JP2009216335A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater having high operation efficiency. <P>SOLUTION: This heat pump water heater is composed of a heat pump 1 constituted by annularly connecting a compressor 2, a radiator 3, a pressure reducing means 4 and an air heat exchanger 5, a hot water storage circuit 18 for storing high temperature hot water in a hot water storage tank 8 by circulating water via the radiator 3 from a bottom part of the hot water storage tank 8 by a blow out pump 7, an expanded water discharge pipe 34 for discharging expanded water from the hot water storage tank 8, a hot water supply mixing valve 23 for forming hot water of the proper temperature by mixing low temperature water from a water supply source (unillustrated) with high temperature water from the hot water storage tank 8, a water supply bypass pipe 22 for introducing the low temperature water such as city water to the hot water supply mixing valve 23 and a heat storage unit 10 for exchanging heat between the expanded water passing through the expanded water discharge pipe 34 and the low temperature water passing through the water supply bypass pipe 22, to raise the water temperature of the low temperature water passing through the water supply bypass pipe 22 by heat energy of the expanded water, so that a high temperature hot water quantity from the hot water storage tank 8 can be reduced, and energy efficiency is improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat pump water heater that stores hot water in a hot water storage tank to supply hot water.

  A conventional heat pump water heater of this type is as shown in FIG. 2 (see, for example, Patent Document 1). FIG. 2 is a circuit diagram of a conventional heat pump water heater described in Patent Document 1. In FIG.

  In FIG. 2, the conventional heat pump water heater includes a hot water storage tank 8 in which low temperature hot water and high temperature hot water are stored in a layered state, and a heat pump 1 as a heating source for heating the hot water. 1, the water in the hot water storage tank 8 is heated and boiled up to be stored and used for hot water supply.

  Initially, the structure of the heat pump 1 which is a heating source is demonstrated. The heat pump 1 includes a compressor 2 that compresses the refrigerant, a radiator 3 that cools the refrigerant, a decompression unit 4 that depressurizes the refrigerant, and an air heat exchanger 5 that evaporates and evaporates the refrigerant. It is connected to the decompression means 4 via the radiator 3 from the side, and further connected to the suction side of the compressor 2.

  In this heat pump 1, the refrigerant compressed by the compressor 2 enters the radiator 3 as a high-temperature and high-pressure refrigerant, and radiates and cools it here. Thereafter, the pressure is reduced in the pressure reducing means 4 to form low-temperature and low-pressure wet steam, and the air heat exchanger 5 exchanges heat with air to evaporate and return to the compressor 2. At this time, the blower 6 forcibly circulates the air to the air heat exchanger 5 in order to increase the heat exchange efficiency of the air heat exchanger 5.

  On the other hand, in the hot water storage circuit 18 for boiling water, the boiling pipe 9 is connected from the lower part of the hot water storage tank 8 to the radiator 3 and further connected from the radiator 3 to the upper part of the hot water storage tank 8.

  The upper part of the hot water storage tank 8 to which the boiling pipe 9 is connected may suffice if the hot water is on the high temperature layer side of the hot water storage tank 8, and the lower part of the hot water storage tank 8 is on the low temperature layer side of the hot water storage tank 8. I just need it.

  In order to send hot water from the hot water storage tank 8 to the radiator 3 and return it to the hot water storage tank 8, a boiling pump 7 capable of arbitrarily changing the output is provided in the middle of the boiling pipe 9.

  In order to maintain the pressure in the hot water storage tank 8, a pressure relief valve 29 that discharges the expansion water is provided. The discharged expansion water passes through the expansion water discharge pipe 34 to the outside from the expansion water sprinkling pipe 36. Discharged.

  In addition, in the heat pump 1, an incoming water temperature sensor 15 that detects the temperature of the low hot water before heating is provided in the vicinity of the inlet side of the radiator 3 of the boiling pipe 9 and a hot water temperature sensor 16 that detects the temperature of the heated hot water. Are provided in the vicinity of the outlet of the radiator 3 in the boiling tube 9.

  And in order to grasp | ascertain the temperature distribution and heat storage amount of the hot water storage tank 8, the several hot water storage temperature sensors 17a-17d are provided in the orthogonal | vertical direction of the outer wall surface of the hot water storage tank 8. FIG.

As a configuration related to hot water supply, a water supply pipe 19 for supplying water from a water supply source is connected to the bottom of the hot water storage tank 8, and the water supply source is decompressed to an appropriate pressure by a pressure reducing valve 20 and supplied to the water supply pipe 19.

