JP2008224070A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater capable of performing a defrosting operation while continuing a hot water supplying operation. <P>SOLUTION: This heat pump water heater comprises a heat pump-type refrigerant cycle, a water-refrigerant heat exchanger 16 exchanging heat with a radiator 5, a first bypass circuit 11 connecting a compressor 4 and the radiator 5, and a pressure reducing means 6 and an air-refrigerant heat exchanger 7, and a second bypass circuit 13 connecting the pressure reducing means 6 and the radiator 5 and the compressor 4 and the air-refrigerant heat exchanger 7 in a state that they are disposed in an integrated housing 1. The first bypass circuit is provided with a first two-way valve 12, and the second bypass circuit is provided with a second two-way valve 15, and a refrigerant heating device 14 for heating the refrigerant by a heater 14a in series. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat pump type heat pump water heater, and more particularly to a heat pump water heater capable of performing a defrosting operation while performing a hot water heating operation during a hot water heating operation.

  Conventionally, hot water heaters that use gas or petroleum as fuel and heat tap water with the combustion heat have been used as hot water heaters.

  These have the advantage of being excellent in hot water properties, but on the other hand, fuel such as gas and oil is necessary and its supply is indispensable, exhaust gas after combustion is released into the atmosphere, causing air pollution, There were problems such as loud sounds.

  Especially in all-electric houses and condominiums where all energy sources are electricity, which has been increasing in recent years, there is no way to supply fuel, so there are more cases where it cannot be used.

  Accordingly, a hot water storage type heat pump type hot water heater equipped with a hot water storage tank has been developed. This solves the problem of hot water heaters due to combustion, and can be installed easily in all-electric homes and condominiums without the need for new infrastructure development. It is possible to ensure high thermal efficiency, and it is possible to store hot water in a hot water storage tank using inexpensive late-night power for operation, and the running cost is gradually reduced. It has become widespread.

  Such a water heater will be described with reference to FIG.

  As shown in FIG. 4, the heat pump hot water heater includes a hot water supply cycle 71 and a refrigerant cycle 72, which are separate main body units. Two boxes of a hot water storage unit including a hot water supply cycle 71 and a heat pump unit including a refrigerant cycle 72 are provided.

  This hot water supply cycle 71 includes a hot water storage tank 75 having a hot water supply port 73 provided on the bottom wall and a hot water supply port 74 provided on the upper wall, a water heat exchange path 76, and a water circulation pump 77, and performs water heat exchange. A passage 76 and a water circulation pump 77 are provided in a circulation passage 80 that connects a water intake 78 and a hot water inlet 79 of the hot water storage tank 75.

  In addition, the refrigerant cycle 72 includes a compressor passage, a water-refrigerant heat exchanger 82 that constitutes the heat exchange path 76, a decompression mechanism 83, and an air-refrigerant heat exchanger 84 that is a refrigerant evaporator in order. The refrigerant | coolant cycle comprised by connecting with 85 is provided.

  Further, the hot water supply cycle 71 and the refrigerant cycle 72 are connected by connecting pipes 86 and 87 arranged on the outdoor side. Then, the low-temperature water supplied from the water supply port 73 and discharged to the circulation path 78 by the water circulation pump 77 is boiled by the water-refrigerant heat exchanger 82 (that is, the water heat exchange path 76) and discharged from the hot water supply port 74. (For example, refer patent document 1).

  This heat pump water heater operates an energy efficient refrigerant cycle (heat pump circuit) 72 using inexpensive electric power at night, and circulates water in the hot water storage tank 75 with a water flow pump 77 while water- The refrigerant heat exchanger 82 warms up to a predetermined hot water temperature, detects that the predetermined hot water temperature has been reached, and stops the operation of the refrigerant cycle 72.

  When hot water is used at the normal hot water supply port 74, it is mixed with tap water having a temperature lower than the hot water temperature in the hot water storage tank 75 to obtain an appropriate temperature desired by the user. The temperature of the hot water stored in the hot water storage tank 75 should be as high as possible, thereby increasing the amount of tap water added to lower the temperature and reducing the amount of hot water removed from the hot water storage tank 75. It is designed to prevent problems such as cutting.

