SYSTEM AND METHOD OF CLEANING CONDENSER FOR BINARY POWER GENERATION

Abstract

A system of cleaning a condenser provided in a circulation flow passage for allowing circulation of a working medium in a binary power generation system, includes: an inlet header into which a cooling medium flows; and a heat exchanger including a plurality of branch ports into which the cooling medium flows from the inlet header. The heat exchanger is configured to perform heat exchange between the working medium and the cooling medium to condense the working medium. The cleaning system includes a switching unit configured to switch a flow of the cooling medium to a direction from the heat exchanger to the inlet header.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a system of cleaning a condenser for binary power generation and a method of cleaning the condenser for binary power generation.

Description of the Related Art

Binary power generation systems configured to generate electric power by using vapor of a low-boiling working medium such as hydrocarbon or ammonia have been recently known. In each of such binary power generation systems, a condenser is used to condense the low-boiling working medium generated after a turbine is rotatably driven. In the condenser, seawater or river water externally supplied is used as a cooling medium to be heat-exchanged with the low-boiling working medium (for example, see Japanese Unexamined Patent Application Publication No. 2016-008042).

Here, the condenser includes: an inlet header into which the cooling medium flows; and a heat exchanger including plural branch ports into which the cooling medium flows from the inlet header, and the heat exchanger is configured to perform heat exchange between the working medium and the cooling medium to condense the working medium. The force in the direction of flow of the cooling medium is likely to act on a surface of the inlet header into which the branch ports are opened; in other words, the force in the direction of pressing against the surface is likely to act thereon. Therefore, foreign substances tend to be adhered to the periphery of the branch ports in the surface.

In particular, if the seawater or the river water is applied as the cooling medium, marine organisms are possibly included in the cooling medium. Accordingly, foreign substances such as marine organisms tend to be adhered to the periphery of the branch ports in the surface. Therefore, a flow passage for the cooling medium in the condenser is blocked with the foreign substances and thus heat exchanging performance of the condenser may deteriorate. Consequently, the condenser is regularly disassembled and cleaned; however, the work to disassemble and clean the condenser is complicated.

SUMMARY OF THE INVENTION

The present invention is thus made in view of the foregoing problems, and it is an object of the present invention to provide a system of cleaning a condenser for binary power generation and a method of cleaning the condenser for binary power generation which enable the removal of foreign substances adhered to the inside of the condenser without disassembling the condenser.

A system of cleaning a condenser for binary power generation according to an aspect of the present invention is a system of cleaning a condenser provided in a circulation flow passage for allowing circulation of a working medium in a binary power generation system. The condenser includes: an inlet header into which a cooling medium flows; and a heat exchanger including a plurality of branch ports into which the cooling medium flows from the inlet header. The heat exchanger is configured to perform heat exchange between the working medium and the cooling medium to condense the working medium. The cleaning system includes a switching unit configured to switch a flow of the cooling medium to a direction from the heat exchanger to the inlet header.

According to this configuration, the cleaning system includes the switching unit configured to switch the flow of the cooling medium to the direction from the heat exchanger to the inlet header. Accordingly, the force to separate foreign substances from the branch ports can be applied by the cooling medium to the foreign substances adhered to the periphery of the branch ports in a surface of the inlet header into which the branch ports are opened. Therefore, the foreign substances adhered to the periphery of the branch ports are easily separated therefrom and thus the foreign substances can be removed without disassembling the condenser.

In the foregoing configuration, the cleaning system may include a first pipe allowing the cooling medium to flow into the inlet header of the condenser. The cleaning system may include a second pipe allowing the cooling medium to flow out of the condenser. The cleaning system may include a third pipe adapted to connect the first pipe to the second pipe. The cleaning system may include a fourth pipe adapted to connect a second portion of the first pipe to a fourth portion of the second pipe. The second portion of the first pipe is located downward, in a flow direction of the cooling medium, of a first portion of the first pipe to which the third pipe is connected. The fourth portion of the second pipe is located downstream, in the flow direction of the cooling medium, of a third portion of the second pipe to which the third pipe is connected. The switching unit may switch from a first state where the cooling medium flows from the first pipe into the condenser to a second state where the cooling medium flows from the first pipe through the third pipe and the second pipe into the condenser.

According to this configuration, the switching unit switches from the first state where the cooling medium flows from the first pipe into the condenser to the second state where the cooling medium flows from the first pipe through the third pipe and the second pipe into the condenser. Therefore, the flow of the cooling medium can be switched to the direction from the heat exchanger to the inlet header by the simple configuration.

In the foregoing configuration, the cleaning system may include a strainer provided in the fourth pipe and configured to remove foreign substances in the cooling medium from the cooling medium.

According to this configuration, the foreign substances separated from the periphery of the branch ports are caught by the strainer; therefore, the foreign substances are further easily removed.

In the foregoing configuration, the cleaning system may include a first pressure meter provided in the first pipe and configured to measure a pressure of the cooling medium flowing from the first pipe to the condenser. The cleaning system may include a second pressure meter provided in the second pipe and configured to measure a pressure of the cooling medium flowing out of the condenser.

According to this configuration, an operator can recognize on the basis of a pressure difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter whether the flow passage for the cooling medium in the condenser is blocked. This is because as the flow passage for the cooling medium in the condenser is gradually blocked, the pressure of the cooling medium at an inlet side in the condenser increases and the pressure of the cooling medium at an outlet side in the condenser decreases.

In the foregoing configuration, the cleaning system may include a control unit configured to, when a pressure difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter has exceeded a predetermined value, control the switching unit to establish the second state.

According to this configuration, when a pressure difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter has exceeded the predetermined value, the second state is automatically established by the control unit. Therefore, an operator does not need to perform switching operation to the second state.

In the foregoing configuration, the control unit may be configured to, when a pressure difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter has reached a value smaller than or equal to the predetermined value, control the switching unit to establish the first state.

According to this configuration, when a pressure difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter has reached a value smaller than or equal to the predetermined value, the first state is automatically established by the control unit. Therefore, an operator does not need to perform switching operation to the first state.

In the foregoing configuration, the cleaning system may include: a first thermometer provided in the first pipe and configured to measure a temperature of the cooling medium flowing from the first pipe into the condenser; and a second thermometer provided in the second pipe and configured to measure a temperature of the cooling medium flowing out of the condenser.

