JP2009186065A - Hot water storage type water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type water supply device that suppresses a rise in power consumption of a boiling operation by suppressing deterioration of the coefficient of performance of a heat pump unit occurring upon performing the boiling operation in a state of medium temperature water being generated in a hot water storage tank. <P>SOLUTION: The hot water storage type water supply device 1 includes: the heat pump unit A having a heat exchanger 12 for boiling water and converting it to hot water; the hot water storage tank 20 for storing the hot water boiled by the heat exchanger 12, a circulation circuit 30 for making water flow from a hot water storage tank lower part 21 to the heat exchanger 12 and returning the hot water that flows out from the heat exchanger 12 to a hot water storage tank upper part 22; and a mixing valve 36 for mixing the medium temperature water, taken out from a water intake opening 23 provided at a hot water storage tank side part 24, with the water flowing into the heat exchanger 12. The flow rate of the medium temperature water taken out from the water intake opening 23 by the mixing valve 36 is controlled to perform the boiling operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In the hot water storage type hot water supply apparatus, water is taken out from the lower part of the hot water storage tank, the water is boiled by a heat pump unit or the like, and the heated hot water is returned from the upper part of the hot water storage tank to the storage tank for storage. At this time, a water layer is formed in the lower part of the hot water storage tank, whereas a hot water layer is formed in the upper part of the hot water storage tank. Further, an intermediate temperature water layer made of intermediate temperature water is formed between the hot water layer and the aqueous layer. When this intermediate temperature water layer expands to the lower part of the hot water storage tank, the temperature of the water taken out from the lower part of the hot water storage tank becomes relatively high.

  For example, the longer the elapsed time from the end of the boiling operation in which water is boiled into hot water and stored in the hot water storage tank, the more easily the intermediate hot water layer extends to the lower part of the hot water storage tank. In addition, if the hot water stored in the hot water storage tank and the bathtub water are supplied to the heat exchanger and heat is exchanged between them, the hot water whose temperature has decreased due to the heat exchange is returned to the hot water storage tank. From the above, it becomes easy for the intermediate temperature water layer to expand to the lower part of the hot water storage tank. For example, in a hot water storage type hot water supply apparatus shown in Patent Document 1, a bath water that has been heated once is heated to a desired temperature using hot water in a hot water storage tank. Without discharging the water, the bath water is heated to a desired temperature by discharging a predetermined amount of warm bath water and adding a predetermined amount of hot water in the hot water storage tank.

JP 2007-127363 A

  However, in the hot water storage type hot water supply apparatus shown in Patent Document 1, when hot water in the hot water storage tank is not added, boiling operation must be performed with relatively high temperature water from the early stage of boiling operation. An increase in power consumption for driving could not be avoided.

  The present invention has been made in view of the above circumstances, and is a hot water storage type that can suppress a decrease in the coefficient of performance of the heat pump unit that occurs when the boiling operation is performed in a state where intermediate temperature water is generated in the hot water storage tank. It aims at obtaining a hot-water supply apparatus.

  In order to solve the above-described problems and achieve the object, the hot water storage type hot water supply apparatus of the present invention includes a heat pump unit having a heat exchanger for boiling water and converting it into hot water, and hot water boiled by the heat exchanger. A hot water storage tank comprising: a hot water storage tank that stores water; and a circulation circuit that causes water to flow from the lower part of the hot water storage tank into the heat exchanger and return the hot water that has flowed out of the heat exchanger to the upper part of the hot water storage tank, It has a mixing valve that mixes the water flowing through the circulation circuit with the medium-temperature water drawn from the intake port provided on the side of the hot water storage tank, and adjusts the flow rate of the medium-temperature water drawn from the water intake port by the mixing valve. It is characterized by performing driving.

