KR101723419B1 - Heat pump system - Google Patents

Abstract

The heat pump system disclosed in this specification comprises a heat pump unit having a heat pump that absorbs heat from outside air to heat the heat, a tank unit having a tank for storing the heat, an auxiliary heat source unit for heating the heat, And a heater provided in a flow path through which the heat flows between the tank and the heat pump. In this heat pump system, it is possible to perform a freeze prevention operation in which the heat is circulated between the tank and the heat pump in order to prevent freezing of the heat, and in the freeze prevention operation, when the temperature of the outside air is high, The fruit is heated, and when the outside temperature is low, the fruit is heated by the heater.

Description

[0001] HEAT PUMP SYSTEM [0002]

The present specification relates to a heat pump system.

Japanese Patent Laid-Open Publication No. 2009-156495 discloses a heat pump unit having a heat pump for absorbing heat absorbed from the outside air to heat a heat medium, There is disclosed a heat pump system including a tank unit having a tank for storing fruit. In this heat pump system, it is possible to perform freeze prevention operation (freeze prevention operation) in which heat is circulated between the tank and the heat pump in order to prevent freezing of the fruit. In this heat pump system, the heat is heated by the heat pump in the freeze prevention operation.

Generally, since heating of a fruit by a heat pump is high in energy efficiency, it is preferable to drive the heat pump to heat the fruit for preventing freezing. In a system in which the heating source (heating source) is provided only outside the heat pump, in the case where it is necessary not only to prevent freeze prevention but also to store heat in the tank even in a state where the outside air temperature is low, , It is necessary to drive the heat pump. However, when the heat pump is driven in a state where the outside air temperature is low, there is a fear that the heat pump is frosted to the evaporator that performs heat exchange between the refrigerant of the heat pump and the outside air. If it is conceived on the evaporator, a drain is generated in accordance with the defrosting operation, so a treatment for preventing freezing of the drain is separately required. Particularly, in a system in which the heating source has only the heat pump, defrosting operation is indispensable, so that it is necessary to prevent freezing of the drain. Therefore, it is preferable that the evaporator of the heat pump is not implanted as much as possible.

The present specification provides techniques for solving the above problems. The present invention provides a technique capable of preventing a situation in which a heat pump system for accumulating heat heated by a heat pump in a tank is conceived on an evaporator of a heat pump due to freeze prevention operation.

The heat pump system disclosed in this specification comprises a heat pump unit having a heat pump that absorbs heat from outside air to heat the heat, a tank unit having a tank for storing the heat, and an auxiliary heat source unit for heating the heat have. The heat pump system further includes an outside air temperature detecting means for detecting the outside air temperature and a heater provided in a flow path for the flow of the heat between the tank and the heat pump. In this heat pump system, it is possible to perform a freeze prevention operation in which the heat is circulated between the tank and the heat pump in order to prevent freezing of the heat. In this heat pump system, the heat is heated by the heat pump when the outside air temperature is high in the freezing prevention operation, and the heat is heated by the heater when the outside air temperature is low.

In the above-described heat pump system, the heating means used in the freeze prevention operation is switched depending on the outside air temperature. When the outside air temperature is high, energy efficiency can be increased by heating the heat by the heat pump. In addition, when the outside air temperature is low, the heat is heated by the heater, and the heat is not heated by the heat pump, so that the heat pump can be prevented from being concealed by the evaporator. According to the above heat pump system, it is possible to prevent a situation in which the evaporator of the heat pump is frozen due to the freeze prevention operation. Also, in the above-described heat pump system, even when the heat pump unit is not driven when the outside air temperature is low, the auxiliary heat source unit can be used to heat the fruit so as to supply hot water for hot water supply So it does not hurt the convenience. As the auxiliary heat source unit, any heating source that can not be conceived upon driving, such as a gas heat source unit, a gas engine cogenerator, a fuel cell, and a heater, may be used.

