JP2013113495A - Hot water storage type hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of stabilizing a temperature of hot water to be supplied to a hot water supply place when switching a heat accumulation hot water supply operation to a combustion hot water supply operation.SOLUTION: A hot water storage type hot water supply system includes a hot water storage tank, an auxiliary heat source machine for heating water from the hot water storage tank when necessary, a heat source machine route for sending water from the hot water storage tank to a hot water supply place through the auxiliary heat source machine, a bypass route for sending water from the hot water storage tank to the hot water supply place without being passed through the auxiliary heat source machine, a bypass control valve arranged on the bypass route, and a flow rate acquisition means for acquiring a total flow rate of water allowed to flow through the heat source machine route and water allowed to flow through the bypass route. The hot water storage type hot water supply system can switch the heat accumulation hot water supply operation to the combustion hot water supply operation and vice versa. In the heat accumulation hot water supply operation of the hot water storage type hot water supply system, an opening degree of the bypass control valve is decreased in accordance with a decrease of the total flow rate acquired by the flow rate acquisition means.

Description

  The present invention relates to a hot water storage type hot water supply system.

  Patent Document 1 discloses a hot water storage type hot water supply system including an auxiliary heat source device. In this hot water storage type hot water supply system, when a sufficient amount of high temperature water is stored in the hot water storage tank, hot water is supplied to the hot water supply location without heating by the auxiliary heat source machine. Hereinafter, the hot water supply operation in such an embodiment is referred to as a heat storage hot water supply operation. By performing the hot water storage hot water operation, the hot water stored in the hot water storage tank decreases. When the hot water storage tank runs out, hot water is supplied to the hot water supply location using heating by the auxiliary heat source machine. Hereinafter, the hot water supply operation in this manner is referred to as a combustion hot water supply operation.

  The hot water storage type hot water supply system of Patent Document 1 has a heat source path that sends water from the hot water storage tank to the hot water supply location via the auxiliary heat source device, and a bypass that sends water from the hot water storage tank to the hot water supply location without going through the auxiliary heat source device. A path and a bypass control valve provided in the bypass path are provided. During the heat storage hot water supply operation, the bypass control valve is fully opened. As a result, the water from the hot water storage tank flows through both the heat source machine path and the bypass path, and the pressure loss when water is sent to the hot water supply point is reduced, so that hot water can be supplied at a sufficient flow rate to the hot water supply point. it can. Further, the bypass control valve is fully closed during the combustion hot water supply operation. Thereby, all the water from the hot water storage tank flows into the heat source unit path, and the temperature adjustment in the auxiliary heat source unit becomes easy.

JP 2010-210182 A

  When the bypass control valve is fully opened in the heat storage hot water supply operation, a lot of water flows through the bypass path with a small pressure loss, and a small amount of water flows through the heat source path with a large pressure loss. This tendency becomes prominent when the hot water supply flow rate to the hot water supply point is small, and most of the water flows through the bypass route, and almost no water flows through the heat source unit route. As a result, water stays inside the heat source unit path. The water staying inside the heat source machine path is gradually cooled by natural heat dissipation and becomes low-temperature water.

  If the hot water storage tank runs out of water and the hot water storage operation is switched from the hot water storage operation to the combustion hot water supply operation with low temperature water remaining in the heat source machine path, the bypass control valve is fully closed, All of the water is sent out to the heat source machine path, and the low-temperature water staying inside the heat source machine path is pushed out to the hot water supply location. In particular, low-temperature water staying in the heat source unit path downstream of the auxiliary heat source unit is sent to the hot water supply location without being heated by the auxiliary heat source unit. When switching from the regenerative hot water supply operation to the combustion hot water supply operation, the hot water supply temperature becomes unstable.

  The technology disclosed in this specification has been created to solve the above problems. In this specification, the technique which can stabilize the hot-water supply temperature to the hot-water supply location at the time of switching from a thermal storage hot-water supply operation to a combustion hot-water supply operation is provided.

