JP2015194299A - water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater that prevents damage of a heat pump by suppressing temperature rise of refrigerant in the heat pump and suppressing pressure rise in the heat pump.SOLUTION: A temperature sensor T1 is positioned above a first layer and at a position where a second layer having higher temperature than the first layer can be detected, in a state where the first layer is left on a bottom layer in a hot water storage tank 3. A boiling up capacity control unit of a control device 100, when a temperature detected by the temperature sensor T1 exceeds a predetermined setting value, controls a heat pump 7 so as to deteriorate a boiling up capacity.

Description

  The present invention relates to a hot water supply apparatus.

  Conventionally, as a hot-water supply apparatus, there exist some which were described in Unexamined-Japanese-Patent No. 2002-340402 (patent document 1). This hot water supply apparatus has a hot water storage tank, a heat pump for boiling water in the hot water storage tank, and a control device for controlling the heat pump.

  The heat pump includes a compressor, a boiling heat exchanger, an expansion valve, and an evaporator. The hot water storage tank is connected to a boiling heat exchanger via a pipe. A temperature sensor is attached to the pipe between the hot water storage tank and the boiling heat exchanger, and the temperature sensor detects the temperature of the water flowing into the boiling heat exchanger. The control device reduces the rotational speed of the compressor when the temperature detected by the temperature sensor exceeds a predetermined set value. Thereby, when the completion of boiling of the hot water storage tank is approaching, the rotational speed of the compressor is reduced, and an increase in the discharge pressure of the compressor is suppressed.

Japanese Patent Laid-Open No. 2002-340402

  By the way, in the said conventional hot water supply apparatus, since the rotation speed of the compressor was made small after detecting the temperature of the water flowing into the boiling heat exchanger, the boiling heat exchanger increased to some extent. Water temperature (medium temperature water) will flow in. As a result, the temperature of the refrigerant in the heat pump rises, the pressure in the heat pump rises, and the heat pump may be damaged.

  Then, the subject of this invention is providing the hot-water supply apparatus which suppresses the temperature rise of the refrigerant | coolant in a heat pump, suppresses the pressure rise in a heat pump, and prevents the failure | damage of a heat pump.

In order to solve the above problems, the hot water supply apparatus of the present invention is:
A hot water storage tank,
A heat pump including a boiling heat exchanger that performs heat exchange with the water in the hot water storage tank to boil the water in the hot water storage tank;
A temperature sensor for detecting the temperature of water in the hot water storage tank;
A boiling capacity control unit for controlling the boiling capacity of the heat pump;
The hot water storage tank has a first layer of low-temperature water at the lowest layer in the hot water storage tank at the start of boiling,
The temperature sensor is located in a state where the first layer remains in the lowermost layer in the hot water storage tank and is located above the first layer and has a second temperature higher than that of the first layer. The layer is in a detectable position,
The boiling capacity control unit controls the heat pump so that the boiling capacity of the heat pump decreases when the temperature detected by the temperature sensor exceeds a predetermined set value. Yes.

  According to the hot water supply apparatus of the present invention, the temperature sensor is located above the first layer and higher than the first layer in a state where the first layer remains in the lowermost layer in the hot water storage tank. The second layer of temperature is in a detectable position. The boiling capacity control unit controls the heat pump so that the boiling capacity of the heat pump is lowered when the temperature sensor exceeds a predetermined set value.

  Accordingly, when the water in the hot water storage tank is boiled by the heat pump, the temperature detected by the temperature sensor exceeds a predetermined set value. Then, the said boiling capacity control part controls a heat pump so that the boiling capacity by a heat pump may fall. At this time, since the first layer of low temperature water remains in the lowermost layer of the hot water storage tank, the medium temperature water in the hot water storage tank is boiled in the heat pump before the boiling capacity control unit lowers the boiling capacity. It can suppress entering into a raising heat exchanger.

  Therefore, the temperature rise of the refrigerant in the heat pump is suppressed, the pressure increase in the heat pump is suppressed, and the heat pump is prevented from being damaged.

  Moreover, in the hot water supply apparatus of one Embodiment, the attachment position with respect to the said hot water storage tank of the said temperature sensor is a position from which the capacity | capacitance below the said temperature sensor in the said hot water storage tank becomes 50 to 80 liters.

  According to the hot water supply apparatus of the above embodiment, the mounting position of the temperature sensor with respect to the hot water storage tank is a position where the capacity of the hot water storage tank below the temperature sensor is 50 liters to 80 liters. Thereby, the part where the capacity | capacitance of the lower side of a hot water storage tank becomes 50 liters to 80 liters can be made into the 1st layer of low temperature water, and a 1st layer can be ensured reliably. Therefore, before the boiling capacity is reduced by the boiling capacity control unit, it is possible to more reliably prevent the medium temperature water in the hot water storage tank from entering the boiling heat exchanger of the heat pump.

  Moreover, in the hot water supply apparatus of one Embodiment, the refrigerant | coolant which flows through the said heat pump is a HFC refrigerant | coolant.

  According to the hot water supply apparatus of the above embodiment, the refrigerant flowing through the heat pump is an HFC refrigerant. The heating capacity of the HFC refrigerant in the boiling heat exchanger is unlikely to drop regardless of the temperature of the water flowing into the boiling heat exchanger from the hot water storage tank. However, the present invention can effectively suppress the temperature rise of the HFC refrigerant in the heat pump.

  In one embodiment of the hot water supply apparatus, the boiling heat exchanger of the heat pump is included in a hot water storage unit including the hot water storage tank.

  According to the hot water supply apparatus of the embodiment, the boiling heat exchanger of the heat pump is included in a hot water storage unit including the hot water storage tank. Although the boiling heat exchanger is disposed at a position close to the hot water storage tank, according to the present invention, it is possible to effectively suppress the medium temperature water in the hot water storage tank from entering the boiling heat exchanger of the heat pump.

  Further, in the hot water supply apparatus according to an embodiment, the boiling capacity control unit decreases the rotation speed of the compressor of the heat pump when the temperature detected by the temperature sensor exceeds a predetermined set value. .

  According to the hot water supply apparatus of the above embodiment, the boiling capacity control unit reduces the rotational speed of the compressor of the heat pump when the temperature detected by the temperature sensor exceeds a predetermined set value. . Thereby, the boiling capability by a heat pump can be reduced effectively.

  Moreover, in the hot water supply apparatus of one embodiment, the boiling capacity control unit increases the opening degree of the expansion valve of the heat pump when the temperature detected by the temperature sensor exceeds a predetermined set value. .

  According to the hot water supply apparatus of the above embodiment, the boiling capacity control unit increases the opening of the expansion valve of the heat pump when the temperature detected by the temperature sensor exceeds a predetermined set value. . Thereby, the boiling capability by a heat pump can be reduced effectively.

  Further, in the hot water supply apparatus according to an embodiment, the boiling capacity control unit reduces the rotation speed of the heat exchange fan of the heat pump when the temperature detected by the temperature sensor exceeds a predetermined set value. To do.

