JP5056083B2 - Heat pump water heater - Google Patents

Description

The present invention relates to a hot water storage type heat pump water heater having a bath reheating function and a heating function.

Conventionally, as this type of water heater, there is one having a reheating function of a bathtub using hot water of a hot water tank.

  FIG. 3 shows a conventional water heater. As shown in the figure, this water heater includes a compressor 51, a heat pump unit 54 having a hot water supply heat exchanger 52 and an evaporator 53, which are refrigerant-to-water heat exchangers, a hot water tank 55, and water-to-water heat exchange. And a hot water supply unit 57 provided with a bath heat exchanger 56 and the like. The hot water storage tank 55 stores hot water heated by the heat pump unit 54 using a hot water supply heat exchanger 52.

  The bath heat exchanger 56 circulates the hot water in the hot water storage tank 55 to heat the hot water in the bathtub 58. That is, the hot water pumped out from the upper part of the hot water storage tank 55 by the heat source side circulation pump 59 is guided to the bath heat exchanger 56 to heat the hot water or water in the bathtub 58 pumped out by the use side circulation pump 60. After that, it returns to the hot water tank 55.

Further, the hot water in the hot water storage tank 55 is poured into the bathtub 58 through the bathtub pouring pipe 61 and further configured to be able to supply hot water by opening the faucet 62 (see, for example, Patent Document 1).
JP 2002-243275 A

  However, the conventional configuration has the following problems.

  In many cases, the bath temperature is about 40 ° C., so that the bath is pumped from the upper part of the hot water tank 55 by the heat source side circulation pump 59 and led to the bath heat exchanger 56. The temperature when returning to the hot water tank 55 after heating the hot water in the bathtub 58 pumped out by the use side circulation pump 60 is around 50 ° C.

  The hot water returned to the hot water storage tank 55 is mixed with the hot water in the hot water storage tank 55, but the temperature of the mixed hot water differs depending on the hot water temperature at the return position of the hot water storage tank 55. In general, in the case of a heat storage type heat pump water heater, the entire hot water storage tank 55 is heated to a set temperature in the late-night time period (for example, from 23:00 to 7:00 of the next morning), which is a time period when electricity charges are low.

At this time, the low temperature water sent from the lower part of the hot water storage tank 55 is heated by the hot water supply heat exchanger 52 to become high temperature water, and is stored from above the hot water storage tank 55. The boundary between the hot water stored in the hot water and the original low-temperature water is not divided as a clear temperature layer, but there is a mixed layer that changes from high temperature to low temperature.

  For this reason, when the boiling operation for boiling the entire hot water storage tank 55 to the set temperature approaches the completion of the boiling, the mixed layer is heated. In this case, the characteristics of the heat pump vary greatly depending on the inlet water temperature of the hot water supply heat exchanger 52. In other words, the higher the inlet water temperature, the higher the discharge pressure of the compressor 51. Accordingly, the operating efficiency deteriorates and the amount of power consumed increases.

  Further, since the discharge pressure rapidly increases when the inlet water temperature becomes high, the boiling operation is terminated when the inlet water temperature reaches a predetermined temperature in order to ensure the reliability of the compressor 51. For example, since the hot water supply load is large in winter, the hot water storage tank 55 is boiled up to 80 ° C. to 90 ° C., but if the inlet temperature of the hot water supply heat exchanger 52 reaches 60 ° C., the operation is stopped because the whole amount has boiled up. And the hot water stored in the middle of the night covers the daytime hot water supply load.

  If the hot water returned to the hot water tank 5 after heating the hot water in the bathtub 58 and the hot water in the hot water tank 55 are mixed, the temperature of the hot water is not less than the predetermined temperature (for example, 60 ° C.). The hot water will not be boiled up again. Therefore, the part of the mixed layer produced by the heating of the bathtub 58 is set so that the temperature of the entire hot water tank 55 is heated to the set temperature (about 80 ° C. to 90 ° C. in winter) in the middle of the night. There is a case where the boiling is completed as it is without being heated to the heated temperature.

  As described above, when almost the entire hot water storage tank 55 is not heated to a high temperature, it cannot cope with the hot water supply load in the daytime, and there is a problem in comfort and convenience due to running out of hot water.

