JP2009063246A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To resolve problems in conventional defrosting methods in a heat pump water heater wherein an electric expansion valve is fully opened to carry out defrosting after hot water storage tank boiling is finished, and a solenoid valve for defrosting is opened to carry out defrosting during hot water storage tank boiling, in a method of fully opening the electric expansion valve to carry out defrosting and using the solenoid valve for defrosting other than the electric solenoid valve, but in the former, it takes a long defrosting time when a defrosting amount is large, in the latter, cost becomes high, and in both, a large amount of waterdrops of molten frost after defrosting adheres to an evaporator, and when the evaporator is driven again in a short time, the waterdrops freeze again and heat exchange performance of air and a coolant in the evaporator is deteriorated. <P>SOLUTION: Three or more defrosting levels are provided corresponding to outside air temperatures or defrosting degrees of the evaporator during defrosting operation of the heat pump water heater, and it has defrosting operation modes corresponding to each level. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to defrosting of an evaporator of a heat pump water heater.

  A conventional heat pump water heater has a large-capacity hot water storage tank, just like an electric water heater, and uses low-cost electricity at night discount to boil hot water in the heat pump circuit and store it in the hot water storage tank. A hot water storage system that uses hot water during the day was common.

  Since the hot water storage type heat pump water heater is operated continuously for a long time at night to store hot water, frost adheres to the evaporator and the performance deteriorates in winter when the outside air temperature is low. As the defrosting operation, a method of performing defrosting by fully opening the expansion valve for refrigerant decompression and flow rate adjustment and sending a high-temperature and high-pressure refrigerant to the evaporator is used for defrosting in addition to the expansion valve. An electromagnetic valve has been proposed in which a high-temperature and high-pressure refrigerant is directly sent to an evaporator to reduce the defrosting time.

  An example of a hot water storage type heat pump water heater provided with the defrosting solenoid valve is disclosed in Patent Document 1.

  According to Patent Document 1, in a heat pump cycle configuration having a compressor, a water heat exchanger, an electric expansion valve, a defrosting electromagnetic valve, and an evaporation heat exchanger, the defrosting method for the evaporation heat exchanger is as follows. When the hot water storage tank is fully heated, the electric expansion valve is fully opened to perform defrosting, and when the hot water storage tank is being heated, the defrosting electromagnetic valve is opened to perform defrosting.

JP 2001-263800 A

  Of the methods for defrosting the evaporator in the conventional heat pump water heater, the method of simply performing the defrosting by fully opening the electric expansion valve takes a long time for defrosting when the amount of frost formation is large.

  Further, in addition to the electric expansion valve shown in Patent Document 1, a defrosting electromagnetic valve is provided to reduce the defrosting time, and therefore a defrosting electromagnetic valve must be added. Cost was also high because of the need for piping.

  In any of the methods, a large amount of frost-melted water droplets adheres to the evaporator after defrosting, and when the operation is restarted within a short time, the water droplets freeze again, and the refrigerant and air in the evaporator. There was a possibility that the heat exchanging performance with would decrease.

  Furthermore, in recent years, hot water storage tanks have been downsized, and those that store hot water for a short time during the day as well as at night, or heat pump operation when using hot water, heat the supplied water with refrigerant to create hot water, and use it directly. Instant heat pump water heaters with a direct hot water supply circuit for supplying hot water to the terminal have been proposed, the operation time of the heat pump may vary, and the amount of frost formation on the evaporator will also vary, so only with conventional high-temperature refrigerant The defrosting operation is not necessarily optimal, and fine defrosting means (defrosting operation mode) has been an issue.

  An object of the present invention is to provide a heat pump water heater that improves defrosting efficiency.

The object of the present invention is as follows.
A heat pump refrigerant circuit in which a compressor, a water refrigerant heat exchanger that performs heat exchange between water supplied from a water supply source and a refrigerant, an expansion valve, and an evaporator are sequentially connected via a refrigerant pipe;
A blower fan for passing outside air through the evaporator;
Operation control means for controlling the compressor, the expansion valve, and the blower fan;
A heat pump water heater equipped with
The operation control means is in a defrosting operation to remove frost formed on the evaporator,
Operating the compressor,
Fully open the expansion valve;
This is achieved by a heat pump water heater that operates the blower fan.