  According to the hot water supply apparatus of the above embodiment, the boiling capacity control unit reduces the rotational speed of the heat exchange fan of the heat pump when the temperature detected by the temperature sensor exceeds a predetermined set value. To do. Thereby, the boiling capability by a heat pump can be reduced effectively.

  According to the hot water supply apparatus of the present invention, the temperature sensor is located above the first layer and higher than the first layer in a state where the first layer remains in the lowermost layer in the hot water storage tank. The second layer of temperature is in a detectable position. The boiling capacity control unit controls the heat pump so that the boiling capacity of the heat pump is lowered when the temperature sensor exceeds a predetermined set value. Thereby, the temperature rise of the refrigerant | coolant in a heat pump is suppressed, the pressure rise in a heat pump is suppressed, and the failure | damage of a heat pump is prevented.

It is a simplified lineblock diagram showing the hot-water supply device of one embodiment of the present invention. It is a block diagram of a hot water supply apparatus. It is explanatory drawing which shows the state of the hot water storage tank at the time of a boiling start. It is explanatory drawing which shows the state of the hot water storage tank which predetermined time passed since boiling start. It is explanatory drawing which shows the control by a boiling capability control part. It is explanatory drawing which shows the effect by the boiling capability control part. It is explanatory drawing which shows the comparative example of the control by a boiling capability control part. It is explanatory drawing which shows the comparative example of the control by a boiling capability control part.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 is a simplified configuration diagram illustrating a hot water supply apparatus according to an embodiment of the present invention. As shown in FIG. 1, the hot water supply apparatus includes a hot water storage unit 1 and an outdoor unit 2 connected to the hot water storage unit 1. The hot water storage unit 1 includes a hot water storage tank 3, a boiling heat exchanger 10, a reheating heat exchanger 20, a control device 100, and the like.

  One end of the pipe L1 is connected to the lower part of the hot water storage tank 3, and the other end of the pipe L1 is connected to a first water inlet port of a boiling mixing valve 50 as an example of a mixing valve. One end of the pipe L <b> 2 is connected to the water outlet port of the boiling mixing valve 50, and the other end of the pipe L <b> 2 is connected to one end of the boiling heat exchanger 10. The other end of the boiling heat exchanger 10 is connected to one end of the pipe L3, and the other end of the pipe L3 is connected to the upper part of the hot water storage tank 3. A boiling circulation pump P1 as an example of a boiling pump is disposed in the pipe L2.

  The piping L1, the piping L2, the boiling heat exchanger 10, and the piping L3 constitute a boiling circuit.

  The hot water in the hot water storage tank 3 is connected to the pipe L1 by driving the hot water circulating pump P1 with the opening degree of the first mixing port 50 (hot water storage tank 3 side) of the boiling mixing valve 50 fully opened. , Circulating through the mixing valve 50 for boiling, the pipe L2, the boiling heat exchanger 10, and the pipe L3.

  The boiling heat exchanger 10 is connected to the outdoor unit 2 through refrigerant pipes L4 and L5. The outdoor unit 2 includes a compressor 71, an expansion valve 72, an air heat exchanger 73, and a heat exchange fan 74. The compressor 71, the boiling heat exchanger 10, the expansion valve 72, and the air heat exchanger 73 are connected in order to constitute the heat pump 7. The heat exchanger fan 74 blows air to the air heat exchanger 73 to exchange heat between the air and the refrigerant.

  The heat pump 7 uses HFC refrigerant, and can control the temperature of the hot water from the boiling heat exchanger 10 in a range of, for example, 50 ° C to 70 ° C. Examples of the HFC refrigerant used in the heat pump 7 include R32, R125, R134a, R404A, R410A, and R407C.

  Next, an external water supply pipe is connected to the lower part of the hot water storage tank 3 through a pipe L11. A pressure reducing valve 11 and a check valve 12 are arranged in this pipe L11 in order from the upstream side. This check valve 12 allows only the flow from the water supply pipe side to the hot water storage tank 3 side.

  One end of the pipe L <b> 21 is connected to the upper part of the hot water storage tank 3, and the other end of the pipe L <b> 21 is connected to the primary water inlet port of the heat exchanger 20. One end of the pipe L22 is connected to the primary water outlet port of the reheating heat exchanger 20, and the other end of the pipe L22 is connected to the second water inlet port of the boiling mixing valve 50.

  The pipe L21, the reheating heat exchanger 20, and the line L22 constitute a bath reheating circuit.

  By driving the boiling circulation pump P1 with the opening on the second water inlet port side (bath reheating circuit side) of the boiling mixing valve 50 fully open, the hot water in the hot water storage tank 3 is removed. Circulate through the pipe L21, the reheating heat exchanger 20 (primary side), the pipe L22, the boiling mixing valve 50, the pipe L2, the boiling heat exchanger 10, and the pipe L3.

  Further, one end of the pipe L31 is connected to the upper part of the hot water storage tank 3, and the other end of the pipe L31 is connected to the first water inlet port of the hot water supply mixing valve 22. A check valve 21 that allows only a flow from the hot water storage tank 3 side to the hot water supply mixing valve 22 is disposed in the pipe L31. One end of the branch pipe L12 is connected to the second water inlet port of the hot water supply mixing valve 22, and the other end of the branch pipe L12 is connected between the pressure reducing valve 11 and the check valve 12 of the pipe L11. The branch pipe L12 is provided with a check valve 23 that allows only the flow from the pipe L11 side to the hot water supply mixing valve 22.

  Then, one end of the pipe L32 is connected to the water outlet port of the hot water supply mixing valve 22, and the other end of the pipe L32 is connected to the hot water tap 60 (a faucet in this embodiment). A water amount sensor 24 is disposed in the pipe L32.

  The branch pipe L12, the pipe L31, the pipe L32, the check valve 21, the hot water supply mixing valve 22, the check valve 23, and the water amount sensor 24 constitute a hot water supply circuit.

  Further, one end of the pipe L33 is connected to the upstream side of the water amount sensor 24 of the pipe L32, and the other end of the pipe L33 is connected to the hot water supply port 9a of the connection adapter 9 provided in the bathtub 4. A hot water filling solenoid valve 25, a check valve 26, a water amount sensor 27, and a check valve 28 are arranged in this order from the upstream side of the pipe L33. The check valves 26 and 28 allow only the flow from the hot water supply mixing valve 22 side to the bathtub 4.

  The pipe L33, the hot water solenoid valve 25, the check valves 26 and 28, and the water amount sensor 27 constitute a bath hot water supply circuit branched from the hot water supply pipe L32 and connected to the bathtub 4.

  One end of the pipe L35 is connected to the water intake port 9b for replenishment of the connection adapter 9, and the other end of the pipe L35 is connected to the water inlet port on the secondary side of the heat exchanger 20. A circulation pump P2 for bath is disposed in the pipe L35. Further, one end of the pipe L34 is connected to the downstream side of the water amount sensor 27 of the pipe L33, and the other end of the pipe L34 is connected to the secondary water outlet port of the heat exchanger 20.

  The hot water in the bathtub 4 is circulated through the pipe L35, the reheating heat exchanger 20 (secondary side), the pipe L34, and the pipe L33 (part) by the bath circulation pump P2.

