according to aspect 18, wherein the refrigerating cycle system includes a compressor (10, 10b), and the fluid pump (32, 300) is arranged so that it can be cooled by the gas-phase refrigerant sucked into the compressor (10, 10b).
According to this invention, the rotary machine can be integratedly arranged. Further, in this constitution, it is possible to cool the liquid pump.
The invention described in aspect 20 employs a heat cycle device according to aspect 18 or 19, wherein the control unit (40) conducts the cooling operation before the operation of the Rankine cycle system (10, 11, 30, 32, 300) is started and/or while the Rankine cycle system (10, 11, 30, 32, 300) is being operated.
According to this invention, the liquid pump can be cooled. Therefore, it is possible to prevent the occurrence of a problem caused by the gas-phase refrigerant. When the cooling operation is executed before the operation of the Rankine cycle system is started, it is possible to reduce the gas-phase refrigerant in the liquid pump. Therefore, the occurrence of an incomplete start of the Rankine cycle system can be suppressed. When the cooling operation is executed in the beginning of the start of the Rankine cycle system, that is, when the cooling operation is executed immediately after the Rankine cycle system is started, it is possible to suppress the occurrence of an incomplete start of the Rankine cycle system. When the cooling operation is executed during the operation of the Rankine cycle system, it is possible to suppress a deterioration of the efficiency of the Rankine cycle system.
The present invention has been devised in order to accomplish the above objects. The invention described in aspect 21 provides a heat cycle comprising: a refrigerating cycle (10, 11, 13, 14) in which refrigerant of low pressure is evaporated so as to absorb heat from a low temperature side and the evaporated gas-phase refrigerant is compressed so as to raise the temperature and the heat absorbed from the low temperature side is radiated to a high temperature side so as to condense the gas-phase refrigerant into the liquid-phase refrigerant; a Rankine cycle (10, 11, 30, 32) including a vapor generator (30) for generating the gas-phase refrigerant by heating the liquid-phase refrigerant of the refrigerating cycle (10, 11, 12, 14) by the waste heat of a heat generating body (20), also including a liquid-phase pipe (31) for connecting a liquid-phase takeout section (12, 52) for taking out the liquid-phase refrigerant from the refrigerating cycle (10, 11, 13, 14) with the vapor generator (30), also including a liquid pump (32, 300) arranged in the liquid-phase pipe (31), for moving the liquid-phase refrigerant to the vapor generator (30), also including an expansion machine (10) for obtaining power by expanding the gas-phase refrigerant, and also including a condenser (11) for condensing the gas-phase refrigerant which has been expanded by the expansion machine (10); a control means (40) for controlling a state of operation of the refrigerating cycle (10, 11, 13, 14) and also controlling a state of operation of a Rankine cycle (10, 11, 30, 32, 300); and a change-over means (35a, 36) for changing over between a case in which a Rankine cycle (10, 11, 30, 32, 300) is operated and a case in which the refrigerating cycle (10, 11, 13, 14) is operated by a signal sent from the control means (40), wherein the control means (40) operates Rankine cycle (10, 11, 30, 32, 300) in such a manner that the refrigerating cycle (10, 11, 13, 14) is operated by the refrigerant condensing operation so as to condense the gas-phase refrigerant into the liquid-phase refrigerant and then the Rankine cycle (10, 11, 30, 32, 300) is operated.
Due to the foregoing, when the refrigerating cycle (10, 11, 13, 14) is operated before the Rankine cycle (10, 11, 30, 32, 300) is operated, the gas-phase refrigerant can be condensed to the liquid-phase refrigerant. As a result, the liquid pump (32, 300) can positively suck the liquid-phase refrigerant from the liquid-phase refrigerant takeout section (12, 52) and move it to the vapor generator 30. Accordingly, the Rankine cycle (10, 11, 30, 32, 300) can be normally started.
In addition, it is possible to suppress a deterioration of the operation efficiency of the liquid pump (32, 300) caused by bubbles in the gas-phase refrigerant. Therefore, it is possible to prevent the efficiency of Rankine cycle from being deteriorated.
The invention described in aspect 22 provides a heat cycle comprising: a refrigerating cycle (10, 11, 13, 14) in which refrigerant at low pressure is evaporated so as to absorb heat from a low temperature side and the evaporated gas-phase refrigerant is compressed so as to raise the temperature and the heat absorbed from the low temperature side is radiated to a high temperature side so as to condense the gas-phase refrigerant into the liquid-phase refrigerant; a Rankine cycle (10, 11, 30, 32, 300) including a vapor generator (30) for generating the gas-phase refrigerant by heating the liquid-phase refrigerant of the refrigerating cycle (10, 11, 12, 14) by the waste heat of a heat generating body (20), also including a liquid-phase pipe (31) for connecting a liquid-phase takeout section (12, 52) for taking out the liquid-phase refrigerant from the refrigerating cycle (10, 11, 13, 14) with the vapor generator (30), also including a liquid pump (32, 300) arranged in the liquid-phase pipe (31), for moving the liquid-phase refrigerant to the vapor generator (30), also including an expansion machine (10) for obtaining power by expanding the gas-phase refrigerant, and also including a condenser (11) for condensing the gas-phase refrigerant which has been expanded by the expansion machine (10); a control means (40) for controlling a state of operation of the refrigerating cycle (10, 11, 13, 14) and also controlling a state of operation of the Rankine cycle (10, 11, 30, 32, 300); and a change-over means (35a, 36) for changing over between the case in which the Rankine cycle (10, 11, 30, 32, 300) is operated and the case in which the refrigerating cycle (10, 11, 13, 14) is operated by a signal sent from the control means (40) wherein, after the Rankine cycle (10, 11, 30, 32, 300) has been operated, the control means (40) judges whether or not the Rankine cycle (10, 11, 30, 32, 300) is normally operated, the Rankine cycle (10, 11, 30, 32, 300) is kept being operated in the case where the operation of the Rankine cycle (10, 11, 30, 32, 300) has been judged to be normal, and in the case where the operation of the Rankine cycle (10, 11, 30, 32, 300) has been judged to be not normal, the control means (40) operates in such a manner that it stops operation of the Rankine cycle (10, 11, 30, 32, 300) and operates the refrigerating cycle (10, 11, 13, 14) so as to conduct the refrigerant condensing operation for recovering the liquid-phase refrigerant and Rankine cycle (10, 11, 30, 32, 300) is operated again after the refrigerant condensing operation.
Due to the foregoing, and only when Rankine cycle (10, 11, 30, 32, 300) is abnormally operated, the refrigerating cycle (10, 11, 13, 14) is operated and the same effect as that of aspect 1 can be exhibited. Therefore, it is possible to prevent the occurrence of a case in which the refrigerating cycle is unnecessarily operated before the Rankine cycle (10, 11, 30, 32, 300) is operated.
The invention described in aspect 23 provides a heat cycle according to aspect 22, further comprising: an upstream refrigerant pressure sensor (42) arranged in a portion on the upstream side of the flow of the refrigerant of the liquid pump (32, 300), the upstream refrigerant pressure sensor (42) outputting a signal of the refrigerant pressure to the control means (40); and a downstream refrigerant pressure sensor (43) arranged in a portion on the downstream side of the flow of the refrigerant of the liquid pump (32; 300), the downstream refrigerant pressure sensor (43) outputting a signal of the refrigerant pressure to the control means (40) wherein, in the case where a value (P2−P1), which is obtained when a detected pressure value (P1) of the upstream refrigerant pressure sensor (42) is subtracted from a detected pressure value (P2) of the downstream refrigerant pressure sensor (43), is higher than a predetermined pressure value (P) when the Rankine cycle (10, 11, 30, 32, 300) is operated, the control means (40) judges that the Rankine cycle (10, 11, 30, 32, 300) is normally operated, and in the case where the value (P2−P1), which is obtained when the detected pressure value (P1) of the upstream refrigerant pressure sensor (42) is subtracted from the detected pressure value (P2) of the downstream refrigerant pressure sensor (43), is not more than the predetermined pressure value (P), the control means (40) judges that the Rankine cycle (10, 11, 30, 32, 300) is not normally operated.
In this connection, when the liquid pump (32, 300) is normally operated, the detected pressure (P1) of the upstream refrigerant pressure sensor (42) is lower than the detected pressure (P2) of the downstream refrigerant pressure sensor (43). Therefore, and specifically when the difference (P2−P1) is not more than the predetermined pressure (P), it is possible to judge that the Rankine cycle (10, 11, 30, 32, 300) is not normally operated.
According to the invention described in aspect 24, there is provided a heat cycle according to aspect 22, in which the control means (40) judges that the Rankine cycle (10, 11, 30, 32, 300) is normally operated in the case where a work-load of the liquid pump (32, 300) is more than a predetermined work-load when the Rankine cycle (10, 11, 30, 32, 300) is operated, and the control means (40) judges that the Rankine cycle (10, 11, 30, 32, 300) is not normally operated in the case where the work-load of the liquid pump (32, 300) is not more than the predetermined work-load when the Rankine cycle (10, 11, 30, 32, 300) is operated.
The invention described in aspect 25 provides a heat cycle according to aspect 24, in which the liquid pump is an electric liquid pump (32) driven by electricity, and the work-load is representated by electric power consumed by the electrically driven liquid pump (32). Thus, the work-load can be specifically calculated.
According to the invention described in aspect 26, there is provided a heat cycle according to one of aspects 21 to 25, in which the expansion machine is a reversible rotary machine (10) having the function of a compressor for compressing the gas-phase refrigerant in the refrigerating cycle (10, 11, 13, 14), the reversible rotary machine (10) is composed being integrated with the liquid pump (32, 300), and the liquid pump (32, 300) is cooled by the gas-phase refrigerant sucked into the reversible rotary machine (10) at the time of operating the refrigerating cycle (10, 11, 13, 14).
Due to the foregoing, the liquid pump (32, 300) is cooled by the gas-phase refrigerant of low temperature which is sucked when the reversible rotary machine (10) functions as a compressor. Therefore, the liquid-phase refrigerant inside the liquid pump (32, 300) is supercooled and the refrigerant inside the liquid pump (32, 300) can be prevented from evaporating. Accordingly, the liquid-phase refrigerant can be positively moved to the vapor generator 30.