  A hot water supply pipe 21 is connected to the upper part of the hot water storage tank 8 to discharge the hot water stored in the hot water and use it for hot water supply, and a water supply bypass pipe 22 from the water supply pipe 19 is connected in the middle thereof. Further, a hot water mixing valve 23 capable of mixing high temperature water from the hot water supply pipe 21 and low temperature water from the water supply bypass pipe 22 at an arbitrary ratio is provided.

  A hot water supply temperature sensor 25 is provided on the downstream side of the hot water supply mixing valve 23 in order to detect the mixed hot water supply temperature, and a hot water supply terminal 24 is connected to the tip thereof.

  As a configuration relating to the pouring of water into the bath, a hot water pouring pipe 28 branched from the middle of the hot water feeding pipe 21 and poured into the bathtub 13 is provided. A bath mixing valve 26 is provided so that low temperature hot water from the water supply bypass pipe 22 can be mixed and poured, and a pouring temperature sensor 35 is provided downstream thereof.

  Moreover, the pouring pipe 28 includes a pouring electromagnetic valve 27, which is arbitrarily opened and closed to automatically pour water into the bathtub 13.

  Regarding the circuit configuration of the bath heating operation for heating and keeping hot water in the bathtub 13, in the use side circuit 31, the hot water in the bathtub 13 is circulated to the bath heat exchanger 14 by the use side pump 12.

  In addition, a bath water temperature sensor 32 is provided to detect the temperature of the hot water in the bathtub 13. In the heat source side circuit 30, the hot water in the hot water storage tank 8 is circulated to the bath heat exchanger 14 by the heat source side pump 11 and circulated to the hot water storage tank 8.

  Further, a circulating temperature sensor 33 for detecting the temperature of the hot water circulated and circulated by the use side pump 12 from the bath heat exchanger 14 is attached.

  The operation of the conventional heat pump water heater configured as described above is as follows.

  As shown in FIG. 2, in the hot water storage operation, the heat pump 1 is used as a heating source and the boiling pump 7 circulates and heats the water in the low-temperature water layer at the lower part of the hot water storage tank 8 to the radiator 3. It is stored as hot water, and the hot water boiled due to the density difference and the water in the low temperature water layer are hardly mixed and stored in the hot water storage tank 8. The hot water stored in the hot water storage tank 8 is used for hot water supply to the use terminal 24 and the bathtub 13.

  In the hot water storage operation, hot water with a low density is stored in the hot water storage tank 8, that is, the water expands, so that the internal pressure of the hot water storage tank 8 increases. If the internal pressure continues to rise, the pressure resistance of the hot water storage tank 8 will be exceeded, and in the worst case, it will be destroyed. Therefore, when the internal pressure of the hot water storage tank 8 reaches a predetermined pressure, the pressure relief valve 29 is opened and By discharging from the water discharge pipe 34, the internal pressure of the storage tank 8 is kept below a predetermined pressure.

However, since discharging high-temperature expansion water is one of the causes of reducing the energy efficiency of the heat pump water heater, in the conventional heat pump water heater, the pressure relief valve 29 is used as a method of effectively using the expansion water. The expanded water discharged is guided to the upper portion of the air heat exchanger 5 through the expanded water discharge pipe 34 and sprayed to the air heat exchanger 5 through the expanded water sprinkling pipe 36, and the refrigerant and heat in the air heat exchanger 5 are sprayed. It is exchanged to absorb heat or to be used as a heat source for defrosting.
JP 2005-009723 A

  However, in the configuration of the conventional heat pump water heater, when the expanded water is sprinkled into the air heat exchanger 5, the sprinkled hot water is deprived of heat and becomes low-temperature water, but part of the sprinkled water is The air heat exchanger 5 remains attached to the surface. For example, if the ambient temperature is equal to or lower than the defrost condition, that is, the temperature of the air exchanged with the air heat exchanger 5 is approximately 2 ° C. or less, the refrigerant flowing through the air heat exchanger 5 is 0 ° C. or less. There was a problem that the hot water sprayed on the surface of the air heat exchanger 5 was frozen as it was, and the heat exchange performance of the air heat exchanger 5 was significantly reduced.

  An object of the present invention is to solve the above-mentioned conventional problems and to provide a heat pump water heater with high operating efficiency by effectively using thermal energy of expansion water without using the air heat exchanger 5. .