The heat pump system described above can be configured so that a heater is installed in the flow path inside the tank unit.

According to the above-described heat pump system, the detection value of the thermistor (the thermistor for detecting the temperature of the heat or the thermistor for detecting the temperature of the refrigerant circulating in the heat pump) in the heat pump unit is influenced by the heat radiation from the heater .

The heat pump system may be configured such that a heater is installed in a flow path for returning the heat from the heat pump to the tank.

Generally, there is a high possibility that the flow path of the fruit from the tank to the heat pump, rather than the flow path from the heat pump to the tank, is frozen. Therefore, it is often the case that the necessity and necessity of the freeze prevention operation are determined on the basis of the temperature of the fruit detected in the flow path from the tank to the heat pump. According to the above heat pump system, since the heater is provided in the flow path from the heat pump to the tank to return the heat, the detection value of the thermistor provided in the flow path for sending the heat from the tank to the heat pump is influenced by the heat radiation from the heater Can be prevented.

According to the heat pump system disclosed in the present specification, it is possible to prevent a situation in which the evaporator of the heat pump is frozen due to the freeze prevention operation.

1 is a diagram schematically showing a configuration of a hot water supply system 10 of an embodiment.
Fig. 2 is a flowchart for explaining the freeze prevention operation performed by the hot water supply system 10 of the embodiment.
3 is a diagram schematically showing the configuration of a modified example of the hot water supply system 10 of the embodiment.

(Example)

Fig. 1 shows a configuration of a hot water supply system (hot water supply system) 10 of the present embodiment. 1, the hot water supply system 10 includes a hot water storage unit 20, an HP heat source unit 40, a gas heat source unit 40, (50), and a controller (11).

The HP heat source unit 40 includes a compressor 41, a first heat exchanger (first heat exchanger) 43 as a condenser, an expansion valve 44, And a heat pump (40a) having a two-heat exchanger (45). In the heat pump 40a, the discharge side of the compressor 41, the four-way valve 42, the refrigerant passage (coolant passage) 43a of the first heat exchanger 43, (Intake side) side of the first heat exchanger 44, the second heat exchanger 45, the four-way valve 42 and the compressor 41 are sequentially connected by a refrigerant pipe (refrigerant pipe) 46, In this order. The refrigerant may be, for example, R744 (CO ₂ refrigerant) or R410A (HFC refrigerant). The first heat exchanger 43 has a refrigerant passage 43a and a circulating water passage 43b. A fan (45a) is provided in the vicinity of the second heat exchanger (45). The second heat exchanger 45 performs heat exchange between the refrigerant and the outside air sent by the fan 45a. The refrigerant pipe 46 is provided with a defrosting path between the discharge side of the compressor 41 and the four-way valve 42 and between the expansion valve 44 and the second heat exchanger 45, 47) are connected. The defrosting valve 47a is provided in the supply path 47.

In the first heat exchanger 43, a circulating king connection path 48 is connected to the inlet side of the circulation water flow path 43b and a circulation return connection path 48 is connected to the outlet side. Path) 49 are connected to each other. An inlet side thermister 48a is provided on the circulating-path connection path 48 and an outlet side thermister 49a is provided on the circulation-return connection path 49. [ The inlet side thermistor 48a detects the temperature of the circulating water flowing into the circulating water flow path 43b of the first heat exchanger 43 and the outlet side thermistor 49a detects the temperature of the circulating water flowing into the circulating water flow path 43b of the first heat exchanger 43. [ And detects the temperature of the circulating water flowing out from the outlet 43b. Actually, each of the thermistors 48a and 49a outputs a detection signal corresponding to the water temperature, and this signal is input to the controller 11 to detect the water temperature. Hereinafter, the expression that the thermistor or the sensor detects also means that the flow rate (flow rate) of the temperature or the water is detected by actually inputting these detection signals to the controller 11. [