  However, in this refrigerant cycle, when the outside air temperature is low, such as in early winter, and operation is performed in a relatively humid environment, frost formation occurs in the air-refrigerant heat exchanger 84 that is a refrigerant evaporator that exchanges heat with the outside air. Therefore, a defrosting operation for removing the frost that has formed frost is required. As the defrosting method, a so-called hot gas bypass method (see, for example, Patent Document 2) and a refrigerant heating means are provided in the refrigerant cycle as shown in FIG. The thing which defrosts by heating a refrigerant | coolant with a heating means is proposed (for example, refer patent document 3).

This is provided with a refrigerant heater 88 on the low-pressure side of the refrigerant cycle 72, and the controller 89 heats the refrigerant with the refrigerant heater 88 during the defrosting operation. The heat capacity of the water-refrigerant heat exchanger 82 may initially cause the temperature of the high-temperature refrigerant to drop, so that sufficient defrosting capability may not be ensured. By providing a refrigerant heating means such as the refrigerant heater 88 and directly heating the refrigerant, the defrosting capability is remarkably improved and the defrosting time is shortened.
JP 2003-222392 A Japanese Examined Patent Publication No. 7-99297 JP 2005-180869 A

  However, in the configurations of Patent Document 1 and Patent Document 2, when the air-refrigerant heat exchanger 84 of the refrigerant cycle 72 is frosted, it takes a long time to defrost. When the defrosting operation is started when the amount of remaining hot water is desired to be reduced, the hot water supply operation cannot be performed because the hot water cannot be supplied from the hot water storage tank 75.

  Similarly, in the configuration of Patent Document 3, when the defrosting operation is started, the electric expansion valve that is the decompression mechanism 83 is almost fully opened, the water circulation pump 77 is stopped, and the heat exchange in the water heat exchanger 82 is performed. suppress. Then, the rotation speed of the compressor 81 is adjusted. Thereby, the refrigerant | coolant with high temperature is pressure-reduced with the decompression device 83, it sends to an air heat exchanger (evaporator), and defrosting is performed.

  In that case, the refrigerant | coolant is heated with the refrigerant | coolant heater 88, and the defrosting capability is improved.

  However, in order to suppress heat exchange in the water heat exchanger 82, the water circulation pump 77 is stopped. Therefore, when the defrosting operation is started when the remaining hot water amount in the hot water storage tank 75 is reduced, the hot water storage tank Since hot water cannot be supplied from 75, the hot water supply operation has to be stopped.

  The present invention solves such a conventional problem, and the refrigerant cycle can be configured with a simple bypass circuit, defrosting can be performed in a short time, and the amount of remaining hot water in the hot water storage tank is considerably reduced. Even in this case, an object is to provide a heat pump water heater capable of performing the defrosting operation while continuing the hot water supply operation.

  In order to solve the above-described conventional problems, a heat pump water heater of the present invention is a heat pump type in which a compressor, a radiator, a decompression unit, and an air-refrigerant heat exchanger are sequentially connected to form a closed circuit and the refrigerant is circulated. A first bypass connecting the refrigerant cycle, a water-refrigerant heat exchanger for exchanging heat with the radiator, the compressor and the radiator, and the pressure reducing means and the air-refrigerant heat exchanger. A circuit, a second bypass circuit for connecting the decompression means and the radiator, and between the compressor and the air-refrigerant heat exchanger are provided, and the first bypass circuit includes a first two-way valve. The second bypass circuit is provided with a second two-way valve and a refrigerant heating device heated by a heater in series, and when the air-refrigerant heat exchanger is defrosted, Open the two-way valve to cool the air-refrigerant heat exchanger. A second bypass circuit for operating the first bypass circuit for allowing the refrigerant to pass, and then opening the two-way valve of the second bypass circuit to flow the refrigerant heated by the refrigerant heating device to the suction side of the compressor It is characterized by driving.

  According to the present invention, the refrigerant cycle can be configured with a simple bypass circuit, defrosting can be performed in a short time, and even when the amount of remaining hot water in the hot water storage tank is considerably reduced, while continuing the hot water supply operation, A defrosting operation can be performed, and a heat pump water heater with excellent continuity of use can be provided to the user, and the capacity of the hot water storage tank can be reduced because there is no fear of running out of hot water. The main body configuration can be obtained.