As the liquid pump (32, 300) and the expansion machine (10) are integrated with each other into one body, the parts composing the liquid pump (32, 300) and the expansion machine (10) can be used in common, which can make the fluid machine smaller in size.
The invention described in aspect 27 provides a heat cycle according to one of aspects 21 to 26, further comprising: an air blowing means (14a) for blowing air conditioned by the refrigerating cycle (10, 11, 13, 14); and an operation demand means (41) for demanding the operation of the refrigerating cycle wherein, in the case of conducting the refrigerant condensing operation, the control means (40) conducts the refrigerant condensing operation without operating the air blowing means (14a) when the operation of the refrigerating cycle (10, 11, 13, 14) is not demanded by the operation demand means (41).
Due to the foregoing, in the refrigerant condensing operation, in which the refrigerating cycle (10, 11, 13, 14) is operated even when an operator of the heat cycle do not demand the operation of the refrigerating cycle (10, 11, 13, 14), a blast of air, the temperature and humidity of which are adjusted, is not sent. Therefore, the refrigerant condensing operation can be conducted without causing discomfort to the operator. In this connection, in the present invention, the term air-conditioning includes temperature adjustment and humidity adjustment.
The invention described in aspect 28 provides a heat cycle according to one of aspects 21 to 27, wherein the condenser (11) is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant, the heat cycle further comprises an outside air temperature sensor (45) for measuring the temperature of the outside air, the control means (40) determines the continuation time (T21) for continuing the refrigerant condensing operation, and the continuation time (T21) is determined on the basis of the outside air temperature.
In this connection, in the refrigerating cycle, the condensing temperature and refrigerant pressure, at which the gas-phase refrigerant is condensed to the liquid-phase refrigerant, are determined by the outside air temperature. That is, in the case where the outside air temperature is high, the refrigerant pressure is increased so as to raise the condensing temperature. On the other hand, the higher the condensing temperature is, the higher the temperature the liquid-phase refrigerant is supercooled to.
Therefore, the control means (40) is made to determine the continuity time (T21) according to a relation between the outside air temperature and the period of time in which the liquid-phase refrigerant is supercooled by the continuous operation of the refrigerating cycle. As a result, the liquid-phase refrigerant can be positively cooled. Therefore, the liquid pump (32, 300) can positively supply the liquid-phase refrigerant to the vapor generator 30.
The invention described in aspect 29 provides a heat cycle according to one of aspects 21 to 27, further comprising a sensor (46, 47) for measuring a physical value having a correlation with a temperature of the refrigerant inside the liquid pump (32, 300), wherein the control means (40) determines the continuation time in which the refrigerant condensing operation is continued, and the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor (46, 47) becomes the temperature at which the refrigerant inside the refrigerant pump (32) is supercooled.
Due to the foregoing, the refrigerant inside the refrigerant pump (32) is positively put into the liquid-phase. Therefore, the liquid pump (32, 300) can positively supply the liquid-phase refrigerant to the vapor generator 30.
For example, when the refrigerant condensing operation is continued until the refrigerant temperature inside the refrigerant pump (32) becomes lower than the minimum refrigerant condensing temperature which is determined by the minimum outside air temperature in the heat cycle using environment, the above effect can be exhibited.
The invention described in aspect 30 provides a heat-cycle according to one of aspects 21 to 27, wherein the condenser (11) is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant, the heat cycle further comprises an outside air temperature sensor (45) for measuring the temperature of the outside air and also comprises a sensor (46, 47) for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump (32, 300), the control means (40) determines the temperature, at which the refrigerant inside the refrigerant pump (32) is supercooled by the outside air temperature, and also determines the continuation time in which the refrigerant condensing operation is continued, and the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor (46, 47) becomes the temperature at which the refrigerant inside the refrigerant pump (32) is supercooled.
Due to the foregoing, the invention provides the same effect as that of aspect 29 and, further, the temperature to which the refrigerant inside the liquid pump (32, 300) is supercooled is determined by the outside air temperature. Therefore, the continuation time of the refrigerant condensing operation can be reduced.
As described in aspect 31, in a heat cycle according to aspect 29 or 30, the sensor for measuring the physical value may be a temperature sensor (46) for measuring the temperature of the housing of the refrigerant pump.
As described in aspect 32, in a heat cycle according to aspect 29 or 30, the refrigerating cycle (10, 11, 13, 14) may include an evaporator (14) for evaporating the refrigerant of low pressure by exchanging heat between the refrigerant of low pressure and air, and the sensor for measuring the physical value may be a temperature sensor (47) for measuring the temperature of air immediately after heat is exchanged with the refrigerant of low pressure.
In this connection, reference numerals in the parentheses described in each means correspond to the specific means shown in the embodiment described later.
These and other objects, features and advantages of the present invention will be more apparent in light of the detailed description of exemplary embodiments thereof as illustrated by the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In one embodiment of the present invention, at the time of operating a Rankine cycle system, the refrigerating cycle system is operated. According to one of the features of the embodiment, in the refrigerating cycle system, a refrigerant condensing operation is conducted in which the refrigerant is compressed by a rotary fluid machine and condensed by a condenser. When this refrigerant condensing operation is conducted, the liquid-phase refrigerant can be positively supplied to the Rankine cycle system. The refrigerant condensing operation can be conducted before the Rankine cycle system is started, or in the beginning of the starting of the Rankine cycle system immediately after the start of the Rankine cycle system or during the operation of the Rankine cycle system. The refrigerant condensing operation can be started in accordance with a signal to indicate the start of Rankine cycle system. When the refrigerant condensing operation is executed before the operation of Rankine cycle system is started, the liquid-phase refrigerant can be positively supplied at the time of starting the Rankine cycle system. When the refrigerant condensing operation is executed simultaneously when the Rankine cycle system is started or immediately after the Rankine cycle system is started, the liquid-phase refrigerant can be positively supplied at the time of starting the Rankine cycle or in the beginning of starting the Rankine cycle. When the refrigerant condensing operation is executed during the operation of the Rankine cycle system, the liquid-phase refrigerant can be positively supplied during the operation of the Rankine cycle system. The refrigerant condensing operation can be started by judging whether or not the liquid-phase refrigerant needs to be supplied to the Rankine cycle system. For example, a trial run of the Rankine cycle system is made, and it is judged from the behavior of the Rankine cycle whether or not the liquid-phase refrigerant is needed. When it is judged that the supply of the liquid-phase refrigerant is needed, the refrigerant condensing operation is started. Alternatively, according to the accumulation of experiential data, an environmental condition in which the liquid-phase refrigerant is lacking is set and, when this condition is satisfied, the refrigerant condensing operation may be started. The refrigerant condensing operation can be stopped after it is conducted for a predetermined period of time or after it has been conducted for a variable period of time. For example, after a fixed constant period of time has passed, the refrigerant condensing operation can be stopped. Alternatively, when it is detected that the state has become a state in which the liquid-phase refrigerant can be supplied or when it is detected that the liquid-phase refrigerant is being stably supplied to Rankine cycle system, the refrigerant condensing operation may be stopped. The refrigerant condensing operation can be conducted when the refrigerating cycle system is operated as a cooling device or a refrigerating device. In this case, a means for increasing the amount of the liquid-phase refrigerant can be provided. For example, a means for providing a state in which an air blowing means for blowing air to the evaporator in the refrigerating cycle is not operated, can be arranged. Alternatively, a means for providing a state in which a volume of blast air is suppressed, can be arranged.
The rotary fluid machine can be provided by a device having both the function of an expansion machine and the function of a compressor. The rotary fluid machine can convert energy between fluid energy and mechanical energy generated by rotation. When the rotary fluid machine is rotated, the fluid is compressed from low pressure to high pressure. When the fluid is moved from the high pressure side to the low pressure side, rotation is generated. The rotary fluid machine may be a displacement type machine or non-displacement type machine. For example, it is possible to use a reversible fluid machine which can reversibly function as an expansion machine or a compressor. In this case, the operation of Rankine cycle system and the operation of the refrigerating cycle system can be selectively executed. In this constitution, before the operation of Rankine cycle system, the refrigerant condensing operation can be executed by the refrigerating cycle system. The rotary fluid machine can be provided with both the expansion machine and the compressor. In this case, the expansion machine and the compressor can be selectively operated. In addition to that, the expansion machine and the compressor can be simultaneously operated.
Another feature will be described below. In the operation of the refrigerating cycle system, the cooling operation for cooling the liquid pump is executed. When the liquid pump is cooled, it is possible to prevent the occurrence of a problem caused by the existence of the gas-phase refrigerant. The cooling operation can be executed before the operation of Rankine cycle system is started and during the operation of Rankine cycle system. When the cooling operation is executed before the operation of the Rankine cycle system is started, it is possible to reduce the gas-phase refrigerant in the liquid pump, and the occurrence of an incomplete start of Rankine cycle system can be suppressed. When the cooling operation is executed at the beginning of the start of the Rankine cycle system immediately after the operation of the Rankine cycle system is started, it is possible to suppress the occurrence of an incomplete start of the Rankine cycle system. When the cooling operation is executed during the operation of the Rankine cycle system, it is possible to prevent the efficiency of the Rankine cycle system from deteriorating. The liquid pump composing the Rankine cycle system can be arranged in the neighborhood of the suction passage of the compressor composing the refrigerating cycle system.
First Embodiment In this embodiment, the heat cycle of the present invention is applied to a vapor pressure compression type refrigerating machine (refrigerating cycle) having a Rankine cycle.
The reversible rotary machine 10 shown in
The motor generator 10a is operated as a power source for supplying power (torque) to the reversible rotary machine 10 in the case where the reversible rotary machine 10 is operated as a compressor. On the other hand, the motor generator 10a is a dynamo-electric machine operated as a generator for generating electric power from the power recovered by the expansion machine, that is, as a generator for generating electric power by the reversible rotary machine 10 in the case where the reversible rotary machine 10 is operated as an expansion machine. In this connection, the structure of the reversible rotary machine 10 will be described later.
The radiator 11 is connected to the discharge side of the reversible rotary machine 10 when the reversible rotary machine 10 is operated as a compressor, and heat is radiated from the refrigerant to the outside air. That is, the radiator 11 is a cooler for cooling the refrigerant by the outside air. The refrigerant flowing out from the radiator 11 flows into the gas-liquid separator 12 (receiver) for separating the gas-phase refrigerant and the liquid-phase refrigerant from each other.
