HEATING SYSTEM

The present invention provides a heating system capable of implementing an inrush current countermeasure without causing an increase in cost. A control means of the heating system repeatedly executes, in a predetermined cycle, a sequence starting operation of the fluid flowing part, the predetermined cycle being divided into a plurality of operation start permitted intervals, and the operation start permitted intervals permitting, among the fluid flowing part, only a specific fluid flowing part determined for each operation start permitted interval, to start operating, and prohibiting the other fluid flowing part other than the specific fluid flowing part from starting to operate.

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Description
BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a heating system that performs heating by causing a fluid heated by a heat source to be circulated to a heating terminal.

Description of the Related Art

A conventional heating system has a fluid flow path for supplying a fluid heated by a heat source to a plurality of heating terminals. A fluid flow path on a heat source side is provided with a circulation pump, and a fluid flow path on a heating terminal side is provided with a plurality of heating terminals and a plurality of external pumps corresponding to the respective heating terminals (JP 2016-109376 A). The heating system performs a heating operation by controlling the operation of the circulation pump and the external pumps on the basis of the temperature of a room, or the like, which is to be heated.

SUMMARY OF THE INVENTION

In the heating system having the above configuration, an operation start instruction may be simultaneously sent to a plurality of pumps among the circulation pump and the plurality of external pumps. Because an inrush current larger than a pump steady-state current flows at the start of operation of the pumps, in a case where the plurality of pumps are started simultaneously, a larger amount of current flows through the entire heating system. In this case, there is a risk of failure occurring in an electronic component or the like due to an allowable current of the heating system being exceeded, and thus there have been various problems including the fact that a power cable, an electronic component or the like having a large current rating is required to increase the allowable current of the heating system, and an increase in cost. Note that there have been similar problems even with heating systems which include, in a fluid flow path on a heating terminal side, a thermal valve (on-off valve) instead of an external pump.

The present invention was conceived in view of the foregoing circumstances, and an object of the present invention is to provide a heating system capable of implementing an inrush current countermeasure without causing an increase in cost.

The heating system according to a first aspect of the disclosure is a heating system, comprising:

    • a heat source having a heating unit configured to heat a fluid;
    • a heating terminal of which a plurality can be installed;
    • an inflow pipe connected to a fluid inlet of the heating unit;
    • an outflow pipe connected to a fluid outlet of the heating unit;
    • a branch supply pipe directly or indirectly connected to the outflow pipe and connected to a fluid inlet of the heating terminal;
    • a branch recovery pipe connected to a fluid outlet of the heating terminal and directly or indirectly connected to the inflow pipe;
    • a plurality of fluid flowing part configured to circulate the fluid by operating; and
    • control means configured to control operation of the plurality of fluid flowing part,
    • in which the fluid flowing part is provided to the inflow pipe or the outflow pipe and is provided to the branch supply pipe or the branch recovery pipe,
    • the fluid flowing part provided to the inflow pipe or the outflow pipe is a pump,
    • the fluid flowing part provided to the branch supply pipe or the branch recovery pipe is a pump or an on-off valve,
    • the control means repeatedly executes, in a predetermined cycle, a sequence to start the operation of the fluid flowing part,
    • the predetermined cycle is divided into a plurality of operation start permitted intervals, and
    • each of the operation start permitted intervals has a control configuration in which, among the fluid flowing part, only a specific fluid flowing part determined for each operation start permitted interval is permitted to start operating, and the other fluid flowing part other than the specific fluid flowing part is prohibited from starting to operate.

According to the configuration of the first aspect of the disclosure, in the operation start permitted interval, the fluid flowing part other than the specific fluid flowing part is prohibited from starting to operate, and thus the number of fluid flowing part that start operating simultaneously is limited. Therefore, in the heating system, when the operation of the fluid flowing part is started, it is possible to restrict an amount of inrush current larger than a steady-state current from flowing simultaneously (the magnitude of the current value or of the amount of electricity). As a result, it is possible to eliminate the need for a countermeasure to increase the allowable current of the heating system by employing a power cable or an electronic component having a large current rating. Accordingly, it is possible to implement an inrush current countermeasure that does not generate a large inrush current at the start of operation of the fluid flowing part, without increasing the cost of the heating system. In addition, because fusing of a current fuse, failure of an electronic component, and the like can be prevented, the reliability of the operation of the heating system can be enhanced.

A heating system according to a second aspect of the disclosure is the heating system according to the first aspect of the disclosure, wherein an operation start prohibited interval for prohibiting the start of operation of all the fluid flowing part is provided between each the operation start permitted intervals.