  In the first invention, a compressor, a radiator, a decompression means, and an air-refrigerant heat exchanger are sequentially connected to form a closed circuit, and a heat pump type refrigerant cycle for circulating the refrigerant and heat exchange with the radiator are performed. A water-refrigerant heat exchanger; a first bypass circuit connecting between the compressor and the radiator; a pressure reducing means and the air-refrigerant heat exchanger; and between the pressure reducing means and the radiator. And a second bypass circuit that connects between the compressor and the air-refrigerant heat exchanger, a first two-way valve is provided in the first bypass circuit, and a second bypass circuit is provided in the second bypass circuit. The two-way valve and the refrigerant heating device are provided in series.

  Thereby, when performing defrosting of the air-refrigerant heat exchanger, the first bypass circuit operation operation of opening the two-way valve of the first bypass circuit and allowing the refrigerant to pass through the air-refrigerant heat exchanger. At the same time, it is possible to perform the second bypass circuit operation in which the two-way valve of the second bypass circuit is opened and the refrigerant heated by the refrigerant heating device flows to the suction side of the compressor, and the hot water supply operation is performed. The defrosting operation can be carried out.

  Therefore, even when the amount of hot water remaining in the hot water storage tank is considerably reduced, it is possible to reduce the capacity of the hot water storage tank by reducing the capacity of the hot water storage tank by allowing the defrosting operation to be performed while continuing the hot water supply operation. Thus, it is possible to greatly improve the installation property. Also, by utilizing a part of the whole refrigerant for the defrosting during the refrigerant cycle, an extremely large amount of refrigerant does not flow to the refrigerant heating device, so that the refrigerant heating device can be made compact and rationalized. Can do.

  According to a second invention, in the heat pump water heater of the first invention, when the air-refrigerant heat exchanger is defrosted, the number of rotations of the compressor is changed, and the first bypass circuit of the first bypass circuit is changed. 1 open the two-way valve to perform the first bypass circuit operation operation of passing the refrigerant through the air-refrigerant heat exchanger, and then open the two-way valve of the second bypass circuit after an arbitrary time, An operation is performed to perform a second bypass circuit operation in which the refrigerant heated by the refrigerant heating device flows to the suction side of the compressor.

  With this configuration, when the two-way valve of the first bypass circuit and the second bypass circuit is opened, the pressure on the suction side of the compressor rises rapidly, the refrigerant circulation amount increases, and a lot of compressor oil is discharged. At this time, the operation to open the two-way valve of the second bypass circuit is delayed for a certain period of time to operate, thereby suppressing the increase in the low pressure on the suction side of the compressor and compressing the oil by minimizing oil discharge. The reliability of the machine can also be increased, and a heat pump water heater excellent in durability can be obtained.

  A third invention is characterized in that, in the heat pump water heater of the first or second invention, the refrigerant heating device is a heater using a heating wire, the piping configuration can be simplified, and the durability is improved. It can be set as the heat pump water heater excellent in.

  According to a fourth aspect of the present invention, in the heat pump water heater of the first to third aspects, the hot water heated by the water-refrigerant heat exchanger is stored in a hot water storage tank, and without passing through the hot water storage tank. It is also characterized by being configured to allow direct water flow.

  With this configuration, the tap water heated by the water-refrigerant heat exchanger can supply hot water to the hot water storage tank and, on the other hand, directly passes through the hot water supply terminal such as a faucet or shower without passing through the hot water storage tank. Therefore, it is possible to provide a heat pump water heater that has excellent quick hot water properties, is easy to use, and does not worry about running out of hot water.

  In addition, it is possible to provide an instantaneous water pump type heat pump water heater in which hot water is supplied from a hot water storage tank at the beginning of operation and the compressor reaches the optimal operating frequency, and the hot water supply is excellent in usability. Can be a machine. At that time, by performing the defrosting operation while performing the hot water supply operation, even when the amount of remaining hot water in the hot water storage tank is reduced, the hot water supply operation can be continuously performed, and usability can be greatly improved.

  According to a fifth invention, in the heat pump water heater of the first to fourth inventions, hot water stored in the water-refrigerant heat exchanger connected to the heat pump refrigerant cycle and the water-refrigerant heat exchanger is stored as hot water. A hot water storage tank, a water supply pipe for supplying tap water, and a hot water supply cycle having a hot water supply pipe connected so as to pass heated hot water to a hot water supply terminal. is there.