  The hot water storage type hot water supply system disclosed in this specification includes a hot water storage tank, an auxiliary heat source device that heats water from the hot water storage tank as needed, and water from the hot water storage tank to the hot water supply location via the auxiliary heat source device. A heat source unit route, a bypass route for sending water from the hot water storage tank to the hot water supply location without going through the auxiliary heat source unit, a bypass control valve provided in the bypass route, water flowing through the heat source unit route, and water flowing through the bypass route A flow rate acquisition means for acquiring the total flow rate is provided. The hot water storage type hot water supply system can be switched between a heat storage hot water supply operation in which hot water is supplied to a hot water supply location without performing heating by an auxiliary heat source device and a combustion hot water supply operation in which heating is performed by an auxiliary heat source device to supply hot water to a hot water supply location. In the hot water storage type hot water supply system, in the heat storage hot water supply operation, the smaller the total flow rate acquired by the flow rate acquisition means, the lower the opening degree of the bypass control valve.

  In the hot water storage type hot water supply system described above, the opening degree of the bypass control valve is lowered as the total flow rate of the water flowing through the heat source unit path and the water flowing through the bypass path is smaller during the heat storage hot water supply operation. Thereby, in the heat storage hot water supply operation, even when the hot water supply flow rate is small, it is possible to reliably flow water through the heat source unit path. Therefore, it is possible to prevent a situation where low-temperature water stays inside the heat source unit path. When switching from the heat storage hot water supply operation to the combustion hot water supply operation, it is possible to prevent a situation where low temperature water is sent from the heat source machine path to the hot water supply location. The hot water supply temperature at the time of switching from the heat storage hot water supply operation to the combustion hot water supply operation can be stabilized.

  In the above hot water storage type hot water supply system, it is preferable to adjust the opening degree of the bypass control valve so that the ratio of the flow rate of water flowing through the bypass path to the flow rate of water flowing through the heat source path is constant in the heat storage hot water supply operation. .

  According to the hot water storage type hot water supply system described above, in the heat storage hot water supply operation, even when the flow rate of hot water supplied to the hot water supply point is small, water can be reliably supplied to the heat source machine path.

  According to the hot water storage type hot water supply system disclosed in the present specification, it is possible to stabilize the hot water supply temperature to the hot water supply point when switching from the heat storage hot water supply operation to the combustion hot water supply operation.

It is a figure which shows typically the structure of the hot water supply system 10 of Example 1. FIG. It is a flowchart explaining operation | movement of the hot water supply system 10 of Example 1. FIG. The figure which shows the relationship between the opening degree of the bypass control valve 74 in the hot water supply system 10 of Example 1, the total flow rate of the water which flows through the heat source unit forward path 54 and the heat source unit bypass path 58, and the heat source unit / bypass flow rate ratio. It is.

  A water heater according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a connection diagram illustrating a schematic configuration of a hot water supply system 10. The hot water supply system 10 supplies hot water at a hot water supply set temperature to a hot water supply location (for example, a faucet, a bathtub, a shower, etc.). As shown in the figure, the hot water supply system 10 includes a heat pump (HP) unit 12, a tank unit 14, a gas heat source device 16, and a controller 15.

  The HP unit 12 includes a heat medium circulation path 20 that circulates a heat medium (carbon dioxide in the present embodiment), an evaporator 22, a compressor 24, a condenser 26, and an expansion valve that are disposed in the heat medium circulation path 20. 28, a heat storage circulation water channel 30, and a heat storage circulation pump 32 disposed in the heat storage circulation water channel 30.

  The evaporator 22 includes a fan 22 a that blows outside air, and is a heat exchanger that exchanges heat between the blown outside air and the heat medium in the heat medium circulation path 20. As will be described later, the evaporator 22 is supplied with a heat medium in a low-pressure, low-temperature liquid state after passing through the expansion valve 28. The evaporator 22 heats the heat medium by exchanging heat between the heat medium and the outside air. The heating medium is vaporized by being heated, and is in a relatively high temperature and low pressure gas state.