For example, in a case where an operation start instruction for each specific fluid flowing part is issued at the end of an arbitrary operation start permitted interval and at the beginning of the next operation start permitted interval (constituting a “predetermined condition”, there is a possibility of a temporary overlap between the inrush currents of the fluid flowing part whose operation is started earlier and subsequently, and of the total value of the inrush currents exceeding an allowable current of the heating system.

According to the configuration of the second aspect of the disclosure, because an operation start prohibited interval is provided between the operation start permitted intervals, even if the fluid flowing part start to operate earlier and subsequently as per the aforementioned predetermined condition, an overlap between the inrush currents of the fluid flowing part is prevented, and hence it is possible to prevent the inrush currents at the time of starting the operation of the fluid flowing part from exceeding the allowable current of the heating system.

A heating system according to a third aspect of the disclosure is the heating system according to the second aspect of the present disclosure,

    • in which a period of the operation start prohibited interval is set to be equal to or longer than a time required for a current value of the fluid flowing part to become a steady-state current after the fluid flowing part starts to operate.

According to the configuration of the third aspect of the disclosure, when the period of the operation start prohibited interval elapses, the current value due to the operation of the specific fluid flowing part, the operation of which was started in the immediately preceding operation start permitted interval, falls within the steady-state current. Therefore, even if each of the fluid flowing part starts to operate earlier and subsequently as per the aforementioned predetermined condition, it is possible to more reliably prevent an inrush current at the time of starting the operation of the fluid flowing part from exceeding an allowable current of the heating system.

A heating system according to a fourth aspect of the disclosure is the heating system according to the second or third aspects of the present disclosure, wherein a period of the operation start permitted interval is set to be a shorter time than a period of the operation start prohibited interval.

By providing the operation start prohibited interval, it is possible to limit the inrush currents of the fluid flowing part which have started to operate earlier and subsequently, so as to prevent overlap between the currents, and it is thus possible to set the period of each operation start permitted interval to be a short time.

As per the configuration of the fourth aspect of the disclosure, by setting the period of the operation start permitted interval to be a shorter time than the period of the operation start prohibited interval, the period of the predetermined cycle of the sequence for starting the operation of the fluid flowing part can be shortened while preventing the allowable current of the heating system from being exceeded due to the inrush currents of the fluid flowing part. Therefore, it is possible to shorten a waiting time from an operation start instruction to an arbitrary fluid flowing part until the start of operation of the fluid flowing part is executed. Therefore, it does not take time to start the heating operation of the heating terminals, thus improving the comfort of the user in the heating environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a configuration of a heating system according to an embodiment;

FIG. 2 is a pump switch circuit diagram;

FIG. 3 is a timing chart for controlling the start of operation of the pumps;

FIG. 4 is a schematic diagram showing a configuration of a heating system according to another embodiment 1; and

FIG. 5 is a schematic diagram showing a configuration of a heating system according to another embodiment 2.

 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of a heating system of the present disclosure will be described with reference to the accompanying drawings.

As illustrated in FIG. 1, a heating system 1 according to an embodiment includes a heat source 2 constituted by a gas-powered hot water heater or an electric water heater or the like, a plurality of heating terminals 3A to 3D, and control means 4 for controlling operation of the heating system 1. The heat source 2 includes a heat exchanger 5 serving as a heating unit that heats a fluid, and circulates the fluid heated by the heat source 2 to each of the heating terminals 3A to 3D to perform a heating operation in each of the heating terminals 3A to 3D. As the fluid, a heating medium such as water (hot water) or antifreeze fluid is used. On the heat source 2 side, a heat source remote controller 21 for remotely operating the heat source 2 is communicably connected to the control means 4. When the operation switch of the heat source remote controller 21 is turned on, the heat source 2 enters an operational state.

The heating system 1 includes an inflow pipe 6 connected to a fluid inlet 51 of the heat exchanger 5 of the heat source 2, an outflow pipe 7 connected to a fluid outlet 52 of the heat exchanger 5 of the heat source 2, a plurality of branch supply pipes 8 having one end connected to a fluid feed pipe 81 and indirectly connected to the outflow pipe 7 and having the other end connected to a fluid inlet 33 of each of the heating terminals 3A to 3D, and a plurality of branch recovery pipes 9 having one end connected to a fluid return pipe 91 and indirectly connected to the inflow pipe 6 and having the other end connected to the fluid outlet 34 of each of the heating terminals 3A to 3D. The inflow pipe 6 is provided with a circulation pump (fluid flowing part) P1. The fluid is made to flow through the heat exchanger 5 by operating the circulation pump P1. The circulation pump P1 is installed in a housing of the heat source 2. The branch supply pipes 8 have external pumps (fluid flowing part) P2 to P5 which are provided so as to correspond to the heating terminals 3A to 3D, respectively. By operating the external pumps P2 to P5, the fluid heated by the heat source 2 is made to flow to the corresponding heating terminals 3A to 3D.