  On the other hand, if the temperature of the hot water returned to the hot water tank 55 after heating the hot water in the bathtub 58 and the hot water mixed with the hot water of the hot water tank 55 is equal to or lower than the predetermined temperature (for example, 60 ° C.). The hot water is again boiled to a high temperature.

  However, since the temperature of the water sent from the bathtub 58 and returning to the hot water tank 55 is originally high, it is mixed with the hot water in the hot water tank 58 and the temperature of the hot water tank 55 is raised, which is 60 ° C. or lower. However, there may be a relatively high temperature. In this case, as described above, there is a problem that the efficiency of the boiling operation is extremely deteriorated.

  The present invention solves the above problems, and when there is a hot water supply request and a bath heating request at the same time, a part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is not returned to the lower part of the hot water tank. It is an object of the present invention to provide a heat pump water heater that is used for direct hot water supply to improve the comfort and convenience by reducing the possibility of running out of hot water and to improve the operation efficiency.

In order to solve the above problems, the heat pump water heater of the present invention, compressors, hot water storage means for connecting the hot water heating means comprises a hot water supply heat exchanger, the lower part and the upper part of the hot water storage tank through the hot water supply heat exchanger And a hot water pipe connected to the upper part of the hot water tank, a water supply pipe connected to the lower part of the hot water tank, and an upper part for providing a bath heat exchanger and connecting the upper and lower parts of the hot water tank respectively. A bath heating means comprising a connecting pipe and a lower connecting pipe and using the hot water in the upper part of the hot water tank as a heat source to control hot water in the bathtub through the bath heat exchanger, and controlling the heat source flow rate circulating through the bath heating means A flow rate control means, a bypass pipe branched from the middle of the lower connecting pipe, a bypass mixing valve for mixing hot water from the tapping pipe and the bypass pipe, and hot water and water supply pipe mixed by the bypass mixing valve Mix with water A hot water supply mixing valve, the temperature of the heat source-side outlet of the bath heat exchanger
A heat source side outlet temperature detection means for detecting and a hot water supply temperature setting means for setting a hot water supply temperature, and when there is a hot water supply request and a bath heating request at the same time, from the upper part of the hot water tank radiated by the bath heat exchanger A part or all of the hot water is directly used for hot water supply, and the target mixing temperature of the bypass mixing valve is set higher than the heat source side outlet temperature of the bath heat exchanger .

With this configuration, the present invention reduces mixing of hot water in the hot water tank with medium-temperature water after heating the bathtub, thereby reducing hot water shortage and improving comfort and convenience and driving efficiency. be able to. In addition, with this configuration, the present invention can provide a stable hot water supply temperature, so that comfort and convenience can be improved, and driving efficiency can be improved.

  The heat pump water heater of the present invention connects an upper part and a lower part of a hot water tank, which is a heat source, to heat water from a bathtub, respectively, to an inlet and an outlet of a bath heat exchanger, and an outlet of the bath heat exchanger. By providing a bypass pipe in the middle of the connection pipe connected to the lower part of the hot water tank, and by connecting the bypass pipe to the hot water pipe via a mixing valve, there was a request for hot water supply and a bath heating request at the same time. In this case, part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger can be used directly for hot water supply without returning it to the lower part of the hot water tank, reducing the possibility of running out of hot water and improving comfort and convenience. Improvement can be achieved and driving efficiency can be improved.

The present invention can be implemented in the form described in each claim, and the first invention includes a hot water heating means provided with a compressor and a hot water heat exchanger, a lower part of the hot water tank via the hot water heat exchanger, Hot water storage means for connecting the upper part, a hot water pipe connected to the upper part of the hot water tank, a water supply pipe connected to the lower part of the hot water tank, and an upper and lower parts of the hot water tank provided with a bath heat exchanger in the middle A bath heating means for heating the hot water in the bathtub through the bath heat exchanger using the hot water in the upper part of the hot water storage tank as a heat source, and the bath heating means, Mixing with a flow rate control means for controlling the circulating heat source flow rate, a bypass pipe branched from the middle of the lower connecting pipe, a bypass mixing valve for mixing hot water from the tapping pipe and the bypass pipe, and the bypass mixing valve Hot water and water from the water supply pipe A hot water supply mixing valve for mixing, and the heat source-side outlet temperature detecting means for detecting the temperature of the heat source-side outlet of the bath heat exchanger, and a hot water supply temperature setting means for setting a hot water temperature, the hot water demand and a bath heating demand When the hot water from the upper part of the hot water storage tank radiated by the bath heat exchanger is directly used for hot water supply, the target mixing temperature of the bypass mixing valve is set to the value of the bath heat exchanger. It is set higher than the heat source side outlet temperature .