  The compressor 24 compresses the heat medium in the heat medium circuit 20 and sends it out to the condenser 26 side. Since the compressor 24 sends out the heat medium in the heat medium circuit 20, the heat medium circulates in the heat medium circuit 20 in the order of the evaporator 22, the compressor 24, the condenser 26, and the expansion valve 28. The heat medium after passing through the evaporator 22 is supplied to the compressor 24. That is, a heat medium having a relatively high temperature and a low-pressure gas state is supplied. When the compressor 24 compresses the heat medium, the heat medium becomes a high-temperature and high-pressure gas state.

  The condenser 26 is a heat exchanger that exchanges heat between the heat medium in the heat medium circuit 20 and the water in the heat storage circuit 30. The heat medium sent out from the compressor 24 is supplied to the heat medium circuit 20 of the condenser 26. That is, a heat medium in a gas state of high temperature and pressure is supplied. In the condenser 26, the water in the heat storage circulation channel 30 is heated by the heat medium. Further, the heat medium is cooled by taking heat away. As a result, the heat medium is at a relatively low temperature and is in a high-pressure liquid state.

  The expansion medium 28 is supplied with the heat medium that has passed through the condenser 26. That is, a relatively low temperature and high pressure liquid heat medium is supplied. When the heat medium passes through the expansion valve 28, the heat medium is decompressed and expanded. As a result, a low-temperature and low-pressure liquid state is obtained. The heat medium that has passed through the expansion valve 28 is supplied to the evaporator 22 as described above.

  When the HP unit 12 is activated, the compressor 24, the fan 22a, and the heat storage circulation pump 32 are driven. Thereby, the heat medium in the heat medium circulation path 20 absorbs heat from the outside air, and the water flowing in the heat storage circulation water path 30 is heated by the heat medium having a high temperature.

  The tank unit 14 includes a hot water storage tank 40, a heat storage circulation forward path 42, a heat storage circulation return path 44, a tank water supply path 46, a tank discharge path 48, a first hot water supply path 50, a second hot water supply path 52, and a heat source machine. A forward path 54, a heat source machine return path 56, a heat source machine bypass path 58, and a tank bypass path 60 are provided.

  The hot water storage tank 40 stores hot water heated by the HP unit 12. A heat storage circulation path 42 is connected near the bottom of the hot water storage tank 40, and a heat storage circulation return path 44 is connected near the top of the hot water storage tank 40. When the heat storage circulation pump 32 of the HP unit 12 is driven, low-temperature water is sucked out from the lower part of the hot water storage tank 40 and is sent to the heat storage circulation water path 30 through the heat storage circulation path 42. The water heated by passing through the condenser 26 is returned to the upper part of the hot water storage tank 40 from the heat storage circulation water passage 30 through the heat storage circulation return passage 44. In the hot water storage tank 40, a high-temperature water layer is formed at the top and a low-temperature water layer is formed at the bottom. Thus, the state in which the high temperature layer and the low temperature layer are formed is called temperature stratification. A tank thermistor 41 for detecting the temperature of the internal water is provided at the upper part of the hot water storage tank 40.

  A tank water supply path 46 is connected to the vicinity of the bottom of the hot water storage tank 40, and a tank water discharge path 48 is connected to the vicinity of the top of the hot water storage tank 40. The tank water supply channel 46 is connected to the water supply, and supplies low temperature water (tap water) to the lower part of the hot water storage tank 40. The tank outlet 48 joins the tank bypass 60 and is connected to the first hot water supply 50, and sends the water in the upper part of the hot water storage tank 40 to the first hot water supply 50. The tank outlet 48 includes a high-temperature water control valve 62 that adjusts the flow of water flowing through the tank outlet 48, a high-temperature water flow sensor 64 that detects the flow of water flowing through the tank outlet 48, and water flowing through the tank outlet 48. A high temperature water thermistor 66 for detecting the temperature of the water is provided.