  The pipe L35, the reheating heat exchanger 20 (secondary side), the pipe L34, and the pipe L33 (part) constitute a bath circulation circuit.

  Furthermore, one end of the pipe L41 is connected to the pipe L21, and the other end of the pipe L41 is connected to the drain port. A relief valve 31 is provided in the pipe L41.

  The hot water storage tank 3 is provided with first to fourth temperature sensors T1 to T4 at substantially equal intervals from the lower side to the upper side. The first to fourth temperature sensors T <b> 1 to T <b> 4 detect the water temperature in the hot water storage tank 3.

  In addition, a temperature sensor T11 that detects the incoming water temperature is provided in the pipe L3, and a temperature sensor T12 that detects the tapping temperature is provided in the pipe L3. The temperature sensor T11 is an example of an incoming water temperature sensor, and the temperature sensor T12 is an example of a tapping temperature sensor.

  Further, the boiling heat exchanger 10 is provided with a temperature sensor T13. In addition, a temperature sensor T <b> 21 for detecting a hot water supply temperature is provided in the pipe L <b> 32 connected to the hot water tap 60 on the downstream side of the water amount sensor 24. In addition, a water level sensor LS, a water flow switch SW, and a temperature sensor T23 are connected to the pipe L35 connected to the bathtub 4 from the connection adapter 9 side between the connection adapter 9 on the bathtub 4 side and the circulation pump P2 for bath. In order. Furthermore, a temperature sensor T22 that detects the temperature of hot water supplied to the bathtub 4 is provided downstream of the check valve 28 of the pipe L33 connected to the bathtub 4 and at a connection point between the pipe L33 and the pipe L34. Yes.

  As shown in FIG. 2, the hot water supply apparatus includes a control device 100 including a microcomputer and an input / output circuit, and a remote controller 200 that transmits and receives signals to and from the control device 100. The control device 100 includes signals from temperature sensors T1 to T4, T11 to T13, T21 to T23, a water level sensor LS, a water flow switch SW, water volume sensors 24 and 27, an outside air temperature sensor (not shown), a remote controller 200, and the like. In response, the heat pump 7, the boiling circulation pump P1, the bath circulation pump P2, the hot water mixing valve 22, the hot water solenoid valve 25, the boiling mixing valve 50, and the like are controlled.

  Further, the control device 100 includes a hot water supply control unit 100a that controls a hot water supply temperature to the hot water tap 60, a hot water supply control unit 100b that controls a hot water supply operation to the bathtub 4 including a “bath hot water filling operation”, and the like. A reheating control unit 100c that controls the “bath reheating operation”, a boiling control unit 100d that controls the operation of boiling hot water in the hot water storage tank 3, and a boiling capacity control unit that controls the heating capacity of the heat pump 7. 100e.

  The hot water supply control unit 100a controls the mixing ratio of the hot water supply mixing valve 22 so that the hot water supply temperature detected by the temperature sensor T21 becomes the hot water supply set temperature.

  When performing a “bath hot water filling operation” in which hot water is supplied from the hot water storage tank 3 into the bath tub 4, the hot water filling electromagnetic valve 25 is opened by the hot water control unit 100 b, and hot water in the hot water storage tank 3 is mixed with the hot water mixing valve. 22 and the bath hot water supply circuit (L33, 25, 26, 27, 28). At this time, the hot water pouring control unit 100b controls the hot water supply mixing valve 22 to mix the hot water from the hot water storage tank 3 and the external water supply based on the target set temperature, and by the water level sensor LS. When the detected water level in the bathtub 4 reaches the set water level, the hot water solenoid valve 25 is closed.

  When performing a “bath reheating operation” in which the hot water in the bath tub 4 is replenished from the hot water storage tank 3, the recirculation control unit 100c controls the bath circulation pump P2 with the hot water filling solenoid valve 25 closed. In operation, the hot water in the bathtub 4 is circulated through the pipe L35, the reheating heat exchanger 20 (secondary side), the pipe L34, and the pipe L33 (part).

  Then, based on the bath temperature of the hot water in the bathtub 4 detected by the temperature sensor T23, the reheating controller 100c performs a reheating operation using the hot water in the hot water storage tank 3 as a heat source without using the heat pump 7. Alternatively, when the amount of heat in the hot water storage tank 3 is not sufficient, the bath pumping operation is performed using the heat pump 7.

  In the “boiling operation” in which hot water in the hot water storage tank 3 is heated by the heat pump 7, the opening control unit 100d fully opens the opening on the first water inlet port side (hot water storage tank 3 side) of the boiling mixing valve 50. The boiling circulation pump P1 is operated in the state of being heated, and the hot water in the hot water storage tank 3 is circulated through the pipe L1, the boiling mixing valve 50, the pipe L2, the boiling heat exchanger 10, and the pipe L3. .

  The boiling control unit 100d controls the heat pump 7 and the boiling circulation pump P1 so that the tapping temperature detected by the temperature sensor T12 becomes the target tapping temperature TS during the boiling operation. Here, the target hot water temperature TS is calculated by the control device 100 based on the amount of hot water supplied from the hot water storage tank 3 and the like. For example, when the amount of hot water used is large, the target hot water temperature TS is as high as 70 ° C., for example, and when the amount of hot water used is small, the target hot water temperature TS is as low as 50 ° C., for example.

  The boiling capacity control unit 100e controls the heat pump 7 so that the boiling capacity of the heat pump 7 is lowered when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. .

  Here, as shown to FIG. 3A, the said hot water storage tank 3 has the 1st layer S1 of low temperature water in the lowest layer in the hot water storage tank 3 at the time of a boiling start. The hot water storage tank 3 has a second layer S2 above the first layer S1, and a third layer S3 above the second layer S2. The second layer S2 is at a higher temperature than the first layer S1. The third layer S3 is at a higher temperature than the second layer S2. For example, the temperature of the first layer S1 is 10 ° C., the temperature of the second layer S2 is 30 ° C., and the temperature of the third layer S3 is 65 ° C. When the total capacity of the hot water storage tank 3 is 320 liters, the first layer S1 is a portion where the lower capacity of the hot water storage tank 3 is 160 liters. Note that the first layer S1, the second layer S2, and the third layer S3 are completely separated in the temperature distribution, but this is for explanation, and in the actual hot water storage tank 3, the first layer S1 The temperature continuously changes at the boundary between the second layer S1, the second layer S2, and the third layer S3.

  As shown in FIG. 3B, the first temperature sensor T1 is positioned above the first layer S1 and the first temperature sensor T1 with the first layer S1 remaining in the lower part of the hot water storage tank 3. It exists in the position which can detect 2nd layer S2 of temperature higher than layer S1. FIG. 3B shows a state of the hot water storage tank 3 after a predetermined time has elapsed since the start of boiling.

  The mounting position of the first temperature sensor T1 with respect to the hot water storage tank 3 is a position where the capacity of the hot water storage tank 3 below the first temperature sensor T1 is 70 liters. That is, the first layer S1 is a portion where the lower volume of the hot water storage tank 3 is 70 liters. If the total capacity of the hot water storage tank 3 is 320 liters, the second layer S2 and the third layer S3 are portions where the upper capacity of the hot water storage tank 3 is 250 liters.