  In the hot water storage type hot water supply apparatus of the present invention, the intermediate temperature water can be extracted from the hot water storage tank, and the intermediate temperature water can be mixed into the water flowing through the circulation circuit, and the mixing amount of the intermediate temperature water at this time is adjusted by the mixing valve. be able to. For this reason, while the water temperature at the bottom of the hot water storage tank is low, medium-temperature water is mixed into the water flowing through the circulation circuit within a range where the coefficient of performance of the heat pump unit does not decrease, and the water is boiled with water at a temperature that decreases the coefficient of performance of the heat pump unit. It is possible to reduce the time required for the raising operation. Thereby, the fall of the coefficient of performance of the heat pump unit resulting from that the water which flows in into a heat exchanger becomes high temperature can be suppressed, and the raise of the power consumption of boiling operation can be suppressed.

  Hereinafter, an embodiment of a hot water storage type hot water supply apparatus according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of Embodiment 1 of a hot water storage type hot water supply apparatus according to the present invention. As shown in the figure, the hot water storage type hot water supply apparatus 1 according to the first embodiment includes a heat pump unit A and a hot water storage tank unit B.

  In the heat pump unit A, the compressor 11, the heat exchanger 12, the expansion valve 13, and the evaporator 14 are sequentially connected by a pipe 15 to constitute a refrigeration cycle. In the heat pump unit A, the refrigerant heated by the pressure increased by the compressor 11 flows into the heat exchanger 12, and exchanges heat with water in the circulation circuit 30 of the hot water storage tank unit B passing through the heat exchanger 12 described later. Do. Thereby, the water in the circulation circuit 30 which flows out from the heat exchanger 12 is boiled to hot water. The refrigerant having exchanged heat with the water in the heat exchanger 12 is decompressed by the expansion valve 13 and the heat is discharged by the evaporator 14. Operation | movement of the heat pump unit A is controlled by the control part 41 of the control apparatus 40 mentioned later.

  The hot water tank unit B includes a hot water tank 20, a circulation circuit 30, and a control device 40. The hot water storage tank unit B is for allowing water to flow into the heat exchanger 12, storing hot water boiled by the heat exchanger 12, and supplying the hot water to the outside. One end of an external water supply pipe 37 serving as a flow path of water from the outside is connected to the lower part of the hot water storage tank 20, and the other end of the external water supply pipe 37 is connected to a water source such as a water supply. In addition, one end of an external hot water supply pipe 38 serving as a flow path of hot water to the outside is connected to the upper part of the hot water storage tank 20, and a hot water tap (not shown) is provided at the other end of the external hot water supply pipe 38. . When the user opens the hot water tap, a predetermined amount of hot water is supplied from the hot water storage tank 20.

  The hot water storage tank 20 is a tank for storing the water supplied from the external water supply pipe 37 and the hot water boiled up by the heat exchanger 12. An external water supply pipe 37 and one end of the circulation circuit 30 are connected to the hot water storage tank lower part 21. The hot water storage tank upper part 22 is connected to an external hot water supply pipe 38 and the other end of the circulation circuit 30. The hot water storage tank side portion 24 is provided with a water intake 23. A medium temperature water pipe 35 is connected to the water intake 23. The formation position of the water intake port 23 in the hot water storage tank 20 is set by the manufacturer of the hot water storage type hot water supply apparatus 1 and is provided in consideration of the position of the intermediate hot water layer formed in the hot water storage tank 20. The hot water storage tank 20 is always kept full with water supplied from the external water supply pipe 37.

  The circulation circuit 30 includes a piping part 31 and a circulation pump P. The piping part 31 is a pipe for allowing water to flow into the heat exchanger 12 from the lower part of the hot water storage tank 21 during the boiling operation and returning the hot water boiled by the heat exchanger 12 to the upper part 22 of the hot water storage tank. The piping part 31 includes a first piping part 31a, a second piping part 31b, and a third piping part 31c.

  The 1st piping part 31a and the 2nd piping part 31b are piping for making water flow in into the heat exchanger 12. As shown in FIG. The first pipe portion 31 a has an upstream end connected to the hot water storage tank lower portion 21 and a downstream end connected to the mixing valve 36. The second piping part 31 b has an upstream end connected to the mixing valve 36 and a downstream end connected to the heat exchanger 12. Therefore, the first piping part 31 a and the second piping part 31 b are divided into an upstream side and a downstream side of the mixing valve 36. The third piping part 31 c is a pipe for returning the hot water boiled by the heat exchanger 12 to the hot water storage tank upper part 22. The third piping portion 31 c has an upstream end connected to the heat exchanger 12 and a downstream end connected to the hot water storage tank upper portion 22.