According to this configuration, an operator can recognize on the basis of a temperature difference between a temperature measured by the first thermometer and a temperature measure by the second thermometer whether the flow passage for the cooling medium in the condenser is blocked. This is because as the flow passage for the cooling medium in the condenser is gradually blocked, the flow rate of the cooling medium decreases and the temperature of the cooling medium at the outlet side of the condenser increases.

In the foregoing configuration, the cleaning system may include a control unit configured to, when a temperature difference between a temperature measured by the first thermometer and a temperature measured by the second thermometer has exceeded a predetermined value, control the switching unit to establish the second state.

According to this configuration, when a temperature difference between a temperature measured by the first thermometer and a temperature measured by the second thermometer has exceeded the predetermined value, the second state is automatically established by the control unit. Therefore, an operator does not need to perform switching operation to the second state.

In the foregoing configuration, the control unit may configured to, when a temperature difference between a temperature measured by the first thermometer and a temperature measured by the second thermometer has reached a value smaller than or equal to the predetermined value, control the switching unit to establish the first state.

According to this configuration, when a temperature difference between a temperature measured by the first thermometer and a temperature measured by the second thermometer has reached a value smaller than or equal to the predetermined value, the flow of the cooling medium is automatically switched to the first state by the control unit. Therefore, an operator does not need to perform switching operation to the first state.

A method of cleaning a condenser for binary power generation according to another aspect of the present invention is a method of cleaning a condenser provided in a circulation flow passage for allowing circulation of a working medium in a binary power generation system. The condenser includes: an inlet header into which a cooling medium flows; and a heat exchanger including a plurality of branch ports into which the cooling medium flows from the inlet header. The heat exchanger is configured to perform heat exchange between the working medium and the cooling medium and condense the working medium. The cleaning method includes the step of switching a flow of the cooling medium to a direction from the heat exchanger to the inlet header.

According to this configuration, the cleaning method includes the step of switching the flow of the cooling medium to the direction from the heat exchanger to the inlet header. Therefore, the force to separate foreign substances from the branch ports can be applied by the switching step to the foreign substances adhered to the periphery of the branch ports. Therefore, the foreign substances adhered to the periphery of the branch ports are easily separated therefrom and thus the foreign substances can be removed without disassembling the condenser.

In the foregoing configuration, the method may include a first branched pipe branched from a first pipe for allowing the cooling medium to flow into the inlet header of the condenser, and the first branched pipe may include a first joint at an end thereof. The method may include a second branched pipe branched from a second pipe for allowing the cooing medium to flow out of the condenser, and the second branched pipe may include a second joint at an end thereof. The method may include a third branched pipe branched from a second portion of the first pipe, which is located downstream, in a flow direction of the cooling medium, of a first portion of the first pipe from which the first branched pipe is branched, and the third branched pipe may include a third joint at an end thereof. The method may include a fourth branched pipe branched from a fourth portion of the second pipe, which is located downstream, in the flow direction of the cooling medium, of a third portion of the second pipe from which the second branched pipe is branched, and the fourth branched pipe may include a fourth joint at an end thereof. The method may include a switching unit configured to stop the flow of the cooling medium between the first portion and the second portion of the first pipe and to stop the flow of the cooling medium between the third portion and the fourth portion of the second pipe. The method may include: a first step of connecting the first branched pipe through the third pipe to the second branched pipe via the first joint and via the second joint; a second step of connecting the third branched pipe through the fourth pipe to the fourth branched pipe via the third joint and via the fourth joint; and a third step of switching by the switching unit from a first state where the cooling medium flows from the first pipe into the condenser to a second state where the cooling medium flows from the first pipe through the third pipe and the second pipe into the condenser.

According to this configuration, the first to third steps are performed; thereby, the flow of the cooling medium can be switched to the direction from the heat exchanger to the inlet header. Therefore, the force to separate foreign substances from the branch ports can be applied to the foreign substances adhered to the periphery of the branch ports. Therefore, the foreign substances adhered to the periphery of the branch ports are easily separated therefrom and thus the foreign substances can be removed without disassembling the condenser.

According to the present invention, a system of cleaning a condenser for binary power generation includes a switching unit configured to switch a flow direction of a cooling medium flowing in a condenser to an opposite direction to the flow direction. Accordingly, the flow direction of the cooling medium is switched to the opposite direction; thereby, the force to separate foreign substances from branch ports can be applied to the foreign substances adhered to the periphery of the branch ports. Therefore, the foreign substances adhered to the periphery of the branch ports are easily separated therefrom and thus the foreign substances can be removed without disassembling the condenser.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram showing a binary power generation system in which a system of cleaning a condenser for binary power generation according to a first embodiment is used.

FIG. 2 is a schematic configuration diagram showing the condenser applied in the system of cleaning the condenser for binary power generation according to the first embodiment.

FIG. 3 is a schematic configuration diagram showing the system of cleaning the condenser for binary power generation during normal operation according to the first embodiment.

FIG. 4 is a schematic configuration diagram showing the system of cleaning the condenser for binary power generation during cleaning of the condenser according to the first embodiment.

FIG. 5 is a schematic configuration diagram showing a system of cleaning the condenser for binary power generation during normal operation according to a second embodiment.

FIG. 6 is a schematic configuration diagram showing the system of cleaning the condenser for binary power generation during cleaning of the condenser according to the second embodiment.

FIG. 7 is a diagram illustrating the control operation of a control unit in the system of cleaning the condenser for binary power generation according to the second embodiment.

FIG. 8 is a schematic configuration diagram showing a system of cleaning the condenser for binary power generation during normal operation according to a third embodiment.

FIG. 9 is a schematic configuration diagram showing the system of cleaning the condenser for binary power generation during cleaning of the condenser according to the third embodiment.

FIG. 10 is a diagram illustrating the control operation of a control unit in the system of cleaning the condenser for binary power generation according to the third embodiment.

FIG. 11 is a schematic configuration diagram showing a system of cleaning the condenser for binary power generation during normal operation of the condenser according to a fourth embodiment.

FIG. 12 is a schematic configuration diagram showing a system of cleaning the condenser for binary power generation during cleaning of the condenser according to the fourth embodiment.