The hot water unit 20 includes a low-temperature bath 21 and a mixer 24. A water supply path 22 for supplying tap water to the low-temperature bath 21 is connected to the bottom of the low-temperature bath 21. [ In the water supply path 22, a pressure reducing valve 23 is provided in the vicinity of the tap water inlet 22a. The pressure reducing valve (23) adjusts the water supply pressure to the water supply path (22). The mixed water supply path 26 of the mixer 24 is connected downstream of the pressure reducing valve 23 in the water supply path 22. A water feed control valve 26a, a feed water flow rate sensor 26b, and a water feed thermistor 26c are provided in the mixed water feed path 26. [ The water supply control valve 26a adjusts the flow rate of the tap water flowing through the mixed water supply passage 26. The feed water flow sensor 26b and the water feed thermistor 26c detect the flow rate and temperature of the tap water flowing through the mixed water feed path 26. When the hot water in the low-temperature bath 21 is reduced or the water supply control valve 26a is opened, the pressure on the downstream side of the pressure reducing valve 23 is lowered. The pressure reducing valve 23 is opened when the pressure on the downstream side is lowered so as to maintain the pressure at a predetermined pressure adjustment value. Therefore, when the hot water in the low-temperature bath 21 is reduced or the water supply control valve 26a of the mixer 24 is opened, tap water is supplied to them.

In the water supply path 22, a drainage path 31 is connected to the downstream side of the connecting portion of the mixed water supply path 26. A drain valve 32 is provided in the middle of the drain path 31. The drain valve 32 can be manually opened and closed. When the drain valve 32 is opened, water in the low-temperature bath 21 is drained to the outside through the drainage path 31.

One end of a circulating highway 33 is connected to the bottom of the low tank 21. One end of a circulating return path 34 is connected to an upper portion of the low tank 21, Respectively. The other end of the circulating king path 33 is connected to the circulating path connecting path 48 of the HP heat source unit 40 and the other end of the circulating return path 34 is connected to the connecting path 49 . The circulating king furnace 33 is provided with a forward path thermistor 36 and a circulation pump 37. The forward path thermistor 36 detects the temperature of water flowing out from the low-temperature bath 21 to the circulating flow path 33. When the circulation pump 37 is driven, water is sucked from the lower part of the low-temperature bath 21 to the circulating flow path 33, and this water flows into the circulating water flow path 43b of the first heat exchanger 43 And is returned to the upper portion of the low-temperature bath (21) through the circulating return path (34). Thus, a circulation path between the low-temperature bath 21 and the heat pump 40a is formed.

In the tank unit 20, an electric freeze prevention heater (freeze prevention heater) 34a is installed in the circulation return path 34 inside. A pressure release path 38 is connected in the middle of the circulating return path 34 and a relief valve 38a is provided in the pressure release path 38. The valve opening pressure of the relief valve 38a is set slightly larger than the pressure adjustment value of the pressure reducing valve 23. When the pressure adjustment of the pressure reducing valve 23 is disabled, the relief valve 38a is opened to prevent the pressure in the low-temperature bath 21 from exceeding the pressure capable of being pressurized. An upper thermistor 39 is attached to the low-temperature bath 21 at a predetermined amount (for example, 30 liters) from its upper end. The upper thermistor (39) detects the temperature of the water above the low-temperature bath (21). The low temperature unit (20) is also provided with an outside temperature thermistor (35) for detecting the outside temperature.

