JP2009150612A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater for reducing a time to release heat to secondary fluid circulating in a utility terminal. <P>SOLUTION: The heat pump type water heater includes a hot water storage tank 1 for storing hot water, a heat pump unit 17 for heating water in the hot water storage tank 1, a circulation pump 11 for feeding water from the lower side of the hot water storage tank 1 into the heat pump unit 17, a boiling circuit for returning high temperature water produced by the heat pump unit 17 into the upper side of the hot water storage tank 1, the utility terminal 8 having a utility secondary circuit 5 in which secondary fluid circulates, and a utility primary circuit 3 for releasing the heat of hot water in the hot water storage tank 1 to the secondary fluid. The hot water heated by the heat pump unit 17 is supplied to the utility primary circuit 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat pump type hot water heater, and more particularly to a circuit for applying heat from hot water in a hot water storage tank to a secondary fluid circulating through a use terminal such as a fluid flowing in floor heating or hot water in a bathtub. .

  FIG. 4 shows a configuration diagram of a heat pump type hot water heater having a function of chasing hot water in a conventional bathtub (see, for example, Patent Document 1). As shown in FIG. 4, the heat pump type hot water heater includes a heat pump unit 117 having a water / refrigerant heat exchanger 109 for heating hot water in the hot water storage tank 101.

  And the lower part of the hot water storage tank 101 and the water refrigerant heat exchanger 109 are connected, a circulation pump 111 is disposed between the hot water storage tank 101 and the water refrigerant heat exchanger 109, and the circulation pump 111 is driven to drive The water in the lower part of the hot water storage tank 101 is sent to the water-refrigerant heat exchanger 109, and the water-refrigerant heat exchanger 109 dissipates heat from the refrigerant to the water, thereby generating high-temperature water.

  Then, the high temperature water generated by the water-refrigerant heat exchanger 109 is supplied to the upper part of the hot water storage tank 1, and the high temperature water is stored in a stacked state from the upper part of the hot water storage tank 1.

  The refrigerant cycle of the heat pump unit 117 uses carbon dioxide as a refrigerant, and is configured by sequentially connecting a water refrigerant heat exchanger 109, a compressor 114, an evaporator 115, and an expansion valve 116 in an annular manner through refrigerant piping. Has been. Then, the refrigerant is compressed by the compressor 114, the refrigerant discharged from the compressor 114 dissipates heat by the water refrigerant heat exchanger 109, is decompressed by the expansion valve 116, and then absorbs heat from the air by the evaporator 115, The gas is again sucked into the compressor 114.

  Next, a portion related to replenishing water in the bathtub 108 will be described.

A reheating primary circuit 103 that connects the upper part of the hot water storage tank 101, the reheating heat exchanger 102 (primary side), the recirculation circulation pump 104, and the lower part of the hot water storage tank 101, the bathtub 108, the bathtub water circulation pump 106, and the reheating A reheating secondary circuit 105 that is connected again to the bathtub 108 via the heating heat exchanger 102 (secondary side) is provided, and when replenishing the water in the bathtub 108, the hot water in the upper part of the hot water storage tank 101 is replenished. The recirculation pump 104 is sent to the reheating heat exchanger 102 (primary side), cooled, and returned to the lower part of the hot water storage tank 101, and the water in the bathtub 108 is reheated by the recirculation water pump 106. It is sent to 102 (secondary side) and returned to the bathtub 108 after heating.
Japanese Patent Laying-Open No. 2005-147583

  However, in the conventional configuration, when the reheating is performed, the hot water of the hot water storage tank 101 is used as a heating source. Therefore, when the amount of heat stored in the hot water storage tank 101 is small and insufficient to perform the reheating, first, It is necessary to secure a sufficient amount of heat storage in the hot water storage tank 101 for operating the heat pump unit to perform reheating, and during this time, the reheating operation is stopped, and as a result, reheating is completed. There was a problem of taking time.

This invention solves the said conventional subject, and it aims at providing the heat pump type water heater which shortens the time to radiate | emit heat to the secondary side fluid which circulates in the utilization terminal (in the conventional example, a bathtub).