  Moreover, the said operation control means is good also as starting the driving | operation of the said ventilation fan after predetermined time progress, after opening the said expansion valve fully at the time of the said defrost operation.

  Moreover, the said operation control means is good also as starting the operation | movement of the said ventilation fan after the surface temperature of the said evaporator reaches predetermined temperature after opening the said expansion valve fully at the time of the said defrost operation.

The object of the present invention is as follows.
A heat pump refrigerant circuit in which a compressor, a water-refrigerant heat exchanger that performs heat exchange between water and the refrigerant, an expansion valve, and an evaporator are sequentially connected via a refrigerant pipe;
A blower fan that takes outside air through the evaporator;
A hot water supply circuit in which a water supply fitting, the water refrigerant heat exchanger, a hot water storage tank, a hot water supply mixing valve, a hot water mixing valve, a flow rate adjusting valve, and a hot water supply fitting are connected via a water pipe;
Operation control means for controlling the operation of the compressor, expansion valve, hot water mixing valve, hot water mixing valve, flow rate adjustment valve, and the like,
The operation control means is achieved by a heat pump water heater having three or more frost levels according to the outside air temperature or the frost level of the evaporator and having a defrost operation mode corresponding to each level.

  Further, the operation control means may be configured such that the defrosting operation mode includes a combination of whether or not the compressor is operated, whether or not the expansion valve is fully opened, and whether or not the blower fan is operated.

  Moreover, the said operation control means is good also as having the defrost operation mode which combined the presence or absence of the opening of the said expansion valve, and the presence or absence of the operation of the said ventilation fan as said defrost operation mode.

  According to the present invention, a heat pump water heater with improved defrosting efficiency can be realized.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, Example 1 when applied to an instantaneous heat pump water heater having a direct hot water supply circuit will be described.

  FIG. 1 shows an embodiment of a component configuration of an instantaneous heat pump water heater to which the present invention is applied.

  The heat pump water heater includes a heat pump refrigerant circuit 40, a hot water supply circuit 45, and an operation control means 50.

  The heat pump refrigerant circuit 40 includes a first heat pump refrigerant circuit 40a and a second heat pump refrigerant circuit 40b, and is a refrigerant disposed in the compressors 1a and 1b and the water refrigerant heat exchanger 2 in a two-cycle system having two components. The side heat transfer tubes 2a and 2b, the expansion valves 3a and 3b, and the evaporators 4a and 4b are sequentially connected via refrigerant piping, respectively, and carbon dioxide as a refrigerant is enclosed therein.

  The compressors 1a and 1b are capable of capacity control, and are operated with a large capacity when supplying a large amount of hot water. Here, the compressors 1a and 1b can control the rotational speed from a low speed (for example, 700 rotations / minute) to a high speed (for example, 7000 rotations / minute) by PWM control, voltage control (for example, PAM control) and a combination control thereof. It has become.

  The water refrigerant heat exchanger 2 includes refrigerant side heat transfer tubes 2a and 2b and water supply side heat transfer tubes 2c and 2d, and performs heat exchange between the refrigerant side heat transfer tubes 2a and 2b and the water supply side heat transfer tubes 2c and 2d. It is configured as follows.

  In general, electromagnetic expansion valves are used as the expansion valves 3a and 3b, and the medium temperature and high pressure refrigerant sent through the water refrigerant heat exchanger 2 is depressurized and sent to the evaporators 4a and 4b as low pressure refrigerant that is easily evaporated. The expansion valves 3a and 3b function to adjust the refrigerant circulation amount in the heat pump circuit by changing the throttle amount of the refrigerant passage, or to fully open (open) the throttle amount so that the medium temperature refrigerant is supplied to the evaporators 4a and 4b in a large amount. It also plays the role of a defrosting device that sends it to defrost.