  The circulation pump P is provided in the second piping part 31b, and circulates the water in the circulation circuit 30 by increasing the pressure in the second piping part 31b. The circulation pump P is connected to a control unit 41 of a control device 40 described later, and the operation is controlled by the control unit 41.

  The intermediate temperature water pipe 35 is a pipe for allowing the intermediate temperature water taken out from the intake port 23 to flow into the mixing valve 36. The intermediate temperature water pipe 35 has an upstream end connected to the water intake 23 and a downstream end connected to the inlet of the mixing valve 36.

  The mixing valve 36 is a three-way valve for mixing the intermediate temperature water in the intermediate temperature water pipe 35 with the water in the first piping portion 31a by switching from the closed direction to the open direction. The mixing valve 36 is connected to the intermediate warm water pipe 35 and the first piping part 31a at the two inlets on the upstream side, and to the second piping part 31b at the outlet on the downstream side. The mixing valve 36 is connected to a control unit 41 of the control device 40 to be described later, and its operation is controlled by the control unit 41. The mixing valve 36 adjusts the valve opening degree when it receives a signal for adjusting the opening degree from the control unit 41. Thereby, the mixing amount of the water from the 1st piping part 31a and the intermediate temperature water from the intermediate temperature water pipe 35 is adjusted. That is, the mixing valve 36 adjusts the flow rate of water flowing into the second piping portion 31b from the first piping portion 31a and the flow rate of intermediate warm water flowing into the second piping portion 31b from the intermediate warm water pipe 35.

  The temperature detection sensor T is provided in the 2nd piping part 31b, and detects the temperature of the water in the 2nd piping part 31b. The temperature detection sensor T is connected to a control unit 41 of the control device 40 to be described later, and periodically detects and detects the temperature of the water flowing in the second piping unit 31b during the boiling operation. The result is output to the control device 40.

  The control device 40 includes a control unit 41 and a storage unit 42 provided on the same control board. The control unit 41 controls operations of the heat pump unit A and the hot water storage tank unit B using information stored in the storage unit 42, control information transmitted from an operation unit (not shown), and the like. The control unit 41 is connected to the heat pump unit A, the mixing valve 36, the circulation pump P, the temperature detection sensor T, and the like.

  The control unit 41 circulates with the heat pump unit A based on the information stored in the storage unit 42 and the detection result of the temperature in the hot water storage tank detected by a tank temperature detection sensor provided in the hot water storage tank 20 (not shown). Control of the operation with the pump P is performed to store a predetermined amount of hot water in the hot water storage tank 20.

  Further, the control unit 41 controls the valve opening degree of the mixing valve 36 using the information stored in the storage unit 42 and the detection result of the water temperature detected by the temperature detection sensor T. The information used here includes the output cycle of the detection result of the water temperature from the temperature detection sensor T, the information indicating the relationship between the detection result of the temperature detection sensor T and the valve opening of the mixing valve 36, the mixing valve The reference value of the water temperature when the opening degree adjustment of 36 is performed. Each said information is stored in the memory | storage part 42 beforehand by the manufacturer of the hot water storage type hot-water supply apparatus 1, for example by the manufacturer.

  A method for determining the reference value of the water temperature when adjusting the opening of the mixing valve 36 will be described. FIG. 2 is a diagram illustrating an example of the relationship between the water temperature and the coefficient of performance (COP) of the heat pump unit. As shown in FIG. 2, the coefficient of performance of the heat pump unit maintains a high value when the temperature of the water flowing into the heat exchanger of the heat pump unit is approximately 20 ° C. or less, while it suddenly increases when the water temperature exceeds 20 ° C. It has dropped to. That is, FIG. 2 shows that when the boiling operation is performed so that the temperature of the water supplied to the heat exchanger of the heat pump unit is approximately 20 ° C. or less, a decrease in the coefficient of performance of the heat pump unit is suppressed. ing.