  With this configuration, the present invention reduces mixing of hot water in the hot water tank with medium-temperature water after heating the bathtub, thereby reducing hot water shortage and improving comfort and convenience and driving efficiency. be able to.

In addition, with this configuration, the present invention can provide a stable hot water supply temperature, so that comfort and convenience can be improved, and driving efficiency can be improved.

  Moreover, this invention is set as the structure which used the heat source side circulation pump and flow control valve which were provided in the heat source side of the bath heat exchanger as a flow control means.

  With this configuration, the present invention enables stable bath heating even when the hot water flow rate or the hot water temperature fluctuates greatly when part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is directly used for hot water supply. As a result, comfort and convenience can be improved.

Moreover, this invention is set as the structure provided with the non-return valve which flows in the direction of the said hot water storage tank in the middle of the lower connection pipe of the hot water storage tank side rather than the branch position of the lower connection pipe which branched the bypass pipe.

With this configuration, the present invention prevents the inflow of hot water from the lower part of the hot water tank when part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is directly used for hot water supply. Since a stable bath heating capability can be ensured without reducing the heat source flow rate from the upper part of the hot water storage tank that radiates heat, it is possible to improve comfort and convenience .

In the present invention, the target mixing temperature of the bypass mixing valve is a predetermined temperature higher than the higher one of the hot water supply set temperature set by the hot water supply temperature setting means and the heat source side outlet temperature of the bath heat exchanger. Only a high temperature is set.

  With this configuration, the present invention can obtain a stable hot water supply temperature, so that it is possible to improve comfort and convenience and improve driving efficiency.

  Furthermore, this invention is set as the structure which raises the target mixing temperature of a bypass mixing valve, when the temperature heated to a bath heat exchanger and returning to a bathtub becomes more than predetermined temperature.

  By this structure, since this invention reduces the heat source side flow volume of a bath heat exchanger, since it can prevent a hot water returning to a bathtub, the improvement of a comfort improvement can be aimed at.

  In the present invention, since the refrigerant used in the heat pump is carbon dioxide, it is possible to achieve high temperature and high efficiency and preservation of the global environment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.
(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump water heater in the first embodiment of the present invention. In FIG. 1, hot water heating means 13 that is a heat source of a hot water heater is a heat pump heat source that constitutes a heat pump cycle including a compressor 1, a hot water supply heat exchanger 2, a decompression device 14, and an evaporator 3 that absorbs atmospheric heat.

  Then, carbon dioxide whose refrigerant pressure on the high pressure side is equal to or higher than the critical pressure is used as the refrigerant. Water is supplied to the hot water tank 5 through a water supply pipe 15 connected to the lower part of the hot water tank 5, and hot water at the upper part of the hot water tank 5 passes through the hot water pipe 16 and is mixed with the hot water at a hot water mixing valve 17. Hot water is supplied from the terminal (faucet 12) through the hot water supply pipe 18 after the temperature is changed to hot water.

  Further, by forming a boiling circuit that sequentially connects the lower part of the hot water tank 5 to the circulation pump 19, the hot water supply heat exchanger 2, and the upper part of the hot water tank 5, the water sent from the hot water tank 5 by the circulation pump 19 is Hot water is stored in the hot water storage tank 5 by being heated by the refrigerant heat in the hot water supply heat exchanger 2.

  A boiling temperature detecting means 20 is provided at the water-side outlet of the hot water supply heat exchanger 2 in order to detect the temperature of the hot water heated by the heat pump heat source.

  The bath heating means 21 includes a bath heat exchanger 6 that is a water / water heat exchanger, a heat source side and a use side water circuit connected thereto, and a heat source side circulation pump 9 and a use side circulation respectively provided in the water circuits. It consists of a pump 10 and the like. The heat source side of the bath heat exchanger 6 is connected to the upper part of the hot water storage tank by the upper connection pipe 22 and is connected to the lower part of the hot water storage tank by the lower connection pipe 23.