The decompressor 13 decompresses and expands the liquid-phase refrigerant which has been separated by the gas-liquid separator 12. This embodiment adopts a temperature-type expansion valve which isentropically decomprresses the refrigerant and controls the degree of opening of the valve so that the degree of superheat of the refrigerant sucked into the reversible rotary machine 10 can become a predetermined value when the reversible rotary machine 10 is operated as a compressor.
The evaporator 14 is a heat absorber for absorbing heat from the refrigerant when the refrigerant decompressed by the decompressor 13 is evaporated. The refrigerant flowing out from the evaporator 14 flows into the reversible rotary machine 10 again. As described above, the vapor compression type refrigerating machine (the refrigerating cycle) to move the heat from the low temperature side to the high temperature side is composed of the compressor (the reversible rotary machine 10), the radiator 11, the gas-liquid separator 12, the decompressor 13 and the evaporator 14. In this connection, the evaporator 14 is provided with a blower 14a for sending a blast of air, which has been conditioned when the refrigerant is evaporated and absorbs heat, into a vehicle room. This blower 14a is controlled by the electronic control unit 40.
In this connection, this embodiment includes an engine cooling circuit for circulating the cooling water to cool the engine 20 which is a heat generating body. The water pump 22 arranged in the engine cooling circuit circulates the engine cooling water, and the radiator 23 is a heat exchanger for cooling the engine cooling water by exchanging heat between the engine cooling water and the outside air. The bypass circuit 24 is a detour circuit by which the cooling water can be flown while by passing the radiator 23, and the thermostat 25 is a flow regulating valve for adjusting a quantity of cooling water which flows into the bypass circuit 24, and a quantity of water which flows into the radiator 23.
In this connection, the water pump 22 is a mechanical type pump driven by the power of the engine 20. However, of course, the water pump 22 may be an electric pump driven by an electric motor.
There is provided a vapor generator 30 in a portion on the downstream side of the refrigerant flow of the engine 20 in the engine cooling circuit, and in the refrigerant circuit to connect the reversible rotary machine 10 with the radiator 11 in the refrigerating cycle. In this vapor generator 30, the refrigerant is heated when heat is exchanged between the refrigerant flowing in the refrigerant circuit and the engine cooling water which has recovered the waste heat from the engine 20.
The three-way valve 21 arranged in the engine cooling circuit changes over between a case in which the engine cooling water flowing out from the engine 20 is circulated in the vapor generator 30 and a case in which the engine cooling water flowing out from the engine 20 is not circulated in the vapor generator 30. In this embodiment, operation of the three-way valve 21 is controlled by the electronic control unit 40.
In this connection, the first bypass circuit 31, which is a liquid-phase pipe, is a refrigerant passage for introducing the liquid-phase refrigerant, which has been separated by the gas-liquid separator 12, to the refrigerant inlet and outlet side of the vapor generator 30 on the radiator 11 side. This first bypass circuit 31 includes: a liquid pump 32 to circulate the liquid-phase refrigerant; and a check valve 33a to allow the refrigerant to flow only onto the vapor generator 30 side from the gas-liquid separator 12 side. In this connection, in this embodiment, the liquid pump 32 is an electrically driven pump and is controlled by the electronic control unit 40.
The second bypass circuit 34 is a refrigerant passage to connect the refrigerant outlet side when the reversible rotary machine 10 is operated as an expansion machine, with the refrigerant inlet side of the radiator 11. This second bypass circuit 34 includes a check valve 33b to allow the refrigerant to flow only onto the refrigerant inlet side of the radiator 11 from the refrigerant outlet side when the reversible rotary machine 10 is operated as an expansion machine.
In this connection, the check valve 33c allows the refrigerant to flow only from the refrigerant outlet side of the evaporator 14 to the suction side of the compressor 10. The opening and closing valve 35a arranged between the vapor generator 30 and the radiator 11 is opened and closed under the control of the electronic control unit 40. The control valve 36 functions as a discharge valve when the reversible rotary machine 10 is operated as a compressor, that is, the control valve 36 functions as a check valve to allow the refrigerant only to flow onto the vapor generator 30 side from the reversible rotary machine 10 side. When the reversible rotary machine 10 is operated as an expansion machine, the control valve 36 is opened. Operation of this control valve 36 is controlled by the electronic control unit 40. As described above, a Rankine cycle is composed in which the refrigerant flows in the reversible rotary machine 10, the condenser 11, the gas-liquid separator 12 and the liquid pump 32.
The electronic control unit 40 includes an input section into which the detection temperature Tw of the water temperature sensor 44 for detecting the temperature of the engine cooling water after the engine cooling water absorbed heat from the engine 20, the air conditioner operation signal (A/C operation demanding signal) sent from the electronic control unit 41 for an air-conditioner, the detection pressure P1 of the upstream refrigerant pressure sensor 42 for detecting the pressure on the upstream side of the liquid pump 32 and the detection pressure P2 of the downstream refrigerant pressure sensor 43 for detecting the pressure on the downstream side of the liquid pump 32 are inputted.
The electronic control unit 40 controls the operations of the control valve 36, the liquid pump 32 and the three-way valve 21 according to the previously stored program on the basis of the detection temperature of the water temperature sensor 44, that is, on the basis of the waste heat temperature Tw and also on the basis of presence or absence of A/C operation demanding signal.
The structure and operation of the reversible rotary machine 10 will be briefly explained as follows.
In the case where the reversible rotary machine 10 is operated as a compressor, the rotor 10b is rotated by the motor generator 10a so that the refrigerant can be sucked and compressed. At the same time, the discharged refrigerant of high pressure is prevented from flowing backward onto the rotor 10b side by the control valve 36.
In the case where the reversible rotary machine 10 is operated as an expansion machine, the control valve 36 is opened and superheated vapor generated by the vapor generator 30 is introduced into the reversible rotary machine 10, so that the rotor 10b can be rotated and thermal energy can be converted into mechanical energy.
Next, operation of the vapor compression type refrigerating machine (the air conditioner) having a Rankine cycle according to this embodiment will be described below. In the vapor compression type refrigerating machine provided with Rankine cycle relating to this embodiment, the operation mode is controlled being changed over by the control means 40 according to the presence or absence of the A/C operation demanding signal and the waste heat temperature Tw. First, the air conditioning operation mode and the waste heat recovering operation mode will be explained as follows.
1. Air Conditioning Operation Mode
In this air conditioning operation mode, while the evaporator 14 is exhibiting a refrigerating capacity, the refrigerant is cooled by the radiator 11. In this connection, in this embodiment, the vapor compression type refrigerating machine is operated only for the cooling operation and the dehumidifying operation in which the cold heat generated by the vapor compression type refrigerating machine is utilized, that is, the heat absorbing action is utilized. The vapor compression type refrigerating machine is not operated for the heating operation, in which the hot heat generated by the radiator 11 is utilized. However, even at the time of heating operation, the operation of the vapor compression type refrigerating machine is the same as that of the cooling operation and the dehumidifying operation.
Specifically, the operation is conducted as follows. Under the condition that the liquid pump 32 is stopped, the opening and closing valve 35a is opened and the control valve 36 is made to function as a discharge valve, the motor generator 10a is energized so as to rotate the rotor 10b, and the three-way valve 21 is operated as shown by the broken line in
Due to the foregoing, the refrigerant circulates in the order of the reversible rotary machine (compressor) 10→the vapor generator 30→the radiator 11→the gas-liquid separator 12→the decompressor 13→the evaporator 14→the reversible rotary machine (compressor) 10. In this connection, as the engine cooling water is not circulated in the vapor generator 30, the refrigerant is not heated by the vapor generator 30, and the vapor generator 30 functions only as a refrigerant passage.
Accordingly, the refrigerant of low pressure, which has been decompressed by the decompressor 13, absorbs heat from the air blowing out into the vehicle room by the blower 14a, and the thus evaporated gas-phase refrigerant is compressed by the reversible rotary machine 10 and the temperature of the refrigerant is raised. The refrigerant of high temperature is cooled and condensed by the outside air in the radiator 11.
In this connection, in the present embodiment, the refrigerant is alternate fleon (HFC-134a). However, as long as the refrigerant can be liquidized on the high pressure side, the refrigerant is not limited to HFC-134a.
2. Waste Heat Recovering Operation Mode
In this operation mode, the air conditioner, that is, the reversible rotary machine 10 is stopped and the waste heat of the engine 20 is recovered so that it can be utilized as usable energy.
Specifically, the liquid pump 32 is operated under the condition that the opening and closing valve 35a is closed and that the control valve 36 is open, and the three-way valve 21 is operated as shown by the solid line in
Due to the foregoing, the refrigerant circulates in the order to the gas-liquid separator 12→the first bypass circuit 31→the vapor generator 30→the reversible rotary machine (expansion machine) 10→the second bypass circuit 34→the radiator 11→the gas-liquid separator 12.
Accordingly, the superheated vapor heated by the vapor generator 30 flows into the reversible rotary machine 10. While the vapor refrigerant, which has flowed into the reversible rotary machine 10, is being isentropically expanded in the reversible rotary machine 10, the enthalpy is decreased. Therefore, the reversible rotary machine 10 gives mechanical energy, which corresponds to decreased enthalpy, to the motor generator 10a. Electric power generated by the motor generator 10a is stored in a capacitor or a battery.
The refrigerant flowing out from the reversible rotary machine 10 is cooled and condensed by the radiator 11 and stored in the gas-liquid separator 12. The liquid-phase refrigerant in the gas-liquid separator 12 is moved to the vapor generator 30 side by the liquid pump 32.
As described above, in the waste heat recovering operation mode, the heat energy, which was lost from the radiator 23 into the atmosphere as the waste heat, is converted into energy such as electric power which can be easily utilized. Therefore, the fuel consumption of the vehicle, that is, the fuel consumption of the engine 20 can be reduced.
Further, in the waste heat recovering operation mode, electric power is generated by the waste heat of the engine 20. Therefore, it becomes unnecessary to drive a generator such as an alternator by the engine 20. Accordingly, the fuel consumption of the engine 20 can be further reduced.
Next, the control conducted by the electronic control unit 40 will be described as follows. In this embodiment, when an A/C operation demand signal is sent from the electronic control unit 41 for the air conditioner to the electronic control unit 40, the compressor 10 integrated with the expansion machine is operated as a compressor, and the supply of the engine cooling water to the vapor generator 30 is stopped, so that the priority can be given to the air conditioning operation mode.