  The tank bypass channel 60 branches from the tank water supply channel 46, joins the tank water discharge channel 48, and is connected to the first hot water supply channel 50. The tank bypass path 60 includes a low-temperature water control valve 68 that adjusts the flow rate of water flowing through the tank bypass path 60, a low-temperature water flow sensor 70 that detects the flow rate of water flowing through the tank bypass path 60, and water flowing through the tank bypass path 60. A low temperature water thermistor 72 that detects the temperature of the water is provided.

  The first hot water supply path 50 is supplied with water in which high-temperature water from the tank outlet path 48 and low-temperature water from the tank bypass path 60 are mixed. When water having a temperature higher than the hot water supply set temperature is stored in the upper part of the hot water storage tank 40, the opening of the tank is adjusted by adjusting the opening of the high temperature water control valve 62 and the opening of the low temperature water control valve 68. By adjusting the ratio between the flow rate of hot water from the water channel 48 and the flow rate of low-temperature water from the tank bypass channel 60, the water adjusted to the hot water supply set temperature can be flowed to the first hot water supply channel 50. The high temperature water control valve 62 and the low temperature water control valve 68 constitute a so-called mixing valve. The first hot water supply path 50 is provided with a first hot water supply thermistor 73 that detects the temperature of the water flowing through the first hot water supply path 50.

  The first hot water supply path 50 is branched into a heat source unit forward path 54 and a heat source unit bypass path 58. The heat source unit forward path 54 is connected to the heat source unit return path 56 via the gas heat source unit 16. The heat source machine return path 56 joins the heat source machine bypass path 58 and is connected to the second hot water supply path 52. The heat source unit bypass path 58 is provided with a bypass control valve 74 that adjusts the flow rate of water flowing through the heat source unit bypass path 58. The second hot water supply passage 52 is provided with a second hot water supply thermistor 76 that detects the temperature of the water flowing through the second hot water supply passage 52.

  The gas heat source unit 16 includes a burner 78 that burns gas, and a combustion heating path 80 that heats water flowing inside using the combustion heat of the burner 78. The upstream side of the combustion heating path 80 is connected to the heat source unit forward path 54, and the downstream side of the combustion heating path 80 is connected to the heat source unit return path 56. The gas heat source unit 16 heats the water received from the heat source unit forward path 54 as necessary, and sends it to the heat source unit return path 56.

  The controller 15 controls the operation of each component of the HP unit 12, the tank unit 14, and the gas heat source machine 16.

  Next, the operation of the hot water supply system 10 will be described with reference to the flowchart of FIG. When the hot water supply system 10 is turned on, the controller 15 performs the following processing.

  In step S2, it waits until the hot water supply flow volume to a hot-water supply location exceeds a predetermined value. In the hot water supply system 10 of the present embodiment, the total flow rate is calculated by adding the high temperature water flow rate detected by the high temperature water flow rate sensor 64 and the low temperature water flow rate detected by the low temperature water flow rate sensor 70 to the hot water supply location. Get the hot water flow rate. When the hot water supply flow rate to the hot water supply location exceeds a predetermined value in step S2 (when it becomes YES), the process proceeds to step S4.

  In step S4, it is determined whether or not the hot water tank 40 has run out of hot water. In the hot water supply system 10 of the present embodiment, when the tank upper temperature Ta detected by the tank thermistor 41 is equal to or higher than the hot water supply set temperature T0, a sufficient amount of hot water is stored in the hot water storage tank 40, and the hot water runs out. Judge that you have not. Note that the determination of running out of hot water in the hot water storage tank 40 may be made by various other methods. If it is determined in step S4 that the hot water storage tank 40 has not run out (NO), the process proceeds to step S6.