  As shown in FIG. 4, there are, for example, three controls as specific controls by the boiling capacity control unit 100e.

  As the first control, the boiling capacity control unit 100e reduces the rotation speed of the compressor 71 of the heat pump 7 when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. To do. In FIG. 4, the rotation speed of the compressor 71 of the heat pump 7 is reduced in two stages.

  As the second control, the boiling capacity control unit 100e increases the degree of opening of the expansion valve 72 of the heat pump 7 when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. To do. In FIG. 4, the opening degree of the expansion valve 72 of the heat pump 7 is increased in two stages.

  As the third control, the boiling capacity control unit 100e determines the number of rotations of the heat exchanger fan 74 of the heat pump 7 when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. Make it smaller. In FIG. 4, the rotational speed of the heat exchange fan 74 of the heat pump 7 is reduced in two steps.

  With any of the first to third controls, the boiling capacity control unit 100e can reduce the boiling capacity of the heat pump 7 in two stages. The control by the boiling capacity control unit 100e may be any one of the first to third controls, or a combination of at least two controls of the first to third controls. May be.

  The effect by the said boiling capability control part 100e is demonstrated using FIG. 1 and FIG.

  When the water in the hot water storage tank 3 is boiled up by the heat pump 7, the temperature detected by the first temperature sensor T1 exceeds a predetermined first set value Th1. Then, the boiling capacity control unit 100e reduces the boiling capacity of the heat pump 7 by one step. Further, when the temperature detected by the first temperature sensor T1 exceeds a predetermined second set value Th2, the boiling capacity control unit 100e further decreases the boiling capacity of the heat pump 7 by one step. .

  At this time, since the first layer S1 (see FIG. 3B) of the low-temperature water remains in the lowermost layer of the hot water storage tank 3, the hot water storage tank before the boiling capacity is reduced by the boiling capacity control unit 100e. It is possible to suppress the medium-temperature water in 3 from entering the boiling heat exchanger 10.

  Therefore, the temperature rise of the hot water from the boiling heat exchanger 10 is suppressed, the temperature rise of the refrigerant in the heat pump 7 is suppressed, and the increase in the discharge pressure of the compressor 71 is suppressed. Thereby, the pressure rise in the heat pump 7 is suppressed, and damage to the heat pump 7 is prevented.

  As the temperature of the water entering the boiling heat exchanger 10 rises, the boiling flow rate by the boiling circulation pump P1 increases. The temperature of the water entering the boiling heat exchanger 10 rises to a predetermined value, and the boiling is completed.

  On the other hand, as a comparative example, as shown in FIG. 6, when the boiling capacity of the heat pump 7 remains constant and does not decrease, the temperature of the hot water from the boiling heat exchanger 10 rises, The refrigerant temperature rises and the discharge pressure of the compressor 71 rises. Thereby, the pressure in the heat pump 7 rises and the heat pump 7 is damaged.

  As another comparative example, as shown in FIG. 7, when the boiling capacity of the heat pump 7 is reduced when the temperature of water entering the boiling heat exchanger 10 exceeds a certain value Th, The temperature of the hot water from the exchanger 10 rises, the temperature of the refrigerant in the heat pump 7 rises, and the discharge pressure of the compressor 71 rises. Thereby, the pressure in the heat pump 7 rises and the heat pump 7 is damaged.

  According to the embodiment, the mounting position of the first temperature sensor T1 with respect to the hot water storage tank 3 is a position where the capacity of the hot water storage tank 3 below the first temperature sensor T1 is 70 liters. . Thereby, the part where the capacity | capacitance of the lower side of the hot water storage tank 3 becomes 70 liter can be made into the 1st layer S1 of low temperature water, and can ensure the 1st layer S1 reliably. Therefore, before the boiling capacity is reduced by the boiling capacity control unit 100e, it is possible to more reliably suppress the medium temperature water in the hot water storage tank 3 from entering the boiling heat exchanger 10 of the heat pump 7.

  According to the embodiment, the refrigerant flowing through the heat pump 7 is an HFC refrigerant. The heating capacity of the HFC refrigerant in the boiling heat exchanger 10 is unlikely to drop regardless of the temperature of the water flowing into the boiling heat exchanger 10 from the hot water storage tank 3. However, according to the present invention, the temperature rise of the HFC refrigerant in the heat pump 7 can be effectively suppressed.

  According to the embodiment, the boiling heat exchanger 10 of the heat pump 7 is included in the hot water storage unit 1 including the hot water storage tank 3. The boiling heat exchanger 10 is disposed at a position close to the hot water storage tank 3, but according to the present invention, it is effective that the medium temperature water in the hot water storage tank 3 enters the boiling heat exchanger 10 of the heat pump 7. Can be suppressed.

  The present invention is not limited to the above-described embodiment, and the design can be changed without departing from the gist of the present invention.

  In the said embodiment, although the said boiling capability control part reduced the boiling capability by a heat pump in two steps, you may make it reduce in one step or three steps or more.

  In the above embodiment, the mounting position of the first temperature sensor with respect to the hot water storage tank is the position where the capacity below the first temperature sensor in the hot water storage tank is 70 liters, but the first temperature sensor in the hot water storage tank is The lower capacity may be a position where the capacity is 50 liters to 80 liters.

  In the above embodiment, the hot water storage tank has three layers of the first layer, the second layer, and the third layer. However, the hot water storage tank may have two or more layers.

  In the above embodiment, HFC is used as the refrigerant of the heat pump, but a CO2 refrigerant and other refrigerants may be used.

  In the above embodiment, the heating heat exchanger of the heat pump is included in the hot water storage unit, but may be included in the outdoor unit.

DESCRIPTION OF SYMBOLS 1 Hot water storage unit 2 Outdoor unit 3 Hot water storage tank 7 Heat pump 10 Boiling heat exchanger 71 Compressor 72 Expansion valve 73 Air heat exchanger 74 Heat exchange fan 100 Controller 100a Hot water supply control part 100b Hot water supply control part 100c Reheating control part 100d Boiling control unit 100e Boiling capacity control unit P1 Boiling circulation pump T1 First temperature sensor S1 First layer S2 Second layer S3 Third layer

  The present invention relates to a hot water supply apparatus.

  Conventionally, as a hot-water supply apparatus, there exist some which were described in Unexamined-Japanese-Patent No. 2002-340402 (patent document 1). This hot water supply apparatus has a hot water storage tank, a heat pump for boiling water in the hot water storage tank, and a control device for controlling the heat pump.

  The heat pump includes a compressor, a boiling heat exchanger, an expansion valve, and an evaporator. The hot water storage tank is connected to a boiling heat exchanger via a pipe. A temperature sensor is attached to the pipe between the hot water storage tank and the boiling heat exchanger, and the temperature sensor detects the temperature of the water flowing into the boiling heat exchanger. The control device reduces the rotational speed of the compressor when the temperature detected by the temperature sensor exceeds a predetermined set value. Thereby, when the completion of boiling of the hot water storage tank is approaching, the rotational speed of the compressor is reduced, and an increase in the discharge pressure of the compressor is suppressed.