  With this configuration, the refrigerant heating unit and the hot water storage tank can be brought close to each other, heat can be efficiently stored in the heat storage body while reducing heat loss, and energy saving can be improved.

  According to a sixth aspect of the present invention, in the heat pump water heater of any one of the first to fifth aspects of the present invention, carbon dioxide gas is used as a refrigerant. With this configuration, the thermal efficiency during high-temperature hot water supply is increased, and the refrigerant Even if it leaks to the outside, the effect on global warming can be greatly reduced compared to the R-410A refrigerant used in general air conditioners, and it is environmentally friendly and heat recyclable. It can be a water heater.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.
(Embodiment 1)
FIG. 1 is a circuit configuration diagram according to an embodiment of the present invention.

  As shown in FIG. 1, the heat pump water heater of the present embodiment accommodates a hot water supply cycle 3 including a refrigerant cycle 2 and a hot water storage tank 17 in a heat pump water heater main body unit 1 that is an integral housing.

  The refrigerant cycle 2 includes a compressor 4 disposed in the heat pump water heater main body unit 1, a radiator 5, a decompression means 6 including, for example, an electric expansion valve, and an air-refrigerant heat exchanger as a refrigerant evaporator. 7 is connected in a ring shape with a refrigerant pipe 8.

  In addition, a blower fan 9 is provided to apply air to the air-refrigerant heat exchanger 7 to increase the evaporation capability. And the 1st bypass circuit 11 which connects the piping 8a between the compressor 4 and the heat radiator 5, the decompression means 6, and the piping 8b of the air-refrigerant heat exchanger 7 is arranged. A first two-way valve 12 is provided in the middle of the first bypass circuit 11. Further, a second bypass circuit 13 is provided for connecting the pipe 8c between the compressor 4 and the air-refrigerant heat exchanger 7 and the pipe 8d between the radiator 5 and the decompression means 6, and this second bypass is provided. In the middle of the circuit 13, a refrigerant heating device 14 and a second two-way valve 15 are provided closer to the compressor 4. And the refrigerant | coolant heating apparatus 14 provides 13b which made the piping 13a of the 2nd bypass circuit 13 spiral, provided the aluminum casting which covers the outer periphery of the spiral 13b, and installed the heater 14a in the vicinity of the spiral 13b. The arrangement is arranged.

  On the other hand, the hot water supply cycle 3 is a water-refrigerant heat exchanger 16 that exchanges heat with the radiator 5 to change tap water or the like into hot water (for example, heat exchange with a double tube structure integrated with the radiator 5). ), A hot water storage tank 17 for storing hot water obtained by the water-refrigerant heat exchanger 16, a water inlet pipe 18 for introducing tap water into the hot water storage tank 17 and the water-refrigerant heat exchanger 16, and a hot water storage tank 17 and water. A hot water supply pipe 20 that supplies hot water from the refrigerant heat exchanger 16 to the hot water supply terminals of the faucet 19a and the shower 19b and a hot water supply circulating water pump 21 that supplies low-temperature water in the hot water storage tank 17 are configured. The tank inlet pipe 22 is a pipe that sends tap water from the inlet pipe 18 to the hot water storage tank 17. The tap water supply pipe 23 is a pipe that directly supplies tap water from the inlet pipe 18 to the radiator 5 (water-refrigerant heat exchanger 16).

  The heat exchange water supply pipe 24 is a pipe that sends low temperature water stored in the hot water storage tank 17 downward by the operation of the hot water supply circulating water pump 21 from the hot water storage tank 17 to the water-refrigerant heat exchanger 16. The hot water is stored in the hot water storage tank 17 and the original mixing valve 26, and a hot water storage three-way valve 27 is provided in the hot water storage tank side pipe 25a.

  The tank hot water supply pipe 28 is a pipe for supplying hot water (usually 60 ° C. to 90 ° C.) from the hot water storage tank 17 to the original mixing valve 26. The original mixing valve 26 is connected to the hot water storage pipe 25 (original mixing valve side pipe 25b). ) And the tank hot water pipe 28 are mixed with warm water or water. The hot water mixing valve 29 is a valve that mixes the hot water that has passed through the original mixing valve 26 and the tap water supplied from the inlet pipe 18 to obtain an appropriate hot water supply temperature and supplies it to the faucet 19a and the shower 19b. .