  The evaporators 4a and 4b are air-refrigerant heat exchangers composed of fins and refrigerant pipes. By operating the blower fans 6a and 6b (including a fan motor for rotating the fan), outside air passes through. And heat exchange between air and refrigerant. The evaporator thermistors 5a and 5b detect the evaporator surface temperature and the amount of frost formation.

  The hot water supply circuit 45 includes a water circulation circuit for performing tank hot water storage, tank hot water supply, direct hot water supply, bath hot water filling, bath reheating, and the like.

  The tank hot water storage circuit is configured by sequentially connecting a hot water storage tank 17, a tank circulation pump 18, a water heat AC amount sensor 11, water supply side heat transfer pipes 2c and 2d, a hot water supply mixing valve 12, and a hot water storage tank 17 via a water pipe. .

  The direct hot water supply circuit includes a water supply fitting 7, a pressure reducing valve 8, a water supply water amount sensor 9, a water supply check valve 10, a water heat AC amount sensor 11, water supply side heat transfer tubes 2c and 2d, a hot water supply mixing valve 12, a hot water mixing valve 13, and a flow rate. An adjustment valve 14 and a kitchen tapping metal fitting 15 are sequentially connected via a water pipe.

  The water supply fitting 7 is connected to a water supply source such as a water supply, and the kitchen tap fitting 15 is connected to a kitchen faucet 16 that is one of the terminals used.

  The tank hot water supply circuit has a water supply fitting 7, a pressure reducing valve 8, a water supply water amount sensor 9, a water supply check valve 10, a hot water storage tank 17, a hot water supply mixing valve 12, a hot water mixing valve 13, a flow rate adjusting valve 14, and a kitchen tapping metal fitting 15. Are sequentially connected through the network.

  The bath hot water circuit includes a water supply fitting 7, a pressure reducing valve 8, a water supply water amount sensor 9, a water supply check valve 10, a water heat AC amount sensor 11, water supply side heat transfer tubes 2c and 2d, a hot water supply mixing valve 12, a hot water mixing valve 13, A flow rate adjustment valve 14, a bath pouring valve 19, a flow switch 20, a bath circulation pump 21, a water level sensor 22, a bath inlet / outlet fitting 23, a bath circulation adapter 24, and a bathtub 25 are sequentially connected via a water pipe. . Moreover, it connects so that hot water can be supplied from the bath entry / exit metal fitting 23 to the bath faucet 29 and the shower (not shown) together with the bathtub 25.

  During bath hot water filling, hot water supply from the hot water storage tank 17 to the bathtub 25 is performed within a range where the amount of hot water in the hot water storage tank 17 does not fall below the minimum required amount, together with direct hot water supply by the bath hot water filling circuit.

  The bath memory circuit includes a bathtub 25, a bath circulation adapter 24, a bath inlet / outlet fitting 23, a water level sensor 22, a bath circulation pump 21, a flow switch 20, a bath heat transfer pipe 27b of a bath heat exchanger 27, and a bath outlet fitting 28. The bath circulation adapter 24 and the bathtub 25 are sequentially connected via a water pipe.

  At the time of bathing, the water circulation of the bath water by the bath chasing circuit was operated, the heat pump and the tank circulation pump 18 were operated, and the hot water on / off valve 26 was fully opened to be heated by the water / refrigerant heat exchanger 2. Hot water is circulated through a hot water heat transfer tube 27a provided in the bath heat exchanger 27, and heat is exchanged between the hot water heat transfer tube 27a and the bath water heat transfer tube 27b, thereby performing bath renewal.

  Next, the operation control means 50 performs the operation / stop of the heat pump refrigerant circuit 40 and the rotation speed control of the compressors 1a, 1b by the setting / operation of the kitchen remote controller 51 and the bath remote controller 52, and the expansion valves 3a, 3b. Adjustment or full opening of refrigerant throttle amount, operation / stop of blower fans 6a, 6b, tank circulation pump 18, bath circulation pump 21, hot water mixing valve 12, hot water mixing valve 13, flow rate adjustment valve 14, bath pouring valve 19, hot water By controlling the on-off valve 26, hot water storage operation, tank hot water supply operation, direct hot water supply operation, defrosting operation, bath hot water operation, and bath chasing operation are performed.