A water mixing device 10 is provided between the inflow pipe 6 and the outflow pipe 7, and the fluid feed pipe 81 and the fluid return pipe 91. Due to the water mixing device 10, the inflow pipe 6 and the outflow pipe 7 are connected by a bypass connection, and the fluid feed pipe 81 and the fluid return pipe 91 are connected by a bypass connection. As a result, the heat source 2 side has a circulation path through which the fluid flows in the inflow pipe 6, the outflow pipe 7, and the heat exchanger 5, and the heating terminal 3 side has a circulation path through which the fluid flows in the fluid feed pipe 81, the fluid return pipe 91, the branch supply pipe 8, the branch recovery pipe 9, and the heating terminals 3, thus enabling heat exchange to be performed between the fluids circulating in the circulation path in the water mixing device 10. Further, due to the water mixing device 10, it is possible to heat the fluid circulating in the circulation path on the heating terminal 3 side without increasing the flow rate of the fluid circulating in the circulation path on the heat source 2 side.

A heating remote controller 31 for remotely operating the heating terminals 3 is connected to each of the heating terminals 3A to 3D so as to be able to communicate with the control means 4. The heating remote controller 31 includes operating parts such as an operation switch and a temperature setting switch for a set temperature, and a display unit, and the like. When an operation switch of the heating remote controller 31 is turned on, a heating operation request from corresponding heating terminals 3A to 3D is outputted to the control means 4. Each of the heating terminals 3A to 3D includes temperature monitoring part 32 such as a thermostat or a temperature sensor. The temperature monitoring part 32 outputs a request for operation/stoppage of the corresponding external pumps P2 to P5 to the control means 4 so that the temperature of the room or the like in which the heating terminals 3A to 3D are installed becomes the set temperature.

The control means 4 includes electronic units such as a microcomputer and a memory, and controls the operation of the heat source 2 and the heating terminals 3 to control the heating operation by the heating terminals 3. The control means 4 is installed in the housing of the heat source 2.

FIG. 2 shows a switch circuit 40 of the pumps P provided to the control means 4. In FIG. 2, a pump denoted by P1 corresponds to the circulation pump P1 of the heat source 2, and pumps denoted by P2 to P5 correspond to the external pumps P2 to P5 of the heating terminals 3A to 3D, respectively. The switch circuit 40 is supplied with electricity from the main power supply 11 via the power cable 12 and the connector C1, and includes relays RY1 to RY5 corresponding to the pumps P1 to P5. The drive sources (such as motors) of the pumps P1 to P5 are connected to the switch circuit 40 via the connector C2. The relays RY1 to RY5 are connected in parallel by a wiring pattern 14. In the switch circuit 40, a switching power supply 13 for supplying electricity to various electronic components and the like included in the heating system 1 is connected to the wiring pattern 14. Note that, in the present specification, the pumps P1 to P5 may be referred to as the pumps P (note that the external pumps P2 to P5 may also be referred to as the external pumps P.), the relays RY1 to RY5 may be referred to as the relays RY, and the heating terminals 3A to 3D may be referred to as the heating terminals 3. When a relay RY is turned on by the switch circuit 40, the electricity of the main power supply 11 is supplied to the drive source of the pump P which corresponds to that relay RY to operate the pump P. The turning on/off of each relay RY is controlled by the control means 4. The control means 4 receives output signals from the temperature monitoring part 32 and the heating remote controllers 31, which are included in each heating terminal 3, from the sensors included in the heat source 2, and from the heat source remote controller 21, and the like, and controls the on/off of each relay RY to control the operation of each pump P. At the start of operation of the pumps P, an inrush current larger than the steady-state current of the pumps P flows through the wiring pattern 14, the connectors C1 and C2, the power cable 12, and the like. In a case where the operation of the plurality of pumps P is simultaneously started, an inrush current may exceed the allowable current of the heating system 1. Therefore, the control means 4 controls the operation of each pump P so that an inrush current at the start of the operation of the pump P does not exceed the allowable current of the heating system 1.

Hereinafter, a control configuration of the control means 4 will be described.