  Then, the hot water that has reached the optimum temperature in the hot water supply mixing valve 29 is supplied to the faucet 19a and the shower 19b through the hot water supply pipe 20.

  Similarly, the hot water that has passed through the original mixing valve 26 and the tap water supplied from the water inlet pipe 18 are mixed by the bath pouring mixing valve 30 to obtain an appropriate hot water supply temperature and pouring into the bath 31. The hot water that has reached the optimum temperature in the bath pouring mixing valve 30 passes through the bath pouring pipe 32, passes through the backflow prevention valve 32 a, is poured into the bath 31, and hot water is poured into the bath.

  When hot water flows from the bath pouring hot water mixing valve 30 to the bath 31, it passes through the bath heat exchanger 33. The bath heat exchanger 33 is a heat exchanger that is used when the hot water in the bath 31 is additionally prepared. The hot water is drawn from the bath by the bath circulating water pump 35 from the bath 31 through the bathtub outlet pipe 34a. Heat exchange between the hot water and hot water in the hot water storage tank 17 drawn from the hot water storage tank 17 by the additional pump 36 and returning to the bath through the bathtub hot water pipe 34b allows the temperature of the bath 31 to be kept constant. Even if the amount of hot water in the bath 31 is not increased, the additional cooking operation for raising the hot water temperature is performed. That is, the bath heat exchanger 33 is a water-water heat exchanger.

  The incoming water flow meter 37 is an instrument that measures the incoming water flow rate, and the hot water supply flow meter 38 is an instrument that measures the hot water flow rate. The discharge valve 39 is a valve used for draining water in the tank to prevent freezing or the like when it is not used for a long time in a cold region or the like, 40a is a pressure relief valve for the hot water storage tank 17, and 40b is a hot water storage tank 17. It is a can body protection valve.

  Hereinafter, the operation of the heat pump water heater will be described based on the drawings.

  When starting normal operation, the first two-way valve 12 of the first bypass circuit 11 and the second two-way valve 15 of the second bypass circuit 13 are closed. The compressor 4 is activated and the refrigerant compressed and discharged to a high pressure is sent to the radiator 5 (water-refrigerant heat exchanger 16) to exchange heat with tap water that has passed through the tap water supply pipe 23. Dissipate heat. Thereby, the tap water flowing through the hot water storage pipe 25 and the original mixing valve 26 is heated to a high temperature.

  The refrigerant flowing out of the radiator 5 (water-refrigerant heat exchanger 16) is decompressed and expanded by the decompression means 6, sent to the air-refrigerant heat exchanger 7, and exchanges heat with the air sent by the blower fan 9. Then, it evaporates and gasifies while passing through the air-refrigerant heat exchanger 7. The gasified refrigerant is again sucked into the compressor 4 and is repeatedly compressed. The gradually heated tap water passes through the original mixing valve side pipe 25b and the original mixing valve 26, and is connected to the faucet 19a and the shower. Hot water is supplied to 19b or poured into the bath 31.

  At that time, the rising of the refrigerant cycle 2 is slow and inferior in the hot water property, so the hot water storage tank 17 compensates for the poor rising. That is, until the refrigerant cycle 2 starts up and reaches a predetermined hot water supply temperature, the hot water that has passed through the tank hot water supply pipe 25 from the hot water storage tank 17 kept at a high temperature and the water-refrigerant heat that has not yet started up. Water that has passed through the exchanger 16 (water that gradually rises in temperature and becomes hot) was mixed by the original mixing valve 26 and further passed through the water inlet pipe 18 by the hot water supply mixing valve 29 and the bath pouring mixing valve 30. Mixing with tap water, hot water supply or pouring is performed at a predetermined temperature.

  Next, when the refrigerant cycle starts, the opening degree of the original mixing valve 26 is adjusted, hot hot water from the hot water storage tank 17 and hot water from the water-refrigerant heat exchanger 16 are mixed at an appropriate temperature, and a hot water supply mixing valve 29 and the bath pouring mixing valve 30, and the hot water mixing valve 29 and the bath pouring mixing valve 30 are mixed with tap water that has passed through the inlet pipe 18 to supply hot water.