  In order to solve the conventional problems, a heat pump type hot water heater of the present invention includes a hot water storage tank for storing hot water, a heat pump unit for heating water in the hot water storage tank, and water in a lower portion of the hot water storage tank. A circulation pump to be sent to the heating tank, a boiling circuit for returning the high-temperature water generated by the heat pump unit to the upper part of the hot water storage tank, a use terminal having a use secondary circuit for circulating a secondary fluid, and hot water in the hot water storage tank A primary circuit for dissipating heat to the secondary fluid, and is configured to be able to supply hot water heated by the heat pump unit to the primary circuit, thereby reducing the amount of heat stored in the hot water storage tank. However, since hot water heated by the heat pump unit can be dissipated directly to the secondary fluid, it is possible to store enough hot water in the hot water storage tank. No, it is possible to provide heat to the secondary side fluid.

  The heat pump type hot water heater of the present invention can provide a heat pump type hot water heater that shortens the time for radiating heat to the secondary fluid circulating in the use terminal.

  The heat pump type hot water heater of the first invention includes a hot water storage tank for storing hot water, a heat pump unit for heating the water in the hot water storage tank, a circulation pump for sending water in the lower part of the hot water storage tank to the heat pump unit, and the heat pump. A boiling circuit for returning the high-temperature water generated by the unit to the upper part of the hot water storage tank, a user terminal having a usage secondary circuit for circulating the secondary side fluid, and the hot water in the hot water storage tank for releasing heat to the secondary side fluid And the use primary circuit is configured to supply hot water heated by the heat pump unit to the use primary circuit, so that the heat pump unit is heated even if the amount of heat stored in the hot water storage tank is small. Since the hot water can be radiated directly to the secondary fluid, heat is given to the secondary fluid without storing enough hot water in the hot water storage tank. It is possible.

  The heat pump type hot water heater of the second invention is the heat pump type hot water heater of the first invention, in particular, the primary circuit used is an upper part of the hot water storage tank, a radiator that radiates heat to the secondary fluid, and the radiator A heating circulation pump for sending hot water in the hot water storage tank and a lower part of the hot water storage tank are connected, and a bypass pipe branched from a pipe for sending hot water from the heat pump unit to the upper part of the hot water storage tank is connected to the upper part of the hot water storage tank. The hot water heated in the heat pump unit by switching the three-way valve to the heat radiator that radiates heat to the secondary fluid It is possible to select whether to send the hot water in the radiator to the radiator.

  In the heat pump type hot water heater of the third invention, particularly in the second invention, in the boiling circuit, a check valve is provided between the branch point of the bypass pipe and the upper part of the hot water storage tank. Hot water can be reliably sent from the heat pump unit to the radiator.

  The heat pump hot water heater of the fourth invention is a flow path for sending hot water in the hot water storage tank to the radiator according to the heating capacity required by the user terminal, particularly in the second or third invention, By controlling the three-way valve so as to switch the flow path of hot water heated by the heat pump unit to the radiator, an optimal method for radiating heat to the secondary fluid can be selected.

The heat pump type hot water heater according to a fifth aspect of the present invention is the heat pump type water heater according to the second or third aspect of the present invention, wherein the flow path for sending hot water in the hot water storage tank to the radiator according to the amount of heat stored in the hot water storage tank, and the heat pump By controlling the three-way valve so as to switch the flow path for supplying hot water heated by the unit to the radiator, an optimum method for radiating heat to the secondary fluid can be selected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump type water heater in the present embodiment. In FIG. 1, the heat pump type water heater of the present embodiment includes a hot water storage tank 1 for storing hot water, and a lower portion of the hot water storage tank 1, a circulation pump 11, a water refrigerant heat exchanger 9, a check valve 19, and a hot water storage tank. A boiling circuit 10 is formed by sequentially connecting the upper portions of 1 with hot water supply pipes. The check valve 19 is arranged so that hot water flows from the water refrigerant heat exchanger 9 to the upper part of the hot water storage tank 1.