A hot water path (25) of the mixer (24) is connected to the upper part of the low-temperature bath (21). The hot water path 25 is provided with a hot water control valve 25a, a hot water flow rate sensor 25b and a hot water thermistor 25c. The hot water control valve 25a regulates the flow rate of the water flowing from the low-temperature bath 21 to the hot water path 25. The hot water flow rate sensor 25b detects the flow rate of water flowing from the low-temperature bath 21 to the hot water path 25. The hot water thermistor 25c detects the temperature of the water flowing through the hot water path 25. The hot water path 25 and the mixed water supply path 26 are joined and connected to the first mixing path 27. The first mixing path 27 is provided with a mixing thermistor 27a for detecting the temperature of the mixed water flowing through the first mixing path 27. [

The hot water unit (20) has a first hot water supply path (29). The hot water supply path 29 is provided with a hot water supply thermistor 29a. A hot tap (60) is connected to the tip of the first hot water supply path (29). The hot water supply tank 60 is disposed in a bathroom, a washroom, a kitchen, and the like (in FIG. 1, these hot water supply tubes 60 are represented by one). The middle of the first mixing path 27 and the middle of the first hot water supply path 29 are connected by a hot water bypass path 28. The hot water supply bypass path 28 is provided with a bypass control valve 28a. In the state where the bypass control valve 28a is opened, the mixed water flowing in the first mixing path 27 flows to the hot water supply bypass path 28 and the bypass control valve 28a is closed, 27 flows into the second mixing path 51 of the gas heat source unit 50 to be described later.

The gas heat source unit 50 includes a burner heat exchanger 52, a burner 53, and the like. The mixed water from the first mixing path 27 of the hot water unit 20 flows into the burner heat exchanger 52 through the second mixing path 51. [ The second mixing path 51 is provided with a water intake thermister 51a, a water supply flow rate sensor 51b and a water quantity servo 51c. The intake thermistor 51a and the hot water flow sensor 51b detect the temperature and the flow rate of the water flowing through the second mixing path 51, respectively. The quantity servo 51c adjusts the flow rate of the water flowing through the second mixing path 51. A gas-fired burner 53 heats the burner heat exchanger 52. The water heated in the burner heat exchanger 52 flows into the first hot water supply path 29 of the hot water unit 20 through the second hot water supply path 54. A tubular thermister 55 is provided in the vicinity of the outlet of the burner heat exchanger 52 and a tapping thermistor 56 is provided on the downstream side of the tubular thermister 55 in the second hot water supply path 54 have. The heat source bypass path (the heat source bypass path) is provided between the downstream side of the water quantity servo 51c in the second mixing path 51 and the tubular thermistor 55 and the hot water tumbling thermistor 56 in the second hot water supply path 54 A heat source unit bypass passage 57) are connected. A heat source bypass control valve 58 is provided at a junction between the second mixing path 51 and the heat source bypass path 57. [ A part of the water flowing through the second mixing path 51 flows into the heat source bypass path 57 by adjusting the opening degree of the heat source bypass control valve 58 so that the flow rate of the water is adjusted.

The controller 11 includes a CPU, a ROM, a RAM, and the like. ROM stores various operation programs. Various signals input to the controller 11 and various data generated in the course of executing processing by the CPU are temporarily stored in the RAM. More specifically, the detection signals of the various thermistors 25c, 26c, 27a, 29a, 35, 36, 39, 48a, 49a, 51a, 55, 56 and the flow rate sensors 25b, 26b, And these pieces of information are temporarily stored. In the controller 11, the CPU outputs drive signals to various units of the hot water unit 20, the HP heat source unit 40, and the gas heat source unit 50 based on the information stored in the ROM or the RAM. Further, a remote controller 13 is connected to the controller 11. The remote controller 13 is provided with a switch 16 for operating the hot water supply system 10, a liquid crystal display (liquid crystal display) 17 for displaying the operation state of the hot water supply system 10, Is input to the controller 11. The controller 11 receives the information set by the user.

(Heat storage operation (heat storage operation))

In the hot water supply system 10, it is possible to perform a heat storage operation in which the water in the low-temperature bath 21 is heated by the heat pump 40a to make hot water of high temperature, and the hot water is stored in the low-

In the heat storage operation, the HP heat source unit 40 drives the compressor 41. The circulating water flowing through the circulating water passage 43b is heated when the refrigerant compressed in the compressor 41 flows through the refrigerant passage 43a of the first heat exchanger 43. [ The refrigerant flowing out of the refrigerant passage 43a expands at the expansion valve 44 and is cooled. When the refrigerant flows through the second heat exchanger 45, the refrigerant absorbs heat from the outside air and is heated. The heated refrigerant flows into the compressor 41 and is compressed again, thereby further raising the temperature.