The control means 4 repeatedly executes, using a predetermined cycle T, one sequence for starting the operation of each pump P. As illustrated in the timing chart of FIG. 3, the predetermined cycle T of one sequence is divided into a plurality of operation start permitted intervals T1, and an operation start prohibited interval T2 is provided between the operation start permitted intervals T1. In each operation start permitted interval T1, the start of operation of only a specific pump determined for each operation start permitted interval T1 among all the pumps P is permitted, and the start of operation of the pumps other than the specific pump is prohibited. In each operation start prohibited interval T2, the start of operation of all the pumps P is prohibited.

In the timing chart of FIG. 3, the predetermined cycle T of one sequence is divided into five operation start permitted intervals T1 labeled (1) to (5), and an operation start prohibited interval T2 is provided between the operation start permitted intervals T1 labeled (1) to (5). In each of the operation start permitted intervals T1 labeled (1) to (5), the pumps P1 to P5 are designated one by one as specific pumps. That is, only during the period of each operation start permitted interval T1, the relays RY (RY1 to RY5) corresponding to the specific pumps P (P1 to P5) defined for each operation start permitted interval T1 are controlled to be able to be turned on. According to such a timing chart, when the operation start instruction to the pumps P is issued, in the period of the operation start permitted interval T1 labeled (1), only the relay RY1 is turned on and only the operation of the pump P1 is started, and the start of the operation of the other pumps P2 to P5 is prohibited. In the period of the operation start permitted interval T1 labeled (2), only the relay RY2 is turned on and only the operation of the pump P2 is started, and the start of the operation of the other pumps P1, P3 to P5 is prohibited. In the period of each of the operation start permitted intervals T1 labeled (3) to (5), only the respective relays RY3 to RY5 are turned on and only the operation of the respective pumps P3 to P5 is started, and the start of the operation of the other pumps P is prohibited. In each operation start prohibited interval T2, the start of operation of all the pumps P1 to P5 is prohibited. That is, in the operation start prohibited interval T2, all the relays RY1 to RY5 are not turned from off to on.

As described above, in the operation start permitted interval T1, the start of operation of only the specific pump defined in the operation start permitted interval T1 is permitted, and the start of operation of the pumps other than the specific pump is prohibited. This is because a pump P for which the operation start instruction is issued at a certain timing is only not started in periods other than the operation start permitted interval T1 for that pump P, and the operation start permitted interval T1 of the pump P exists in each predetermined cycle T, and thus the start of operation is executed as time advances and the operation start permitted interval T1 of the pump P is reached. Depending on the timing of the operation start instruction, the execution of the start of operation of the pump P is on placed on standby only for at most the period of the predetermined cycle T, but the operation start instruction itself is effective, and thus it is not necessary for the user or the like to issue the operation start instruction again.

In addition, in the operation start permitted interval T1, only the start of operation of other pumps other than the specific pump is prohibited, while action during operation of the other pumps and action to stop operation thereof are continued without being prohibited. In the timing chart of FIG. 3, for example, the operating state of the operating pump P1 is continued without action during operation thereof being prohibited in each of the operation start permitted intervals T1 labeled (2) to (5). In the pumps P2 and P3, the relays RY2 and RY3 are turned off and the operation thereof is stopped without prohibiting the stoppage operation in the operation start permitted interval T1 labeled (4).

The number of the plurality of operation start permitted intervals T1 within the predetermined cycle T can be set to, for example, the same number as the maximum number of pumps that can be installed in the heating system 1. In the heating system 1 according to the embodiment, because a maximum of four heating terminals 3 can be installed, a total of five pumps, namely, one circulation pump P1 on the heat source 2 side and four external pumps P2 to P5 on each heating terminal 3 side is the maximum number of pumps. In this case, five operation start permitted intervals T1 labeled (1) to (5) are provided in the predetermined cycle T in accordance with the maximum number of five. Note that the number of the operation start permitted intervals T1 provided is at least two at the beginning, and may be configured to be added to, as necessary, by an input means (for example, a dip switch or the like connected to the control means 4) (in a case where an operation start permitted interval T1 is added, an operation start prohibited interval T2 is created simultaneously).

In each operation start permitted interval T1, one pump P is designated as a specific pump. Specifically, the pumps P1 to P5 are allocated one by one to correspond to the operation start permitted intervals T1 labeled (1) to (5). In each operation start permitted interval T1, which pump P is determined as a specific pump may be set in advance at the time of factory shipment or the like, or may be set arbitrarily. For example, the circulation pump P1 (the heat source 2) and the external pumps P2 to P5 (the heating terminals 3A to 3D) may be selected for each operation start permitted interval T1 by a dip switch or the like connected to the control means 4. One pump P may be designated as the specific pump as per the embodiment, or a plurality of pumps P (where the number of pumps is smaller than the total number of pumps) may be designated. In a case where a plurality of pumps P are designated as specific pumps, the number of pumps that can be designated is limited within a range in which a total value of the inrush currents when the plurality of pumps P simultaneously start to operate does not exceed the allowable current of the heating system 1.