  The control unit 41 shown in FIG. 1 sets the reference value of the temperature of the water flowing into the heat exchanger 12 to about 20 ° C. when performing the boiling operation with the hot water tank 20 in the middle temperature water layer. The valve opening degree of the mixing valve 36 is controlled so that the temperature of the water flowing into the heat exchanger 12 becomes a temperature close to the reference value.

  Here, an example of the opening adjustment control of the mixing valve 36 by the control unit 41 will be described. First, the control unit 41 determines whether or not the boiling operation is started. When it is determined that the boiling operation is not started, the control unit 41 does not control the opening adjustment of the mixing valve 36, and when it is determined that the boiling operation is started, the controller 41 does not adjust the opening of the mixing valve 36. Start control.

  The control part 41 which started control of the mixing valve 36 acquires the detection result of the water temperature by the temperature detection sensor T, and judges whether the water temperature in the 2nd piping part 31b is more than a reference value. If it is determined that the detected water temperature is lower than the reference value, the control unit 41 outputs an opening degree adjustment signal to the mixing valve 36 so that the opening degree of the mixing valve 36 is opened by a predetermined opening ratio. The flow rate of the intermediate temperature water from the intermediate temperature water pipe 35 is increased with respect to the flow rate of the water from the one piping part 31a. On the other hand, when determining that the detected water temperature is higher than the reference value, the control unit 41 outputs an opening adjustment signal to the mixing valve 36 so that the opening of the mixing valve 36 is closed by a predetermined opening ratio. The flow rate of the intermediate temperature water from the intermediate temperature water pipe 35 is decreased with respect to the flow rate of the water from the first piping part 31a. The controller 41 repeats the adjustment of the valve opening of the mixing valve 36 until the water temperature detected by the temperature detection sensor T rises and the mixing valve 36 is fully closed. The control unit 41 performs control to mix the medium temperature water from the medium temperature water pipe 35 into the water from the first piping unit 31a in a range where the water temperature detected by the temperature detection sensor T does not exceed the above-described reference value. Next, the operation of the boiling operation in the hot water storage type hot water supply apparatus 1 shown in FIG. 1 will be described.

  In the hot water storage type hot water supply device 1, when the boiling operation is started, the control unit receives an operation setting set by a user through an operation unit (not shown) in the control device 40 or a boiling operation start time set in the storage unit 42 in advance. 41 outputs an operation start signal to the heat pump unit A and the circulation pump P. When the hot water generated during the previous boiling operation remains in the hot water storage tank 20, a hot water layer is formed in the upper part of the hot water storage tank 20 at the start of the boiling operation, and an aqueous layer is formed in the lower part thereof. An intermediate temperature water layer is formed between the hot water layer and the water layer, but the water in the water layer formed in the lower part of the hot water storage tank 20 is circulated from the lower part of the hot water storage tank 21 at the start of the boiling operation. Flows into the circuit 30.

  Subsequently, the control part 41 starts control of the valve opening degree of the mixing valve 36, and makes the water temperature detected by the temperature detection sensor T the temperature close | similar to a reference value. The intermediate temperature water in the hot water storage tank 20 flows from the intermediate temperature water pipe 35 into the circulation circuit 30 through the mixing valve 36.

  As the time elapses from the start of the boiling operation, the hot water returned to the hot water storage tank upper part 22 expands the hot water layer in the hot water storage tank 20 in the direction of the hot water storage tank lower part 21. The temperature of the incoming water gradually rises. As already described with reference to FIG. 2, when the temperature of the water supplied to the heat exchanger 12 becomes higher than a certain level, the coefficient of performance of the heat pump unit A rapidly decreases. Since the mixing valve 36 is controlled as described above, the temperature of the water supplied to the heat exchanger 12 sharply decreases the coefficient of performance of the heat pump unit A as compared with the case where the intermediate temperature water is not drawn out by the intermediate temperature water pipe 35. It takes longer time to reach the temperature to be heated.