FIG. 13 is a schematic configuration diagram showing a method of cleaning the condenser for binary power generation during normal operation of the condenser according to a fifth embodiment.

FIG. 14 is a schematic configuration diagram showing the method of cleaning the condenser for binary power generation during cleaning of the condenser according to the fifth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described with reference to the drawings. For the purpose of illustration, each of the drawings simply shows major components to be required for describing a system of cleaning a condenser for binary power generation according to each of the embodiments of the present invention. Accordingly, the system of cleaning the condenser for binary power generation according to each embodiment of the present invention can include any components that are not shown in the drawings referred to as by the specification.

First Embodiment

FIG. 1 is a schematic configuration diagram illustrating a binary power generation system 1 in which a system of cleaning a condenser for binary power generation is used. The binary power generation system 1 is a power generation system utilizing a Rankine cycle. The binary power generation system 1 includes a condenser 6, a circulation pump 8, a heater 10, and an expander 14. The condenser 6, the circulation pump 8, the heater 10, and the expander 14 are provided in a circulation flow passage 4 in the mentioned order. A circulation circuit is configured in the binary power generation system 1 such that a working medium flows through the circulation flow passage 4 via the heater 10, the expander 14, the condenser 6 and the circulation pump 8 in the mentioned order. A cooling medium having a boiling point lower than the boiling point of water is applied as the working medium.

The circulation pump 8 is provided downstream of the condenser 6 (between the heater 10 and the condenser 6) in the circulation flow passage 4. The circulation pump 8 serves to circulate the working medium in the circulation flow passage 4. The circulation pump 8 pressurizes the liquid working medium condensed in the condenser 6 to a predetermined pressure and thereafter pumps the working medium to the heater 10. For example, a centrifugal pump provided with an impeller as a rotor or a gear pump including a rotor formed by a pair of gears is applied as the circulation pump 8. The circulation pump 8 is controlled to be driven by a controller 30. The function of the controller 30 includes a pump control unit 30a. The pump control unit 30a is configured to control the number of rotations of the circulation pump 8. The pump control unit 30a controls the circulation pump 8 to be driven so that the degree of superheat of the working medium may fall within a preliminarily-established range. Also, the pump control unit 30a controls the circulation pump 8 to start and stop.

The heater 10 is provided downstream of the circulation pump 8 (between the circulation pump 8 and the expander 14) in the circulation flow passage 4. The heater 10 includes a working medium flow passage 10a through which the working medium flows and a heat source medium flow passage 10b through which a heat source medium flows. The heat source medium flow passage 10b is connected to a heat source medium circuit 72. The heat source medium supplied from an external heat source flows through the heat source medium flow passage 10b. The working medium flowing through the working medium flow passage 10a is heat-exchanged with the heat source medium flowing through the heat source medium flow passage 10b to evaporate. The heat source medium may include, for example, hot water, water vapor, or the like.

A generator 16 is connected to the expander 14. A gaseous working medium is expanded in the expander 14; thereby, the power to drive the generator 16 can be derived.

FIG. 2 is a schematic configuration diagram illustrating the condenser 6 applied in a system X1 of cleaning the condenser 6 for binary power generation. The condenser 6 serves to condense the gaseous working medium discharged from the expander 14 to generate the liquid working medium. The condenser 6 includes: a heat exchanger 6a configured to conduct heat exchange between the working medium and a cooling medium and condense the working medium; an inlet header 6b for allowing inflow of the cooling medium into the heat exchanger 6a; and an outlet header 6c for allowing outflow of the cooling medium that has flowed through the heat exchanger 6a. As long as the condenser 6 is provided with an inlet header to which after-mentioned plural branch ports of the heat exchanger 6a are opened, any of a plate condenser, a shell-and-tube condenser, and a fin-and-tube condenser can be used as the condenser 6.

The heat exchanger 6a is formed such that working medium flow passages S1 through each of which the gaseous working medium flows and cooling medium flow passages S2 through each of which the cooling medium flows are arranged alternately side by side with each other in an up to down direction. The flow direction of the working medium is different by 90 degrees from the flow direction of the cooling medium. The heat exchanger 6a includes: plural branch ports 11 for allowing inflow of the cooling medium from the inlet header 6b; and plural joint ports 12 for allowing outflow of the cooling medium to the outlet header 6c.

The inlet header 6b is formed to be elongated in a direction perpendicular to the flow direction of the cooling medium. An inflow port 17 for the cooling medium is formed in a surface 13 of the inlet header 6b, which is located upstream in the flow direction of the cooling medium. A first pipe 18 for allowing the cooling medium from a supply source of the cooling medium into the inlet header 6b is connected to the inflow port 17. The supply source (not shown) of the cooling medium may include, for example, seawater or river water. The plural branch ports 11 are provided at intervals and opened to a surface 19 of the inlet header 6b, which is located downstream in the flow direction of the cooling medium.

The outlet header 6c is formed to be elongated in a direction perpendicular to the flow direction of the cooling medium. The plural joint ports 12 are opened to a surface 20 of the outlet header 6c, which is located upstream in the flow direction of the cooling medium. An outflow port 22 for the cooling medium is formed in a surface 21 of the outlet header 6c, which is located downstream in the flow direction of the cooling medium. A second pipe 23 for allowing the cooling medium to flow out from the outlet header 6c into the supply source of the cooling medium is connected to the outflow port 22.

Here, the operation of the binary power generation system 1 will be described. When the circulation pump 8 is driven, the liquid working medium pumped from the circulation pump 8 flows into the working medium flow passage 10a of the heater 10. The working medium is heated by the heat source medium flowing through the heat source medium flow passage 10b, therefore evaporating. The working medium evaporated in the heater 10 is supplied into the expander 14. The working medium is supplied into the expander 14 and thereby the expander 14 is rotatably driven. As a result, the generator 16 is driven to generate electric power. The working medium expanded in the expander 14 is discharged into the circulation flow passage 4. The gaseous working medium discharged from the expander 14 is supplied into the working medium flow passages S1 of the condenser 6. In the condenser 6, the working medium is cooled by the cooling medium flowing through the cooling medium flow passages S2 to be condensed to the liquid working medium. The liquid working medium flows through the circulation flow passage 4 to be suctioned into the circulation pump 8. In the circulation flow passage 4, such circulation is repeated and thereby electric power is generated in the generator 16.