In a case where the number of operation start permitted intervals T1 within the predetermined cycle T is the same as the maximum number of pumps that can be installed in the heating system 1, for example, in a case where the number of heating terminals 3 installed is smaller than the maximum number of pumps that can be installed in the heating system 1, or in a case where a plurality of pumps P are set as the specific pumps, an empty operation start permitted interval T1 in which a specific pump is not designated can be obtained within the predetermined cycle T. In this case, the predetermined cycle T may have an empty operation start permitted interval T1, or the predetermined cycle T may be made a short period by deleting the empty operation start permitted interval T1 (for example, turning off the dip switch connected to the control means 4, or the like).

The period of the operation start prohibited interval T2 is set to be equal to or longer than the time required for the current value by the operation of the pump to become a steady-state current after the operation of the pump is started. The pump referred to herein may be a general pump that can be installed in this heating system 1, or a pump having the largest inrush current among the pumps that can be installed in this heating system 1 may be assumed.

The steady-state current may refer to a current in a state in which a temporal change in the current value of the pumps decreases and the pump current flows in a regular manner. Examples of cases where the pump current value may be said to represent a steady-state current include a case where the amount of variation in the pump execution current (pump current value) is no more than 20%/s, a case where 100 ms have elapsed since the start of pump operation, and a case where the pump current value becomes 30% or less of the peak current. That is, the time required for the steady-state current to be reached can be arbitrarily determined, such as the amount of variation in the pump execution current, the time elapsed since the start of pump operation, and the ratio to the peak current value of the pumps. However, whether the current is a steady-state current can be appropriately determined according to conditions such as the pump type and the load of the heating system 1. In addition, the time required for the steady-state current may be determined by an experiment or the like.

The period of the operation start permitted interval T1 is set to be a shorter time than the period of the operation start prohibited interval T2. For example, in the embodiment, the period of the operation start permitted interval T1 is 50 ms, and the period of the operation start prohibited interval T2 is 100 ms. In this case, because there are five operation start permitted intervals T1 and five operation start prohibited intervals T2 within the predetermined cycle T, a period of one predetermined cycle T (one sequence) is 750 ms. Because the operation start prohibited interval T2 is provided between the operation start permitted intervals T1, the period of the operation start permitted interval T1 may be as short as possible as the time required to enable the start of operation of the pumps P. Note that the period of the operation start permitted interval T1 may be the same time as or a longer time than the period of the operation start prohibited interval T2.

Next, a control operation for starting the operation of each pump will be described.

While a power supply is turned on by the heat source 2 or the like, and the power supply of the heating system 1 is switched on, the control means 4 repeatedly executes, using a predetermined cycle T, one sequence for starting the operation of the pumps P1 to P5. In a case where the operation of the heat source 2 and all the heating terminals 3 has been stopped and the operation switch of the heating remote controller 31 is turned on in any one of the plurality of heating terminals 3A to 3D, the control means 4 is required to start the operation of the heat source 2 and start the operation of the heating terminals 3 simultaneously. In this case, the operation start request of the heat source 2 serves as an operation start instruction for the circulation pump P1, and the operation start requests of the heating terminals 3 serve as operation start instructions for the external pumps P corresponding to the heating terminals 3. Therefore, the control means 4 is simultaneously instructed to start the operation of the circulation pump P1 and the corresponding external pump P.

When instructions to start the operation of the circulation pump P1 and the corresponding external pump P are issued simultaneously, regardless of the timing of the simultaneous instructions to start the operation, the control means 4 turns on only the relays RY corresponding to specific pumps in the period T1 to start the operation of the specific pumps when the period of the operation start permitted interval T1, in which the circulation pump P1 and the corresponding external pump P are defined as the specific pumps, is reached in the period of the predetermined cycle T, and prohibits the start of operation of, and does not turn on, the corresponding relays RY of pumps other than the specific pumps. During the period of the operation start prohibited interval T2, the start of the operation of all the pumps P1 to P5 is prohibited.