  The hot water storage tank 20 is provided with a hot water storage temperature sensor (not shown), and when the temperature of the hot water detected by the hot water storage temperature sensor reaches a certain temperature, the control unit 41 secures a necessary amount of hot water in the hot water storage tank 20. It judges that it is carried out, and ends boiling operation.

  FIG. 3 is a diagram illustrating an example of the relationship between the accumulated power consumption during boiling operation and the water temperature. As shown in FIG. 3, in the hot water storage type hot water supply apparatus 1 indicated by the solid line Q, the water supplied to the heat exchanger 12 due to the influence of intermediate temperature water flowing into the circulation circuit 30 from the intermediate temperature water pipe 35 through the mixing valve 36. The temperature of the water increases to the reference value Ts relatively early, but thereafter, the inflow amount of the medium-temperature water is controlled by the control unit 41 within a range not exceeding the reference value Ts. It becomes constant. From the time q1 to the end of boiling, the temperature of the water supplied to the heat exchanger 12 increases rapidly due to the expansion of the hot water layer in the hot water storage tank. However, the temperature of the water supplied to the heat exchanger 12 is maintained below the reference value Ts as compared with the conventional hot water storage hot water supply device indicated by the one-dot chain line R, that is, the hot water storage hot water supply device that does not extract the intermediate temperature water during the boiling operation. The time taken is longer (q1> r1).

  The accumulated power consumption when the temperature of the water supplied to the heat exchanger 12 is maintained below the reference value Ts is constant with respect to the boiling time because a high coefficient of performance is obtained in the heat pump unit A. The accumulated power consumption when the water temperature exceeds the reference value Ts, indicating an increase rate, increases rapidly because the coefficient of performance of the heat pump unit A decreases. In the conventional hot water storage type hot water supply apparatus indicated by the alternate long and short dash line R, the water temperature is from the time r1 corresponding to about one third of the time from the start of the boiling operation to the end of the boiling operation until the completion of the boiling operation. The accumulated power consumption increases rapidly as it increases rapidly. On the other hand, in the hot water storage type hot water supply device 1 indicated by the solid line Q, since the time during which the water temperature is maintained below the reference value Ts is long (q1> r1), the accumulated consumption is compared with the conventional hot water storage type hot water supply device. The amount of power is reduced by N.

  That is, the hot water storage type hot water supply device 1 suppresses a decrease in the coefficient of performance of the heat pump unit A when the boiling operation is performed in a state where intermediate temperature water is generated in the hot water storage tank 20, and as a result, during the boiling operation To reduce power consumption.

  In the first embodiment, the reference value Ts is one point, but the present invention is not limited to this. For example, the valve opening of the mixing valve 36 is increased by a predetermined opening ratio, and the reference value Tsl for increasing the flow rate of the intermediate warm water flowing from the intermediate warm water pipe 35 into the circulation circuit 30 and the valve opening of the mixing valve 36 are predetermined. It is also possible to use two reference values, that is, a reference value Tsh that reduces the flow rate of the intermediate temperature water flowing from the intermediate temperature water pipe 35 into the circulation circuit 30 by the opening ratio. Further, although a hot water storage temperature sensor (not shown) is used as a hot water temperature detecting means for determining the end of the boiling operation, the present invention is not limited to this, and for example, the temperature detection sensor T also serves as the hot water storage temperature sensor. It may be.

Embodiment 2. FIG.
FIG. 4 is a configuration diagram of Embodiment 2 of the hot water storage type hot water supply apparatus according to the present invention. A hot water storage type hot water supply apparatus 100 shown in FIG. 4 includes a second water intake 123, a second intermediate hot water pipe 135, a hot water supply switching valve 151, a bypass pipe 152, a first electromagnetic valve 153, and a second electromagnetic valve 154. 1 has the same configuration as the hot water storage type hot water supply apparatus 1 shown in FIG. Moreover, the 3rd piping part 31c shown in FIG. 1 is divided into the upstream 3rd piping part 31cu of the upstream of the hot water supply switching valve 151, and the downstream 3rd piping part 31cd of the downstream. Among the structural members shown in FIG. 4, those that are functionally common to the structural members shown in FIG. 1 are given the same reference numerals as those used in FIG. 1 and description thereof is omitted.