  Finally, the opening of the original mixing valve 26 is adjusted, the tank hot water supply pipe 25 side is closed, and the hot water passing through the tank hot water supply pipe 25 from the hot water storage tank 17 is not used. Hot water obtained by heating the tap water passing through the pipe 23 with the water-refrigerant heat exchanger 16 of the refrigerant cycle 2 is sent to the hot water supply mixing valve 29 and the bath pouring mixing valve 30 through the original mixing valve 26. Then, it is mixed with tap water that has passed through the water inlet pipe 18 to obtain a predetermined temperature, and hot water is supplied to the faucet 19a and the shower 19b and poured into the bath 31.

  That is, the controller 41 of the refrigerant cycle 2 and the controller 42 of the hot water supply cycle grasp the rising state of the refrigerant cycle 2 and adjust the opening degree of the original mixing valve 26, the hot water mixing valve 29, and the bath pouring mixing valve 30. Control for supplying hot water at a predetermined temperature to the hot water supply terminal is performed.

  Further, when the user closes the faucet 19a and the shower 19b, or when it is not necessary to supply hot water because an appropriate amount of hot water is accumulated in the bath 31, the hot water circulating water pump 21 is driven and the hot water storage three-way valve 27 is opened. For the hot water supply operation, a hot water storage operation in which hot water is stored in the hot water storage tank 17 is performed.

  In this way, depending on the rising state of the refrigerant cycle 2, hot water stored in the hot water storage tank 17 is used to supply hot water to the hot water supply terminal (faucet 19 a, shower 19 b, bath 31), without using the hot water storage tank 17. The hot water obtained by heating with the water-refrigerant heat exchanger 16 can be directly supplied to the hot water supply terminal.

  Thereby, in this Embodiment, real-time hot water supply is enabled, the hot water hot water performance which can supply hot water when a user wants to supply hot water can be ensured, and a heat pump water heater which is easy to use can be provided. In other words, by ensuring this quick hot water performance, the capacity of the hot water storage tank 17 can be made smaller than that of the hot water storage type heat pump water heater, which in turn leads to the compactness of the main unit 1 and installation characteristics. It is possible to realize a significant improvement in cost, cost reduction, and improvement in usability.

  Further, even when the amount of remaining hot water in the hot water storage tank is reduced, the hot water heated by the water-refrigerant heat exchanger 16 is directly supplied to the hot water supply terminal without passing through the hot water storage tank 17. However, at that time, when the air-refrigerant heat exchanger 7 is frosted, heat is not exchanged, so that hot water is not supplied. Therefore, in this case, the operation of the first two-way valve, the second two-way valve, the refrigerant heating device, etc. is performed according to the time chart as shown in FIG.

  When it is determined that defrosting is started by the defrosting start determining means by the temperature sensors 7c and 7d and the control device 41 disposed in the pipe 7a connected to the air-refrigerant heat exchanger 7, in step 1, The first two-way valve 12 in the first bypass circuit 11 is energized, and the first two-way valve 12 is opened. In accordance with this, the decompression means 6 composed of the electric expansion valve is closed to the closed state or almost closed, and the rotation speed of the compressor 4 is gradually decreased.

  Next, when the rotational speed of the compressor 4 is lowered to a predetermined rotational speed in Step 2, the second two-way valve 15 of the second bypass circuit 13 is opened and the heater 14a of the refrigerant heating device 14 is energized. At the same time, the blower fan 9 is further stopped. The reason why the heater 14a of the refrigerant heating device 14 is energized after the rotation speed of the compressor 4 is lowered is to prevent the current capacity from being increased by the refrigerant heating device 14 and the breaker from falling, or in anticipation thereof. This is to eliminate the need to set the current capacity higher.

  In Step 3, the refrigerant heating operation is performed, and at the same time, the defrosting operation is performed. In the refrigerant heating operation, the refrigerant heated by the heater 14a of the refrigerant heating device 14 is sent to the compressor 4 via the pipe 8c, and the compressor 4 performs the refrigerant conveyance operation. Thereby, the refrigerant heated by the refrigerant heating device is sent to the radiator 5, sent to the refrigerant heating device 14 via the second two-way valve 15, and heated again.