  Further, the operation control means 50 controls the rotation speed of the compressors 1a and 1b, and immediately after the start of operation, the operation control means 50 operates at a predetermined high speed rotation speed in order to shorten the heating start-up time. At the time of operation, control is performed so as to operate at a rotation speed corresponding to the heating temperature.

  Further, the operation control means 50 controls operation / stop of the heat pump refrigerant circuit, adjustment of the throttle amount of the expansion valves 3a, 3b or full open, and operation stop of the blower fans 6a, 6b when frost is formed at a low temperature.

  Further, in the heat pump water heater, in addition to the thermistors for evaporators 5a and 5b for detecting the surface temperature of the evaporators 4a and 4b, temperature thermistors (not shown) for detecting the temperatures of the respective parts and the discharges of the compressors 1a and 1b. A pressure sensor (not shown) for detecting pressure, a water level sensor 20 for detecting the water level in the bathtub 25, and the like are provided. Each detection signal is configured to be input to the operation control means 50, and the operation control means 50 controls each device based on these signals.

  The hot water on / off valve 26 is provided between the water refrigerant heat exchanger 2 and the bath heat exchanger 27, and closes the water circuit and exchanges heat for the bath from the water refrigerant heat exchanger 2 except when bathing. This is to prevent heat leakage to the container 27.

  FIG. 2 is a flowchart showing an operation in the case where the defrosting operation is performed by the bath hot water operation and the subsequent frost formation in the first embodiment.

  In the instantaneous heat pump water heater, defrosting is necessary when the ambient temperature is low in winter and the heat pump refrigerant circuit 40 is operated for a long time. The operation of the heat pump water heater is tank hot water, wash water, kitchen hot water, hot water bathing, bathing, showering, etc. In the case of the instantaneous type, the hot water storage tank 17 has a small capacity, so Since the time is the longest and the necessity of defrosting is high, FIG. 2 demonstrates the defrosting operation after bath hot water filling operation.

  First, when hot water filling is started using hot water (step 60), the heat pump refrigerant circuit 40 is operated, and the throttle amounts of the expansion valves 3a and 3b are adjusted together with the rotation speed control of the compressors 1a and 1b. A hot water supply operation in accordance with the tension temperature is started (step 61). As described above, at the time of bath hot water filling, tank hot water supply from the hot water storage tank 17 to the bathtub 25 is performed in addition to the direct hot water supply by the bath hot water filling circuit as long as the amount of hot water in the hot water storage tank 17 does not fall below the minimum required amount.

  Eventually, when the amount of hot water in the bath reaches a specified amount and the use of hot water (bath hot water) ends (step 62), the hot water supply operation is stopped (step 63), and the evaporator thermistors 5a and 5b form frost. The amount or the evaporator temperature is detected, and the necessity of defrosting is determined (step 64).

  In the defrosting necessity determination (step 64), when it is determined that the amount of frost formation is large and defrosting is necessary, the expansion valve is fully opened and the heat pump refrigerant circuit and the fan are operated to perform the defrosting operation. (Step 65) Further, the end of the defrosting is determined (step 66), and after confirming that the defrosting is completed, the defrosting operation is ended (step 67).

  Further, in the determination of the necessity of defrosting (step 64), if it is determined that frost is not formed or the amount of frost formation is small and defrosting is not necessary, the defrosting operation (step 65) is not performed. Control is made so that the defrosting operation is completed (step 67).