  In order to solve the above-described conventional problems, the heat pump water heater of the present invention includes a heat pump configured by annularly connecting a compressor, a radiator, a decompression unit, and an air heat exchanger, and a boiling pump. A hot water storage circuit that circulates water from the bottom through the radiator to store hot hot water in the hot water storage tank, an expansion water discharge pipe that discharges expansion water from the hot water storage tank, and hot water and water supply source from the hot water storage tank A hot water supply mixing valve for mixing low temperature water from the hot water supply water into an appropriate temperature hot water, a water supply bypass pipe for introducing low temperature water such as city water to the hot water supply mixing valve, and expansion water passing through the expansion water discharge pipe It is composed of a heat storage unit containing a heat storage material arranged so that heat can be exchanged with the low-temperature water passing through the water supply bypass pipe, and heat energy of the expansion water is exchanged with the heat storage material in the heat storage unit. So The accumulated, when using the hot water, such as hot water, the by heat storage material and heat exchange with the cold water through the water supply bypass pipe can be raised temperature. The hot water mixing valve mixes the hot water from the hot water storage tank and the low temperature water from the hot water bypass pipe to adjust the appropriate temperature, so the temperature will be adjusted appropriately if the temperature of the low temperature water from the hot water bypass pipe rises. Therefore, the amount of hot water from the hot water storage tank can be reduced, and energy efficiency is improved.

  The heat pump water heater of the present invention exchanges heat energy of expansion water with the heat storage material in the heat storage unit and stores the heat energy in the heat storage material, and when using hot water such as hot water, the low temperature water passing through the water supply bypass pipe and the heat storage unit Since the water temperature can be raised by exchanging heat with the heat storage material, the operation efficiency can be increased.

In the first invention, a heat pump configured by connecting a compressor, a radiator, a decompression means, and an air heat exchanger in an annular shape, and a boiling pump circulates water from the bottom of the hot water storage tank through the radiator to increase the temperature. A hot water storage circuit for storing hot water in the hot water storage tank, an expansion water discharge pipe for discharging expansion water from the hot water storage tank, hot water from the hot water storage tank and low temperature water from a water supply source, Heat exchange between the hot water supply mixing valve, the hot water supply bypass pipe for introducing low-temperature water such as city water to the hot water supply mixing valve, the expansion water passing through the expansion water discharge pipe, and the low temperature water passing through the water supply bypass pipe It is composed of a heat storage unit that encloses a heat storage material that is arranged so that the thermal energy of the expansion water can be exchanged with the heat storage material in the heat storage unit and stored in it, and when using hot water such as hot water, Vipa It can raise the water temperature by heat exchange with the cold water the heat storage material through the tube. The hot water mixing valve mixes the hot water from the hot water storage tank and the low temperature water from the hot water bypass pipe to adjust the appropriate temperature, so the temperature will be adjusted appropriately if the temperature of the low temperature water from the hot water bypass pipe rises. Therefore, the amount of hot water from the hot water storage tank can be reduced, and energy efficiency is improved.

  In the second invention, in particular, the heat storage material of the first invention is a latent heat storage material, and since the latent heat of the heat storage material can be used, the amount of heat storage per unit volume in the heat storage material can be increased and is compact. Can be

  The third aspect of the invention uses a refrigerant whose pressure is raised to a critical pressure or higher in the heat pump circuit of the first or second invention, and the refrigerant flowing through the radiator is pressurized to a critical pressure or higher by a compressor. Therefore, it does not condense even if the heat is taken away by the radiator and the temperature drops. Therefore, it becomes easy to form a temperature difference between the refrigerant and water in the entire radiator, and the heat exchange efficiency can be increased.

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

(Embodiment 1)
FIG. 1 is a circuit diagram of a heat pump water heater in the first embodiment of the present invention. In addition, about the same part as the said conventional heat pump water heater, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In FIG. 1, the heat pump water heater in the present embodiment connects the heat storage unit 10 in the middle of the expansion water discharge pipe 34 and in the middle of the water supply bypass pipe 22, and stores the expansion water discharged from the hot water storage tank 8. After being led to the unit 10, the heat is discharged between the high-temperature expanded water passing through the expanded water discharge pipe 34 and the low-temperature water passing through the water supply bypass pipe 22, and the other configuration. Since this is the same as a conventional heat pump water heater, the same parts are denoted by the same reference numerals and the description thereof is omitted.

  The heat storage unit 10 uses a latent heat storage material as a heat storage material, and includes a heat exchanger (not shown) of the heat storage material and a fluid.

  The heat pump 1 in the present embodiment uses carbon dioxide as a refrigerant, and the refrigerant compressed by the compressor 2 enters the radiator 3 as a high-temperature and high-pressure supercritical refrigerant and radiates heat here. To cool.

  The operation and action of the water heater in the present embodiment configured as described above will be described.