FIG. 3 is a schematic configuration diagram illustrating the system X1 of cleaning the condenser 6 for binary power generation during normal operation. The system X1 of cleaning the condenser 6 for binary power generation includes a third pipe 24 and a fourth pipe 25. The third pipe 24 establishes a connection between the first pipe 18 and the second pipe 23. The fourth pipe 25 establishes a connection between a second portion P2 of the first pipe 18 and a fourth portion P4 of the second pipe 23. The second portion P2 is located downstream, in the flow direction of the cooling medium, of a first portion P1 of the first pipe 18 to which the third pipe 24 is connected. The fourth portion P4 is located downstream, in the flow direction of the cooling medium, of a third portion P3 of the second pipe 23 to which the third pipe 24 is connected. The system X1 of cleaning the condenser 6 for binary power generation further includes: a switching unit 26 configured to switch the flow of the cooling medium to a direction from the heat exchanger 6a to the inlet header 6b; and a strainer 27 configured to remove foreign substances in the cooling medium from the cooling medium.

The switching unit 26 includes a first on-off valve 26a interposed between the first portion P1 and the second portion P2 of the first pipe 18, a second on-off valve 26b interposed between the third portion P3 and the fourth portion P4 of the second pipe 23, a third on-off valve 26c provided in the third pipe 24, and a fourth on-off valve 26d provided in the fourth pipe 25. The switching unit 26 can switch from a first state where the cooling medium flows from the first pipe 18 into the condenser 6 to a second state where the cooling medium flows from the first pipe 18 through the third pipe 24 and the second pipe 23 into the condenser 6. Specifically, the switching unit 26 opens the first on-off valve 26a and the second on-off valve 26b and closes the third on-off valve 26c and the fourth on-off valve 26d, thereby establishing the first state. The switching unit 26 closes the first on-off valve 26a and the second on-off valve 26b and opens the third on-off valve 26c and the fourth on-off valve 26d, thereby establishing the second state. Manual valves that can manually open and close flow passages of fluid may be applied as the first to fourth on-off valves 26a to 26d.

The system X1 of cleaning the condenser 6 for binary power generation according to the first embodiment operates as follows. In order to bring the flow of the cooling medium into the first state during normal operation, the first on-off valve 26a and the second on-off valve 26b are opened by an operator and the third on-off valve 26c and the fourth on-off valve 26d are closed by the operator. Thus, the flow of the cooling medium is brought into the first state where the cooling medium flows from the first pipe 18 into the condenser 6 and then flows out into the second pipe 23.

Here, as show in FIG. 2, the force in the flow direction of the cooling medium, i.e. the force in a direction in which foreign substances FS are pushed against the surface 19 is likely to act on the surface 19 of the inlet header 6b, which is located downstream in the flow direction of the cooling medium. Therefore, the foreign substances FS are easily adhered to the surface 19 of the inlet header 6b, which is located downstream in the flow direction of the cooling medium.

FIG. 4 is a schematic configuration diagram illustrating the system X1 of cleaning the condenser 6 for binary power generation during cleaning of the condenser 6. When a predetermined time has elapsed during normal operation, in order to bring the flow of the cooling medium into the second state, the first on-off valve 26a and the second on-off valve 26b are closed by an operator and the third on-off valve 26c and the fourth on-off valve 26d are opened by the operator. Thus, the cooling medium flows from the first pipe 18 through the third pipe 24 and the second pipe 23 into the condenser 6 and then flows out to the first pipe 18. The cooling medium flows out to the first pipe 18, thereafter flowing through the fourth pipe 25 to the second pipe 23.

At this time, the cooling medium in the condenser 6 flows in the direction from the heat exchanger 6a to the inlet header 6b, as shown in FIG. 2. Accordingly, the force in such a direction to separate the foreign substances FS from the branch ports 11 acts on the foreign substances FS adhered to the periphery of the branch ports 11 in the surface 19 of the inlet header 6b, which is located downstream in the flow direction of the cooling medium. Therefore, the foreign substances FS adhered to the periphery of the branch ports 11 in the surface 19 of the inlet header 6b, which is located downstream in the flow direction of the cooling medium easily separate from the periphery of the branch ports 11. Consequently, the foreign substances FS can be removed without disassembling the condenser 6.

The foreign substances FS separated from the periphery of the branch ports 11 are discharged together with the cooling medium into the first pipe 18, thereafter flowing through the fourth pipe 25. At this time, the foreign substances FS in the cooling medium are removed from the cooling medium by the strainer 27. Therefore, the foreign substances FS are easily removed.

Second Embodiment

Next, a cleaning system X2 for the condenser 6 for binary power generation according to a second embodiment will be described with reference to FIG. 5 and FIG. 6. In the second embodiment, only differences from the first embodiment will be described, and the same configurations as those of the first embodiment will be assigned with the same reference numbers and thus will not be described.

FIG. 5 is a schematic configuration diagram illustrating the system X2 of cleaning the condenser 6 for binary power generation during normal operation. FIG. 6 is a schematic configuration diagram illustrating the system X2 of cleaning the condenser 6 for binary power generation during cleaning of the condenser 6. The system X2 of cleaning the condenser 6 for binary power generation according to the second embodiment includes a first pressure meter 31, a second pressure meter 32, a switching unit 33, and a control unit 34. The switching unit 33 of the second embodiment is different from that of the first embodiment where manual valves for manually opening and closing flow passages of fluid are used in that automatic valves for opening and closing flow passages of fluid on the basis of an electric signal are used. Other configurations of the switching unit 33 of the second embodiment are similar to the configurations of the first embodiment.

The first pressure meter 31 includes a first pressure sensor (not shown) for measuring the pressure of the cooling medium flowing from the first pipe 18 into the condenser 6. The first pressure meter 31 is provided in the first pipe 18. The second pressure meter 32 includes a second pressure sensor (not shown) for measuring the pressure of the cooling medium flowing out of the condenser 6. The second pressure meter 32 is provided in the second pipe 23. Pressure values measured by the first pressure sensor and the second pressure sensor are output therefrom as electric signals to the control unit 34.