  In the defrosting operation (step 65), the heat pump refrigerant circuit is operated, the expansion valves 3a and 3b are fully opened, and the blower fans 6a and 6b are operated, so that water droplets adhering to the evaporators 4a and 4b are melted. Since fresh outside air can be sequentially blown onto the frost on the surfaces of the evaporators 4a and 4b, when the outside air temperature is a positive temperature, the defrosting on the surfaces of the evaporators 4a and 4b can be promoted. Even at times, it has the effect of preventing re-condensation of water drops after defrosting.

  Further, since it takes several minutes from the start of the defrosting operation until the frost starts to melt, the operation of the blower fans 6a and 6b is delayed in time from the operation of the heat pump refrigerant circuit. That is, the operation of the blower fans 6a and 6b is started after a predetermined time has elapsed from the start of operation of the heat pump refrigerant circuit. Alternatively, the operation of the blower fans 6a and 6b is started after the surface temperature of the evaporator reaches a predetermined temperature.

  Thus, the operation time of the blower fans 6a and 6b is shortened and energy is saved. The defrosting effect could not be expected because the expansion valve is fully opened and the start time of the blower fan is shifted so that the frost melts to some extent and water drops are eliminated by starting the blower fan. Appropriate defrosting operation can be performed even when the outside air temperature is low.

  As described above, according to the first embodiment, the defrosting solenoid valve is not used, the expansion valve and the blower fan, which are necessary components for the heat pump circuit, are used, and at the time of defrosting, the expansion valve is fully opened while operating the heat pump. Since the operation of the blower fan is performed, when the outside air temperature is 0 ° C. or higher, the defrosting effect by the outside air temperature can be obtained. It has the effect of preventing refreezing during operation after defrosting, and can improve defrosting efficiency at low cost.

  Next, Example 2 when applied to an instantaneous heat pump water heater having a direct hot water supply circuit will be described. The component configuration of the instantaneous heat pump water heater is the same as that shown in FIG.

  FIG. 3 is a flowchart showing an operation in the case of performing a bath hot water operation and a subsequent defrosting operation corresponding to a frosting state in the second embodiment.

  First, when hot water filling is started using hot water (step 70), the heat pump refrigerant circuit 40 is operated, and the throttle amounts of the expansion valves 3a and 3b are adjusted together with the rotation speed control of the compressors 1a and 1b. A hot water supply operation in accordance with the tension temperature is started (step 71). As described above, at the time of bath hot water filling, tank hot water supply from the hot water storage tank 17 to the bathtub 25 is performed in addition to the direct hot water supply by the bath hot water filling circuit as long as the amount of hot water in the hot water storage tank 17 does not fall below the minimum required amount.

  When the amount of hot water in the bath reaches a specified amount and the use of hot water (bath bathing) ends (step 72), the hot water supply operation is stopped (step 73), and the outside temperature measurement and evaporation by the thermistors 5a and 5b for the evaporator are performed. The amount of frost formation or the evaporator temperature is detected and the frost formation level is determined (step 74).

  Here, a setting example of the frost level will be described with reference to FIG.

  In FIG. 4, the outside air temperature and the amount of frost formation are used as factors of the frost formation level, but the outside air temperature and the evaporator temperature, or only the outside air temperature or the amount of frost formation may be used.

  In addition, in the frost level setting of FIG. 4, the amount of frost assumes the case where the outside temperature is about −7 ° C. to + 7 ° C. and the heat pump is continuously operated for about 30 to 40 minutes in winter.

  The frosting level is set, for example, in four stages, and the defrosting means (defrosting operation mode) corresponding to the frosting level is operated / stopped (presence / absence of operation) of the heat pump refrigerant circuit 40, and the expansion valves 3a, 3b are normally operated. The ABCD is set in four stages according to the combination of the throttle amount, full open (presence of full open), and operation / stop of the blower fans 6a and 6b (presence of operation).

  The frosting level A is the case where the outside air temperature is about + 7 ° C. or higher, the frost is not formed or the amount of frost formation is very small and the necessity of the defrosting operation is the lowest, and the heat pump refrigerant circuit 40 and the blower fans 6a and 6b Is not operated, and the expansion valves 3a and 3b are also kept at the normal throttle amount. That is, the defrosting operation is not performed and the frost naturally melts by stopping the heat pump.