On the contrary, even when an A/C operation demanding signal is not sent from the electronic control unit 41 for the air conditioner to the electronic control unit 40 and when the waste heat temperature Tw is not less than a predetermined temperature, the engine cooling water is supplied to the vapor generator 30, and the reversible rotary machine 10 is operated as an expansion machine, so that the waste heat recovering operation mode can be conducted.
When an A/C operation demanding signal is not sent from the electronic control unit 41 for the air conditioner to the electronic control unit 40 and when the waste heat temperature Tw is not more than a predetermined temperature, under the condition that the supply of the engine cooling water to the vapor generator 30 is stopped, an electric current supplied to the reversible rotary machine 10 is stopped, that is, an electric current supplied to the motor generator 10a is stopped.
In this connection,
In the case where the A/C operation demanding signal has been sent from the electronic control unit 41 for the air conditioner to the electronic control unit 40, the Rankine cycle is not operated, and the air conditioning operation mode is executed (S2).
On the other hand in the case where the A/C operation demanding signal has not been sent from the electronic control unit 41 for the air conditioner to the electronic control unit 40, it is judged whether or not the Rankine cycle is operated according to the waste heat temperature Tw, that is, it is judged whether or not the waste heat recovering operation mode is executed (S3). When the waste heat temperature Tw is not less than the predetermined temperature, the result of judgment is determined to be 1, and the Rankine cycle is executed (S4). When the waste heat temperature Tw is lower than the predetermined temperature, the result of judgment is determined to be 0, and Rankine cycle is not executed.
In this connection, in this embodiment, whether or not the Rankine cycle is operated according to the waste heat temperature Tw is judged according to the following predetermined hysteresis control judgment. When the waste heat temperature Tw is decreasing, in the case where the waste heat temperature Tw is not less than the predetermined temperature Tw1, the result of judgment is determined to be 1 and the Rankine cycle is executed. In the case where the waste heat temperature Tw is lower than the predetermined temperature Tw1, the result of judgment is determined to be 0 and the Rankine cycle is not executed. When the waste heat temperature Tw is increasing, in the case where the waste heat temperature Tw is not less than the predetermined temperature Tw2, which is higher than the predetermined temperature Tw1 by a predetermined temperature, the result of judgment is determined to be 1 and the Rankine cycle is executed. In the case where the waste heat temperature Tw is lower than the predetermined temperature Tw2, the result of judgment is determined to be 0 and the Rankine cycle is not executed. In this way, a predetermined hysteresis control judgment is conducted.
Next, referring to
Next, the timer is reset (S420). This timer stores the elapsed time (seconds) from the start of the waste heat recovering operation mode and the air conditioning operation mode. After that, the electronic control unit 40 sets the liquid pump 32 in motion and starts the waste heat recovering operation mode (S430). After that, in S440 and S450, the waste heat recovering operation mode is operated until the predetermined period of time T1 (s) (20 seconds in this embodiment) passes.
After that, the electronic control unit 40 judges whether or not the pressure difference (P2−P1) between the detection pressure P1 of the upstream refrigerant pressure sensor 42 and the detection pressure P2 of the downstream refrigerant pressure sensor 43 is higher than the setting pressure P (0.3 MPa in this embodiment) (S460). In the case where the pressure difference (P2−P1) is higher than the setting pressure P (0.3 MPa in this embodiment), that is, in the case where the liquid pump 32 gives pressure to the liquid-phase refrigerant and feeds the refrigerant, the program proceeds to S5 in
In the case where the pressure difference (P2−P1) is lower than the setting pressure P (0.3 MPa in this embodiment), it is judged that the liquid pump 32 cannot apply pressure to the liquid-phase refrigerant. In more detail, it is judged that the gas-phase refrigerant is mixed in the liquid-phase refrigerant so that the liquid pump 32 can not apply pressure to the refrigerant. Therefore, the refrigerant condensing operation (S470 to S500) is conducted.
In the refrigerant condensing operation (S470 to S500), after the stopping of the waste heat recovering operation mode (S470), the air conditioning operation mode is started (S480). After that, in S490 and S500, the air conditioning operation mode is operated until the predetermined period of time T2 (s) (10 seconds in this embodiment) passes. Then, after the refrigerant condensing operation has been conducted (S470 to S500), the counter value is set at (the counter value +1).
In S520, it is judged whether or not the counter value is higher than the normal value C (3 times in this embodiment). In the case where the counter value is not more than the normal value C, the program returns to S420. In the case where the counter value is higher than the normal value C, it is judged that Rankine cycle is in an abnormal state, and operation of the system is stopped.
In this connection, in the refrigerant condensing operation (S470 to S500), A/C operation demanding signal is not issued. Therefore, the blower 14a is not operated. Due to the foregoing, conditioned air is not blown into the vehicle compartment. Therefore, the refrigerant condensing operation can be conducted without a making the passenger uncomfortable.
Next, the operational effects of the first embodiment will be enumerated as follows.
(1) It is possible to prevent bubbles from being mixed into the liquid-phase pipe 31 and the liquid pump 32. Therefore, the occurrence of such a problem that the refrigerant can not be supplied by the liquid pump 32 can be prevented, and the operation efficiency of the refrigerant can be prevented from being deteriorated.
According to this embodiment, in the case where the Rankine cycle is judged to be in an abnormal state, the air conditioning operation mode (the refrigerating cycle) is operated, so that the gas-phase refrigerant can be condensed to the liquid-phase refrigerant. Further, the refrigerant staying in a complicated portion of the refrigerant passage in the refrigerating cycle, for example, the refrigerant staying in the evaporator 14, can be accumulated in the gas-liquid separator 12 in the form of liquid refrigerant. After that, by operating the waste heat recovering operation mode (the Rankine cycle), it is possible to prevent bubbles from being mixed into the liquid-phase pipe 31, which is different from the conventional example.
Accordingly, the liquid pump 32 can positively supply the liquid-phase refrigerant to the vapor evaporator 30. Accordingly, the waste heat recovering operation mode (the Rankine cycle) can be normally started and operated.
In addition, it is possible to prevent the deterioration of the operational efficiency of the liquid pump 32 which is caused when bubbles of the gas-phase refrigerant are mixed into the liquid-phase pipe 31 and the liquid pump 32. That is, it is possible to prevent the occurrence of the problem that the efficiency of the Rankine cycle is deteriorated.
(2) The control means 40 judges whether the waste heat recovering operation mode (the Rankine cycle) is normal or abnormal. In the case where the waste heat recovering operation mode (the Rankine cycle) is normal, the waste heat recovering operation mode is continued. In the case where the waste heat recovering operation mode (the Rankine cycle) is abnormal, the air conditioning operation mode is operated. Accordingly, it is possible to prevent the air conditioning mode being unnecessarily executed.
(3) As the difference value (P2−P1) between the upstream side pressure value P1 and the downstream side pressure value P2 of the liquid pump 32 is compared with the predetermined pressure value P, it is possible to specifically judge whether the waste heat recovering operation mode is normal or abnormal.
In this connection, when the liquid pump 32 is normally operated, the pressure value P1 detected by the upstream side refrigerant pressure sensor 42 becomes lower than the pressure value P2 detected by the downstream side refrigerant pressure sensor 43. Due to the foregoing, in the case where the difference value (P2.
P1) is specifically not more than the predetermined pressure value P, it is possible to judge that operation of the waste heat recovering operation mode is abnormal.
(4) Due to the waste heat recovering operation mode, it is possible to convert the thermal energy which used to be lost from the radiator 23 into the atmosphere into energy such as electric power which can be easily put into practical use. Therefore, it is possible to reduce the fuel consumption of the vehicle, that is, it is possible to reduce the fuel consumption of the engine 20. In more detail, as electric power is generated by the waste heat of the engine 20, it is possible to reduce the necessity to drive the generator such as an alternator by the engine 20. Accordingly, the fuel consumption of the engine 20 can be reduced.
In this connection, the pressure in the evaporator at the time of the air conditioning operation mode, that is, the pressure at the check valve 33c on the evaporator side, which is approximately 0.3 MPa in this embodiment, is lower than the pressure at the check valve 33c on the side opposite to the evaporator, which is approximately 1 MPa in this embodiment, in the case of recovering energy by the compressor integrated with an expansion machine. The check valve 33c prevents the refrigerant from flowing backward to the evaporator, due to this difference in pressure, at the time of waste heat recovery operation mode. However, at the time of the waste heat recovery operation mode, when the radiator and the evaporator are communicated with each other, the pressure on the evaporator side, that is, the pressure in the evaporator, which is approximately 0.3 MPa in this embodiment, may be increased to the pressure of the check valve 33c on the side opposite to the evaporator, which is approximately 1 MPa in this embodiment, and a malfunction of the check valve 33c may be caused and the energy recovering operation mode (Rankine cycle) may fuil.
Therefore, this embodiment includes a temperature type expansion valve in which the flow rate adjusting section and the decompressing section for decompressing the passing refrigerant are integrated with each other into one body. In this case, the flow rate adjusting section adjusts the degree of opening of the refrigerant passage to the shutoff side in the case where the degree of superheat of the refrigerant at the outlet of the evaporator is low, and the flow rate adjusting section also adjusts the degree of opening of the refrigerant passage to the full opening side in the case where the degree of superheat of the refrigerant at the outlet of the evaporator is high. This temperature-type expansion valve functions as a refrigerant shutoff means for shutting off a flow of the refrigerant into the evaporator at the time of recovering energy.
Due to the foregoing, when the compressor stops sucking the refrigerant, the pressure at the outlet of the evaporator becomes the saturated pressure of the evaporator temperature in a very short period of time. At this time, the temperature-type expansion valve is completely closed and shuts off the refrigerant passage, and therefore the pressure in the evaporator can be prevented from increasing in the case where energy is recovered by the energy recovering machine. Therefore, even when the energy recovering operation is continuously conducted, the pressure in the evaporator is not increased so that the pipe can be prevented from being damaged and a malfunction of the back-flow preventing means can be prevented.