When a pressure difference between a pressure value measured by the first pressure meter 31 and a pressure value measured by the second pressure meter 32 has exceeded a predetermined value, the control unit 34 controls the switching unit 33 to switch so that the flow of the cooling medium is brought into the second state. Further, when a pressure difference between a pressure value measured by the first pressure meter 31 and a pressure value measured by the second pressure meter 32 has reached a value smaller than or equal to the predetermined value, the control unit 34 controls the switching unit 33 to switch so that the flow of the cooling medium is brought into the first state. The predetermined value can be set accordingly in consideration of, for example, the pressure of a pump for pumping the cooling medium and a pressure loss and on the basis of a pressure difference assumed when the flow passage for the cooling medium in the condenser 6 is actually blocked. For example, the predetermined value can be set to a pressure difference generated when a pressure value measured by the second pressure meter 32 has been half a pressure value measured by the first pressure meter 31.

FIG. 7 is a diagram illustrating the control operation of the control unit 34 in the system X2 of cleaning the condenser 6 for binary power generation. The control unit 34 receives electric signals from the first pressure sensor and the second pressure sensor (step ST1). The control unit 34 receives the electric signals in step ST1 and thereafter subtracts a pressure value measured by the second pressure sensor from a pressure value measured by the first pressure sensor; thereby computing a pressure difference (step ST2). The control unit 34 computes the pressure difference and thereafter determines whether the pressure difference is smaller than or equal to the predetermined value. When the control unit 34 has determined that the pressure difference is smaller than or equal to the predetermined value (Yes in step ST3), the processing goes to step ST4. On the other hand, when the control unit 34 has determined that the pressure difference is larger than the predetermined value (No in step ST3), the processing goes to step ST6.

In step ST4, the control unit 34 determines whether the flow of the cooling medium is presently in the first state. When the control unit 34 has determined that the flow of the cooling medium is presently in the first state (Yes in step ST4), the processing returns to step ST1. On the other hand, when the control unit 34 has determined that the flow of the cooling medium is presently in the second state (No in step ST4), the processing goes to step ST5. In step ST5, the control unit 34 sends to the first to fourth on-off valves 26a to 26d control signals for switching the flow of the cooling medium to the first state (step ST5). In other words, the control unit 34 sends to the first on-off valve 26a and the second on-off valve 26b the control signals for opening the flow passage for the cooling medium and sends to the third on-off valve 26c and the fourth on-off valve 26d the control signals for closing the flow passage for the cooling medium. Accordingly, the flow passage for the cooling medium is opened by the first on-off valve 26a and the second on-off valve 26b and the flow passage for the cooling medium is closed by the third on-off valve 26c and the fourth on-off valve 26d. Thus, the flow of the cooling medium is switched from the second state to the first state. When the flow of the cooling medium has been switched from the second state to the first state, the control unit 34 returns the processing to step ST1 (step ST5).

In step ST6, the control unit 34 determines whether the flow of the cooling medium is presently in the second state. When the control unit 34 has determined that the flow of the cooling medium is presently in the second state (Yes in step ST6), the processing returns to step ST1. On the other hand, when the control unit 34 has determined that the flow of the cooling medium is presently in the first state (No in step ST6), the processing goes to step ST7. In step ST7, the control unit 34 sends to the first to fourth on-off valves 26a to 26d control signals for switching the flow of the cooling medium to the second state (step ST7). In other words, the control unit 34 sends to the first on-off valve 26a and the second on-off valve 26b the control signals for closing the flow passage for the cooling medium and sends to the third on-off valve 26c and the fourth on-off valve 26d the control signals for opening the flow passage for the cooling medium. Accordingly, the flow passage for the cooling medium is closed by the first on-off valve 26a and the second on-off valve 26b and the flow passage for the cooling medium is opened by the third on-off valve 26c and the fourth on-off valve 26d. Thus, the flow of the cooling medium is switched from the first state to the second state. When the flow of the cooling medium has been switched from the first state to the second state, the control unit 34 returns the processing to step ST1 (step ST7). The control unit 34 repeats the processing of steps ST1 to ST7 until a power supply of the system X2 of cleaning the condenser 6 for binary power generation according to the second embedment is turned off

If the flow passage for the cooling medium in the condenser 6 is blocked, the system X2 of cleaning the condenser 6 for binary power generation according to the second embodiment is automatically switched to the second state where the cooling medium flows from the first pipe 18 through the third pipe 24 and the second pipe 23 into the condenser 6. Therefore, foreign substances FS adhered to the periphery of the branch ports 11 are automatically separated. Consequently, the foreign substances FS can be removed without disassembling the condenser 6.

When a pressure difference between a pressure value measured by the first pressure meter 31 and a pressure value measured by the second pressure meter 32 has reached a value smaller than or equal to the predetermined value, the system X2 of cleaning the condenser 6 for binary power generation according to the second embodiment is automatically switched to the first state where the cooling medium flows from the first pipe 18 via the condenser 6 to the second pipe 23. Therefore, when the blocking of the flow passage for the cooling medium in the condenser 6 is solved, an operator does not need to perform the switching operation to the first state.

The system X2 of cleaning the condenser 6 for binary power generation according to the second embodiment includes the control unit 34. Alternatively, the cleaning system X2 may not include the control unit 34. In this case, an operator determines on the basis of a pressure difference between a pressure value measured by the first pressure meter 31 and a pressure value measured by the second pressure meter 32 whether the flow passage for the cooling medium in the condenser 6 is blocked. If the operator has determined that the flow passage for the cooling medium in the condenser 6 is blocked, the operator manually performs the switching operation of the first to fourth on-off valves 26a to 26d so that the flow of the cooling medium is brought into the second state. Likewise, if the operator has determined on the basis of the pressure difference that the blocking of the flow passage for the cooling medium in the condenser 6 is solved, the operator manually performs the switching operation of the first to fourth on-off valves 26a to 26d so that the flow of the cooling medium is brought into the first state. In this case, manual valves are applied as the first to fourth on-off valves 26a to 26d.

The control unit 34 controls to switch between the first state and the second state on the basis of the pressure difference. Alternatively, the control unit 34 may control to switch between the first state and the second state on the basis of a pressure ratio.