  The frosting level B is a case where the outside air temperature is about + 2 ° C. to + 7 ° C., frost is formed but is relatively small amount, the heat pump refrigerant circuit 40 is not operated, the expansion valves 3a and 3b are fully opened, and the blower fan 6a and 6b are operated. That is, the operation of the heat pump is stopped to save power, and the high-temperature refrigerant heat whose heat is dissipated in the water heat exchanger 2 due to the stoppage of hot water supply is reduced to the evaporators 4a and 4b through the fully opened expansion valves 3a and 3b. Conduct heat to defrost. Further, by operating the blower fans 6a and 6b, it is an optimum method for saving energy by means of taking in outside air at a temperature of + 2 ° C. to + 7 ° C. and defrosting the evaporators 4a and 4b.

  The frosting level C is a general frosting state when the outside air temperature is about −5 ° C. to + 2 ° C., operates the heat pump refrigerant circuit 40, fully opens the expansion valves 3a and 3b, and evaporates the high-temperature refrigerant. It sends to 4a and 4b and performs defrosting in earnest. The fans 6a and 6b are also operated, but not for taking in the outside air temperature but for removing water droplets on the surfaces of the evaporators 4a and 4b melted by the refrigerant heat to promote defrosting and restarting after defrosting. This is in order to prevent re-freezing of the water droplets in the event of failure. Therefore, it is more effective that the operation of the blower fans 6a and 6b is delayed with respect to time than the operation of the defrosting heat pump refrigerant circuit 40 as in the first embodiment.

  The frosting level D is when the outside air temperature is less than about −5 ° C., and even during the winter, especially at low temperatures, and the absolute humidity is low, so the amount of frosting does not increase so much. It takes. As the defrosting means, similarly to the frost level C, the heat pump refrigerant circuit 40 is operated, the expansion valves 3a and 3b are fully opened, the high-temperature refrigerant is sent to the evaporators 4a and 4b, and defrosting is performed in earnest. However, since the outside air temperature is low, the blower fans 6a and 6b are not operated during defrosting, but are operated only before and after the defrosting to remove water droplets on the surfaces of the evaporators 4a and 4b.

  The above defrosting level setting and the corresponding defrosting means are examples, but as the defrosting means, at least the operation / stop of the heat pump refrigerant circuit 40, the full opening of the expansion valves 3a, 3b, and the blower fans 6a, 6b. There are three items of operation and stop, and in order to optimize the defrosting operation, three or more frost levels are required.

  In this way, by providing three or more frost levels according to the outside air temperature or the degree of frost formation on the evaporator, by controlling the expansion valve and the blower fan corresponding to each level and performing three or more types of defrosting means, Detailed defrosting operation corresponding to the amount of frost formation can be performed, especially suitable for heat pump water heaters of the type that repeats short-time operation by reducing the size of the hot water storage tank, low cost and energy saving corresponding to diversification The defrosting means which aimed at can be provided.

  Returning to FIG. 3, when the frost level is determined (step 74), defrosting is performed by the defrosting means (steps 75a to 75d) corresponding to the frost level as described in detail in FIG. . In addition, when defrosting is performed, the blower fans 6a and 6b are operated to remove water droplets on the surfaces of the evaporators 4a and 4b, so that the water droplets can be prevented from freezing when operated after defrosting.

  Next, the evaporator thermistors 5a and 5b perform defrosting completion determination (step 76) of the evaporators 4a and 4b. If there is residual frost, the defrosting operation is continued, and if it is determined that defrosting is complete, the heat pump refrigerant circuit. The operation of 40 and the operation of the blower fans 6a and 6b are stopped, the expansion valves 3a and 3b are returned to the normal opening, and the defrosting operation is ended (step 67).

  As described above, since the defrosting operation using both the expansion valve fully opened and the blower fan operation is performed, the defrosting effect by the outside air temperature can be obtained when the outside air temperature is 0 ° C. or more, and the frost melts and adheres to the evaporator. By removing the water droplets by blowing air, defrosting is promoted and freezing is prevented at the time of re-operation after defrosting, and the defrosting performance can be improved at low cost.