Heating of the bathtub 8 is sent from the hot water tank 5 to the bath heat exchanger 6 by the heat source side circulation pump 9 and from the bathtub 8 to the bath heat exchanger 6 by the use side circulation pump 10. This is done by exchanging heat with warm water or hot water.

  The bypass pipe 24 branched from the middle of the lower connection pipe 23 is connected to a bypass mixing valve 25 provided in the middle of the hot water pipe 16.

  Further, the pump control means 26 controls the rotational speed of the heat source side circulation pump 9. Further, the heat source side outlet temperature detecting means 27 for detecting the heat source side outlet temperature is provided at the heat source side outlet of the bath heat exchanger 6, and the use side inlet temperature detection for detecting the respective water temperatures at the inlet and outlet on the use side. Means 28 and utilization side outlet temperature detection means 29 are provided.

  Here, the flow rate control means 30 is formed by the pump control means 26, the heat source side circulation pump 9, the use side inlet temperature detection means 28 and the heat source side outlet temperature detection means 27, and this flow rate control means is a heat source in the bath heating means 21. Control the heating capacity in the bath heat exchanger by controlling the side flow rate.

  Further, a hot water supply temperature detecting means 31 for detecting the temperature of hot water mixed by the mixing valve is provided on the outlet side of the hot water supply mixing valve 17, and the temperature of hot water mixed by the mixing valve is detected on the outlet side of the bypass mixing valve 25. Bypass temperature detection means 32 is provided. Further, a hot water supply temperature setting means 33 for setting a desired hot water supply temperature by a remote controller (not shown) and a bypass mixing valve control means 34 for controlling the operation of the bypass mixing valve 25 are provided.

  About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In FIG. 1, first, the hot water supply heating mode will be described.

  If there is a request (not shown) for boiling the hot water storage tank 5, a hot water supply heating operation using atmospheric heat is performed with a heat pump heat source. In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 1 is heated to a hot water supply heat exchanger 2 where heat is exchanged with the water sent from the lower part of the hot water tank 5 to dissipate the heat. The pressure is reduced by the apparatus 14, and heat is absorbed from the atmosphere by the evaporator 3, gasified, and returned to the compressor 1. At this time, the number of revolutions of the circulation pump 19 is controlled so that the outlet water temperature of the hot water supply heat exchanger 2 becomes a predetermined temperature with the high-temperature refrigerant flowing into the hot water supply heat exchanger 2, and hot water of a predetermined temperature is It flows in from and is stored.

  Next, the normal single hot water supply mode will be described. When the faucet 12 serving as a hot water supply terminal is opened, the bypass mixing valve control means 34 fully opens the bypass mixing valve 25 to the hot water storage tank 5 side (usually, this position is the initial setting position).

  The opening of the hot water mixing valve 17 is based on the temperature obtained from the hot water temperature detecting means 31 so that the outlet (mixing) temperature of the hot water mixing valve 17 becomes the hot water temperature setting temperature set by the hot water temperature setting means 33. By controlling the above, hot water having a predetermined hot water temperature is supplied from the tap 12.

  Next, the normal single bath heating mode will be described.

  Now, when there is a bath heating request (not shown), the flow rate control means 30 drives the use side circulation pump 10 and the heat source side circulation pump 9. And the water sent from the bathtub 8 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 5 sent by the heat source side circulation pump 9 in the bath heat exchanger 6. Return to bathtub 8.

The hot water sent from the hot water storage tank 5 by the heat source side circulation pump 9 exchanges heat with the hot water in the bathtub 8 sent by the use side circulation pump 10 and the hot water stored in the bath heat exchanger 6. Return to the bottom of the tank 5. At this time, the flow rate control means 30 controls the flow rate of the heat source side circulation pump 9 in order to efficiently heat the bath with the necessary capacity.

  For example, the flow rate of hot water on the heat source side is controlled according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6. That is, the flow rate control means 30 detects the heat source side outlet temperature and the use side inlet temperature of the bath heat exchanger 6 obtained from the heat source side outlet temperature detection means 27 and the use side inlet temperature detection means 28, and both of them. The rotational speed of the heat source side circulation pump 9 is controlled so that the temperature difference becomes a predetermined temperature (for example, 5K). By controlling in this way, even if the temperature of the bathtub 8 changes, the return temperature to the hot water tank 5 can be made relatively low, and the bath heating ability can be made relatively large.