Third Embodiment

FIG. 8 is a schematic configuration diagram illustrating a system X3 of cleaning the condenser 6 for binary power generation during normal operation. FIG. 9 is a schematic configuration diagram illustrating the system X3 of cleaning the condenser 6 for binary power generation during cleaning of the condenser 6. The system X3 of cleaning the condenser 6 for binary power generation according to the third embodiment includes, in place of the first pressure meter 31 and the second pressure meter 32 of the second embodiment, a first thermometer 41 for measuring the temperature of the cooling medium flowing from the first pipe 18 into the condenser 6 and a second thermometer 42 for measuring the temperature of the cooling medium flowing out of the condenser 6. The system X3 of cleaning the condenser 6 for binary power generation according to the third embodiment further includes a control unit 43 in place of the control unit 34 of the second embodiment. Other configurations of the third embodiment are similar to the configurations of the second embodiment and thus will be assigned with the same reference numbers as the second embodiment and will not be described.

The first thermometer 41 includes a first temperature sensor (not shown) for measuring the temperature of the cooling medium flowing from the first pipe 18 into the condenser 6. The first thermometer 41 is provided in the first pipe 18. The second thermometer 42 includes a second temperature sensor (not shown) for measuring the temperature of the cooling medium flowing out of the condenser 6. The second thermometer 42 is provided in the second pipe 23. The temperatures measured by the first temperature sensor and the second temperature sensor are output therefrom as electric signals to the control unit 43.

When a temperature difference between the temperature measured by the first thermometer 41 and the temperature measured by the second thermometer 42 has exceeded a predetermined value, the control unit 43 controls the switching unit 33 to switch so that the flow of the cooling medium is brought into the second state. Further, when a temperature difference between the temperature measured by the first thermometer 41 and the temperature measured by the second thermometer 42 has reached a value smaller than or equal to the predetermined value, the control unit 43 controls the switching unit 33 to switch so that the flow of the cooling medium is brought into the first state. The predetermined value can be set accordingly in consideration of, for example, the specific heat of the cooling medium and the temperature of the working medium to be heat-exchanged with the cooling medium and on the basis of a temperature difference assumed when the flow passage for the cooling medium in the condenser 6 is actually blocked. For example, the predetermined value can be set to a pressure difference generated when the temperature measured by the second thermometer 42 has become twice as high as the temperature measured by the first thermometer 41.

FIG. 10 is a diagram illustrating the control operation of the control unit 43 in the system X3 of cleaning the condenser 6 for binary power generation. When receiving the electric signals from the first temperature sensor and the second temperature sensor, the control unit 43 subtracts the temperature value measured by the first temperature sensor from the temperature measured by the second temperature sensor to compute a temperature difference (step ST8). Other steps of the third embodiment are similar to the steps of the second embodiment and thus will not be described.

According to the system X3 of cleaning the condenser 6 for binary power generation according to the third embodiment, when a temperature difference between the temperature measured by the first thermometer 41 and the temperature measured by the second thermometer 42 has exceeded the predetermine value, the flow of the cooling medium is automatically switched to the second state. Accordingly, foreign substances FS adhered to the periphery of the branch ports 11 are automatically separated therefrom; therefore, the foreign substances can be removed without disassembling the condenser 6.

According to the system X3 of cleaning the condenser 6 for binary power generation according to the third embodiment, when a temperature difference between the temperature measured by the first thermometer 41 and the temperature measured by the second thermometer 42 has reached a value smaller than or equal to the predetermine value, the flow of the cooling medium is automatically switched to the first state. Accordingly, when the blocking of the flow passage for the cooling medium in the condenser 6 is solved, an operator does not need to perform switching operation to the first state.

The system X3 of cleaning the condenser 6 for binary power generation according to the third embodiment includes the control unit 34. Alternatively, the system X3 may not include the control unit 34. In this case, an operator performs the switching operation from the first state to the second state in the same way as in the case of the second embodiment where the control unit 34 is not provided.

In the system X2 of cleaning the condenser 6 for binary power generation according to the second embodiment, the predetermined value is set on the basis of a pressure difference, and in the system X3 of cleaning the condenser 6 for binary power generation according to the third embedment, the predetermined value is set on the basis of a temperature difference. Alternatively, each of the predetermine values may be set on the basis of a difference between flow rates. In this case, a first flowmeter (not shown) for measuring the flow rate of the cooling medium flowing from the first pipe 18 into the condenser 6 and a second flowmeter (not shown) for measuring the flow rate of the cooling medium flowing out of the condenser 6 are provided.

Fourth Embodiment

FIG. 11 is a schematic configuration diagram illustrating a system X4 of cleaning the condenser 6 for binary power generation during normal operation of the condenser 6. The system X4 of cleaning the condenser 6 for binary power generation according to a fourth embodiment is different from the system X1 according to the first embodiment in that three-way valves are applied as a switching unit 51 for reversing the flow direction of the cooling medium in the condenser 6. Other configurations of the fourth embodiment are similar to the configurations of the first embodiment and thus will be assigned with the same reference numbers as the first embodiment and will not be described.

The switching unit 51 includes: a first three-way valve 51a provided on the first portion P1 in the first pipe 18; and a second three-way valve 51b provided on the fourth portion P4 in the second pipe 23. The first three-way valve 51a is configured to open and close the flow passage of the first pipe 18 and to open and close the flow passage of the third pipe 24. The second three-way valve 51b is configured to open and close the flow passage of the second pipe 23 and to open and close the flow passage of the fourth pipe 25.

The system X4 of cleaning the condenser 6 for binary power generation according to the fourth embodiment operates as follows. In order that the flow of the cooling medium is brought into the first state during normal operation, firstly, an operator opens the flow passage of the first pipe 18 of the first three-way valve 51a and closes the flow passage of the third pipe 24, and in addition, the operator opens the flow passage of the second pipe 23 of the second three-way valve 51b and closes the flow passage of the fourth pipe 25. Thus, the system X4 of cleaning the condenser 6 for binary power generation according to the fourth embodiment is brought into the first state where the cooling medium flows from the first pipe 18 into the condenser 6 and then flows out to the second pipe 23.

FIG. 12 is a schematic configuration diagram illustrating the system X4 of cleaning the condenser 6 for binary power generation. When a predetermined time has elapsed during normal operation, in order to bring the flow of the cooling medium into the second state, an operator closes the flow passage of the first pipe 18 of the first three-way valve 51a and opens the flow passage of the third pipe 24, and in addition, the operator closes the flow passage of the second pipe 23 of the second three-way valve 51b and opens the flow passage of the fourth pipe 25. Thus, the system X4 of cleaning the condenser 6 for binary power generation according to the fourth embodiment is brought into the second state where the cooling medium flows from the first pipe 18 through the third pipe 24 and the second pipe 23 into the condenser 6.