  As described above, according to these embodiments, a defrosting solenoid valve is not provided, and various frost conditions are supported by combined operation control of the expansion valve and the blower fan, which are necessary components for the heat pump circuit. It is possible to perform defrosting operation finely and improve defrosting efficiency at low cost. Furthermore, it is possible to save energy and prevent refreezing after defrosting by using optimal defrosting means corresponding to various frosting conditions depending on diversified use conditions of heat pump water heaters. Can be played.

  In the above defrosting operation, the case where the present invention is applied to an instantaneous heat pump water heater has been described. However, the present invention can be applied not only to an instantaneous heat pump water heater but also to a hot water storage heat pump water heater, and has the same effect. be able to.

It is a schematic diagram which shows one Example of schematic structure of a heat pump refrigerant circuit, a hot water supply circuit, an operation control means, and components. It is a flowchart which shows a hot water supply operation and subsequent defrost operation control. It is a flowchart which shows a hot water supply operation and subsequent defrost operation control. An example of frost formation level setting is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Compressor 2 Water refrigerant | coolant heat exchanger 3a, 3b Expansion valve 4a, 4b Evaporator 5a, 5b Evaporator thermistor 6a, 6b Blower fan 8 Pressure reducing valve 12 Hot water mixing valve 13 Hot water mixing valve 14 Flow rate adjustment valve 17 Hot water storage tank 18 Tank circulation pump 19 Bath pouring valve 21 Bath circulation pump 25 Bath 27 Heat exchanger 40 for bath Heat pump refrigerant circuit 40a First heat pump refrigerant circuit 40b Second heat pump refrigerant circuit 45 Hot water supply circuit 50 Operation control means 51 Kitchen remote control 52 Bath remote control

Claims (6)

A heat pump refrigerant circuit in which a compressor, a water refrigerant heat exchanger that performs heat exchange between water supplied from a water supply source and a refrigerant, an expansion valve, and an evaporator are sequentially connected via a refrigerant pipe;
A blower fan for passing outside air through the evaporator;
Operation control means for controlling the compressor, the expansion valve, and the blower fan;
A heat pump water heater equipped with
The operation control means is in a defrosting operation to remove frost formed on the evaporator,
Operating the heat pump refrigerant circuit;
Fully open the expansion valve;
A heat pump water heater for operating the blower fan. In claim 1,
In the defrosting operation, the operation control means starts the operation of the blower fan after a predetermined time has elapsed after fully opening the expansion valve. In claim 1,
In the defrosting operation, the operation control means starts the operation of the blower fan after the expansion valve is fully opened and then the surface temperature of the evaporator reaches a predetermined temperature. A heat pump refrigerant circuit in which a compressor, a water-refrigerant heat exchanger that performs heat exchange between water and the refrigerant, an expansion valve, and an evaporator are sequentially connected via a refrigerant pipe;
A blower fan for taking in outside air through the evaporator;
A hot water supply circuit in which a water supply fitting, the water refrigerant heat exchanger, a hot water storage tank, a hot water supply mixing valve, a hot water mixing valve, a flow rate adjusting valve, and a hot water supply fitting are connected via a water pipe;
Operation control means for controlling the operation of the compressor, expansion valve, hot water mixing valve, hot water mixing valve, flow rate adjustment valve, and the like,
The operation control means is a heat pump water heater having a defrosting operation mode corresponding to each level by providing three or more frosting levels according to the outside air temperature or the frosting degree of the evaporator. In claim 4,
The operation control means is characterized in that the defrosting operation mode comprises a combination of whether or not the heat pump refrigerant circuit is operated, whether or not the expansion valve is fully opened, and whether or not the blower fan is operated. In claim 5,
The operation control means has, as the defrosting operation mode, a defrosting operation mode in which the expansion valve is fully opened and the blower fan is operated.

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