Second Embodiment The constitution of this embodiment is the same as that of the first embodiment except that the upstream refrigerant pressure sensor 42 and the downstream refrigerant pressure sensor 43, which are provided in the first embodiment, are eliminated and, further, except that an electric current consumed by the liquid pump 32 is measured by the electronic control unit 40 (shown in
However, concerning the detail of S4 of
On the other hand, in the case where electric power is not more than the predetermined electric power consumption W, the program proceeds to S470. An operation to be conducted after that is the same as that of the first embodiment.
Due to the foregoing, without providing the upstream refrigerant pressure sensor 42 and the downstream refrigerant pressure sensor 43 which are indispensable components for the first embodiment, it is possible to judge whether the waste heat recovering operation mode (Rankine cycle) is normal or abnormal. Therefore, the cost of the overall heat cycle can be reduced.
In this connection, in this embodiment, the operational effects (1) to (4) described in the first embodiment can also be exhibited.
Third Embodiment The constitution of this embodiment is the same as that of the first embodiment, however, a portion of the control in S4 (shown in
In this connection, in the case where the liquid refrigerant in the gas-liquid separator 12 is a saturated liquid, although the liquid refrigerant remains in the gas-liquid separator 12, cavitation is caused in a portion of low pressure in the liquid pump 32. In this case, when the air conditioning operation mode is started for a short period of time and pressure in the gas-liquid separator 12 is raised so as to change the liquid-phase refrigerant into supercooled liquid, the generation of cavitation can be reduced.
In this embodiment, when the counter value is 0, that is, after it has been judged that the waste heat recovering operation mode is in an abnormal state (S460 in
In this connection, the operational effects (1) to (4) described in the first embodiment can also be exhibited in this embodiment.
Fourth EmbodimentIn the first, the second and third embodiment, the time T2 (S), in which the refrigerant condensing operation is conducted, is set at a predetermined period of time (10 seconds). However, in this embodiment, the time T2 is changed according to the state of operation of the air conditioning operation mode. This is a point different from the first, the second and the third embodiment.
In this embodiment, it is determined so that T21 can be extended as the value of Tam is increased. When the outside temperature is high, the condensing temperature is made high. Therefore, the temperature at which the liquid-phase refrigerant can be supercooled is also made high. However, the time to cool the refrigerant is extended due to the heat capacities of the other parts composing the heat cycle. Therefore, the relation between the outside air temperature which was previously measured and the time at which the liquid-phase refrigerant can be supercooled is stored in the electronic control unit 40, and T21 is determined by the value of Tam.
The control flow of the electronic control unit 40 of this embodiment is different as follows. As shown in
Due to the foregoing, it is possible to ensure the operating time of the air conditioning operation mode necessary for making the liquid-phase refrigerant put into the supercooled state. Therefore, the operating time of the air conditioning operation mode in the unnecessary refrigerant condensing operation can be reduced. Further, the operational effects (1) to (4) described in the first embodiment can be exhibited.
Fifth Embodiment In the first to the fourth embodiment, the reversible rotary machine 10 and the liquid pump 32 are composed separately from each other. However, in the present invention, as shown in the overall arrangement view of
Further, this embodiment is different in the following points. The reversible rotary machine 10 is attached with a liquid pump section housing temperature sensor 46 for measuring the temperature of the pump housing of the liquid pump section 300, and the output value Twp of the liquid pump section housing temperature sensor 46 is inputted into the electronic control unit 40. The other points of the structure of this embodiment are the same as those of the fourth embodiment.
Next, referring to the sectional view of
The compression and expansion section 100 has the same structure as that of the well known scroll-type compression mechanism. Specifically, the compression and expansion section 100 includes: a stationary scroll (shell) 102 fixed to the stator housing 230 of the generator and motor section 200 via the middle housing 101; a movable scroll 103 composing a movable member which is rotated in the space formed between the middle housing 101 and the stationary scroll 102; and a valve mechanism section 107 for opening and closing the communicating passage 105, 106 to communicate the operation chamber V1 with the high pressure chamber 104.
In this case, the stationary scroll 102 includes: a plate-shaped base plate portion 102a; and a spiral tooth portion 102b protruding from the base plate portion 102a to the movable scroll 103 side. On the other hand, the movable scroll 103a includes: a spiral tooth portion 103b contacted and meshed with the tooth portion 102b; and a base plate portion 103a in which the tooth portion 103b is formed. When the movable scroll 103 is rotated under the condition that both the tooth portions 102b and 103b are contacted with each other, the volume of the operation chamber V1, which is composed of both the scrolls 102 and 103, can be extended and reduced.
The shaft 108 is pivotally supported by the middle housing 101 via the bearing 108b and is also pivotally supported by the stator housing 230 via the bearing 108c. One end portion in the longitudinal direction of the shaft 108 is a crank shaft having an eccentric portion 108a which is eccentric with respect to the rotary central axis. The lip seal 108d is a shaft seal device for preventing the refrigerant from leaking outside the stator housing 230 from a gap between the shaft 108 and the stator housing 230. The movable scroll 103 is pivotally attached to the eccentric portion 108a via the bearing 103c.
The rotation preventing mechanism 109 is composed so that the movable scroll 103 can be rotated around the eccentric portion 108a by one rotation while the shaft 108 is being rotated by one rotation. Therefore, when the shaft 108 is rotated, the movable scroll 103 is revolved round the rotary central axis of the shaft 108 without being rotated. Further, as the operation chamber V1 is displaced to the central side from the outer diameter side of the movable scroll 103, the volume of the operation chamber V1 is reduced. In this connection, a pin-ring-(pin-hole) type rotation-preventing mechanism 109 is adopted in this embodiment.
The communication passage 105 makes the operation chamber V1, the volume of which becomes minimum at the time of pump mode, communicate with the high pressure chamber 104, that is, the communication passage 105 is a discharge port for discharging the compressed refrigerant. The communication passage 106 makes the operation chamber V1, the volume of which becomes minimum at the time of the waste heat recovery operation mode, communicate with the high pressure chamber 104, that is, the communication passage 106 is a inflow port for guiding the superheated vapor (the gas-phase refrigerant) of high temperature and high pressure from the high pressure chamber 104 into the operation chamber V1.
The high pressure chamber 104 is a space formed in a gap between the valve mechanism housing 107i and the opposite surface to the surface on which the tooth portion 102b of the base plate portion 102a of the movable scroll 102 is composed. The high pressure chamber 104 has a function of smoothing a pulsation of the refrigerant discharged from the communicating passage 105 (referred to as a discharge port 105 hereinafter). In this high pressure chamber 104, the high pressure port 110, which is connected to the heater 30 and the radiator 11 side, is provided.
The low pressure port 111 connected to the evaporator 14 and the second bypass circuit 34 side is provided in the stator housing 230 and communicated with the outermost diameter portion of the operation chamber V1 via the inner space 230a in the generator and motor section 200 and via the middle housing 101.
Next, the valve mechanism section 107 will be explained in detail as follows. In the high pressure chamber 104, on the opposite face to the face on which the tooth portion 102b of the base plate portion 102a of the movable scroll 102 is composed, the discharge valve 107a and the valve stopping plate or stopper 107b are fixed by the bolts 107c. The discharge valve 107a is a read-valve-shaped check valve for preventing the refrigerant, which has been discharged from the discharge port 105, from flowing backward from the high pressure chamber 104 into the operation chamber V1. The stopper 107b is a valve stopping plate for regulating the degree of the maximum opening of the discharge valve 107a.
The spool 107d is a valve body for opening and closing the communicating passage 106 (referred to as an inflow port 106 hereinafter). The electromagnetic valve 107e is a control valve for controlling pressure in the back pressure chamber 107f by controlling the communicating state of the low pressure port 111 side with the back pressure chamber 107f. The spring 107g is an elastic means for giving an elastic force to the spool 107d so that the inflow port 106 can be closed. The throttle 107h is a resistance means for communicating the back pressure chamber 107f with the high pressure chamber 104 while the throttle 107h has a predetermined passage resistance. In this connection, the spool 107d, the electromagnetic valve 107e and the spring 107g are arranged in the valve mechanism housing 107i, and the back pressure chamber 107f and the throttle 107h are integrated with the valve mechanism housing 107i into one body.
When the electromagnetic valve 107e is opened, the pressure in the back pressure chamber 107f is decreased to be lower than the pressure in the high pressure chamber 104. Therefore, while the spool 107d is compressing the spring 107g, it is displaced to the right in the drawing, so that the inflow port 106 can be opened. In this connection, a pressure loss in the throttle 107h is very large. Therefore, the quantity of the refrigerant flowing from the high pressure chamber 104 into the back pressure chamber 107f is negligibly small.
On the contrary, when the electromagnetic valve 107e is closed, the pressure in the back pressure chamber 107 and the pressure in the high pressure chamber 104 become equal to each other. Accordingly, the spool 107d is displaced to the lower side in the drawing by a force generated by the spring 107g. Therefore, the inflow port 106 can be closed. Accordingly, a pilot-type electric opening and closing valve for opening and closing the inflow port 106 can be composed of the spool 107d, the electromagnetic valve 107e, the back pressure chamber 107f, the spring 107g and the throttle 107h etc. In this connection, the electromagnetic valve 107e is controlled by the electronic control unit 40. The generator and motor section 200 is a brushless DC motor having a stator 210 and a rotor 220 rotated on the inner circumferential side of the stator 210. The stator 210 is a stator coil in which a coil is wound round an iron core made of magnetic material such as steel. This stator 210 is fixed in the inner circumferential section of the stator housing 230.
The rotor 220 is a magnet rotor in which a permanent magnet is embedded. On the inner circumferential side of the rotor 220, a key groove not shown is formed, so that the rotor 220 can be integrally fixed to the shaft 108 by the key groove.
The liquid pump section 300 has the same structure as that of a well-known scroll-type compressor mechanism. Specifically, the liquid pump section 300 includes: a stationary scroll (shell) 302 fixed to the stator housing 230 of the generator and motor section 200 via the pump housing 301; a movable scroll 303 which is a movable member rotated in a space formed between the pump housing 301 and the stationary scroll 302; and an operation chamber V2 etc.
In this case, the stationary scroll 302 includes: a plate-shaped base plate portion 302a; and a spiral tooth portion 302b protruding from the base plate portion 302a to the movable scroll 303 side. On the other hand, the movable scroll 303 includes: a spiral tooth portion 303b contacted and meshed with the tooth portion 302b; and a base plate portion 303a in which the tooth portion 303b is formed. When the movable scroll 303 is rotated while both the tooth portions 302b, 303b are in contact with each other, the operation chamber V2 composed of both the scrolls 302, 303 is moved from the refrigerant suction port 309 side described later to the refrigerant discharge port 308 side.