  In the hot water storage operation in which hot water is stored in the hot water storage tank 8, the heat pump 1 causes the refrigerant compressed by the compressor 2 to enter the radiator 3 as a high-temperature and high-pressure refrigerant in a supercritical state, where it radiates and cools. Thereafter, the pressure is reduced in the pressure reducing means 4 to become low-temperature and low-pressure wet steam, and the air heat exchanger 5 exchanges heat with air to evaporate and return to the compressor 2. At this time, the blower 6 forcibly circulates the air to the air heat exchanger 5 in order to increase the heat exchange efficiency of the air heat exchanger 5.

  At this time, the low temperature hot water in the lower part of the hot water storage tank 8 is sent to the radiator 3 by the boiling pump 7 and is heated by absorbing the heat of the radiator 3.

  That is, in the hot water storage operation in which the hot water in the low temperature layer under the hot water storage tank 8 is heated by the heat pump 1 and returned to the hot water storage tank 8, the boiling pump 7 is driven to heat the low temperature water from the hot water storage tank 8, The heated hot water is sent to the upper part of the hot water storage tank 8 through the boiling pipe 9.

Then, the temperature of the water heated by the heat pump 6 is detected by the tapping temperature sensor 16 and the output of the boiling pump 7 is changed to control the tapping temperature from the heat pump 6 so that the heating becomes the target temperature. Do.

  In this way, hot water is stored in the hot water storage tank 8, and the amount of heat stored in the hot water storage tank 8 is detected based on the temperatures detected by the hot water storage temperature detection means 17 a, 17 b, 17 c, 17 d and the incoming water temperature sensor 15. When the predetermined amount of heat storage is reached, the heat pump 1 is stopped.

  Furthermore, during the hot water storage operation, hot water with a low density is stored in the hot water storage tank 8, that is, the water expands, so that the internal pressure of the hot water storage tank 8 increases. If the internal pressure of the hot water storage tank 8 continues to rise, the worst case is that it exceeds the pressure resistance of the hot water storage tank 8 and breaks. Therefore, when the internal pressure of the hot water storage tank 8 reaches a predetermined pressure, the pressure relief valve 29 is opened. By discharging hot water as expansion water from the expansion water discharge pipe 34, the internal pressure of the storage tank 8 is kept below a predetermined pressure.

  The discharged expanded water is guided to the heat storage unit 10 through the expanded water discharge pipe 34. In the heat storage unit 10, the latent heat storage material and the expanded water exchange heat and the latent heat storage material absorbs the thermal energy of the expanded water, and then the expanded water is discharged to the outside.

  In the hot water supply operation to the hot water supply terminal 24, when the hot water supply terminal 24 is opened for hot water supply, hot water in the hot water storage tank 8 is discharged from the hot water supply pipe 21 and supplied from the water supply pipe 19 to the hot water storage tank 8.

  Moreover, the hot water temperature is changed by changing the mixing ratio of the low temperature water from the water supply bypass pipe 22 branched from the water supply pipe 19 and the high hot water from the hot water storage tank 8 with the hot water mixing valve 23 and mixing them. Then, hot water is supplied to the hot water supply terminal 24.

  At this time, the heat storage unit 10 is installed in the middle of the water supply bypass pipe 22, and the latent heat storage material and the low-temperature water passing through the water supply bypass pipe 22 exchange heat. Thermal energy is stored in the latent heat storage material during hot water storage operation, and the temperature of the low-temperature water passing through the feed water bypass pipe 22 rises as the low-temperature water absorbs the heat energy. Water passing through the hot water supply bypass pipe 22 whose temperature has risen is sent to the hot water supply mixing valve 23.

  The mixing ratio at this time is controlled according to the hot water temperature detected by the hot water temperature sensor 25, and is kept at the hot water temperature selected by the user by a remote controller (not shown). Since hot water is supplied at a predetermined temperature by mixing the high-temperature water and low-temperature water in the hot water storage tank 8 and lowering the temperature, the flow rate on the high-temperature water side can be reduced by increasing the temperature on the low-temperature water side.

  In the pouring operation to the bath, when the pouring operation is started, the pouring solenoid valve 27 is opened, the water supply is branched by the water supply bypass pipe 22, and hot water from the hot water storage tank 8 and low temperature water from the water supply source are bathed. In the mixing valve 26, the mixing ratio is changed and mixed, whereby the pouring temperature is changed and the bath 13 is poured.

  The mixing ratio at this time is controlled according to the pouring temperature detected by the pouring temperature sensor 35, and is kept at the pouring temperature selected by the user by a remote controller (not shown).