  The hot water supply switching valve 151 causes water to flow into the bypass pipe 152 from the upstream third piping section 31cu by switching from closed to open, and switches from the upstream third pipe section 31cu to the downstream third piping by switching from open to closed. This is a three-way valve that allows water to flow into the portion 31cd. In the hot water supply switching valve 151, the upstream third piping part 31 cu is connected to the inlet on the upstream side, and the downstream third piping part 31 cd and the bypass pipe 152 are connected to the two outlets on the downstream side. . The hot water supply switching valve 151 is connected to the control unit 41, and its operation is controlled by the control unit 41. The hot water supply switching valve 151 adjusts the valve opening when receiving an opening adjustment signal from the control unit 41. One end of the bypass pipe 152 is connected to the outlet of the hot water supply switching valve 151, and the other end is connected to the inlet of the mixing valve 36.

  The hot water storage tank side portion 24 is provided with a first water intake 23 and a second water intake 123. One end of the first intermediate hot water pipe 35 is connected to the first water intake port 23, and the other end is connected to the bypass pipe 152. The first intermediate hot water pipe 35 is provided with a first electromagnetic valve 153 that allows the first intake port 23 and the bypass pipe 152 to communicate with each other by switching from closed to open. The first electromagnetic valve 153 is connected to the control unit 41 and receives an open / close signal from the control unit 41.

  The second intake port 123 is provided above the hot water storage tank side portion 24 relative to the first intake port 23. The second intermediate hot water pipe 135 has one end connected to the second water intake 123 and the other end connected to the bypass pipe 152. The second intermediate hot water pipe 135 is provided with a second electromagnetic valve 154 that allows the second water intake 123 and the bypass pipe 152 to communicate with each other by switching from closed to open. The second electromagnetic valve 154 is connected to the control unit 41 and receives an open / close signal from the control unit 41.

  Next, the operation of the boiling operation in the hot water storage type hot water supply apparatus 100 will be described. In the initial stage of the boiling operation, the control unit 41 outputs an open signal to the hot water supply switching valve 151 and the mixing valve 36, and the water flowing from the heat exchanger 12 into the upstream third piping unit 31cu is bypassed. It is made to flow into the 2nd piping part 31b via 152. The water that has flowed into the second piping part 31b flows into the heat exchanger 12, is boiled up again, and flows into the upstream third piping part 31cu. The control unit 41 continues to output an open signal to the hot water supply switching valve 151 and the mixing valve 36 until the water temperature detected by the temperature detection sensor T reaches a predetermined hot water temperature. Therefore, the low temperature hot water boiled by the heat exchanger 12 immediately after the start of operation does not flow out to the upper part of the hot water storage tank 20 until the predetermined hot water temperature is reached. Thereby, the destruction of the layer boundary between the hot water layer and the water layer caused by the flow of low temperature hot water boiled by the heat exchanger 12 immediately after the start of operation into the hot water storage tank upper portion 22 is suppressed, and the inside of the hot water storage tank 20 Therefore, the temperature rise of the water layer formed in the hot water storage tank lower part 21 can be suppressed. Here, the predetermined hot water temperature means a temperature at which the destruction of the temperature stratification in the hot water storage tank 20 can be substantially suppressed.