  In step S6, the opening degrees of the hot water control valve 62 and the low temperature water control valve 68 are adjusted so that the hot water supply temperature to the hot water supply point coincides with the hot water supply set temperature T0. Adjustment of the opening degree of the high-temperature water control valve 62 and the low-temperature water control valve 68 can be performed by various methods. For example, the opening degrees of the high temperature water control valve 62 and the low temperature water control valve 68 are adjusted based on the temperature Tb detected by the high temperature water thermistor 66, the temperature Tc detected by the low temperature water thermistor 72, and the hot water supply set temperature T0. May be. Alternatively, the opening degrees of the high temperature water control valve 62 and the low temperature water control valve 68 may be adjusted based on the temperature Td detected by the first hot water supply thermistor 73 and the hot water supply set temperature T0. By adjusting the opening degree of the high temperature water control valve 62 and the low temperature water control valve 68, water adjusted to the hot water supply set temperature T0 is supplied to the first hot water supply path 50.

  In step S8, the opening degree of the bypass control valve 74 is adjusted. In the hot water supply system 10 of the present embodiment, the opening degree of the bypass control valve 74 is adjusted in accordance with the total flow rate of the water flowing through the heat source unit forward path 54 and the water flowing through the heat source unit bypass path 58, that is, the hot water flow rate to the hot water supply location. .

  FIG. 3 shows the relationship between the opening degree of the bypass control valve 74, the total flow rate of water flowing through the heat source unit forward path 54 and the water flowing through the heat source unit bypass path 58, and the heat source unit / bypass flow rate ratio. The heat source unit / bypass flow rate ratio here indicates the ratio of the flow rate of water flowing through the heat source unit bypass path 58 to the flow rate of water flowing through the heat source unit forward path 54. When the opening degree of the bypass control valve 74 is constant, the heat source unit / bypass flow rate ratio is substantially constant regardless of the total flow rate if the total flow rate is a certain level. However, as the total flow rate decreases, the heat source machine / bypass flow rate ratio increases rapidly. This means that when the total flow rate decreases, most of the water from the first hot water supply path 50 flows through the heat source unit bypass path 58 and almost no water flows through the heat source unit forward path 54.

  Therefore, in the hot water supply system 10 of the present embodiment, bypass control is performed according to the total flow rate of water flowing through the heat source unit forward path 54 and water flowing through the heat source unit bypass path 58 so that the heat source unit / bypass flow rate ratio is substantially constant. The opening degree of the valve 74 is adjusted. More specifically, when the total flow rate exceeds a predetermined value (for example, 12 liters / minute), the opening degree of the bypass control valve 74 is set to 100%. In this case, the heat source unit / bypass flow rate ratio is substantially constant regardless of the total flow rate. When the total flow rate is lower than the predetermined value, the opening degree of the bypass control valve 74 is lowered so that the heat source unit / bypass flow rate ratio is kept substantially constant. The opening degree of the bypass control valve 74 is calculated, for example, from the relationship shown in FIG. 3 by linear interpolation to calculate the opening degree of the bypass control valve 74 that realizes a constant heat source unit / bypass flow rate ratio for an arbitrary total flow rate. Can be set. Accordingly, even when the total flow rate is small, it is possible to reliably send hot water to the heat source unit forward path 54 and prevent water from staying in the gas heat source unit 16 and the heat source unit return path 56. After adjusting the opening degree of the bypass control valve 74 in step S8, the process proceeds to step S10.

  In step S10, it is determined whether or not the hot water supply to the hot water supply location is completed. In the hot water supply system 10 of the present embodiment, it is determined that the hot water supply to the hot water supply location is completed when the hot water supply flow rate to the hot water supply location is below a predetermined value. When it is determined in step S10 that the hot water supply has ended (in the case of YES), the hot water supply system 10 ends the hot water supply operation. If it is determined that the hot water supply has not ended (NO), the process returns to step S4.

  In a series of operations from step S6 to step S10, the hot water supply system 10 performs hot water supply to the hot water supply location using high-temperature water stored in the hot water storage tank 40 without heating by the gas heat source unit 16. Yes. That is, the hot water supply system 10 performs a heat storage hot water supply operation. If this heat storage hot water supply operation is continued, the hot water stored in the hot water storage tank 40 will decrease, and the hot water storage tank 40 will run out of hot water.

  If it is determined in step S4 that the hot water storage tank 40 has run out (YES), the process proceeds to step S12.