  In the radiator 5, hot water obtained by heating the tap water that has passed through the inlet pipe 18 with the water-refrigerant heat exchanger 16 of the refrigerant cycle 2 is supplied via the original mixing valve 26 to the hot water supply mixing valve 29 and the bath injection. It is sent to the hot water mixing valve 30 and mixed with the tap water that has passed through the water inlet pipe 18 to obtain a predetermined temperature, and hot water is supplied to the faucet 19a and the shower 19b, and hot water is poured into the bath 31.

  However, since the refrigerant heating device 14 heats the refrigerant with the heater 14a and exchanges heat with the radiator 5, the temperature at which the molten metal is poured tends to decrease slightly, but it is used more sufficiently than it stops. It will be possible to use it with excellent properties. In the defrosting operation, the high-temperature refrigerant sent from the compressor 4 passes through the first bypass circuit 11 through the pipe 8a, passes through the first two-way valve 12, passes through the pipe 8b, and air- It is sent to the refrigerant heat exchanger 7 and the air-refrigerant heat exchanger 7 is defrosted. In the pipe 8b, there is a throttle pipe 8e between the first bypass circuit 11 and the air-refrigerant heat exchanger 7, which stabilizes the operability of the electric expansion valve 6 that is a pressure reducing device.

  In step 4, as soon as the defrosting is completed, the heater 14a is turned off in the refrigerant heating device 14, the second two-way valve 15 is also closed, and the compressor 4 is gradually returned to a predetermined rotational speed, which is a pressure reducing device. The electric expansion valve 6 is gradually opened to a predetermined opening, and the blower fan 9 is also rotated at a predetermined rotational speed.

  In step 5, the first two-way valve 12 is closed and the state before the defrosting is restored, the normal heat pump operation is performed, and hot water is stored.

  Thus, even when the amount of remaining hot water in the hot water storage tank 17 is considerably reduced, the defrosting operation can be performed while continuing the hot water supply operation, so that the usability can be greatly improved.

  Moreover, since the opportunity to use the hot water storage tank 17 is reduced, it is possible to make the hot water storage tank 17 compact and, in turn, to make the housing compact, and a heat pump water heater that greatly improves installation characteristics. It can be.

  Further, as shown in the time chart of FIG. 2, when defrosting the air-refrigerant heat exchanger 7, the first two-way valve of the first bypass circuit 11 is made while changing the rotation speed of the compressor 4. 12 is opened, the first bypass circuit operation operation is performed to allow the refrigerant to pass through the air-refrigerant heat exchanger 7, and then, after an arbitrary time, the second two-way valve 15 of the second bypass circuit 13 is opened, The two-way valve of the first bypass circuit 11 and the second bypass circuit 13 is simultaneously opened by performing the second bypass circuit operation in which the refrigerant heated by the refrigerant heating device 14 flows to the suction side of the compressor 4. Then, the pressure on the suction side of the compressor 4 suddenly increases, the refrigerant circulation amount increases, and a large amount of oil is discharged from the compressor 4, but the operation of opening the two-way valve of the second bypass circuit 13 is performed for a certain period of time. By delaying and operating, the suction side of the compressor 4 Suppressing the pressure rise, the oil discharge can also increase the reliability of the compressor by minimizing, can also be a good heat pump water heater durability.

  Furthermore, since the refrigerant heating device 14 is a heater 14a using a heating wire, ON-OFF energization is easy, the piping configuration can be simplified, and a heat pump water heater excellent in durability can be obtained.

  FIG. 3 is a perspective internal view of the main unit 1, and the refrigerant heating device 14 is arranged below the main unit 1 adjacent to the radiator 5 (water-refrigerant heat exchanger 16). This is because the coolant heating device 14 is provided with an aluminum casting that covers the outer periphery of 13b in which the pipe 13a is formed in a spiral shape.

  Further, in this heat pump water heater, since carbon dioxide is used as a refrigerant, even if the refrigerant leaks to the outside, the influence on global warming is affected by the refrigerant of R-410A used in general air conditioners. As compared with the above, it can be greatly reduced, and an environment-friendly heat pump water heater can be obtained.