In this connection, the compression ratio of the scroll type compression mechanism of the liquid pump section 300 is 1. Therefore, even when the liquid-phase refrigerant is sucked into the operation chamber V2, the liquid-phase refrigerant is not compressed. Accordingly, a malfunction of the liquid pump section 300 is not caused by compression of the liquid-phase refrigerant.
The pump shaft 304 is pivotally supported by the pump housing 301 via the bearing 304b. One end portion of the pump shaft 304 in the longitudinal direction is a crank shaft having an eccentric portion 304a which is eccentric with respect to the rotary central axis. The pump shaft 304 is connected to an end portion of the shaft 108, which is a member composing the compression expansion section 100 and the generator and motor section 200, on the side opposite to the side on which the eccentric portion 108a is provided via the one-way clutch 305.
The one-way clutch 305 is a power transmission means having a function of transmitting a rotary drive force of the shaft 108 to the pump shaft 304 only in the waste heat recovery operation mode. The movable scroll 303 is pivotally connected to the eccentric portion 304a via the bearing 303c.
By the rotation preventing mechanism 306, 307, while the pump shaft 304 is being rotated by one rotation, the movable scroll 303 is rotated round the eccentric portion 304a by one rotation. Therefore, when the pump shaft 304 is rotated, the movable scroll 303 is revolved round the rotary central axis of the pump shaft 304 without being rotated. Further, the operation chamber V2 is gradually displaced from the outer diameter side to the central side. In this connection, the pin-ring-type (pin-hole-type) mechanism is adopted as the rotation preventing mechanism 306, 307 in this embodiment.
The refrigerant discharge port 308 is a port from which the liquid-phase refrigerant is discharged. The refrigerant discharge port 308 is arranged at a position so that the refrigerant discharge port 308 can be communicated with the operation chamber V2 when the operation chamber V2 is moved to the central side of the liquid pump section 200. The refrigerant suction port 309 is a port from which the liquid-phase refrigerant is sucked. The refrigerant suction port 309 is arranged at a position so that the refrigerant suction port 309 can be communicated with the operation chamber V2 when the operation chamber V2 is moved to the outer diameter side of the liquid pump section 200.
In this connection, the liquid pump section housing temperature sensor 46 is attached to the pump housing 301, and the output value Twp of the liquid pump section housing temperature sensor 46 is inputted into the electronic control unit 40.
Next, the operation of the vapor compression type refrigerating machine having a Rankine cycle of this embodiment will be described below.
In the air conditioning operation mode, electric power is supplied to the generator and motor section 200 of the reversible rotary machine 10, and the electromagnetic valve 107e is closed and the three-way valve 21 is changed over as shown by the broken line in
When electric power is supplied to the generator and motor section 200, the rotor 220 and the shaft 108 are rotated integrally with each other. Due to this rotation, the reversible rotary machine 10 sucks the gas-phase refrigerant from the low pressure port 111, compresses the gas-phase refrigerant in the operation chamber V1 and discharges the gas-phase refrigerant from the high pressure port 110.
As the electromagnetic valve 107c is closed, the valve mechanism section 107 functions as a check valve which only allows the refrigerant to flow from the reversible rotary machine 10 side to the vapor generator 30 side. In the air conditioning operation mode, the one-way clutch 305 does not transmit the rotary drive force from the shaft 108 to the pump shaft 304. Therefore, the liquid pump section 300 is not operated.
Due to the foregoing, in the air conditioning operation mode, the same refrigerating cycle as that of the first embodiment can be composed. Further, as the gas-phase refrigerant of low pressure, which is sucked from the low pressure port 111 of the compression and expansion section 100, is evaporated in the evaporator 14 and the temperature of the gas-phase refrigerant is lowered, when the gas-phase refrigerant passes the inner space 230a, it cools the liquid pump section 300 via the contact face 230b of the liquid pump section 300 of the stator housing 230. Due to the foregoing, the liquid-phase refrigerant in the liquid pump section 300 is supercooled. Accordingly, when the waste heat recovery operation mode is conducted after the air conditioning operation mode, the liquid pump section 300 can positively supply the liquid-phase refrigerant to the vapor generator 30.
Next, in the waste heat recovery operation mode, the electromagnetic valve 107e is opened, and the three-way valve 21 is changed over as shown by the solid line in
Due to the foregoing, in the waste heat recovery operation mode, the same Rankine cycle as that of the first embodiment can be composed.
In this connection, in the waste heat recovery operation mode, the gas-phase refrigerant of low pressure flowing out from the low pressure port 111 of the compression and expansion section 100 is superheated by the vapor generator 30. Thus, the temperature of the gas-phase refrigerant is raised high. Therefore, the following problems may be encountered. As the gas-phase refrigerant of high temperature also passes through the inner space 230a, the liquid pump section 300 may be heated by the gas-phase refrigerant of high temperature via the contact face 230b, and the liquid-phase refrigerant in the liquid pump section 300 may be heated and evaporated.
However, in the waste heat recovery operation mode, the liquid pump section 300 is operated, and the liquid-phase refrigerant does not stay in the liquid pump section 300, which is different from the air conditioning operation mode, but passes through inside the liquid pump section 300. Therefore, as the liquid-phase refrigerant is sent to the vapor generator 30 before it is evaporated, there is no possibility that the refrigerant inside the liquid pump 300 is evaporated.
Next, the control operation conducted by the electronic control unit 40 will be described as follows. In this embodiment, in the same manner as that of the first embodiment, the electronic control unit 40 controls the air conditioning operation mode and the waste heat recovery mode. However, in this embodiment, the control in the case of operating the Rankine cycle (S4) is different from that of the first embodiment.
Specifically, the control is conducted as follows. As shown in
In this case, it is possible to grasp the refrigerant condensing temperature from the outside air temperature Tam. Since the liquid pump section housing temperature Twp has a correlation with the refrigerant temperature in the liquid pump section 300, it is possible to grasp the refrigerant temperature in the liquid pump section 300. Further, when the refrigerant temperature in the liquid pump section 300 is lower than the refrigerant condensing temperature, it can be judged that the refrigerant in the liquid pump section 300 is in the supercooled state.
Therefore, in this embodiment, the refrigerant condensing temperature is set aft (outside air temperature Tam+α), wherein α=15° C. in this embodiment, and the refrigerant condensing operation is conducted until (β×liquid pump section housing temperature Twp) is decreased to a value not higher than (outside air temperature Tam+α). In this case, β is a multiplier for controlling. Therefore, when the waste heat recovery mode is operated after the completion of the refrigerant condensing operation, because the refrigerant inside the liquid pump is in the supercooled state, the liquid pump section 300 can positively move the liquid-phase refrigerant to the vapor generator 30.
Of course, the operation may be conducted as follows. Even in the case where the outside air temperature Tam is not measured, the minimum refrigerant condensing temperature (for example, 10° C.) is previously determined from the minimum outside air temperature in the environment in which the heat cycle is used, and the refrigerant condensing operation is conducted until (β×liquid pump section housing temperature Twp) is decreased to a value not higher than the minimum refrigerant condensing temperature. Due to the foregoing, it is possible to eliminate the outside air temperature sensor 45. Accordingly, the manufacturing cost of the entire heat cycle can be reduced.
In this connection, even in this embodiment, the operational effects (1) to (4) described in the first embodiment can be exhibited.
Sixth Embodiment The above explanations are made into the fifth embodiment in which the liquid pump section housing temperature sensor 46 for measuring the pump housing temperature of the liquid pump section 300 is provided. However, in this embodiment, as shown in
The evaporator blowout temperature Te outputted from the evaporator blowout temperature sensor 47 is a temperature of the gas-phase refrigerant of low pressure in the air conditioning operation mode and a temperature of the gas-phase refrigerant of low pressure sucked into the reversible rotary machine 10. That is, the evaporator blowout temperature Te outputted from the evaporator blowout temperature sensor 47 is the same temperature as that of the gas-phase refrigerant to cool the liquid pump section 300. Therefore, the evaporator blowout temperature Te outputted from the evaporator blowout temperature sensor 47 has a correlation with the temperature inside the liquid pump section 300. Accordingly, as shown in steps S417 and S503 shown in
In the first to the sixth embodiment, a reversible rotary machine 10 is used which functions as a compressor in a refrigerating cycle and also functions as an expansion machine in a Rankine cycle. However, in this embodiment, as shown in
The compressor 10b has a function of sucking, compressing and discharging the refrigerant. This compressor 10b is driven by the engine 20 via the engine side pulley 49, the belt 50 and the compressor side pulley 51 through the electromagnetic clutch 48, which is controlled by the electronic control unit 40.
The structure of the expansion machine 10c is the same as that of the reversible rotary machine 10 of the fifth embodiment. In the expansion machine 10c, the expansion section 100, the generator section 200 and the liquid pump section 300 are integrated with each other into one body. However, there is no chance that the expansion machine functions as a compressor. Therefore, the shaft 108 and the pump shaft 30 are connected with each other into one body without using a one-way clutch or other devices.
When a drive force is transmitted to the compressor by the electronic control unit 40, the refrigerant is circulated in the order of the compressor 10b→the radiator 11→the gas-liquid separator 12→the decompressor 13→the evaporator 14→the compressor 10b. Due to the foregoing, the same refrigerating cycle, as that of the first embodiment, can be composed.
When the electronic control unit 40 changes over the three-way valve 21 so that the engine coolant can flow through the vapor generator 30, the refrigerant, which has been superheated by the vapor generator 30, expands in the expansion section 100, so that the generator section 200 and the liquid pump section 300 are operated. Electric power generated by the generator section 200 is stored in the battery via the electronic control unit 40. The liquid pump section 300 further moves the liquid-phase refrigerant to the vapor generator 30.
The gas-phase refrigerant flowing out from the expansion section 100 is circulated in the order of the expansion machine 10c→the radiator 11→the gas-liquid separator 12→the liquid pump section 300→the vapor generator 30→the expansion machine 10c. Due to the foregoing, the same Rankine cycle as that of the first embodiment can be composed.