The system X4 of cleaning the condenser 6 for binary power generation according to the fourth embodiment is configured to switch between the first state and the second state by two valves, that is, the first three-way valve 51a and the second three-way valve 51b; therefore, the switching operation is easy compared to the foregoing first to third embodiments.

Fifth Embodiment

FIG. 13 is a schematic configuration diagram illustrating a method of cleaning the condenser 6 for binary power generation during normal operation of the condenser 6. The method of cleaning the condenser 6 for binary power generation of a fifth embodiment is different from that of the first embodiment in that the third pipe 24 and the fourth pipe 25 are not provided during normal operation. Furthermore, the method of cleaning the condenser 6 for binary power generation according to the fifth embodiment is different from that of the first embodiment in that a switching unit 61 is provided in place of the switching unit 26 of the first embodiment. Other configurations of the fifth embodiment are similar to the configurations of the first embodiment and thus will be assigned with the same reference numbers as the first embodiment and will not be described.

A cleaning system X5 used in the method of cleaning the condenser 6 for binary power generation according to the fifth embodiment includes: a first branched pipe 62 branched from the first pipe 18 and provided with a first joint 62a at an end thereof; and a second branched pipe 63 branched from the second pipe 23 and provided with a second joint 63a at an end thereof. The cleaning system X5 used in the method of cleaning the condenser 6 for binary power generation according to the fifth embodiment includes a third branched pipe 64 branched from the second portion P2. The second portion P2 is located downstream, in the flow direction of the cooling medium, of the first portion P1 of the first pipe 18 on which the first branched pipe 62 is located. A third joint 64a is provided at an end of the third branched pipe 64. The cleaning system X5 used in the method of cleaning the condenser 6 for binary power generation according to the fifth embodiment includes a fourth branched pipe 65 branched from the fourth portion P4. The fourth portion P4 is located downstream, in the flow direction of the cooling medium, of the third portion P3 of the second pipe 23 on which the second branched pipe 63 is located. A fourth joint 65a is provided at an end of the fourth branched pipe 65.

The switching unit 61 includes: a fifth on-off valve 61a interposed between the first portion P1 and the second portion P2 of the first pipe 18; and a sixth on-off valve 61b interposed between the third portion P3 and the fourth portion P4 of the second pipe 23.

In the method of cleaning the condenser 6 for binary power generation according to the fifth embodiment, an operator opens the fifth on-off valve 61a and closes the sixth on-off valve 61b so that the flow of the cooling medium is brought into the first state during normal operation. Thus, the cleaning system X5 used in the method of cleaning the condenser 6 for binary power generation according to the fifth embodiment is brought into the first state where the cooling medium flows from the first pipe 18 into the condenser 6 and flows out to the second pipe 23. At this time, the first to fourth joints 62a to 65a of the first to fourth branched pipes 62 to 65 are closed; therefore, no cooling medium flows out of the first to fourth branched pipes 62 to 65.

FIG. 14 is a schematic configuration diagram illustrating the method of cleaning the condenser 6 for binary power generation during cleaning of the condenser 6. When a predetermined time has elapsed during normal operation, an operator performs the following first to fourth steps to bring the flow of the cooling medium into the second state.

Firstly, the operator stops a pump (not shown) provided upstream in the first pipe 18 to stop the flow of the cooling medium. Next, the operator performs the first step of connecting the first branched pipe 62 through the third pipe 24 to the second branched pipe 63 via the first joint 62a and via the second joint 63a. After the first step, the operator performs the second step of connecting the third branched pipe 64 through the fourth pipe 25 to the fourth branched pipe 65 via the third joint 64a and via the fourth joint 65a. After the second step, the operator performs the third step of closing the fifth on-off valve 61a and the sixth on-off valve 61b. Finally, the operator activates the pump (not shown) provided upstream in the first pipe 18 to flow the cooling medium.

Accordingly, the flow of the cooling medium is stopped between the first portion P1 and the second portion P2 of the first pipe 18 and between the third portion P3 and the fourth portion P4 of the second pipe 23. Therefore, the cooling medium flows through the first pipe 18, the first branched pipe 62, the third pipe 24, the second branched pipe 63, the second pipe 23, the condenser 6, the first pipe 18, the third branched pipe 64, the fourth pipe 25, the fourth branched pipe 65, and the second pipe 23 in the mentioned order. Thus, the flow of the cooling medium is switched to the second state; therefore, cleaning of the condenser 6 is performed.

After a predetermined time has elapsed during cleaning of the condenser, in order to switch the flow of the cooling medium to the first state, the operator stops the pump (not shown) provided upstream in the first pipe 18 to stop the flow of the cooling medium. Thereafter, the operator removes the third pipe 24 and the fourth pipe 25 and closes the first to fourth joints 62a to 65a. Finally, the operator activates the pump (not shown) provided upstream in the first pipe 18 to flow the cooling medium. Thus, the operator switches the flow of the cooling medium from the second state to the first state.

According to the method of cleaning the condenser 6 for binary power generation of the fifth embodiment, the first to third steps are performed; thereby, the flow of the cooling medium can be switched to a direction from the heat exchanger 6a to the inlet header 6b. Accordingly, the force in a direction to separate foreign substances from the branch ports 11 can be applied to the foreign substances adhered to the periphery of the branch ports 11. Therefore, the foreign substances adhered to the periphery of the branch ports 11 are easily separated therefrom. Consequently, the foreign substances can be removed without disassembling the condenser 6.

According to the method of cleaning the condenser 6 for binary power generation of the fifth embodiment, as long as the blocking of the flow passage for the cooling medium in the condenser 6 does not occur, the operator may not have to perform the first step to the third step. Therefore, the method of cleaning the condenser 6 for binary power generation of the fifth embodiment can reduce installation costs.