Japanese Patent Laid-Open No. 2002-340402

  By the way, in the said conventional hot water supply apparatus, since the rotation speed of the compressor was made small after detecting the temperature of the water flowing into the boiling heat exchanger, the boiling heat exchanger increased to some extent. Water temperature (medium temperature water) will flow in. As a result, the temperature of the refrigerant in the heat pump rises, the pressure in the heat pump rises, and the heat pump may be damaged.

  Then, the subject of this invention is providing the hot-water supply apparatus which suppresses the temperature rise of the refrigerant | coolant in a heat pump, suppresses the pressure rise in a heat pump, and prevents the failure | damage of a heat pump.

In order to solve the above problems, the hot water supply apparatus of the present invention is:
A hot water storage tank,
A heat pump including a boiling heat exchanger that performs heat exchange with the water in the hot water storage tank to boil the water in the hot water storage tank;
A temperature sensor for detecting the temperature of water in the hot water storage tank;
A boiling capacity control unit for controlling the boiling capacity of the heat pump;
The hot water storage tank at the start boiling, the a first layer of low-temperature water which is located lowermost of the hot water storage tank, the first positioned above the layer of a temperature higher than the low temperature water A second layer made of medium-temperature water, and a third layer made of high-temperature water at a higher temperature than the medium-temperature water located above the second layer ,
The temperature sensor is above the lowermost layer of the hot water storage tank in a state in which the first layer remains, the warm water temperature constituting the second layer located above the said first layer In a detectable position,
The boiling capacity control unit controls the heat pump so that the boiling capacity of the heat pump decreases when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value. It is characterized by that.

According to the hot water supply device of the present invention, the temperature sensor is in a state in which the lowermost layer in the hot water storage tank remains the first layer, in forming the second layer is positioned above the first layer It is in a position where the temperature of hot water can be detected. The boiling capacity control unit controls the heat pump so that the boiling capacity of the heat pump decreases when the temperature of the medium-temperature water detected by the temperature sensor exceeds a predetermined set value.

  Accordingly, when the water in the hot water storage tank is boiled by the heat pump, the temperature detected by the temperature sensor exceeds a predetermined set value. Then, the said boiling capacity control part controls a heat pump so that the boiling capacity by a heat pump may fall. At this time, since the first layer of low temperature water remains in the lowermost layer of the hot water storage tank, the medium temperature water in the hot water storage tank is boiled in the heat pump before the boiling capacity control unit lowers the boiling capacity. It can suppress entering into a raising heat exchanger.

  Therefore, the temperature rise of the refrigerant in the heat pump is suppressed, the pressure increase in the heat pump is suppressed, and the heat pump is prevented from being damaged.

  Moreover, in the hot water supply apparatus of one Embodiment, the attachment position with respect to the said hot water storage tank of the said temperature sensor is a position from which the capacity | capacitance below the said temperature sensor in the said hot water storage tank becomes 50 to 80 liters.

  According to the hot water supply apparatus of the above embodiment, the mounting position of the temperature sensor with respect to the hot water storage tank is a position where the capacity of the hot water storage tank below the temperature sensor is 50 liters to 80 liters. Thereby, the part where the capacity | capacitance of the lower side of a hot water storage tank becomes 50 liters to 80 liters can be made into the 1st layer of low temperature water, and a 1st layer can be ensured reliably. Therefore, before the boiling capacity is reduced by the boiling capacity control unit, it is possible to more reliably prevent the medium temperature water in the hot water storage tank from entering the boiling heat exchanger of the heat pump.

  Moreover, in the hot water supply device of one embodiment, the refrigerant flowing through the heat pump is an HFC refrigerant.

  According to the hot water supply apparatus of the above embodiment, the refrigerant flowing through the heat pump is an HFC refrigerant. The heating capacity of the HFC refrigerant in the boiling heat exchanger is unlikely to drop regardless of the temperature of the water flowing into the boiling heat exchanger from the hot water storage tank. However, the present invention can effectively suppress the temperature rise of the HFC refrigerant in the heat pump.

  In one embodiment of the hot water supply apparatus, the boiling heat exchanger of the heat pump is included in a hot water storage unit including the hot water storage tank.

  According to the hot water supply apparatus of the embodiment, the boiling heat exchanger of the heat pump is included in a hot water storage unit including the hot water storage tank. Although the boiling heat exchanger is disposed at a position close to the hot water storage tank, according to the present invention, it is possible to effectively suppress the medium temperature water in the hot water storage tank from entering the boiling heat exchanger of the heat pump.

Further, in the hot water supply apparatus according to one embodiment, the boiling capacity control unit rotates the compressor of the heat pump when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value. Reduce the number.

According to the hot water supply apparatus of the embodiment, the boiling capacity control unit rotates the compressor of the heat pump when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value. Reduce the number. Thereby, the boiling capability by a heat pump can be reduced effectively.

Further, in the hot water supply apparatus according to an embodiment, the boiling capacity control unit opens the expansion valve of the heat pump when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value. Increase the degree.

According to the hot water supply apparatus of the above embodiment, the boiling capacity control unit opens the expansion valve of the heat pump when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value. Increase the degree. Thereby, the boiling capability by a heat pump can be reduced effectively.

Further, in the hot water supply apparatus according to an embodiment, the boiling capacity control unit is configured to control the heat exchange fan of the heat pump when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value. Reduce the rotation speed.

According to the hot water supply apparatus of the above embodiment, the boiling capacity control unit, when the temperature of the medium temperature water detected by the temperature sensor exceeds a predetermined set value, the heat exchange fan of the heat pump. Reduce the rotation speed. Thereby, the boiling capability by a heat pump can be reduced effectively.

According to the hot water supply apparatus of the present invention, the temperature sensor is configured such that the first layer remains in the lowermost layer in the hot water storage tank, and the intermediate temperature water of the second layer located above the first layer is present. It is in a position where temperature can be detected. The boiling capacity control unit controls the heat pump so that the boiling capacity of the heat pump decreases when the temperature of the medium-temperature water detected by the temperature sensor exceeds a predetermined set value. Thereby, the temperature rise of the refrigerant | coolant in a heat pump is suppressed, the pressure rise in a heat pump is suppressed, and the failure | damage of a heat pump is prevented.

It is a simplified lineblock diagram showing the hot-water supply device of one embodiment of the present invention. It is a block diagram of a hot water supply apparatus. It is explanatory drawing which shows the state of the hot water storage tank at the time of a boiling start. It is explanatory drawing which shows the state of the hot water storage tank which predetermined time passed since boiling start. It is explanatory drawing which shows the control by a boiling capability control part. It is explanatory drawing which shows the effect by the boiling capability control part. It is explanatory drawing which shows the comparative example of the control by a boiling capability control part. It is explanatory drawing which shows the comparative example of the control by a boiling capability control part.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 is a simplified configuration diagram illustrating a hot water supply apparatus according to an embodiment of the present invention. As shown in FIG. 1, the hot water supply apparatus includes a hot water storage unit 1 and an outdoor unit 2 connected to the hot water storage unit 1. The hot water storage unit 1 includes a hot water storage tank 3, a boiling heat exchanger 10, a reheating heat exchanger 20, a control device 100, and the like.