In this case, the high pressure refrigerant discharge port of the compressor 10b and the low pressure refrigerant flow-out port of the expansion machine 10c are joined to each other at the pipe confluence section X. However, as the compressor 10b has a discharge valve, the refrigerant of low pressure flowing out from the expansion machine 10c does not flow backward from the high pressure refrigerant discharge port of compressor 10b into the compressor 10b. Further, the high pressure refrigerant discharged from the compressor 10b does not flow backward from the low pressure refrigerant flow-out port of the expansion machine 10c into the expansion machine 10c because the check valve 33b is provided.
The upstream refrigerant pressure sensor 42, the downstream refrigerant pressure sensor 43 and the water temperature sensor 44 measure the same physical values as those of the first embodiment, and the measured values are inputted into the electronic control unit 40.
Therefore, according to this embodiment, it is possible to conduct control in the same manner as that of the first embodiment. Further, it is possible to conduct control while the refrigerating cycle and Rankine cycle are independent from each other. That is, when the refrigerant condensing operation is conducted by the refrigerating cycle before the waste heat recovery operation mode is operated by a Rankine cycle, the same effect as that of the first embodiment can be provided. When the refrigerating cycle is operated simultaneously when a Rankine cycle is operated, a sufficiently large quantity of the liquid-phase refrigerant can be stored in the gas-liquid separator 12 by the refrigerating cycle. Therefore, no bubbles of the gas-phase refrigerant enter the liquid pump section 300. Accordingly, the liquid-phase refrigerant can be positively sent to the vapor generator 30.
Another Embodiment The vapor compression type refrigerating machine provided with Rankine cycle, to which the present invention can be applied, is not limited to the specific constitution described in the above embodiments. The vapor compression type refrigerating machine may have the constitution shown in
In the control conducted in the third to the seventh embodiment, the refrigerant pressure sensor 42, 43 of the first embodiment is used. However, of course, the same effect can be provided when the control conducted according to the electric power consumption of the liquid pump of the second embodiment may be applied. The control of the third embodiment may be applied to the fourth to the seventh embodiment.
The heat transfer fin temperature of the evaporator 14 or the pressure of the low pressure port 111 of the compressor may be used as physical values having a correlation with the refrigerant temperature in the liquid pump 32 and the liquid pump section 300 used in the fifth or the sixth embodiment.
In the embodiments described above, the recovered energy is stored in a capacitor. However, the recovered energy may be stored as mechanical energy such as kinetic energy stored by a flywheel or elastic energy stored by a spring.
In the above embodiments, the reversible rotary machine 10 is used, that is, the vane type and the scroll type fluid machine are used as a compressor and an expansion machine. However, it should be noted that the present invention is not limited to the above specific embodiment.
In the above embodiments, when the waste heat recovering operation mode is controlled, a predetermined hysteresis is provided. However, it should be noted that the present invention is not limited to the above specific embodiments.
It should be noted that the application of the present invention is not limited to a vehicle.
The heat generating body is not limited to an internal combustion engine, that is, the heat generating body can be variously changed, for example, the heat generating body may be a fuel cell (FC).
An opening and closing valve (for example, an electromagnetic valve for opening and closing when it is energized) and a capillary tube may be arranged as a refrigerant shutoff means.
Due to the foregoing, as the electromagnetic valve positively shuts off the refrigerant passage, the type of the decompressing means is not limited to the temperature-type expansion valve, but an inexpensive capillary tube can be used. Further, it is possible to make the accumulator cycle, in which an accumulator is arranged on the downstream side of the refrigerant flow of the evaporator 14 at the time of air conditioning operation mode instead of the gas-liquid separator (receiver) arranged on the downstream side of the refrigerant flow of the radiator 11 at the time of air conditioning operation mode, exhibit the above operational effects.
In the above embodiment, the heater is arranged in series between the radiator and the compressor integrated with an expansion machine. However, it is possible to operate Rankine cycle even when the heater is arranged in parallel between the radiator and the compressor integrated with an expansion machine.
Waste heat generated from various devices mounted on a vehicle, for example, suction heat generated from a turbine, heat generated from an inverter and waste heat generated from auxiliary devices may be used as a heat source to heat the refrigerant. Only one heat source may be used to heat the refrigerant. Alternatively, a plurality of heat sources may be used to heat the refrigerant.
The application of the present invention is not limited to an air conditioner for vehicle use. It is possible to apply the present invention to a stationary type refrigerating cycle (refrigerating machine).
In the above embodiment, the temperature-type expansion valve is exemplarily shown in which a flow rate of the refrigerant is adjusted according to the temperature of a temperature-detecting cylinder and the temperature at the outlet of the evaporator. However, the temperature-type expansion valve is not limited to the above type. For example, it is possible to use an electronic-type expansion valve having a flow rate adjusting section in which a thermistor is used for the temperature detecting section and the degree of opening of a refrigerant passage is adjusted by an actuator according to the detected temperature.
As long as it agrees with the concept of the present invention described in the scope of claim of the patent, any embodiment may be included in the present invention. It should be noted that the present invention is not limited to the above specific embodiments.
Claims
1. A heat cycle device comprising:
- a rotary fluid machine for mutually converting between fluid energy of refrigerant and mechanical rotary energy;
- a condenser for condensing the refrigerant supplied from the rotary fluid machine;
- a Rankine cycle system including a fluid pump for moving the refrigerant supplied from the condenser and also including a vapor generator for heating the refrigerant, which has been moved by the fluid pump, by the heat of a heat generating body;
- a refrigerating cycle system including an evaporator for evaporating the refrigerant supplied from the condenser; and
- a control unit for conducting a refrigerant condensing operation in which the refrigerant in the refrigerating cycle system is compressed by the rotary fluid machine at the time of operating the Rankine cycle system and the compressed refrigerant is condensed by the condenser.
2. A heat cycle device according to claim 1, the control unit including:
- a judging means for judging whether or not the Rankine cycle system is normally operated after the operation of the Rankine cycle system was started; and
- a control means for continuing the operation of the Rankine cycle system in the case where it is judged that the Rankine cycle system is normally operated, and for conducting the refrigerant condensing operation in the case where it is judged that the Rankine cycle system is not normally operated.
3. A heat cycle device according to claim 2, further comprising:
- an upstream refrigerant pressure sensor for measuring pressure of the refrigerant, arranged in an upstream side portion of the refrigerant flow of the fluid pump; and
- a downstream refrigerant pressure sensor for measuring pressure of the refrigerant, arranged in a downstream side portion of the refrigerant flow of the fluid pump, wherein
- the judging means judges that the Rankine cycle is normally operated at the time of operating the Rankine cycle system in the case where a difference (P2−P1) between the detected pressure of the downstream refrigerant pressure sensor and the detected pressure (P) of the upstream refrigerant pressure sensor is larger than the predetermined pressure (P), and the judging means judges that the Rankine cycle is not normally operated at the time of operating the Rankine cycle system in the case where the difference (P2−P1) between the detected pressure (P2) of the downstream refrigerant pressure sensor and the detected pressure (P1) of the upstream refrigerant pressure sensor is not more than the predetermined pressure (P).
4. A heat cycle device according to claim 2, wherein the judging means judges that the Rankine cycle system is normally operated in the case where a work-load of the liquid pump is heavier than a predetermined work-load at the time of operating the Rankine cycle system, and the judging means judges that the Rankine cycle system is not normally operated in the case where the work-load of the liquid pump is not more than the predetermined work-load at the time of operating the Rankine cycle system.
5. A heat cycle device according to claim 4, wherein the liquid pump is an electric liquid pump, and the work-load is represented by electric power consumed by the electric liquid pump.
6. A heat cycle device according to one of claim 1, further comprising an air blowing means for blowing air, the temperature of which is adjusted by the refrigerating cycle system, wherein
- the control unit conducts the refrigerant condensing operation under the condition that the air blowing means is not operated.
7. A heat cycle device according to claim 1, further comprising a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump, wherein
- the control unit determines the time, which has passed from the start of the refrigerant condensing operation to when the physical value measured by the sensor shows that the refrigerant inside the refrigerant pump is in the supercooled state, to be the continuation time for continuing the refrigerant condensing operation.
8. A heat cycle device according to claim 1, wherein the condenser is a heat exchanger for condensing the refrigerant by exchanging heat between the outside air and the refrigerant,
- the heat cycle device further comprising:
- an outside air temperature sensor for measuring the temperature of the outside air; and
- a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump, wherein
- the control unit determines a target temperature at which the refrigerant inside the refrigerant pump is in the supercooled state according to the outside air temperature measured by the outside air temperature sensor, and further the control unit determines the time, which has passed from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the target temperature, to be the continuation time for continuing the refrigerant condensing operation.
9. A heat cycle device according to claim 7, wherein the sensor is a temperature sensor for measuring the temperature of the housing of the refrigerant pump.
10. A heat cycle device according to claim 7, wherein the sensor is a temperature sensor for measuring the temperature of air immediately after heat was exchanged with the refrigerant in the evaporator.
11. A heat cycle device according to claim 1, wherein the condenser is a heat exchanger for condensing the refrigerant by exchanging heat between the outside air and the refrigerant,
- further comprising an outside air temperature sensor for measuring the outside air temperature, wherein
- the control unit includes a continuation time setting means for determining the continuation time (T21), in which the refrigerant condensing operation is continued, according to the temperature measured by the outside air temperature sensor.
12. A heat cycle device according to claim 1, wherein the rotary fluid machine is a reversible rotary machine capable of being reversibly operated as an expansion machine for obtaining power when the refrigerant is expanded, or operated as a compressor for compressing the refrigerant when power is supplied to the compressor.
13. A heat cycle device according to claim 12, wherein the control unit conducts the refrigerant condensing operation by operating the rotary fluid machine as a compressor before the rotary fluid machine is operated as an expansion machine and the operation of the Rankine cycle system is started.
14. A heat cycle device according to claim 12, wherein the reversible rotary machine is composed being integrated with the fluid pump into one body, and
- the fluid pump is arranged so that it can be cooled by the gas-phase refrigerant sucked into the reversible rotary machine at the time of operating the refrigerating cycle system.
15. A heat cycle device according to claim 1, wherein the rotary fluid machine includes an expansion machine for expanding the refrigerant to obtain power and a compressor for compressing the refrigerant when power is supplied to the compressor.