The water in the low-temperature bath 21 is drawn from the bottom of the low-temperature bath 21 to the circulating king 33 by the circulation pump 37 being operated. The water sucked into the circulating kingpin 33 is heated when passing through the circulating water flow path 43b of the first heat exchanger 43 of the HP heat source unit 40 and the temperature rises. The warmed water whose temperature has risen is returned to the upper portion of the low-temperature bath (21) by flowing through the circulating return path (34). As a result of this circulation, in the low-temperature bath 21, a temperature-modulated layer in which a high-temperature layer is laminated is formed on the low-temperature layer. When the hot water is continuously returned to the low-temperature bath 21, the thickness (depth) of the high-temperature layer gradually increases, and the hot water is stored in the entire low- If the temperature stratification layer is formed in the low-temperature bath 21, the high-temperature hot water is sent to the hot water path 25 connected to the upper portion of the low-temperature bath 21, .

(Hot water operation)

In the hot water supply operation, the first hot water supply operation for supplying the mixed water adjusted to the hot water supply set temperature in the mixer 24 as hot water in the hot water supply conduit 60 via the hot water bypass path 28, And the second hot water supply operation in which the mixed water adjusted to a temperature lower than the temperature is heated by the gas heat source unit 50 and supplied as hot water from the hot water supply source 60 is executed.

When the detected water temperature of the upper thermistor 39 of the low-temperature bath 21 is equal to or higher than the first reference temperature (for example, the hot water setting temperature + 5 ° C) higher than the hot water setting temperature set on the remote controller 13, . In the first hot water supply operation, the controller 11 sets the bypass control valve 28a to the open state and the quantity servo 51c to the fully closed state. The controller 11 adjusts the opening degree of the hot water control valve 25a and the opening degree of the water supply control valve 26a so that the water temperature detected by the mixing thermistor 27a becomes the hot water setting temperature. The mixed water adjusted to the hot water set temperature is supplied as hot water from the hot water supply conduit 60 through the hot water bypass path 28 and the hot water supply path 29 after flowing through the first mixing path 27.

On the other hand, when the detected water temperature of the upper thermistor 39 is lower than the first reference temperature, the second hot water supply operation is performed. In the second hot water supply operation, the controller 11 sets the bypass control valve 28a to the fully closed state and sets the quantity servo 51c to a predetermined opening degree. The controller 11 controls the opening degree of the hot water control valve 25a so that the water temperature detected by the mixing thermistor 27a becomes the second reference temperature (for example, the hot water setting temperature -5 deg. C) And adjusts the opening degree of the opening 26a. The mixed water adjusted to the second reference temperature flows through the first mixing path 27 and the second mixing path 51 of the gas heat source unit 50 and flows into the burner heat exchanger 52 to be supplied to the burner 53 . The heating capacity of the burner 53 is controlled so that the temperature of the water detected by the tube thermistor 55 provided at the outlet of the burner heat exchanger 52 becomes 60 DEG C or higher. Accordingly, the generation of condensation water in the piping can be suppressed. A part of the mixed water flowing through the second mixing path 51 flows into the second hot water supply path 54 through the heat source bypass path 57 and the water of at least 60 ° C from the burner heat exchanger 52, The water at the second reference temperature from the bypass path 57 is mixed and the water at the hot water setting temperature is sent to the first hot water supply path 29. The water adjusted to the set hot water temperature in this way is supplied as hot water from the hot water supply conduit 60 through the first hot water supply path 29. Accordingly, even when hot water stored in the low-temperature bath 21 is consumed during the first hot water supply operation, the hot water adjusted to the hot water set-up temperature can be continuously supplied as hot water.