  One end of the pipe L1 is connected to the lower part of the hot water storage tank 3, and the other end of the pipe L1 is connected to a first water inlet port of a boiling mixing valve 50 as an example of a mixing valve. One end of the pipe L <b> 2 is connected to the water outlet port of the boiling mixing valve 50, and the other end of the pipe L <b> 2 is connected to one end of the boiling heat exchanger 10. The other end of the boiling heat exchanger 10 is connected to one end of the pipe L3, and the other end of the pipe L3 is connected to the upper part of the hot water storage tank 3. A boiling circulation pump P1 as an example of a boiling pump is disposed in the pipe L2.

  The piping L1, the piping L2, the boiling heat exchanger 10, and the piping L3 constitute a boiling circuit.

  The hot water in the hot water storage tank 3 is connected to the pipe L1 by driving the hot water circulating pump P1 with the opening degree of the first mixing port 50 (hot water storage tank 3 side) of the boiling mixing valve 50 fully opened. , Circulating through the mixing valve 50 for boiling, the pipe L2, the boiling heat exchanger 10, and the pipe L3.

  The boiling heat exchanger 10 is connected to the outdoor unit 2 through refrigerant pipes L4 and L5. The outdoor unit 2 includes a compressor 71, an expansion valve 72, an air heat exchanger 73, and a heat exchange fan 74. The compressor 71, the boiling heat exchanger 10, the expansion valve 72, and the air heat exchanger 73 are connected in order to constitute the heat pump 7. The heat exchanger fan 74 blows air to the air heat exchanger 73 to exchange heat between the air and the refrigerant.

  The heat pump 7 uses HFC refrigerant, and can control the temperature of the hot water from the boiling heat exchanger 10 in a range of, for example, 50 ° C to 70 ° C. Examples of the HFC refrigerant used in the heat pump 7 include R32, R125, R134a, R404A, R410A, and R407C.

  Next, an external water supply pipe is connected to the lower part of the hot water storage tank 3 through a pipe L11. A pressure reducing valve 11 and a check valve 12 are arranged in this pipe L11 in order from the upstream side. This check valve 12 allows only the flow from the water supply pipe side to the hot water storage tank 3 side.

  One end of the pipe L <b> 21 is connected to the upper part of the hot water storage tank 3, and the other end of the pipe L <b> 21 is connected to the primary water inlet port of the heat exchanger 20. One end of the pipe L22 is connected to the primary water outlet port of the reheating heat exchanger 20, and the other end of the pipe L22 is connected to the second water inlet port of the boiling mixing valve 50.

  The pipe L21, the reheating heat exchanger 20, and the line L22 constitute a bath reheating circuit.

  By driving the boiling circulation pump P1 with the opening on the second water inlet port side (bath reheating circuit side) of the boiling mixing valve 50 fully open, the hot water in the hot water storage tank 3 is removed. Circulate through the pipe L21, the reheating heat exchanger 20 (primary side), the pipe L22, the boiling mixing valve 50, the pipe L2, the boiling heat exchanger 10, and the pipe L3.

  Further, one end of the pipe L31 is connected to the upper part of the hot water storage tank 3, and the other end of the pipe L31 is connected to the first water inlet port of the hot water supply mixing valve 22. A check valve 21 that allows only a flow from the hot water storage tank 3 side to the hot water supply mixing valve 22 is disposed in the pipe L31. One end of the branch pipe L12 is connected to the second water inlet port of the hot water supply mixing valve 22, and the other end of the branch pipe L12 is connected between the pressure reducing valve 11 and the check valve 12 of the pipe L11. The branch pipe L12 is provided with a check valve 23 that allows only the flow from the pipe L11 side to the hot water supply mixing valve 22.

  Then, one end of the pipe L32 is connected to the water outlet port of the hot water supply mixing valve 22, and the other end of the pipe L32 is connected to the hot water tap 60 (a faucet in this embodiment). A water amount sensor 24 is disposed in the pipe L32.

  The branch pipe L12, the pipe L31, the pipe L32, the check valve 21, the hot water supply mixing valve 22, the check valve 23, and the water amount sensor 24 constitute a hot water supply circuit.

  Further, one end of the pipe L33 is connected to the upstream side of the water amount sensor 24 of the pipe L32, and the other end of the pipe L33 is connected to the hot water supply port 9a of the connection adapter 9 provided in the bathtub 4. A hot water filling solenoid valve 25, a check valve 26, a water amount sensor 27, and a check valve 28 are arranged in this order from the upstream side of the pipe L33. The check valves 26 and 28 allow only the flow from the hot water supply mixing valve 22 side to the bathtub 4.

  The pipe L33, the hot water solenoid valve 25, the check valves 26 and 28, and the water amount sensor 27 constitute a bath hot water supply circuit branched from the hot water supply pipe L32 and connected to the bathtub 4.

  One end of the pipe L35 is connected to the water intake port 9b for replenishment of the connection adapter 9, and the other end of the pipe L35 is connected to the water inlet port on the secondary side of the heat exchanger 20. A circulation pump P2 for bath is disposed in the pipe L35. Further, one end of the pipe L34 is connected to the downstream side of the water amount sensor 27 of the pipe L33, and the other end of the pipe L34 is connected to the secondary water outlet port of the heat exchanger 20.

  The hot water in the bathtub 4 is circulated through the pipe L35, the reheating heat exchanger 20 (secondary side), the pipe L34, and the pipe L33 (part) by the bath circulation pump P2.

  The pipe L35, the reheating heat exchanger 20 (secondary side), the pipe L34, and the pipe L33 (part) constitute a bath circulation circuit.

  Furthermore, one end of the pipe L41 is connected to the pipe L21, and the other end of the pipe L41 is connected to the drain port. A relief valve 31 is provided in the pipe L41.

  The hot water storage tank 3 is provided with first to fourth temperature sensors T1 to T4 at substantially equal intervals from the lower side to the upper side. The first to fourth temperature sensors T <b> 1 to T <b> 4 detect the water temperature in the hot water storage tank 3.

  In addition, a temperature sensor T11 that detects the incoming water temperature is provided in the pipe L3, and a temperature sensor T12 that detects the tapping temperature is provided in the pipe L3. The temperature sensor T11 is an example of an incoming water temperature sensor, and the temperature sensor T12 is an example of a tapping temperature sensor.

  Further, the boiling heat exchanger 10 is provided with a temperature sensor T13. In addition, a temperature sensor T <b> 21 for detecting a hot water supply temperature is provided in the pipe L <b> 32 connected to the hot water tap 60 on the downstream side of the water amount sensor 24. In addition, a water level sensor LS, a water flow switch SW, and a temperature sensor T23 are connected to the pipe L35 connected to the bathtub 4 from the connection adapter 9 side between the connection adapter 9 on the bathtub 4 side and the circulation pump P2 for bath. In order. Furthermore, a temperature sensor T22 that detects the temperature of hot water supplied to the bathtub 4 is provided downstream of the check valve 28 of the pipe L33 connected to the bathtub 4 and at a connection point between the pipe L33 and the pipe L34. Yes.