According to the method of cleaning the condenser 6 for binary power generation of the fifth embodiment, respective on-off valves (not shown) for opening and closing the flow passage for the cooling medium may be provided in the first to fourth branched pipes 62 to 65. Therefore, in a state where the on-off valves are closed, an operator can connect the third pipe 24 to the first branched pipe 62 and the second branched pipe 63 without stopping the flow of the cooling medium. Likewise, the operator can connect the fourth pipe 25 to the third branched pipe 64 and the fourth branched pipe 65 without stopping the flow of the cooling medium.

In the foregoing embodiments, the strainer 27 for removing the foreign substances FS in the cooling medium from the cooling medium is provided in the fourth pipe 25. Alternatively, the strainer 27 may not be provided. In this case, the foreign substances FS in the cooling medium are released together with the cooling medium into the sea or the river. Therefore, marine organisms adhered to the inside of the condenser 6 will be returned into the sea or the like, which is environmentally friendly.

Claims

1. A system of cleaning a condenser for binary power generation, the condenser being provided in a circulation flow passage for allowing circulation of a working medium in a binary power generation system, wherein

the condenser comprises:

an inlet header into which a cooling medium flows; and

a heat exchanger including a plurality of branch ports into which the cooling medium flows from the inlet header, the heat exchanger being configured to perform heat exchange between the working medium and the cooling medium to condense the working medium, and

the cleaning system comprises a switching unit configured to switch a flow of the cooling medium to a direction from the heat exchanger to the inlet header.

2. The system of cleaning the condenser for binary power generation according to claim 1, comprising:

a third pipe adapted to connect a first pipe for allowing the cooling medium to flow into the inlet header of the condenser, to a second pipe for allowing the cooling medium to flow out of the condenser; and

a fourth pipe adapted to connect a second portion of the first pipe to a fourth portion of the second pipe, the second portion being located downward, in a flow direction of the cooling medium, of a first portion of the first pipe to which the third pipe is connected, the fourth portion being located downstream, in the flow direction of the cooling medium, of a third portion of the second pipe to which the third pipe is connected,

wherein the switching unit switches from a first state where the cooling medium flows from the first pipe into the condenser to a second state where the cooling medium flows from the first pipe through the third pipe and the second pipe into the condenser.

3. The system of cleaning the condenser for binary power generation according to claim 2, comprising a strainer provided in the fourth pipe and configured to remove foreign substances in the cooling medium from the cooling medium.

4. The system of cleaning the condenser for binary power generation according to claim 2, comprising:

a first pressure meter provided in the first pipe and configured to measure a pressure of the cooling medium flowing from the first pipe into the condenser; and

a second pressure meter provided in the second pipe and configured to measure a pressure of the cooling medium flowing out of the condenser.

5. The system of cleaning the condenser for binary power generation according to claim 4, comprising

a control unit configured to, when a difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter has exceeded a predetermined value, control the switching unit to establish the second state.

6. The system of cleaning the condenser for binary power generation according to claim 5, wherein the control unit is configured to, when a difference between a pressure value measured by the first pressure meter and a pressure value measured by the second pressure meter has reached a value smaller than or equal to the predetermined value, control the switch means to establish the first state.

7. The system of cleaning the condenser for binary power generation according to claim 2, comprising:

a first thermometer provided in the first pipe and configured to measure a temperature of the cooling medium flowing from the first pipe into the condenser; and

a second thermometer provided in the second pipe and configured to measure a temperature of the cooling medium flowing out of the condenser.

8. The system of cleaning the condenser for binary power generation according to claim 7, comprising

a control unit configured to, when a temperature difference between a temperature measured by the first thermometer and a temperature measured by the second thermometer has exceeded a predetermined value, control the switching unit to establish the second state.

9. The system for the condenser for binary power generation according to claim 8, wherein the control unit is configured to, when a temperature difference between a temperature measured by the first thermometer and a temperature measured by the second thermometer has reached a value smaller than or equal to the predetermined value, control the switching unit to establish the first state.

10. A method of cleaning a condenser for binary power generation, the condenser being provided in a circulation flow passage for allowing circulation of a working medium in a binary power generation system, wherein

the condenser comprises:

an inlet header into which a cooling medium flows; and

a heat exchanger including a plurality of branch ports into which the cooling medium flows from the inlet header, the heat exchanger being configured to perform heat exchange between the working medium and the cooling medium to condense the working medium, and

the cleaning method comprises the step of switching a flow of the cooling medium to a direction from the heat exchanger to the inlet header.

11. The method of cleaning the condenser for binary power generation according to claim 10, comprising:

a first branched pipe branched from a first pipe for allowing the cooling medium to flow into the inlet header of the condenser, the first branched pipe including a first joint at an end thereof;

a second branched pipe branched from a second pipe for allowing the cooing medium to flow out of the condenser, the second branched pipe including a second joint at an end thereof;

a third branched pipe branched from a second portion of the first pipe, which is located downstream, in a flow direction of the cooling medium, of a first portion of the first pipe from which the first branched pipe is branched, the third branched pipe including a third joint at an end thereof;

a fourth branched pipe branched from a fourth portion of the second pipe, which is located downstream, in the flow direction of the cooling medium, of a third portion of the second pipe from which the second branched pipe is branched, the fourth branched pipe including a fourth joint at an end thereof; and

a switching unit configured to stop the flow of the cooling medium between the first portion and the second portion of the first pipe and to stop the flow of the cooling medium between the third portion and the fourth portion of the second pipe, wherein

the method comprises:

a first step of connecting the first branched pipe through the third pipe to the second branched pipe via the first joint and via the second joint;

a second step of connecting the third branched pipe through the fourth pipe to the fourth branched pipe via the third joint and via the fourth joint; and

a third step of switching by the switching unit from a first state where the cooling medium flows from the first pipe into the condenser to a second state where the cooling medium flows from the first pipe through the third pipe and the second pipe into the condenser.

12. The system of cleaning the condenser for binary power generation according to claim 3, comprising:

a first pressure meter provided in the first pipe and configured to measure a pressure of the cooling medium flowing from the first pipe into the condenser; and

a second pressure meter provided in the second pipe and configured to measure a pressure of the cooling medium flowing out of the condenser.

13. The system of cleaning the condenser for binary power generation according to claim 3, comprising:

a first thermometer provided in the first pipe and configured to measure a temperature of the cooling medium flowing from the first pipe into the condenser; and

a second thermometer provided in the second pipe and configured to measure a temperature of the cooling medium flowing out of the condenser.