  In step S12, the bypass control valve 74 is fully closed. As a result, the entire amount of water flowing through the first hot water supply passage 50 is sent out to the heat source unit forward passage 54.

  In step S14, the gas heat source unit 16 is operated. The water that has flowed from the first hot water supply path 50 to the heat source machine forward path 54 is heated by the gas heat source machine 16, then flows from the heat source machine return path 56 to the second hot water supply path 52, and is sent to the hot water supply location.

  In step S16, the heating power in the gas heat source unit 16 is adjusted so that the hot water supply temperature to the hot water supply location matches the hot water supply set temperature T0. The adjustment of the thermal power in the gas heat source device 16 can be performed based on, for example, the temperature Te detected by the second hot water supply thermistor 76 and the hot water supply set temperature T0.

  In step S18, as in step S10, it is determined whether or not the hot water supply to the hot water supply location is completed. When it is determined in step S18 that the hot water supply has ended (in the case of YES), the hot water supply system 10 ends the hot water supply operation after stopping the gas heat source unit 16 in step S20. If it is determined in step S18 that the hot water supply has not ended (NO), the process returns to step S16.

  In a series of operations from step S12 to step S18, the hot water supply system 10 uses the heating by the gas heat source unit 16 to supply hot water to the hot water supply location. That is, the hot water supply system 10 performs the combustion hot water supply operation.

  If the bypass control valve 74 is always fully opened in the heat storage hot water supply operation, most of the water from the first hot water supply passage 50 flows through the heat source device bypass passage 58, the heat source device forward passage 54, the gas heat source device 16, the heat source. Only a small amount of water flows through the machine return path 56. In particular, when the flow rate of hot water to the hot water supply point is small, this tendency becomes remarkable, and almost no water flows through the heat source unit forward path 54, the gas heat source unit 16, and the heat source unit return path 56. In such a case, the temperature of the water staying in the heat source unit forward path 54, the gas heat source unit 16, and the heat source unit return path 56 is lowered by natural heat dissipation. Thereafter, when the heat storage hot water supply operation is switched to the combustion hot water supply operation, the water remaining in the gas heat source machine 16 and the heat source machine return path 56 is removed from the gas heat source machine by fully closing the bypass control valve 74 in step S12. Without being heated at 16, it is supplied to the hot water supply location via the second hot water supply path 52. As a result, low temperature water is temporarily supplied to the hot water supply location, and the hot water supply temperature becomes unstable.

  Regarding the above point, in the hot water supply system 10 of the present embodiment, as shown in step S8, in the heat storage hot water supply operation, the bypass is performed according to the total flow rate of the water flowing through the heat source unit forward path 54 and the water flowing through the heat source unit bypass path 58. The opening degree of the control valve 74 is adjusted. With such a configuration, even when the flow rate of hot water to the hot water supply point is small, water is reliably sent to the heat source unit forward path 54, the gas heat source unit 16 and the heat source unit return path 56, and the heat source unit forward path 54, gas It is possible to prevent water from staying in the heat source unit 16 and the heat source unit return path 56. When switching from the heat storage hot water supply operation to the combustion hot water supply operation, it is possible to prevent a situation in which low temperature water is sent from the gas heat source device 16 or the heat source device return path 56 to the hot water supply location. The hot water supply temperature at the time of switching from the heat storage hot water supply operation to the combustion hot water supply operation can be stabilized.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  In the above embodiment, the case where the hot water heated by the HP unit 12 is stored in the hot water storage tank 40 has been described. Unlike this, for example, a configuration may be adopted in which high-temperature water heated by a solar water heater is stored in the hot water storage tank 40. Or it is good also as a structure which stores the hot water heated using the waste heat of a cogeneration system in the hot water storage tank 40. FIG.