  As shown in FIG. 2, the hot water supply apparatus includes a control device 100 including a microcomputer and an input / output circuit, and a remote controller 200 that transmits and receives signals to and from the control device 100. The control device 100 includes signals from temperature sensors T1 to T4, T11 to T13, T21 to T23, a water level sensor LS, a water flow switch SW, water volume sensors 24 and 27, an outside air temperature sensor (not shown), a remote controller 200, and the like. In response, the heat pump 7, the boiling circulation pump P1, the bath circulation pump P2, the hot water mixing valve 22, the hot water solenoid valve 25, the boiling mixing valve 50, and the like are controlled.

  Further, the control device 100 includes a hot water supply control unit 100a that controls a hot water supply temperature to the hot water tap 60, a hot water supply control unit 100b that controls a hot water supply operation to the bathtub 4 including a “bath hot water filling operation”, and the like. A reheating control unit 100c that controls the “bath reheating operation”, a boiling control unit 100d that controls the operation of boiling hot water in the hot water storage tank 3, and a boiling capacity control unit that controls the heating capacity of the heat pump 7. 100e.

  The hot water supply control unit 100a controls the mixing ratio of the hot water supply mixing valve 22 so that the hot water supply temperature detected by the temperature sensor T21 becomes the hot water supply set temperature.

  When performing a “bath hot water filling operation” in which hot water is supplied from the hot water storage tank 3 into the bath tub 4, the hot water filling electromagnetic valve 25 is opened by the hot water control unit 100 b, and hot water in the hot water storage tank 3 is mixed with the hot water mixing valve. 22 and the bath hot water supply circuit (L33, 25, 26, 27, 28). At this time, the hot water pouring control unit 100b controls the hot water supply mixing valve 22 to mix the hot water from the hot water storage tank 3 and the external water supply based on the target set temperature, and by the water level sensor LS. When the detected water level in the bathtub 4 reaches the set water level, the hot water solenoid valve 25 is closed.

  When performing a “bath reheating operation” in which the hot water in the bath tub 4 is replenished from the hot water storage tank 3, the recirculation control unit 100c controls the bath circulation pump P2 with the hot water filling solenoid valve 25 closed. In operation, the hot water in the bathtub 4 is circulated through the pipe L35, the reheating heat exchanger 20 (secondary side), the pipe L34, and the pipe L33 (part).

  Then, based on the bath temperature of the hot water in the bathtub 4 detected by the temperature sensor T23, the reheating controller 100c performs a reheating operation using the hot water in the hot water storage tank 3 as a heat source without using the heat pump 7. Alternatively, when the amount of heat in the hot water storage tank 3 is not sufficient, the bath pumping operation is performed using the heat pump 7.

  In the “boiling operation” in which hot water in the hot water storage tank 3 is heated by the heat pump 7, the opening control unit 100d fully opens the opening on the first water inlet port side (hot water storage tank 3 side) of the boiling mixing valve 50. The boiling circulation pump P1 is operated in the state of being heated, and the hot water in the hot water storage tank 3 is circulated through the pipe L1, the boiling mixing valve 50, the pipe L2, the boiling heat exchanger 10, and the pipe L3. .

  The boiling control unit 100d controls the heat pump 7 and the boiling circulation pump P1 so that the tapping temperature detected by the temperature sensor T12 becomes the target tapping temperature TS during the boiling operation. Here, the target hot water temperature TS is calculated by the control device 100 based on the amount of hot water supplied from the hot water storage tank 3 and the like. For example, when the amount of hot water used is large, the target hot water temperature TS is as high as 70 ° C., for example, and when the amount of hot water used is small, the target hot water temperature TS is as low as 50 ° C., for example.

  The boiling capacity control unit 100e controls the heat pump 7 so that the boiling capacity of the heat pump 7 is lowered when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. .

  Here, as shown to FIG. 3A, the said hot water storage tank 3 has the 1st layer S1 of low temperature water in the lowest layer in the hot water storage tank 3 at the time of a boiling start. The hot water storage tank 3 has a second layer S2 above the first layer S1, and a third layer S3 above the second layer S2. The second layer S2 is at a higher temperature than the first layer S1. The third layer S3 is at a higher temperature than the second layer S2. For example, the temperature of the first layer S1 is 10 ° C., the temperature of the second layer S2 is 30 ° C., and the temperature of the third layer S3 is 65 ° C. When the total capacity of the hot water storage tank 3 is 320 liters, the first layer S1 is a portion where the lower capacity of the hot water storage tank 3 is 160 liters. Note that the first layer S1, the second layer S2, and the third layer S3 are completely separated in the temperature distribution, but this is for explanation, and in the actual hot water storage tank 3, the first layer S1 The temperature continuously changes at the boundary between the second layer S1, the second layer S2, and the third layer S3.

  As shown in FIG. 3B, the first temperature sensor T1 is positioned above the first layer S1 and the first temperature sensor T1 with the first layer S1 remaining in the lower part of the hot water storage tank 3. It exists in the position which can detect 2nd layer S2 of temperature higher than layer S1. FIG. 3B shows a state of the hot water storage tank 3 after a predetermined time has elapsed since the start of boiling.

  The mounting position of the first temperature sensor T1 with respect to the hot water storage tank 3 is a position where the capacity of the hot water storage tank 3 below the first temperature sensor T1 is 70 liters. That is, the first layer S1 is a portion where the lower volume of the hot water storage tank 3 is 70 liters. If the total capacity of the hot water storage tank 3 is 320 liters, the second layer S2 and the third layer S3 are portions where the upper capacity of the hot water storage tank 3 is 250 liters.

  As shown in FIG. 4, there are, for example, three controls as specific controls by the boiling capacity control unit 100e.

  As the first control, the boiling capacity control unit 100e reduces the rotation speed of the compressor 71 of the heat pump 7 when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. To do. In FIG. 4, the rotation speed of the compressor 71 of the heat pump 7 is reduced in two stages.

  As the second control, the boiling capacity control unit 100e increases the degree of opening of the expansion valve 72 of the heat pump 7 when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. To do. In FIG. 4, the opening degree of the expansion valve 72 of the heat pump 7 is increased in two stages.

  As the third control, the boiling capacity control unit 100e determines the number of rotations of the heat exchanger fan 74 of the heat pump 7 when the temperature detected by the first temperature sensor T1 exceeds a predetermined set value. Make it smaller. In FIG. 4, the rotational speed of the heat exchange fan 74 of the heat pump 7 is reduced in two steps.

  With any of the first to third controls, the boiling capacity control unit 100e can reduce the boiling capacity of the heat pump 7 in two stages. The control by the boiling capacity control unit 100e may be any one of the first to third controls, or a combination of at least two controls of the first to third controls. May be.

  The effect by the said boiling capability control part 100e is demonstrated using FIG. 1 and FIG.

  When the water in the hot water storage tank 3 is boiled up by the heat pump 7, the temperature detected by the first temperature sensor T1 exceeds a predetermined first set value Th1. Then, the boiling capacity control unit 100e reduces the boiling capacity of the heat pump 7 by one step. Further, when the temperature detected by the first temperature sensor T1 exceeds a predetermined second set value Th2, the boiling capacity control unit 100e further decreases the boiling capacity of the heat pump 7 by one step. .