  That is, hot water is poured into the bathtub 13 by mixing the hot water and water in the hot water storage tank 8 to lower the temperature.

At this time, similarly to the hot water supply operation, the heat storage unit 10 is installed in the middle of the water supply bypass pipe 22, and the latent heat storage material and the low-temperature water passing through the water supply bypass pipe 22 exchange heat. Thermal energy is stored in the latent heat storage material during hot water storage operation, and the temperature of the low-temperature water rises as the low-temperature water absorbs the heat energy. Water passing through the hot water supply bypass pipe 22 whose temperature has risen is sent to the hot water supply mixing valve 23.

  Since hot water is supplied at a predetermined temperature by mixing the high-temperature water and low-temperature water in the hot water storage tank 8 and lowering the temperature, the flow rate on the high-temperature water side can be reduced by increasing the temperature on the low-temperature water side.

  In the bath heating operation for heating the hot water in the bathtub 13, the heat of the hot water in the hot water storage tank 8 is radiated to the hot water in the bathtub 13.

  In the use side circuit 31, the flow path switching means (not shown) circulates hot water in the bathtub 13 to the bath heat exchanger 14 by the use side pump 12. On the other hand, in the heat source side circuit 30, the hot water in the hot water storage tank 8 is circulated to the bath heat exchanger 14 by the heat source side pump 11 and circulated to the hot water storage tank 8.

  In the bath heat exchanger 14, the hot water in the high-temperature heat source side circuit 30 and the hot water in the usage-side circuit 31 having a low temperature exchange heat to heat the hot water in the usage-side circuit 31. This series of operations is continued until the bath temperature sensor 32 determines that the predetermined bath temperature has been reached.

  As described above, the expansion water discharge pipe 34 for discharging the expansion water of the hot water storage tank 8, the hot water mixing valve 23 for mixing the high temperature hot water and the low temperature water from the hot water storage tank 8 into an appropriate temperature hot water, the hot water supply The mixing valve 23 has a water supply bypass pipe 22 that guides low-temperature water such as city water so that hot water passing through the expansion water discharge pipe 34 and low-temperature water passing through the water supply bypass pipe 22 can exchange heat. By installing the heat storage unit 10 that encloses the heat storage material disposed in the heat storage material, the thermal energy of the expansion water is stored by exchanging heat with the heat storage material in the heat storage unit 10, and when hot water such as hot water is used, the water supply bypass pipe 22 is used. It is possible to increase the water temperature by exchanging heat between the low-temperature water passing through and the heat storage material in the heat storage unit 10, and the amount of hot water used in the hot water storage tank 8 can be reduced, so that energy efficiency is improved.

  As described above, the heat pump water heater according to the present invention stores the thermal energy of the expansion water by exchanging heat with the heat storage material in the heat storage unit, and when using hot water such as hot water, the low-temperature water and the heat storage unit that pass through the water supply bypass pipe Since the water temperature can be raised by exchanging heat with the internal heat storage material and the amount of hot water used in the hot water storage tank can be reduced, it is useful as a heat pump water heater with high energy efficiency.

Circuit diagram of heat pump water heater in Embodiment 1 of the present invention Circuit diagram of conventional heat pump water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pump 2 Compressor 3 Radiator 4 Pressure reducing means 5 Air heat exchanger 7 Boiling pump 8 Hot water storage tank 10 Heat storage unit 18 Hot water storage circuit 22 Water supply bypass pipe 23 Hot water mixing valve 34 Expansion water discharge pipe

Claims (3)

A heat pump configured by annularly connecting a compressor, a radiator, a pressure reducing unit, and an air heat exchanger, and a boiling pump circulates water from the bottom of the hot water storage tank through the heat radiator to supply hot hot water to the hot water storage tank. A hot water storage circuit for storing water, an expansion water discharge pipe for discharging expansion water from the hot water storage tank, and hot water mixing for mixing hot water from the hot water storage tank and low temperature water from a water supply source to obtain appropriate hot water A valve, a feed water bypass pipe for introducing low temperature water such as city water to the hot water supply mixing valve, and an expansion water passing through the expansion water discharge pipe and a low temperature water passing through the feed water bypass pipe are arranged so as to be able to exchange heat. A heat pump water heater comprising a heat storage unit including a heat storage material. The heat pump water heater according to claim 1, wherein the heat storage material is a latent heat storage material. The heat pump water heater according to claim 1 or 2, wherein a refrigerant whose pressure is raised to a critical pressure or more is used in the heat pump circuit.

Images