  Next, the simultaneous hot water bath heating mode when there is a hot water request and a bath heating request will be described. In this case, the control of the hot water supply mixing valve 17 is the same as that in the single hot water supply mode. Further, the flow rate control means 30 controls the flow rate of the heat source side circulation pump 9 as in the case of the single bath heating mode. That is, the flow rate of hot water on the heat source side is controlled according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6.

  Further, the bypass mixing valve control means 34 is based on the temperature obtained from the bypass temperature detection means 32 so that the target mixing temperature is set higher than the hot water supply set temperature set by the hot water supply temperature setting means 33. The opening of the bypass mixing valve 25 is controlled.

  At this time, the hot water in the upper part of the hot water tank 5 whose flow rate is controlled by the heat source side circulation pump 9 radiates heat in the bath heat exchanger 6, and then a part or all of the high temperature hot water passes through the bypass pipe 24 and the low temperature of the bypass mixing valve 25. The hot water in the upper part of the hot water tank 5 supplied from the high temperature side inlet of the bypass mixing valve 25 is mixed with the high temperature hot water supplied from the high temperature side inlet of the bypass mixing valve 25 to reach the predetermined bypass mixing temperature and enters the high temperature side inlet of the hot water mixing valve 17. Furthermore, it is controlled to the hot water supply set temperature by mixing with the water supplied from the water supply pipe 15 supplied from the low temperature side inlet of the hot water supply mixing valve 17, and goes out from the faucet 12.

  The remaining hot water that does not pass through the bypass pipe 24 returns to the lower part of the hot water storage tank 5. In the case of the conventional example shown in FIG. 3, all the hot water in the hot water tank used for heating the bath returns to the hot water tank 5 and is mixed with the hot water in the hot water tank 5 and finally boiled again to a high temperature. However, in the embodiment of the present invention, part or all of the hot water in the hot water tank used for heating the bath is directly used for hot water supply, and therefore, all the amount of heat given to the hot water is used up. To improve.

  In addition, since less hot water returns to the hot water tank 5, it is less likely to reduce the temperature of the hot water by mixing with the hot water of the hot water tank 5 or water, or to raise the temperature of the water. Issues such as lowering the efficiency of raising are also reduced.

  In the above description, the bypass mixing valve control unit 34 sets the temperature obtained from the bypass temperature detection unit 32 so that the target mixing temperature is set higher than the hot water supply set temperature set by the hot water supply temperature setting unit 33. Although the opening degree of the bypass mixing valve 25 is originally controlled, it is more preferable to determine from the hot water supply set temperature set by the hot water supply temperature setting means 33 and the temperature of the heat source side outlet of the bath heat exchanger 6. The hot water of the hot water tank used for heating can be used effectively.

  That is, when the target mixing temperature is lower than the heat source side outlet temperature of the bath heat exchanger 6, the opening degree of the bypass mixing valve 25 is fully opened in the direction of the low temperature side inlet. At this time, depending on the hot water supply flow rate, there is a possibility that the heat source side flow rate control of the bath heat exchanger 6 cannot be performed, so the target mixing temperature of the bypass mixing valve 25 is higher than the heat source side outlet temperature of the bath heat exchanger 6. Must be set.

  Further, since the hot water mixed by the bypass mixing valve 25 enters the high temperature side inlet of the hot water supply mixing valve 17, the target mixing temperature of the bypass mixing valve 25 is higher than the hot water supply set temperature set by the hot water supply temperature setting means 33. There is a need to. Eventually, the target mixing temperature of the bypass mixing valve 25 is higher by a predetermined temperature than the higher one of the hot water supply set temperature set by the hot water supply temperature setting means 33 and the heat source side outlet temperature of the bath heat exchanger 6. What is necessary is just to set to temperature.

  In addition, when bath heating is performed in the simultaneous hot water bath heating mode, the bathtub temperature rises, the temperature of the hot water returning to the bathtub increases, and the person taking the bath may become uncomfortable. This is a case where the heat source side flow rate of the bath heat exchanger 6 is large and the capacity is excessive.