  At this time, since the first layer S1 (see FIG. 3B) of the low-temperature water remains in the lowermost layer of the hot water storage tank 3, the hot water storage tank before the boiling capacity is reduced by the boiling capacity control unit 100e. It is possible to suppress the medium-temperature water in 3 from entering the boiling heat exchanger 10.

  Therefore, the temperature rise of the hot water from the boiling heat exchanger 10 is suppressed, the temperature rise of the refrigerant in the heat pump 7 is suppressed, and the increase in the discharge pressure of the compressor 71 is suppressed. Thereby, the pressure rise in the heat pump 7 is suppressed, and damage to the heat pump 7 is prevented.

  As the temperature of the water entering the boiling heat exchanger 10 rises, the boiling flow rate by the boiling circulation pump P1 increases. The temperature of the water entering the boiling heat exchanger 10 rises to a predetermined value, and the boiling is completed.

  On the other hand, as a comparative example, as shown in FIG. 6, when the boiling capacity of the heat pump 7 remains constant and does not decrease, the temperature of the hot water from the boiling heat exchanger 10 rises, The refrigerant temperature rises and the discharge pressure of the compressor 71 rises. Thereby, the pressure in the heat pump 7 rises and the heat pump 7 is damaged.

  As another comparative example, as shown in FIG. 7, when the boiling capacity of the heat pump 7 is reduced when the temperature of water entering the boiling heat exchanger 10 exceeds a certain value Th, The temperature of the hot water from the exchanger 10 rises, the temperature of the refrigerant in the heat pump 7 rises, and the discharge pressure of the compressor 71 rises. Thereby, the pressure in the heat pump 7 rises and the heat pump 7 is damaged.

  According to the embodiment, the mounting position of the first temperature sensor T1 with respect to the hot water storage tank 3 is a position where the capacity of the hot water storage tank 3 below the first temperature sensor T1 is 70 liters. . Thereby, the part where the capacity | capacitance of the lower side of the hot water storage tank 3 becomes 70 liter can be made into the 1st layer S1 of low temperature water, and can ensure the 1st layer S1 reliably. Therefore, before the boiling capacity is reduced by the boiling capacity control unit 100e, it is possible to more reliably suppress the medium temperature water in the hot water storage tank 3 from entering the boiling heat exchanger 10 of the heat pump 7.

  According to the embodiment, the refrigerant flowing through the heat pump 7 is an HFC refrigerant. The heating capacity of the HFC refrigerant in the boiling heat exchanger 10 is unlikely to drop regardless of the temperature of the water flowing into the boiling heat exchanger 10 from the hot water storage tank 3. However, according to the present invention, the temperature rise of the HFC refrigerant in the heat pump 7 can be effectively suppressed.

  According to the embodiment, the boiling heat exchanger 10 of the heat pump 7 is included in the hot water storage unit 1 including the hot water storage tank 3. The boiling heat exchanger 10 is disposed at a position close to the hot water storage tank 3, but according to the present invention, it is effective that the medium temperature water in the hot water storage tank 3 enters the boiling heat exchanger 10 of the heat pump 7. Can be suppressed.

  The present invention is not limited to the above-described embodiment, and the design can be changed without departing from the gist of the present invention.

  In the said embodiment, although the said boiling capability control part reduced the boiling capability by a heat pump in two steps, you may make it reduce in one step or three steps or more.

  In the above embodiment, the mounting position of the first temperature sensor with respect to the hot water storage tank is the position where the capacity below the first temperature sensor in the hot water storage tank is 70 liters, but the first temperature sensor in the hot water storage tank is The lower capacity may be a position where the capacity is 50 liters to 80 liters.

  In the above embodiment, the hot water storage tank has three layers of the first layer, the second layer, and the third layer. However, the hot water storage tank may have two or more layers.

  In the above embodiment, HFC is used as the refrigerant of the heat pump, but a CO2 refrigerant and other refrigerants may be used.

  In the above embodiment, the heating heat exchanger of the heat pump is included in the hot water storage unit, but may be included in the outdoor unit.

DESCRIPTION OF SYMBOLS 1 Hot water storage unit 2 Outdoor unit 3 Hot water storage tank 7 Heat pump 10 Boiling heat exchanger 71 Compressor 72 Expansion valve 73 Air heat exchanger 74 Heat exchange fan 100 Controller 100a Hot water supply control part 100b Hot water supply control part 100c Reheating control part 100d Boiling control unit 100e Boiling capacity control unit P1 Boiling circulation pump T1 First temperature sensor S1 First layer S2 Second layer S3 Third layer

Claims (7)

A hot water storage tank (3),
A heat pump (7) including a boiling heat exchanger (10) for exchanging heat with water in the hot water storage tank (3) to boil water in the hot water storage tank (3);
A temperature sensor (T1) for detecting the temperature of water in the hot water storage tank (3);
A boiling capacity control unit (100e) for controlling the boiling capacity of the heat pump (7),
The hot water storage tank (3) has a first layer (S1) of low temperature water at the lowest layer in the hot water storage tank (3) at the start of boiling,
The temperature sensor (T1) is located above the first layer (S1) with the first layer (S1) remaining in the lowermost layer in the hot water storage tank (3) and the temperature sensor (T1). The second layer (S2) having a temperature higher than that of the first layer (S1) is in a detectable position,
When the temperature detected by the temperature sensor (T1) exceeds a predetermined set value, the boiling capacity control unit (100e) is configured so that the boiling capacity of the heat pump (7) decreases. A hot water supply apparatus for controlling the heat pump (7). The hot water supply apparatus according to claim 1,
The mounting position of the temperature sensor (T1) with respect to the hot water storage tank (3) is a position where the capacity of the hot water storage tank (3) below the temperature sensor (T1) is 50 liters to 80 liters. A hot water supply device. The hot water supply apparatus according to claim 1 or 2,
The hot water supply apparatus, wherein the refrigerant flowing through the heat pump (7) is an HFC refrigerant. The hot water supply device according to any one of claims 1 to 3,
The hot water supply device, wherein the boiling heat exchanger (10) of the heat pump (7) is included in a hot water storage unit (1) including the hot water storage tank (3). In the hot water supply device according to any one of claims 1 to 4,
When the temperature detected by the temperature sensor (T1) exceeds a predetermined set value, the boiling capacity control unit (100e) sets the rotation speed of the compressor (71) of the heat pump (7). A hot water supply device characterized by being made small. In the hot water supply device according to any one of claims 1 to 5,
When the temperature detected by the temperature sensor (T1) exceeds a predetermined set value, the boiling capacity control unit (100e) controls the opening degree of the expansion valve (72) of the heat pump (7). A hot water supply device that is enlarged. The hot water supply apparatus according to any one of claims 1 to 6,
When the temperature detected by the temperature sensor (T1) exceeds a preset value, the boiling capacity control unit (100e) rotates the heat exchange fan (74) of the heat pump (7). The hot water supply device characterized by making small.

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