  As described above, in the heat pump water heater of the present invention, the compressor 4, the radiator 5, the decompression means 6, and the air-refrigerant heat exchanger 7 are sequentially connected to form a closed circuit and circulate the refrigerant. 1st bypass which connects between a cycle, the water-refrigerant heat exchanger 16 which heat-exchanges with the heat radiator 5, the compressor 4 and the heat radiator 5, and the decompression means 6 and the air-refrigerant heat exchanger 7 A circuit 11, a second bypass circuit 13 that connects between the decompression means 6 and the radiator 5, and between the compressor 4 and the air-refrigerant heat exchanger 7, and arranges them in an integral housing 1, The first bypass circuit is provided with a first two-way valve 12, and the second bypass circuit is provided with a second two-way valve 15 and a refrigerant heating device 14 heated by a heater 14a in series, and the air-refrigerant heat exchanger 7 is provided. When the defrosting is performed, the first two-way valve 12 of the first bypass circuit 11 is opened. The air-refrigerant heat exchanger 7 is made to operate in a first bypass circuit that allows the refrigerant to pass through. Then, the second two-way valve 15 of the second bypass circuit 13 is opened, and the refrigerant heated by the refrigerant heating device 14 is removed. The second bypass circuit operation that flows to the suction side of the compressor 4 is performed, and the defrosting operation can be performed while the hot water supply operation is performed, so that the usability is excellent and the hot water storage tank is further downsized. It becomes possible, and it can be set as the heat pump water heater excellent also in compactness.

  As described above, the present invention is applied to a heat pump water heater that generates hot water in a heat pump cycle and supplies hot water, and is suitable for, for example, a domestic instantaneous water heater or a commercial hot water supply device.

The circuit block diagram of the heat pump water heater in the 1st Embodiment of this invention Time chart of the heat pump water heater A perspective view of the heat pump water heater Circuit diagram of a conventional heat pump water heater Other circuit configuration diagram of conventional heat pump water heater

Explanation of symbols

1 Main unit (housing)
2 Refrigerant cycle 3 Hot water supply cycle 4 Compressor 5 Radiator 6 Pressure reducing means (electric expansion valve)
7 Air-refrigerant heat exchanger 9 Blower fan 11 First bypass circuit 12 First two-way valve 13 Second bypass circuit 14 Refrigerant heating device 14a Heater 15 Second two-way valve 16 Water-refrigerant heat exchanger 17 Hot water storage tank 18 Water pipe 19a faucet (hot water supply terminal)
19b Shower (hot water supply terminal)

Claims (6)

A compressor, a radiator, a decompression means, and an air-refrigerant heat exchanger are connected in sequence to form a closed circuit, and a heat-pump refrigerant cycle that circulates the refrigerant, and a water-refrigerant heat exchanger that exchanges heat with the radiator A first bypass circuit connecting between the compressor and the radiator, between the decompression means and the air-refrigerant heat exchanger, between the decompression means and the radiator, and the compressor A second bypass circuit connecting between the air-refrigerant heat exchanger is provided, the first bypass circuit is provided with a first two-way valve, and the second bypass circuit is provided with a second two-way valve and refrigerant heating. A heat pump water heater characterized in that devices are provided in series. When performing defrosting of the air-refrigerant heat exchanger, the first two-way valve of the first bypass circuit is opened and the air-refrigerant heat exchanger is changed while changing the rotation speed of the compressor. The first bypass circuit operation for allowing the refrigerant to pass is performed, and then, after an arbitrary time, the two-way valve of the second bypass circuit is opened, and the refrigerant heated by the refrigerant heating device is brought to the suction side of the compressor. 2. The heat pump water heater according to claim 1, wherein the second bypass circuit operation is performed. The heat pump water heater according to claim 1 or 2, wherein a heater is used as the refrigerant heating device. The hot water heated by the water-refrigerant heat exchanger is stored in a hot water storage tank, and also has a configuration capable of directly passing water to a hot water supply terminal without going through the hot water storage tank. The heat pump water heater according to any one of the above. The heat pump refrigerant cycle, the water-refrigerant heat exchanger connected to the hot water storage tank for storing hot water heated by the water-refrigerant heat exchanger, a water inlet pipe for supplying tap water, and heated The heat pump water heater according to any one of claims 1 to 4, wherein a hot water supply cycle including a hot water supply pipe connected so as to pass hot water to a hot water supply terminal is housed in an integrated housing. The heat pump water heater according to any one of claims 1 to 5, wherein carbon dioxide gas is used as the refrigerant.

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