16. A heat cycle device according to claim 15, wherein the control unit conducts the refrigerant condensing operation by operating the compressor before the expansion machine is operated and the operation of the Rankine cycle system is started.
17. A heat cycle device according to claim 15, wherein the control unit conducts the refrigerant condensing operation by operating the compressor simultaneously when the expansion machine is operated and the operation of the Rankine cycle system is started.
18. A heat cycle device comprising:
- a Rankine cycle system including a fluid pump for moving refrigerant and also including a vapor generator for heating the refrigerant, which has been moved by the fluid pump, by the heat of a heat generating body;
- a refrigerating cycle system including an evaporator for evaporating the refrigerant; and
- a control unit for conducting the cooling operation for cooling the fluid pump by operating the refrigerating cycle system at the time of operating the Rankine cycle system.
19. A heat cycle device according to claim 18, wherein the refrigerating cycle system includes a compressor, and the fluid pump is arranged so that it can be cooled by the gas-phase refrigerant sucked into the compressor.
20. A heat cycle device according to claim 18, wherein the control unit conducts the cooling operation before the operation of the Rankine cycle system is started and/or while the Rankine cycle system is being operated.
21. A heat cycle comprising:
- a refrigerating cycle in which refrigerant of low pressure is evaporated so as to absorb heat from a low temperature side and the evaporated gas-phase refrigerant is compressed so as to raise the temperature and the heat absorbed from the low temperature side is radiated to a high temperature side so as to condense the gas-phase refrigerant into the liquid-phase refrigerant;
- a Rankine cycle including a vapor generator for generating the gas-phase refrigerant by heating the liquid-phase refrigerant of the refrigerating cycle by the waste heat of a heat generating body, also including a liquid-phase pipe for connecting a liquid-phase takeout section for taking out the liquid-phase refrigerant from the refrigerating cycle, with the vapor generator, also including a liquid pump arranged in the liquid-phase pipe, for moving the liquid phase refrigerant to the vapor generator, also including an expansion machine for obtaining power by expanding the gas-phase refrigerant, and also including a condenser for condensing the gas-phase refrigerant which has been expanded by the expansion machine;
- a control means for controlling a state of operation of the refrigerating cycle and also controlling a state of operation of Rankine cycle; and
- a change-over means for changing over between a case in which the Rankine cycle is operated and a case in which the refrigerating cycle is operated by a signal sent from the control means, wherein
- the control means operates the Rankine cycle in such a manner that the refrigerating cycle is operated by the refrigerant condensing operation so as to condense the gas-phase refrigerant into the liquid-phase refrigerant and then the Rankine cycle is operated.
22. A heat cycle comprising:
- a refrigerating cycle in which refrigerant of low pressure is evaporated so as to absorb heat from a low temperature side and the evaporated gas-phase refrigerant is compressed so as to raise the temperature and the heat absorbed from the low temperature side is radiated to a high temperature side so as to condense the gas-phase refrigerant into the liquid-phase refrigerant;
- a Rankine cycle including a vapor generator for generating the gas-phase refrigerant by heating the liquid-phase refrigerant of the refrigerating cycle by the waste heat of a heat generating body, also including a liquid-phase pipe for connecting a liquid-phase takeout section for moving the liquid-phase refrigerant from the refrigerating cycle, with the vapor generator, also including a liquid pump arranged in the liquid-phase pipe, for moving the liquid-phase refrigerant to the vapor generator, also including an expansion machine for obtaining power by expanding the gas-phase refrigerant, and also including a condenser for condensing the gas-phase refrigerant which has been expanded by the expansion machine;
- a control means for controlling a state of operation of the refrigerating cycle and also controlling a state of operation of Rankine cycle; and
- a change-over means for changing over between the case in which the Rankine cycle is operated and the case in which the refrigerating cycle is operated by a signal sent from the control means, wherein
- after the Rankine cycle has been operated, the control means judges whether or not the Rankine cycle is normally operated,
- in the case where operation of the Rankine cycle has been judged to be normal, the Rankine cycle is kept operated and
- in the case where operation of the Rankine cycle has been judge to be not normal, the control means operates in such a manner that it stops the operation of the Rankine cycle and operates the refrigerating cycle so as to conduct the refrigerant condensing operation for recovering the liquid-phase refrigerant and the Rankine cycle is operated again after the refrigerant condensing operation.
23. A heat cycle according to claim 22, further comprising:
- an upstream refrigerant pressure sensor arranged in a portion on the upstream side of the flow of the refrigerant of the liquid pump, the upstream refrigerant pressure sensor outputting a signal of the refrigerant pressure to the control means; and
- a downstream refrigerant pressure sensor arranged in a portion on the downstream side of the flow of the refrigerant of the liquid pump, the downstream refrigerant pressure sensor outputting a signal of the refrigerant pressure to the control means, wherein
- in the case where a value (P2−P1), which is obtained when a detected pressure value (P1) of the upstream refrigerant pressure sensor is subtracted from a detected pressure value (P2) of the downstream refrigerant pressure sensor, is higher than a predetermined pressure value (P) when the Rankine cycle is operated, the control means judges that the Rankine cycle is normally operated, and in the case where the value (P2−P1), which is obtained when the detected pressure value (P1) of the upstream refrigerant pressure sensor is subtracted from the detected pressure value of the downstream refrigerant pressure sensor, is not more than the predetermined pressure value (P), the control means judges that the Rankine cycle is not normally operated.
24. A heat cycle according to claim 22, wherein the control means judges that the Rankine cycle is normally operated in the case where a work-load of the liquid pump is more than a predetermined work-load when the Rankine cycle is operated, and
- the control means judges that the Rankine cycle is not normally operated in the case where the work-load of the liquid pump is not more than the predetermined work-load when the Rankine cycle is operated.
25. A heat cycle according to claim 24, wherein the liquid pump is an electric liquid pump driven by electricity, and
- the work-load is represented by electric power consumed by the electrically-driven liquid pump.
26. A heat cycle according to claim 21, wherein the expansion machine is a reversible rotary machine having the function of a compressor for compressing the gas-phase refrigerant in the refrigerating cycle,
- the reversible rotary machine is integrated with the liquid pump, and
- the liquid pump is cooled by the gas-phase refrigerant sucked into the reversible rotary machine at the time of operating the refrigerating cycle.
27. A heat cycle according to claim 21, further comprising:
- an air blowing means for blowing air conditioned by the refrigerating cycle; and
- an operation demand means for demanding the operation of the refrigerating cycle, wherein
- in the case of conducting the refrigerant condensing operation, the control means conducts the refrigerant condensing operation without operating the air blowing means when the operation of the refrigerating cycle is not demanded by the operation demand means.
28. A heat cycle according to claim 21, wherein,
- the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,
- the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air,
- the control means determines the continuation time (T21) for continuing the refrigerant condensing operation, and
- the continuation time (T21) is determined on the basis of the outside air temperature.
29. A heat cycle according to claim 21, further comprising a sensor for measuring a physical value having a correlation with a temperature of the refrigerant inside the liquid pump, wherein
- the control means determines the continuation time in which the refrigerant condensing operation is continued, and
- the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.
30. A heat cycle according to claim 21, wherein
- the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,
- the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air and also comprises a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump,
- the control means determines the temperature at which the refrigerant inside the refrigerant pump is supercooled by the outside air temperature, and also determines the continuation time in which the refrigerant condensing operation is continued, and the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.
31. A heat cycle according to claim 30, wherein the sensor for measuring the physical value is a temperature sensor for measuring the temperature of the housing of the refrigerant pump
32. A heat cycle according to claim 30, wherein the refrigerating cycle includes an evaporator for evaporating the refrigerant of low pressure by exchanging heat between the refrigerant of low pressure and air, and
- the sensor for measuring the physical value is a temperature sensor for measuring the temperature of air immediately after heat is exchanged with the refrigerant of low pressure.
33. A heat cycle device according to claim 8, wherein the sensor is a temperature sensor for measuring the temperature of the housing of the refrigerant pump.
34. A heat cycle device according to claim 8, wherein the sensor is a temperature sensor for measuring the temperature of air immediately after heat was exchanged with the refrigerant in the evaporator.
35. A heat cycle according to claim 22, wherein the expansion machine is a reversible rotary machine having the function of a compressor for compressing the gas-phase refrigerant in the refrigerating cycle,
- the reversible rotary machine is integrated with the liquid pump, and
- the liquid pump is cooled by the gas-phase refrigerant sucked into the reversible rotary machine at the time of operating the refrigerating cycle.
36. A heat cycle according to claim 22, further comprising:
- an air blowing means for blowing air conditioned by the refrigerating cycle; and
- an operation demand means for demanding the operation of the refrigerating cycle, wherein
- in the case of conducting the refrigerant condensing operation, the control means conducts the refrigerant condensing operation without operating the air blowing means when the operation of the refrigerating cycle is not demanded by the operation demand means.
37. A heat cycle according to claim 22, wherein,
- the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,
- the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air,
- the control means determines the continuation time (T21) for continuing the refrigerant condensing operation, and
- the continuation time (T21) is determined on the basis of the outside air temperature.
38. A heat cycle according to claim 22, further comprising a sensor for measuring a physical value having a correlation with a temperature of the refrigerant inside the liquid pump, wherein
- the control means determines the continuation time in which the refrigerant condensing operation is continued, and
- the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.
39. A heat cycle according to claim 22, wherein
- the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,
- the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air and also comprises a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump,
- the control means determines the temperature at which the refrigerant inside the refrigerant pump is supercooled by the outside air temperature, and also determines the continuation time in which the refrigerant condensing operation is continued, and the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.
40. A heat cycle according to claim 29, wherein the sensor for measuring the physical value is a temperature sensor for measuring the temperature of the housing of the refrigerant pump
41. A heat cycle according to claim 29, wherein the refrigerating cycle includes an evaporator for evaporating the refrigerant of low pressure by exchanging heat between the refrigerant of low pressure and air, and
- the sensor for measuring the physical value is a temperature sensor for measuring the temperature of air immediately after heat is exchanged with the refrigerant of low pressure.
Type: Application
Filed: May 31, 2005
Publication Date: Dec 1, 2005
Applicants: DENSO Corporation (Kariya-city), Nippon Soken, Inc. (Nishio-shi)
Inventors: Atsushi Inaba (Kariya-city), Tadashi Hotta (Nishio-shi)
Application Number: 11/141,134