(Defrosting operation)

When the heat pump 40a is driven in a state where the outside temperature is low, such as during the winter season, the second heat exchanger 45 may be frosted. If the second heat exchanger 45 is concealed, heat exchange efficiency with the outside air is lowered, and the heating capacity of the heat pump 40a is lowered. Thus, in the hot water supply system 10 of the present embodiment, when defrosting the second heat exchanger 45, defrosting operation for defrosting from the second heat exchanger 45 can be executed. In the defrosting operation, the HP heat source unit 40 drives the compressor 41 with the defrost valve 47a opened. As a result, the high-temperature refrigerant discharged (discharged) from the compressor 41 flows into the second heat exchanger 45 through the secondary-glass path 47 and returns to the compressor 41 as indicated by the broken arrow in Fig. Lt; / RTI > The high-temperature refrigerant can flow from the second heat exchanger (45) to the second heat exchanger (45).

(Freezing prevention operation (freeze prevention operation))

The circulating water passage 43b of the first heat exchanger 43, the circulating water passage 33, the circulating water passage connecting passage 48, and the circulating water passage connecting passage 43 are not opened, The circulating water may stay in the connection path 49 and the circulating return path 34 by the circulating return, and the circulating water may be frozen in these pipes. If the circulation number is frozen, the heat storage operation can not be performed until the frozen circulation water is melted. Thus, in the hot water supply system 10 of the present embodiment, it is possible to perform the freeze prevention operation for preventing freezing of the circulating water when the temperature of the circulating water is lowered due to the low outside temperature. Hereinafter, the freezing prevention operation performed by the hot water supply system 10 will be described with reference to FIG.

In step S202, it is determined whether or not the temperature of the circulating water is below a predetermined temperature (for example, 10 DEG C). In the following description, the temperature of the circulating water means the temperature of the circulating water in the circulating royal road 33 detected by the forward thermistor 36 and the temperature of the circulating water path 48 The temperature of the circulating water in the lower portion of the circulating water. When the temperature of the circulating water is equal to or higher than the predetermined temperature (NO in step S202), the process returns to step S202. If the temperature of the circulating water is below the predetermined temperature (YES in step S202), the process proceeds to step S204.

In step S204, it is determined whether or not the outside air temperature detected by the outside air temperature thermistor 35 falls below a predetermined temperature (for example, 5 DEG C). When the outside air temperature is equal to or higher than the predetermined temperature (NO in step S204), the process returns to step S202. If the outside air temperature falls below the predetermined temperature (YES in step S204), the process proceeds to step S206.

In step S206, the circulation pump 37 is driven. As a result, the circulating water is drawn from the lower portion of the low-temperature bath 21, and the circulating flow path 33, the circulating-king connecting path 48, the circulating water flow path 43b of the first heat exchanger 43, The circulating water is returned to the upper part of the low-temperature bath 21 via the circulating return passage 49 and the circulating return passage 34 sequentially. The circulating water flows through the circulating water passage 33, the circulating-water connecting passage 48, the circulating water passage 43b of the first heat exchanger 43, the circulating-return connecting passage 49, ) Is replaced with the number of circles inside.

In step S208, the temperature of the circulating water (the temperature of the circulating water in the circulating royal road 33 detected by the forward thermistor 36 and the temperature of the circulating water in the circulating royal road connection 48 detected by the inlet thermistor 48a (For example, a temperature lower than the predetermined temperature (for example, 13 [deg.] C)). When residual heat remains in the low-temperature storage tank 21 at the time when the freeze prevention operation is started in step S206, the circulation pump 37 is driven to circulate the circulating warm air 33, the circulating warm air connection path 48, The circulating water flow path 43b of the first heat exchanger 43, the circulating return path 49 and the circulating return path 34 are replaced by the warm circulating water from the low- In this case, it is not necessary to continue the freeze prevention operation further. Therefore, if the temperature of the circulating water is equal to or higher than the predetermined temperature (YES) in step S208, the process proceeds to step S228 to stop the circulation pump 37 to end the freezing prevention operation. If the temperature of the circulating water has not reached the predetermined temperature in step S208 (NO), the process proceeds to step S210.

