JP2009097799A - Heat pump water heater - Google Patents

Abstract

An object of the present invention is to provide a heat pump water heater capable of preventing a rise in water temperature in a hot water storage tank and performing a hot water supply operation with high energy efficiency.
A refrigerant circuit in which a compressor 31, a hot water supply heat exchanger 32, a decompression device 33, and an evaporator 34 are sequentially connected, a circulation pump 43, and the hot water supply heat exchanger 32 are sequentially passed through the storage tank 41. A hot water supply circuit 46 for heating water, a three-way valve 44 provided downstream of the hot water supply heat exchanger 32 in the hot water supply circuit 46, an upstream side of the circulation pump 43 of the three-way valve 44 and the hot water supply circuit 46, A heat pump hot water supply apparatus comprising a bypass circuit 47 connected and provided with a heat dissipating means 48 in the bypass circuit 47 to prevent an increase in water temperature in the lower part of the hot water tank 41 and to perform a hot water supply operation with high energy efficiency. Can do.
[Selection] Figure 1

Description

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

  Conventionally, this type of heat pump hot-water supply apparatus has what is shown in FIG. 2 (for example, refer patent document 1). As shown in FIG. 2, this water heater includes a hot water tank 2 and a heat source by a heat pump 3, and is connected from the lower part of the hot water tank 2 to the heat pump 3 by a boiling pipe 11 and from the heat pump 3 to the upper part of the hot water tank 2. is doing.

  In the bath heating heat exchanger 19 for heating the hot water in the bathtub 6, the use side is connected to circulate the hot water in the bathtub 6 by the bath circulation pump 27, and the heat source side by the circulation pump 23. Hot water at the upper part of the hot water tank 2 is circulated and circulated to the lower part of the hot water tank 2.

In this way, by operating the bath circulation pump 27 and the circulation pump 23, the hot water on the heat source side and the low temperature water on the use side exchange heat in the bath heating heat exchanger 19, so that the temperature of the hot water in the bathtub 6 can be kept or increased. A whisper is done. Further, the hot water on the heat source side is sent from the upper part of the hot water tank 2 to the bath heating heat exchanger 19 by the circulation pump 23, exchanges heat with the low temperature water on the use side, and then circulates near the lower part of the hot water tank 2.
Japanese Patent Application Laid-Open No. 2004-293737

  However, in the above configuration, medium temperature water of about 30 to 50 ° C. is stored in the hot water tank 2 by heat exchange in the bath heating heat exchanger 19. Medium temperature water cannot be used for bathing because the temperature of the hot water is low. Further, if the medium-temperature water is stored as it is, the amount of heat stored in the hot water tank 2 is reduced, which causes hot water shortage. Therefore, although medium temperature water will be heated with the heat pump 3, since the temperature of the hot water was high, there existed a subject that the efficiency reduction of the heat pump 3 was caused.

  This invention solves the said conventional subject, and it aims at providing the heat pump hot water supply apparatus which can prevent the water temperature rise in a hot water storage tank, and can implement hot water supply operation with high energy efficiency.

  In order to solve the above-described conventional problems, a heat pump hot water supply apparatus of the present invention includes a compressor, a hot water heat exchanger, a decompression device, a refrigerant circuit in which an evaporator is sequentially connected, a circulation pump, and the hot water heat exchanger. A hot water supply circuit for heating the water in the hot water storage tank in order, a three-way valve provided on the downstream side of the heat exchanger for hot water supply of the hot water supply circuit, an upstream side of the circulation pump of the three-way valve and the hot water supply circuit, A heat pump hot water supply apparatus comprising a connected bypass circuit and provided with a heat dissipating means in the bypass circuit, can prevent an increase in water temperature in the lower part of the hot water tank, and can perform hot water supply operation with high energy efficiency.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump hot water supply apparatus which can prevent the water temperature rise in a hot water storage tank and can implement the hot water supply operation with high energy efficiency can be provided.

1st invention is the hot water supply which heats the water in a hot water storage tank through the refrigerant circuit which connected the compressor, the hot water supply heat exchanger, the decompression device, and the evaporator sequentially, the circulation pump, and the said hot water supply heat exchanger in order. A circuit, a three-way valve provided downstream of the hot water supply heat exchanger of the hot water supply circuit, and a bypass circuit connecting the three-way valve and the upstream side of the circulation pump of the hot water supply circuit, the bypass circuit A heat pump hot water supply apparatus provided with a heat dissipating means can prevent an increase in the water temperature in the lower part of the hot water tank and can perform a hot water supply operation with high energy efficiency.

  In the second invention, since carbon dioxide is used as the refrigerant in the refrigerant circuit of the first invention, the hot water supply can be heated at high efficiency, and even if the refrigerant leaks to the outside, global warming can be achieved. The impact of is very small.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a heat pump water heater in the first embodiment of the present invention.