For example, in a case where the operation switch of the heating remote controller 31 of the heating terminal 3B is turned on while the heat source 2 and the operation of all the heating terminals 3 has been stopped, the control means 4 is required to start the operation of the heat source 2 and start the operation of the heating terminal 3B simultaneously. Therefore, the control means 4 is instructed to start the operation of the circulation pump P1 of the heat source 2 and the external pump P3 of the heating terminal 3B simultaneously. In this case, during the period of the predetermined cycle T, the control means 4 turns on the relay RY1 and starts the operation of only the circulation pump P1 during the period of the operation start permitted interval T1 labeled (1). (1) During the period of the operation start permitted interval T1, the start of the operation of the pumps P other than the circulation pump P1 is prohibited. Therefore, the operation of the pumps P2 to P5 including the external pump P3 is not started simultaneously with the start of the operation of the circulation pump P1. Further, during the period of the operation start permitted interval T1 labeled (3), the relay RY3 is turned on and only the operation of the external pump P3 is started. (3) During the period of the operation start permitted interval T1, the start of operation of the pumps P other than the external pump P3 is prohibited. Therefore, the operation of the pumps P1, P2, P4, and P5 including the circulation pump P1 is not started simultaneously with the start of the operation of the external pump P3. During the period of the operation start prohibited interval T2, the start of operation of all the pumps P is prohibited, and hence the circulation pump P1 and the external pump P3 do not start to operate simultaneously.

Next, when the operation of the heating terminals 3 is underway, the circulation pump P1 of the heat source 2 is operating, and the control means 4 controls the operation/stoppage of the external pumps P2 to P5 on the basis of the monitored temperature of the temperature monitoring part 32 built into the heating terminal 3. Here, in a case where the external pumps P of a plurality of heating terminals 3 are simultaneously instructed to start operating from a state where the operation of the external pumps P2 to P5 of the plurality of heating terminals 3 has been stopped, the control means 4 turns on only the relays RY corresponding to the those external pumps P to start the operation of specific external pumps P during the period of the operation start permitted interval T1, in which the external pumps P are defined as the specific pumps, in the period of the predetermined cycle T, and prohibits the start of operation of, and does not turn on, pumps other than the specific external pumps P when the corresponding relays RY are turned off. Similarly, the start of the operation of all the pumps P1 to P5 is prohibited during the period of the operation start prohibited interval T2.

For example, in a case where the external pumps P3 and P5 of the heating terminals 3B and 3D are instructed to start operating simultaneously from a state where the operation of the external pumps P3 and P5 has been stopped, the control means 4 turns on the relay RY3 and starts operating only the external pump P3 during the period of the operation start permitted interval T1 labeled (3) in the period of the predetermined cycle T, irrespective of the timing of the simultaneous operation start instructions. During the period of the operation start permitted interval T1 labeled (3), the start of operation of the pumps P other than the external pump P3 is prohibited. Therefore, the operation of the pumps P1, P2, P4, and P5 including the external pump P5 is not started simultaneously with the start of the operation of the external pump P3. In addition, during the period of the operation start permitted interval T1 labeled (5), the relay RY5 is turned on, and the operation of only the external pump P5 is started. During the period of the operation start permitted interval T1 labeled (5), the start of operation of the pumps P other than the external pump P5 is prohibited. Therefore, the operation of the pumps P1, P2, P3, and P4 including the external pump P3 is not started simultaneously with the start of the operation of the external pump P5. During the period of the operation start prohibited interval T2, the start of operation of all the pumps P is prohibited, and hence the external pump P3 and the external pump P5 do not start to operate simultaneously.

The “operation start prohibition”, which is denoted by the operation start permitted interval T1 and the operation start prohibited interval T2, only prohibits turning the relays RY from off to on to start the operation of the pumps P. That is, for the pumps P already in operation, the operation state of the pumps P is continued without turning off the on state of the corresponding relays RY, and the operation to turn the relays RY of the pumps P in operation from on to off to stop the operation of the pump P is not prohibited. For example, referring to the timing chart of FIG. 3, in the operation start permitted interval T1 labeled (4), the start of operation of the pumps P1, P2, P3, and P5, which are pumps other than the external pump P4 is prohibited, but the operation of the operating pump P1 is continued without being prohibited, and the operation to stop the operation of the operating pumps P2 and P3 is executed without being prohibited.

As described above, according to the present embodiment, in the operation start permitted interval T1, the start of operation is permitted only for a specific pump and the start of operation is executed, and the start of operation of pumps other than the specific pump is prohibited. Therefore, the number of pumps P that start operating simultaneously is limited. Thus, in the heating system 1, when the operation of the pumps P is started, it is possible to restrict an amount of inrush current larger than a steady-state current from flowing simultaneously (the magnitude of the current value or of the amount of electricity). Therefore, it is possible to eliminate the need for a countermeasure to increase the allowable current of the heating system 1 by employing a power cable 12 or an electronic component having a large current rating. Accordingly, it is possible to implement an inrush current countermeasure that does not generate a large inrush current at the start of operation of the pumps P, without increasing the cost of the heating system 1. In addition, because fusing of a current fuse, failure of an electronic component, and the like can be prevented, the reliability of the operation of the heating system 1 can be enhanced.