  In this case, it is necessary to lower the heat source side flow rate of the bath heat exchanger 6. Therefore, when the use-side outlet temperature detection means 29 becomes a predetermined temperature (for example, 60 ° C.) or higher, the bypass mixing valve control means 34 controls to increase the target mixing temperature of the bypass mixing valve 25.

  In this way, the opening of the bypass mixing valve 25 opens in the direction of the high temperature side inlet, and conversely, the low temperature side inlet closes. Since the temperature of returning hot water is lowered and hot water can be prevented from returning to the bathtub, the comfort can be improved.

  In addition, since the refrigerant used in the heat pump is carbon dioxide, hot water having a high temperature (approximately 90 ° C.) can be stored in the hot water tank 5, so that hot water can be prevented and high efficiency can be achieved. The global environment can be protected.

In addition, in the said description, it was set as the structure heated by the hot water of the hot water storage tank 5, However, It is applicable not only to bath heating but uses, such as heating using the heat of the hot water storage tank 5, and a bathroom heating dryer.
(Embodiment 2)
FIG. 2 is a configuration diagram of a heat pump water heater in the second embodiment of the present invention. 2 is different from the first embodiment shown in FIG. 1 in that a flow rate control valve 35 is provided in the middle of the bypass pipe 24, and the lower connecting pipe on the hot water tank side with respect to the branching position of the lower connecting pipe branched from the bypass pipe. Is provided with a check valve 36 that flows in the direction of the hot water tank.

  Here, the pump control means 26, the heat source side circulation pump 9, the use side inlet temperature detection means 28, the heat source side outlet temperature detection means 27, and the flow rate control valve 35 form a flow rate control means 30. The heating capacity in the bath heat exchanger is controlled by controlling the heat source side flow rate in the bath heating means 21.

  About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. The hot water supply heating mode, the single hot water supply mode, and the single bath heating mode are the same as those in the first embodiment shown in FIG. explain. In this case, the control of the hot water supply mixing valve 17 is the same as that in the single hot water supply mode. Further, the flow control means 30 first sets the flow control valve 35 to the initial opening.

  Then, the flow rate of the heat source side circulation pump 9 is controlled. That is, the flow rate of hot water on the heat source side is controlled according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6.

  Further, the bypass mixing valve control means 34 is based on the temperature obtained from the bypass temperature detection means 32 so that the target mixing temperature is set higher than the hot water supply set temperature set by the hot water supply temperature setting means 33. The opening of the bypass mixing valve 25 is controlled.

  However, when the hot water supply flow rate increases, the heat source side flow rate of the bath heat exchanger 6 may not be controlled only by the heat source side circulation pump 9. That is, even if the rotation speed of the heat source side circulation pump 9 is the minimum rotation speed or stopped, the heat source side flow rate becomes too large, and the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6 This is a case where it becomes impossible to control the temperature difference with the target temperature difference.

  In such a case, the opening degree of the flow rate control valve 35 is reduced to reduce the flow rate on the heat source side. That is, the number of rotations of the heat source side circulation pump 9 is set so that the flow rate control means 30 makes the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6 a target temperature difference. As a result, even if the rotation speed of the heat source side circulation pump 9 is the minimum rotation speed or stopped, if the temperature difference becomes a predetermined temperature difference larger than the target temperature difference, the opening degree of the flow control valve 35 By controlling the above, the temperature difference is controlled to a target temperature difference.

  On the contrary, even if the opening degree of the flow control valve 35 is fully opened, if the temperature difference becomes a predetermined temperature difference smaller than the target temperature difference, the temperature difference is set to the target by the number of rotations of the heat source side circulation pump 9. Control to temperature difference.

  In the above description, the flow control valve 35 is provided in the middle of the bypass pipe 24. However, the flow control valve 35 is provided in the heat source circuit upstream of the branch position of the lower connection pipe that branches the bypass pipe. However, the same effect can be obtained.

  In the case of Embodiment 1 in FIG. 1, when the hot water supply flow rate is large and the heat source side flow rate is small, the flow may flow from the lower connection pipe 23 to the bypass pipe 24. At this time, since the hot water mixed with the hot water from the lower part of the hot water storage tank 5 passing through the lower connection pipe 23 and the hot water from the heat source side outlet of the bath heat exchanger 6 enters the low temperature side inlet of the bypass mixing valve 25, bypass mixing The valve control means 34 cannot perform a predetermined opening degree control by the bypass mixing valve 25.