  On the other hand, the heat pump type water heater of the present embodiment has a heat pump unit having a heat pump cycle formed by sequentially connecting the water refrigerant heat exchanger 9, the compressor 14, the evaporator 15, and the expansion valve 16 in an annular manner with refrigerant piping. 17 is provided. Since carbon dioxide is used for the refrigerant of the heat pump cycle, the high pressure side exceeds the critical pressure, so that the water flowing through the water refrigerant heat exchanger 9 does not condense even if the temperature drops and the temperature drops. The water refrigerant heat exchanger 9 makes it easy to form a temperature difference between the refrigerant and the water, so that hot water can be obtained and the heat exchange efficiency can be increased. In addition, since relatively inexpensive and stable carbon dioxide is used for the refrigerant, the product cost can be reduced and the reliability can be improved. In addition, carbon dioxide has an ozone depletion coefficient of zero and a global warming coefficient of about 1/700 of the alternative refrigerant HFC-407C, which is very small.

  Further, in the heat pump unit 17, the refrigerant is compressed by the compressor 14, the refrigerant discharged from the compressor 14 dissipates heat by the water refrigerant heat exchanger 9, is decompressed by the expansion valve 16, and then is discharged from the air by the evaporator 15. The heat is absorbed and sucked into the compressor 14 again in a gas state. In the capacity control of the compressor 14 and the opening degree control of the expansion valve 16, the temperature of the discharged refrigerant detected by a thermistor (not shown) provided on the discharge side of the compressor 14 is maintained at a preset temperature. To be controlled.

  Also, the hot water in the hot water storage tank 1 flows into the water / refrigerant heat exchanger 9 by exchanging the circulation pump 11, exchanges heat with the refrigerant, returns to the hot water storage tank 1 again, and in the stacked state, Hot water is stored at the top.

  In addition, the utilization primary circuit 3 is formed by sequentially connecting the upper part of the hot water storage tank 1, the radiator 2, the heating circulation pump 4 that circulates the hot water in the hot water storage tank, and the lower part of the hot water storage tank 1 with hot water supply pipes.

  Furthermore, the utilization secondary circuit 5 is formed by connecting the utilization terminal circulation pump 6 which circulates the hot water in the bathtub 8 which is a utilization terminal, and the bathtub 8, and the heat radiator 2 sequentially in cyclic | annular form with hot water supply piping. In addition, although this embodiment demonstrates a utilization terminal as a bathtub, it is not limited to this and may be comprised with a floor heating, a radiation heating panel, etc. instead of a bathtub. In this Embodiment, the bathtub 8 containing bathtub water is assumed as a utilization terminal, and the reheating function which heats bathtub water to predetermined temperature is assumed as a function of a utilization side. In addition, as a heat pump type hot water supply device, a hot water supply function of mixing hot water and water in a generally installed hot water storage tank 1 to a predetermined temperature and discharging the hot water to the bathtub 8, or hot water having a predetermined temperature and amount to the bathtub 8 automatically. There is an automatic hot water filling function for pouring hot water, but in this embodiment, since it is not directly related to the present invention, illustration and description are omitted.

  Further, a bypass pipe 21 branches from between the check valve 19 and the water refrigerant heat exchanger 9, and is connected to the primary use circuit 3 between the upper part of the hot water storage tank 1 and the radiator 2 via the three-way valve 20. The The three-way valve 20 is configured to be able to switch between a flow path for sending hot water from the bypass pipe 21 to the radiator 2 and a flow path for sending hot water from the upper part of the hot water storage tank 1 to the radiator 2. In the drawings showing the present embodiment, the flow path is formed at the white portion of the three-way valve 20 and the flow path is closed at the black portion. For example, FIG. 1 shows a state where the primary usage circuit 3 forms a flow path.

  A thermistor 12 is attached to a pipe connecting the water refrigerant heat exchanger 9 and the upper part of the hot water storage tank 1 so that the outlet temperature of the water refrigerant heat exchanger 9 can be detected. A thermistor 13 is attached so that the temperature of the upper part of the tank 1 can be detected. Moreover, the thermistor 7 which can detect the temperature of bathtub water is attached between the heat radiator 2 and the bathtub 8 in the utilization secondary circuit 5.