Furthermore, in the embodiment, the predetermined cycle T of one sequence for starting the operation of each pump P is divided into a plurality of operation start permitted intervals T1. Therefore, in a case where operation start instructions are simultaneously issued to a plurality of pumps P, for example, the start of operation of a specific pump is not always delayed, as in the case of control to delay the start of operation of the second and subsequent pumps P, and the first and next pumps P to start operating change depending on the timing of the operation start instructions.

For example, when the operation start instructions for the pumps P1 and P3 among the five pumps P are issued simultaneously, in a case where the timing of the operation start instruction is the operation start permitted interval T1 labeled (1), operation of the pump P1 is first started and then operation of the pump P3 is started; in a case where the timing of the operation start instruction is the operation start permitted interval T1 labeled (2), operation of the pump P3 is first started and then the pump P1 is started; in a case where the timing of the operation start instruction is the operation start permitted interval T1 labeled (3), the pump P3 is first started and then the pump P1 is started; in a case where the timing of the operation start instruction is the operation start permitted interval T1 labeled (4), the pump P1 is first started and then the pump P3 is started; and, in a case where the operation start instruction timing is in the operation start permitted interval T1 labeled (5), the operation of the pump P1 is first started, and then the operation of the pump P3 is started. As described above, because the pumps P that start to operate first and next change depending on the timing of the operation start instructions, there is an advantage that it is possible to suppress the delay in the start of operation of a certain pump P at all times by means of simple control.

Incidentally, in a case where the predetermined cycle T is divided into a plurality of operation start permitted intervals T1, for example, in a case where the start of operation of each specific pump P is executed at the end of an arbitrary operation start permitted interval T1 and at the start of the next operation start permitted interval T1, there is a temporary overlap between the inrush currents of the pumps P whose operation is started earlier and subsequently, and thus there is the concern that the total value of the inrush currents may exceed the allowable current of the heating system 1. However, in the present embodiment, because the operation start prohibited interval T2 for prohibiting the start of operation of all the pumps P is provided between the operation start permitted intervals T1, even if the pumps P start to operate earlier or subsequently in the previous or subsequent operation start permitted interval T1, an overlap between the inrush currents of the pumps P is suppressed due to the elapse of the time of the operation start prohibited interval T2. Therefore, it is possible to reliably suppress an inrush current at the start of operation of the pump P from exceeding an allowable current of the heating system 1.

In addition, because the period of the operation start prohibited interval T2 is set to be equal to or longer than the time required for the current value of the pump P to become a steady-state current after the operation of the arbitrary pump P is started, the current value due to the operation of the specific pump started in the operation start permitted interval T1 is no more than the steady-state current due to the elapse of the period of the operation start prohibited interval T2 immediately thereafter. Therefore, even if each pump P starts to operate earlier or subsequently in the previous or subsequent operation start permitted interval T1, it is possible to more reliably suppress an inrush current at the start of operation of the pumps P from exceeding an allowable current of the heating system 1.

Furthermore, by providing the operation start prohibited interval T2, the inrush currents of the pumps P whose operation is started earlier or subsequently are limited so as to prevent an overlap between the currents, and it is therefore possible to set the period of each operation start permitted interval T1 to be a short time. As per the embodiment, by setting the period of the operation start permitted interval T1 to be a shorter time than the period of the operation start prohibited interval T2, the period of the predetermined cycle T of one sequence for starting the operation of the pumps P can be shortened while preventing the allowable current of the heating system 1 from being exceeded due to the inrush currents of the pumps P. Therefore, it is possible to shorten a waiting time from an operation start instruction to an arbitrary pump P until the start of operation of the fluid pumps P is executed. Therefore, it does not take time to start the heating operation of the heating terminals 3, thus improving the comfort of the user in the heating environment.

Note that, in the embodiment, in a case where a plurality of specific pumps are used, the circulation pump P1 of the heat source 2 may be defined as a specific pump in all the operation start permitted intervals T1. With this configuration, when an operation start instruction for the circulation pump P1 of the heat source 2 is issued, the start of the operation of the circulation pump P1 is permitted in all the operation start permitted intervals T1. Therefore, when an operation start instruction is issued, the start of operation of the circulation pump P1 of the heat source 2 is executed with almost no waiting time. Accordingly, a decrease in heating performance of each heating terminal 3 due to non-operation of circulation pump P1 can be suppressed.