  In the above embodiment, the hot water flow rate detected by the high temperature water flow rate sensor 64 and the low temperature water flow rate detected by the low temperature water flow rate sensor 70 are added together, so that the hot water supply flow rate to the hot water use location, that is, the heat source machine forward path. The total flow rate of the water flowing through 54 and the water flowing through the heat source unit bypass 58 is acquired. Unlike this, for example, a flow rate sensor is separately provided in the first hot water supply path 50 or the second hot water supply path 52, and the hot water supply flow rate from the detected value to the hot water supply location, that is, the water flowing through the heat source unit forward path 54 and the heat source unit bypass A total flow rate of water flowing through the path 58 may be acquired. Alternatively, since the hot water supply flow rate from the hot water supply system 10 to the hot water supply location is the same as the water supply flow rate from the water supply to the hot water supply system 10, a flow rate sensor for detecting the water supply flow rate from the water supply to the hot water supply system 10 is separately provided. The detected value may be a hot water supply flow rate to the hot water supply location, that is, a total flow rate of water flowing through the heat source unit forward path 54 and water flowing through the heat source unit bypass path 58.

  In the above embodiment, the configuration in which the tank bypass passage 60 branched from the tank water supply passage 46 joins the tank discharge passage 48 on the upstream side of the first hot water supply passage 50 has been described. Unlike this, the tank bypass passage 60 branched from the tank water supply passage 46 may be joined to the second hot water supply passage 52. In this case, the high-temperature water flow rate detected by the high-temperature water flow rate sensor 64 corresponds to the total flow rate of the water flowing through the heat source unit forward path 54 and the water flowing through the heat source unit bypass path 58.

  In the above embodiment, the configuration in which the opening degree of the bypass control valve 74 is adjusted so that the heat source unit / bypass flow rate ratio is substantially constant has been described. Alternatively, the opening degree of the bypass control valve 74 may be adjusted so that the flow rate of water flowing through the heat source unit forward path 54 is substantially constant. However, the above embodiment is more practical because the opening degree of the bypass control valve 74 when the total flow rate exceeds a predetermined value may be substantially constant and adjustment is easy.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

DESCRIPTION OF SYMBOLS 10 Hot water supply system 12 Heat pump unit 14 Tank unit 15 Controller 16 Gas heat source machine 20 Heat medium circulation path 22 Evaporator 22a Fan 24 Compressor 26 Condenser 28 Expansion valve 30 Heat storage circulation water path 32 Heat storage circulation pump 40 Hot water storage tank 41 Tank thermistor 42 Heat storage Circulation path 44 Heat storage circulation path 46 Tank supply path 48 Tank outlet path 50 First hot water path 52 Second hot water path 54 Heat source machine forward path 56 Heat source machine return path 58 Heat source machine bypass path 60 Tank bypass path 62 High temperature water control valve 64 High temperature water flow rate Sensor 66 Hot Water Thermistor 68 Low Temperature Water Control Valve 70 Low Temperature Water Flow Sensor 72 Low Temperature Water Thermistor 73 First Hot Water Thermistor 74 Bypass Control Valve 76 Second Hot Water Thermistor 78 Burner 80 Combustion Heating Path

Claims (2)

A hot water storage tank,
An auxiliary heat source machine that heats water from the hot water storage tank as needed,
A heat source machine path for sending water from the hot water storage tank to the hot water supply point via the auxiliary heat source machine,
A bypass route for sending water from the hot water storage tank to the hot water supply location without going through the auxiliary heat source machine,
A bypass control valve provided in the bypass path;
It has a flow rate acquisition means to acquire the total flow rate of water flowing through the heat source machine path and water flowing through the bypass path,
It is possible to switch between a regenerative hot water supply operation that supplies hot water to a hot water supply location without heating by an auxiliary heat source device, and a combustion hot water supply operation that supplies heat to a hot water supply location by heating with an auxiliary heat source device,
In a hot water storage hot water operation, a hot water storage hot water supply system is characterized in that the smaller the total flow rate acquired by the flow rate acquisition means, the lower the opening of the bypass control valve.   2. The hot water storage system according to claim 1, wherein the opening degree of the bypass control valve is adjusted so that a ratio of a flow rate of water flowing through the bypass path to a flow rate of water flowing through the heat source path is constant in the heat storage hot water supply operation. Hot water system.

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