In step S210, it is determined whether or not the outside air temperature is equal to or higher than a predetermined temperature (for example, 6 ° C). When the outside air temperature rises to the temperature at which the circulating water is not likely to freeze after the freezing prevention operation is started in step S206, it is not necessary to continue the freezing prevention operation further. Therefore, if the outside air temperature is equal to or higher than the predetermined temperature (YES) in step S210, the process proceeds to step S228 to stop the circulation pump 37 to end the freeze prevention operation. If it is determined in step S210 that the outside air temperature has not reached the predetermined temperature (NO), the process proceeds to step S212.

In step S212, it is determined whether or not a predetermined time (for example, 30 minutes) has elapsed after driving the circulation pump 37 in step S206. If the predetermined time has not elapsed (NO in step S212), the process returns to step S208. When the predetermined time has elapsed (YES in step S212), the process proceeds to step S214. The reason for advancing from step S212 to step S214 is that the temperature of the circulating water does not reach the predetermined temperature until the predetermined time passes after driving the circulation pump 37 (that is, ) And the outside temperature does not rise. In this case, in the hot water supply system 10 of the present embodiment, the circulating water is heated by the processing after step S214.

In step S214, it is determined whether or not the outside air temperature falls below a predetermined temperature (for example, -10 ° C). Generally, heating of the circulating water by the heat pump 40a is high in energy efficiency, so it is preferable to heat the circulating water for preventing freezing by driving the heat pump 40a. However, when the outside air temperature is low, heating by the heat pump 40a may cause the second heat exchanger 45 to be concealed. If it is conceived on the second heat exchanger 45, a drain is generated in accordance with the defrosting operation, so that a treatment for preventing freezing of the drain is separately required. For this reason, it is preferable that the second heat exchanger 45 is not flotated as much as possible. Thus, in the hot water supply system 10 of the present embodiment, when the circulating water is heated in the freeze prevention operation, the heating means is switched in accordance with the outside air temperature.

If the outside air temperature is equal to or higher than the predetermined temperature (NO) in step S214, the process proceeds to step S216. In step S216, the compressor 41 is driven to start heating the circulating water by the heat pump 40a. In step S218, the temperature of the circulating water (the temperature of the circulating water in the circulating royal road 33 detected by the forward thermistor 36 and the temperature of the circulating water in the circulating royal road connecting path 48 detected by the inlet thermistor 48a) (For example, a temperature lower than the predetermined temperature (e.g., 30 DEG C)). In step S218, when the temperature of the circulating water becomes equal to or higher than the predetermined temperature (YES), the compressor 41 is stopped in step S220, and the heating of the circulating water by the heat pump 40a is terminated. Thereafter, the processing advances to step S228 to stop the circulation pump 37 to end the freeze prevention operation.

If it is determined in step S214 that the outside air temperature exceeds the predetermined temperature (NO), the process proceeds to step S222. In step S222, the freeze prevention heater 34a is turned on to start heating the circulating water by the freeze prevention heater 34a. In step S224, the process waits until the outside air temperature becomes equal to or higher than a predetermined temperature (for example, -8 DEG C). In step S224, when the outside air temperature becomes equal to or higher than the predetermined temperature (YES), the freeze prevention heater 34a is turned off in step S226, and the heating of the circulation water by the freeze prevention heater 34a is terminated. Thereafter, the processing advances to step S228 to stop the circulation pump 37 to end the freeze prevention operation.

As described above, in the hot water supply system 10 of the present embodiment, when the outdoor temperature is high, the circulation water is heated by the heat pump 40a while the freezing prevention operation is performed. When the outdoor temperature is low, ) To heat the circulating water. With this configuration, it is possible to prevent a situation in which the second heat exchanger 45 of the heat pump 40a is frozen due to the freeze prevention operation.