In addition, the circulation pump P1 of the heat source 2 may be configured to immediately start operating in response to an operation start instruction without being limited to the operation start permitted interval T1 and the operation start prohibited interval T2. However, in this case, it is assumed that the inrush current does not exceed the allowable current of the heating system 1 even when a plurality of external pumps P is included and the circulation pump P1 and the specific pump (one external pump P or a plurality of external pumps P which is fewer than the total number of external pumps P) simultaneously start to operate.

OTHER EMBODIMENTS

As shown in FIG. 4, a heating system 1A according to another embodiment 1 is configured such that an inflow pipe 6 and an outflow pipe 7 on a heat source 2 side are directly connected to a branch supply pipe 8 and a branch recovery pipe 9 on a heating terminal 3 side. That is, the other embodiment 1 does not include the water mixing device 10 (see FIG. 1). As a result, the fluid heated by the heat exchanger 5 is directly fed from the outflow pipe 7 to each heating terminal 3 through each branch supply pipe 8, thereby improving the heating raising performance of each heating terminal 3. Configurations and operational effects other than those described above in the other embodiment 1 are the same as those in the above embodiment.

As shown in FIG. 5, as a heating system 1B according to another embodiment 2, each of a plurality of heating terminals 3 is provided with thermal valves N1 to N4 as on-off valves N serving as fluid flowing part. Each of the thermal valves N1 to N4 is configured such that the valve is opened by the corresponding relay RY being turned on in response to an operation start instruction to energize an electromagnetic coil. In this case, the control means 4 applies the operation start control (see FIGS. 2 and 3) of the external pumps P2 to P5 according to the above embodiment to the operation start control when the thermal valves N1 to N4 are opened. That is, the operation start control of the present invention is performed using the circulation pump P1 and the thermal valves N1 to N4 as fluid flowing part. The heating system 1B according to the other embodiment 2 does not include the water mixing device 10 like the other embodiment 1. Configurations and operational effects other than those described above in the other embodiment 2 are the same as those of the above embodiment.

Note that the present invention is not limited to or by the above embodiments, and various modifications can be made within the scope of the patent claims. For example, the operation start prohibited interval T2 may not be provided between the operation start permitted intervals T1. Moreover, in the heating system, only one heating terminal 3 may be installed.

Claims

1. A heating system, comprising:

a heat source having a heating unit configured to heat a fluid;
a heating terminal of which a plurality can be installed;
an inflow pipe connected to a fluid inlet of the heating unit;
an outflow pipe connected to a fluid outlet of the heating unit;
a branch supply pipe directly or indirectly connected to the outflow pipe and connected to a fluid inlet of the heating terminal;
a branch recovery pipe connected to a fluid outlet of the heating terminal and directly or indirectly connected to the inflow pipe;
a plurality of fluid flowing part configured to circulate the fluid by operating; and
control means configured to control operation of the plurality of fluid flowing part,
wherein the fluid flowing part is provided to the inflow pipe or the outflow pipe and is provided to the branch supply pipe or the branch recovery pipe,
the fluid flowing part provided to the inflow pipe or the outflow pipe is a pump,
the fluid flowing part provided to the branch supply pipe or the branch recovery pipe is a pump or an on-off valve,
the control means repeatedly executes, in a predetermined cycle, a sequence to start the operation of the fluid flowing part,
the predetermined cycle is divided into a plurality of operation start permitted intervals, and
each of the operation start permitted intervals has a control configuration in which, among the fluid flowing part, only a specific fluid flowing part determined for each operation start permitted interval is permitted to start operating, and the other fluid flowing part other than the specific fluid flowing part is prohibited from starting to operate.

2. The heating system according to claim 1, wherein an operation start prohibited interval for prohibiting all the fluid flowing part from starting to operate is provided between each the operation start permitted intervals.

3. The heating system according to claim 2, wherein a period of the operation start prohibited interval is set to be equal to or longer than a time required for a current value of the fluid flowing part to become a steady-state current after operation of the fluid flowing part is started.

4. The heating system according to claim 2, wherein a period of the operation start permitted interval is set to be a shorter time than a period of the operation start prohibited interval.

5. The heating system according to claim 3, wherein a period of the operation start permitted interval is set to be a shorter time than a period of the operation start prohibited interval.

Patent History
Publication number: 20240255157
Type: Application
Filed: Jan 11, 2024
Publication Date: Aug 1, 2024
Inventor: Shingo Kondo (Nagoya-shi)
Application Number: 18/409,962
Classifications
International Classification: F24D 19/10 (20060101); F24D 3/18 (20060101);