  In the heat pump type water heater configured as described above, a method for replenishing hot water in the bathtub 8 which is a use terminal will be described below.

  In FIG. 1, the three-way valve 20 shows a state where a flow path is formed in the primary usage circuit 3. That is, the hot water in the upper part of the hot water storage tank 1 is supplied to the radiator 2. FIG. 2 shows the flow of hot water when the hot water in the bathtub 8 is driven in this state. In FIG. 2, the flow of hot water is indicated by arrows.

  The heating circulation pump 4 is operated, the hot water in the upper part of the hot water storage tank 1 is sent to the radiator 2 (primary side), and returned to the lower part of the hot water storage tank 1. At the same time, the use terminal circulation pump 6 is operated to send the bathtub water in the bathtub 8 to the radiator 2 (secondary side) and return it to the bathtub 8.

  In the radiator 2, the hot water in the hot water storage tank 1 and the low temperature bath water in the bathtub 8 (for example, 30 ° C. at the start of the reheating operation) exchange heat, the hot water in the hot water storage tank 1 is cooled, and the bathtub water in the bathtub 8 Is heated. The chasing operation is performed until the bath water temperature detected by the thermistor 7 reaches a predetermined temperature (for example, 40 ° C.) determined by a control device (not shown) or until a predetermined time elapses.

  On the other hand, in the normal state when the heat storage amount of the hot water storage tank 1 is secured (for example, when the hot water 50L or more at the upper part of the hot water storage tank 1 exists at 85 ° C.), the hot water of the hot water storage tank 1 is used to recharge. The performance of reheating is higher (for example, the reheating output is about 11 kW), and the cost of electricity is reduced because hot water stored with cheap nighttime electric power is used.

  However, if the hot water supply is used frequently and the hot water in the hot water storage tank 1 is low, it is inconvenient that the hot water supply cannot be used for a while if the hot water in the hot water storage unit 1 is used up. Further, when the hot water in the hot water storage unit 1 is used up, the hot water in the hot water storage tank 1 cannot be replenished.

  In such a case, it is necessary to secure a sufficient amount of heat storage in the hot water storage tank 1 to operate the heat pump unit 17 for reheating, during which time the reheating operation is stopped and as a result, reheating is completed. There was a problem of taking time (for example, 30 minutes).

In addition, when the bath water temperature of the bathtub 8 is high (for example, the bath water temperature is 38 ° C. with respect to the target boiling temperature of 40 ° C.) and the reheating capability may be small (for example, about 4 kW for the reheating output), When the hot water in the tank 1 is used, the temperature drop in the radiator 2 is small, and hot water at a higher temperature is sent to the lower part of the hot water storage tank 1, and when the hot water storage operation is performed later, the coefficient of performance COP of the heat pump unit 17 is set. It gets worse.

  For this reason, it may be cheaper to reheat with the heat pump unit 17 without using the hot water in the hot water storage tank 1. Therefore, in such a case, the reheating operation is performed using the heating capability of the heat pump unit 17.

  As described above, when the amount of heat stored in the hot water storage tank 1 is insufficient (when the hot water of 85 ° C. cannot be secured in the upper part of the hot water storage tank 1 or when the hot water runs out), the required reheating output is small. In such a case (for example, when the difference between the bath water temperature at the start of reheating and the target boiling temperature is 3 ° C. or less), the flow path is appropriately switched by the three-way valve 20 and the heat pump unit 17 is used for heating. Make a whisper. FIG. 3 shows the flow of hot water at this time.

  In FIG. 3, the three-way valve 20 forms a flow path that connects the boiling circuit 10 and the reheating primary circuit 3 from the downstream of the three-way valve 20 to the hot water storage tank 1 via the three-way valve bypass pipe 21. I am doing. The check valve 19 is provided to form the closed circuit.