In the above-described hot water supply system 10, the freeze prevention heater 34a is provided not in the HP heat source unit 40 but inside the low temperature unit 20. With this configuration, the detection value of the thermistor in the HP heat source unit 40 (the inlet side thermistor 48a for detecting the temperature of the circulating water, the outlet side thermistor 49a, and the thermistor for detecting the temperature of the refrigerant) It is possible to prevent the heat from being affected by the heat radiation from the freeze prevention heater 34a.

In addition, in the hot water supply system 10 described above, when the outside air temperature is lower than a predetermined temperature (for example, -10 ° C) in the heat storage operation, not only the freezing prevention operation, The second heat exchanger 45 may be prevented from being concealed. According to the hot water supply system 10 described above, the hot water supply temperature can be supplied to the hot water supply outlet 60 by the second hot water supply operation using the gas heat source unit 50. It is possible to prevent the heat pump 40a from being concealed to the second heat exchanger 45 without impairing the convenience of the user.

In the above-described hot water supply system 10, the freeze prevention heater 34a is installed in the circulation return path 34, not in the circulating warm path 33. [ With this configuration, it is possible to prevent the detection value of the forward thermistor 36 from being influenced by heat radiation from the freeze prevention heater 34a.

3, the freeze prevention heater 34a is provided in the circulating-path connecting path 48 inside the HP heat source unit 40. In this case, It is possible to prevent a situation in which the heat pump 40a is concealed in the second heat exchanger 45 due to the prevention operation.

In the above embodiment, the constitution has been described in which tap water (water (hot water) supplied by hot water is used as the fruit to be circulated between the heat pump 40a and the low-temperature bath 21). Alternatively, antifreeze (antifreeze liquid) is used as the fruit to be circulated between the heat pump 40a and the low-temperature bath 21, and the amount of the antifreeze stored in the tap water (constant water) A heat exchanger for exchanging heat between the low-temperature bath 21 and the low-temperature bath 21 may be separately provided.

In the above embodiment, the configuration in which the fruit stored in the low-temperature bath 21 is used for hot water supply has been described. Alternatively, for example, the fruit stored in the low-temperature bath 21 may be used for heating the floor heating, the bathroom drying radiator, or the like. Or the fruit stored in the low-temperature bath 21 may be used for both the hot water supply and the heating.

Although specific examples of the present invention have been described in detail above, they are merely illustrative and do not limit the scope of the claims. The techniques described in the claims include various modifications and changes to the specific examples described above. Furthermore, the technical elements described in the present specification or drawings may exhibit technological usefulness alone or in various combinations, and are not limited to combinations described in the claims at the time of filing. Further, the techniques exemplified in the present specification or drawings are intended to achieve a plurality of objectives at the same time, and have technological usefulness as the achievement of one of them.

Claims (3)

A heat pump unit having a heat pump for absorbing heat from the outside air to heat the heat medium;
A tank unit having a tank for storing fruit,
An auxiliary heat source unit (auxiliary heat source unit) that heats the fruit supplied from the tank to the fruit utilization site
A heat pump system comprising:
An outside temperature detecting means (outside temperature detecting means) for detecting an outside temperature,
A heater is installed in the flow path between the tank and the heat pump.
Further,
In order to prevent the freezing of the fruit, it is possible to perform freeze prevention operation (freeze prevention operation) in which heat is circulated between the tank and the heat pump while circulating the heat,
A heat pump system for heating a fruit by a heat pump when the outside air temperature is high and for heating the fruit by a heater when the outside air temperature is low in freeze prevention operation.
The method according to claim 1,
And a heater is provided in a flow path inside the tank unit.
3. The method of claim 2,
A heat pump system in which a heater is provided in a flow path for returning heat from a heat pump to a tank.

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