  Therefore, in the second embodiment, a check valve 36 that flows in the direction of the hot water tank is provided in the middle of the lower connection pipe on the hot water tank side from the branch position of the lower connection pipe that branches the bypass pipe. Thereby, the inflow from the hot water tank 5 can be prevented.

  In this way, even if the hot water flow rate increases or fluctuates, some or all of the hot water in the hot water tank used for bath heating is used directly for hot water while maintaining efficient bath heating. Since all the heat given to the hot water is used up, the efficiency is greatly improved.

  As described above, the heat pump water heater according to the present invention is configured to directly use hot water whose temperature has decreased after heating a heat radiating means such as a bathtub with high-temperature hot water in a hot water tank for hot water supply. Since the operation efficiency can be improved, the present invention can be applied not only to bath heating but also to uses such as heating using hot water stored in a bathroom or bathroom heating dryer.

The block diagram of the heat pump water heater in the 1st Embodiment of this invention The block diagram of the heat pump water heater in the 2nd Embodiment of this invention Configuration diagram of heat pump water heater in conventional example

DESCRIPTION OF SYMBOLS 1 Compressor 2 Hot water supply heat exchanger 5 Hot water storage tank 6 Bath heat exchanger 8 Bathtub 15 Water supply pipe 16 Hot water discharge pipe 17 Hot water supply mixing valve 21 Bath heating means 22 Upper connection pipe 23 Lower connection pipe 24 Bypass pipe 25 Bypass mixing valve 30 Flow control Means 33 Hot water supply temperature setting means

Claims (6)

Hot water supply heating means comprising a compressor, a hot water supply heat exchanger, hot water storage means for connecting the lower and upper parts of the hot water storage tank via the hot water supply heat exchanger, a hot water pipe connected to the upper part of the hot water storage tank, and the hot water storage A water supply pipe connected to the lower part of the tank; an upper connection pipe and a lower connection pipe for connecting a bath heat exchanger to the upper and lower parts of the hot water tank; A bath heating means for heating the hot water in the bathtub through the bath heat exchanger as a heat source, a flow rate control means for controlling the heat source flow rate circulating through the bath heating means, and a bypass pipe branched from the middle of the lower connecting pipe A hot water mixing valve that mixes hot water mixed in the bypass mixing valve with water from the water supply pipe, and a hot water mixing valve that mixes the hot water from the hot water pipe and the water from the water supply pipe . Detect temperature at outlet of heat source side Comprising a heat source-side outlet temperature detecting means that, the hot water temperature setting means for setting a hot water temperature, when the hot water supply request and the bath heating request was simultaneously hot water from the hot water tank top having released heat in the bath heat exchanger The heat pump water heater is characterized in that a part or all of the above is directly used for hot water supply, and the target mixing temperature of the bypass mixing valve is set to be higher than the heat source side outlet temperature of the bath heat exchanger . The heat pump water heater according to claim 1, wherein a heat source side circulation pump and a flow rate control valve provided on the heat source side of the bath heat exchanger are used as the flow rate control means. The heat pump water heater according to claim 1 or 2, further comprising a check valve that flows in the direction of the hot water storage tank in the middle of the lower connection pipe on the hot water storage tank side from a branch position of the lower connection pipe branching the bypass pipe. . The target mixing temperature of the bypass mixing valve is a temperature that is higher by a predetermined temperature than the higher one of the hot water supply set temperature set by the hot water supply temperature setting means and the temperature at the heat source side outlet of the bath heat exchanger. The heat pump water heater according to any one of claims 1 to 3 . The temperature according to any one of claims 1 to 4 , wherein the target mixing temperature of the bypass mixing valve is increased when a temperature returned to the bathtub by being heated by the bath heat exchanger is equal to or higher than a predetermined temperature. Heat pump water heater. The heat pump water heater according to any one of claims 1 to 5 , wherein the refrigerant circuit of the heat pump is a supercritical refrigerant circuit whose pressure is equal to or higher than a critical pressure, and heats water with a refrigerant whose pressure is increased to the critical pressure or higher. .

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