  Next, the control unit 41 outputs an open signal to the second electromagnetic valve 154, and causes the medium temperature water that has flowed into the second medium temperature water pipe 135 from the second outlet 123 to flow into the mixing valve 36. Next, the control unit 41 controls the valve opening degree of the mixing valve 36 shown in the first embodiment, and causes the medium temperature water flowing into the mixing valve 36 to flow into the circulation circuit 30 and is detected by the temperature detection sensor T. Set the water temperature to be close to the reference value. When time elapses from the start of the boiling operation and the water temperature detected by the temperature detection sensor T becomes higher than a certain level, the control unit 41 changes the electromagnetic valve that should output an open signal from the second electromagnetic valve 154 to the first electromagnetic valve. Switching to 153, the valve opening degree of the mixing valve 36 shown in the first embodiment is controlled. Therefore, the hot water storage type hot water supply apparatus 100 can draw out the intermediate hot water in response to the change in the position of the intermediate hot water layer in the vertical direction of the hot water storage tank 20 accompanying the expansion of the hot water layer in the hot water storage tank 20 during the boiling operation. . For this reason, it is possible to secure a longer time for maintaining the temperature of the water supplied to the heat exchanger 12 at the reference value Ts (see FIG. 2), compared to the case where the medium-temperature water is drawn out from one outlet. .

  In the second embodiment, the two intake ports 23 and 123 are provided. However, the present invention is not limited to this, and three or more intake ports may be provided. In addition, the timing of switching between opening and closing of the hot water supply switching valve 151, the first electromagnetic valve 153, and the second electromagnetic valve 154 is determined using the water temperature detected by the temperature detection sensor T provided in the second piping portion 31b. The present invention is not limited to this. For example, in addition to the temperature detection sensor T shown in FIG. 1, a temperature detection sensor may be separately provided in the second piping portion 31b, or the upstream side third piping portion 31cu and the bypass may be provided. A temperature detection sensor may be newly provided in any of the pipes 152.

  As described above, the hot water storage type hot water supply apparatus according to the present invention suppresses the decrease in the coefficient of performance of the heat pump unit that occurs when the boiling operation is performed in a state where intermediate temperature water is generated in the hot water storage tank. It is suitable for application to a hot water storage type hot water supply apparatus that suppresses an increase in power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of Embodiment 1 of the hot water storage type hot water supply apparatus concerning this invention. It is a figure which shows an example of the relationship between water temperature and the coefficient of performance (COP) of a heat pump unit. It is a figure which shows an example of the relationship between the water temperature at the time of boiling operation, and integrated power consumption. It is a block diagram of Embodiment 2 of the hot water storage type hot-water supply apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Hot water storage type hot water supply device 12 Heat exchanger 20 Hot water storage tank 21 Hot water storage tank lower part 22 Hot water storage tank upper part 23,123 Water intake 24 Hot water storage tank side part 30 Circulation circuit 31 Piping part 31a First piping part 31b Second piping part 31c First 3 piping section 31 cu upstream third piping section 31 cd downstream third piping section 35 medium temperature water pipe 36 mixing valve 37 external water supply pipe 38 external hot water supply pipe 40 control device 41 control section 42 storage section 151 hot water supply switching valve 152 bypass piping 153 first 1 Solenoid valve 154 2nd solenoid valve A Heat pump unit B Hot water tank unit P Circulation pump T Temperature detection sensor

Claims (4)

A heat pump unit having a heat exchanger for boiling water to convert it into hot water, a hot water storage tank for storing hot water boiled by the heat exchanger, and water flowing into the heat exchanger from the lower part of the hot water storage tank A hot water flowing out of the heat exchanger and a circulation circuit for returning the hot water to the upper part of the hot water storage tank,
It has a mixing valve that mixes the water flowing through the circulation circuit with the medium temperature water drawn from the intake port provided on the side of the hot water storage tank, and adjusts the flow rate of the medium temperature water drawn from the water intake port by the mixing valve. A hot water storage type hot water supply device that performs boiling operation.   2. The hot water storage type hot water supply according to claim 1, wherein the opening degree of the mixing valve is adjusted so that a temperature of water supplied to the heat exchanger becomes a reference value or less during the boiling operation. apparatus.   The hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the mixing valve is a three-way valve.   The hot water storage type hot water supply apparatus according to any one of claims 1 to 3, wherein a plurality of water intake ports for drawing out the medium temperature water are formed in a vertically distributed manner on the side of the hot water storage tank. .

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