  In this state, the heating circulation pump 4 and the heat pump unit 17 are operated, and hot water heated by the water-refrigerant heat exchanger 9 is sent to the radiator 2 (primary side). At the same time, the use terminal circulation pump 6 is operated to send hot water in the bathtub 8 to the radiator 2 (secondary side) and return to the bathtub 8.

  In the radiator 2, the hot water (for example, 85 ° C.) heated by the water-refrigerant heat exchanger 9 and the low-temperature bathtub water in the bathtub 8 exchange heat, and the bathtub water in the bathtub 8 is heated. The chasing operation is performed until the bath water temperature detected by the thermistor 7 reaches a predetermined temperature determined by a control device (not shown) or until a predetermined time elapses. In this way, by directly performing the reheating operation using the heating capability of the hot pump unit 17, even if the reheating operation cannot be performed using the hot water of the conventional hot water storage tank 1, the renewal operation is continued without stopping. As a result, it is possible to shorten the time required for renewal.

  As described above, by switching the flow path by the three-way valve 20 and the check valve 19, the hot water heated by the water-refrigerant heat exchanger 9 or the hot water in the upper part of the hot water storage tank is supplied to the radiator 2 (primary side). When the amount of heat stored in the hot water storage tank 1 is small or the required reheating output is small, the hot water heated by the water refrigerant heat exchanger 9 is supplied to the radiator 2 (primary It is possible to provide a heat pump water heater that can reduce the time until completion of reheating without stopping the reheating operation until the amount of heat stored in the hot water storage tank 1 can be secured.

  As described above, the present invention can be applied not only to a use terminal as a bathtub but also to a floor heating or a radiant heating panel.

The block diagram of the hot water storage type water heater in Embodiment 1 of this invention The block diagram of the hot water storage type water heater in Embodiment 1 of this invention The block diagram of the hot water storage type water heater in Embodiment 1 of this invention Configuration of a conventional hot water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Radiator 3 Use primary circuit 4 Heating circulation pump 5 Use secondary circuit 6 Use terminal circulation pump 7 Thermistor 8 Bath 9 Water refrigerant heat exchanger 10 Boiling circuit 11 Circulation pump 12 Thermistor 13 Thermistor 14 Compressor 15 Evaporator 16 Expansion valve 17 Heat pump unit 19 Check valve 20 Three-way valve 21 Bypass pipe

Claims (5)

A hot water storage tank for storing hot water, a heat pump unit for heating the water in the hot water storage tank, a circulation pump for sending water below the hot water storage tank to the heat pump unit, and hot water generated by the heat pump unit for the hot water storage tank A heating circuit for returning to the upper part, a utilization terminal having a utilization secondary circuit through which a secondary fluid circulates, and a utilization primary circuit for radiating hot water in the hot water storage tank to the secondary fluid, A heat pump type hot water heater configured to be able to supply hot water heated by a heat pump unit to the primary circuit used. The utilization primary circuit includes an upper part of the hot water storage tank, a radiator that radiates heat to the secondary fluid, a heating circulation pump that sends hot water in the hot water storage tank to the radiator, and a lower part of the hot water storage tank And a bypass pipe branched from a pipe for feeding hot water from the heat pump unit to the upper part of the hot water storage tank, and connected via a three-way valve between the upper part of the hot water storage tank and the radiator. The heat pump type water heater according to claim 1. The heat pump type hot water heater according to claim 2, wherein a check valve is provided between a branch point of the bypass pipe and an upper portion of the hot water storage tank in the boiling circuit. According to the heating capacity required at the user terminal, the flow path for sending hot water in the hot water storage tank to the radiator and the flow path for sending hot water heated by the heat pump unit to the radiator are switched. The heat pump type water heater according to claim 2 or 3, wherein the three-way valve is controlled. According to the amount of heat stored in the hot water storage tank, the three-way so as to switch between a flow path for sending hot water in the hot water storage tank to the radiator and a flow path for sending hot water heated by the heat pump unit to the radiator. The heat pump type hot water supply device according to claim 2 or 3, wherein a valve is controlled.

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