  In FIG. 1, a compressor 31, a hot water supply heat exchanger 32, a pressure reducing device 33, and an evaporator 34 are connected in an annular shape in this order, and carbon dioxide gas is sealed as a refrigerant to form a refrigerant circulation circuit. A fan 35 is provided for blowing air. Further, a hot water supply circuit 46 in which a hot water storage tank 41, a water intake port 42 at the lower part of the hot water storage tank, a circulation pump 43, a heat exchanger 32 for hot water supply, a three-way valve 44, and a hot water return port 45 at the upper part of the hot water tank are sequentially connected, A bypass circuit 47 connected to a pipe between the water inlet 42 at the lower part of the hot water tank and the circulation pump 43 via a bath heating heat exchanger 48 is configured, and the high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 31 is It flows into the hot water supply heat exchanger 32 and heats the water sent from the circulation pump 43 here.

  In the bath heating heat exchanger 48 for heating the hot water in the bathtub 50, the use side is connected to circulate the hot water in the bathtub 50 by a bath circulation pump 49.

  Furthermore, the incoming water temperature sensor 51 for detecting the incoming water temperature flowing into the hot water heat exchanger 32, the outgoing water temperature sensor 52 for detecting the outgoing water temperature flowing out from the hot water heat exchanger 32, and the incoming water flowing into the bath heating heat exchanger 48. A bath temperature sensor 53 for detecting the temperature, a bath return temperature sensor 54 for detecting the temperature of the hot water returning from the bath heating heat exchanger 48 to the bath, an outdoor air temperature sensor 55 for detecting the outdoor air temperature, and a refrigerant temperature discharged from the compressor 31 are detected. A discharge temperature sensor 56 and an evaporator outlet temperature sensor 57 for detecting the outlet refrigerant temperature of the evaporator 34 are provided, and the operating frequency of the compressor 31, the opening of the decompression device 33, the rotational speed of the fan 35, the circulation pump 43 and the bath circulation are provided. A control device 58 for controlling the rotational speed of the pump 49 is provided. Carbon dioxide is used as the refrigerant.

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

  In normal operation, when the operation of the heat pump hot water supply device is started, the circulation pump 43 and the fan 35 are operated, and the incoming water temperature sensor 51 measures the incoming water temperature flowing into the hot water supply heat exchanger 32 from the hot water storage tank 41, and the outdoor The outdoor air temperature is measured by the air temperature sensor 55, the discharge refrigerant temperature of the compressor 31 is measured by the discharge temperature sensor 56, and the operating frequency of the compressor 31 and the pressure reducing device are determined by the incoming water temperature, the outdoor air temperature, the discharge refrigerant temperature, and the hot water target temperature. The initial opening P1 of 33 is selected and determined from a preset table, and the operation of the compressor 31 is started.

  The refrigerant discharged from the compressor 31 is a low-temperature and low-pressure refrigerant at the start of operation of the compressor 31, but gradually becomes a high-temperature and high-pressure superheated gas refrigerant as the number of rotations of the compressor 31 increases.

  The high-temperature and high-pressure refrigerant flows into the hot water supply heat exchanger 32 where it exchanges heat with the water sent from the circulation pump 43 and heats it. Then, the refrigerant becomes a medium temperature and high pressure, and after being decompressed by the decompression device 33, flows into the evaporator 34, where it exchanges heat with the outside air blown by the fan 35, evaporates and returns to the compressor 31.

  On the other hand, the hot water supplied by the circulation pump 43 is heated by the hot water heat exchanger 32, and the hot water temperature is lower by a first predetermined value (for example, 10 deg) than the preset hot water temperature (for example, 80 ° C) (70 ° C). When the temperature is lower (for example, 65 ° C.), the hot water is controlled so that the three-way valve 44 communicates with the hot water heat exchanger 32 and the bypass circuit 47, and is returned to the circulation pump 43 via the bypass circuit 47. Further, when the hot water temperature becomes higher than a temperature (70 ° C.) lower than a preset hot water supply temperature (for example, 80 ° C.) by a first predetermined value (for example, 10 deg), the three-way valve 44 returns the hot water to the hot water supply heat exchanger 32 and the hot water tank. The hot water flows into the upper part of the hot water storage tank 41 and is gradually stored from above, and hot water accumulates in the hot water storage tank 41 as the boiling operation time elapses.

  When the boiling operation is almost completed, the temperature of water flowing from the lower part of the hot water storage tank 41 via the circulation pump 43 becomes higher, and when the incoming water temperature exceeds the set value, it is determined that hot water has been stored in the hot water storage tank 41, and the compressor 31 circulates. The operation of the pump 43 and the fan 35 is stopped, and boiling is completed.

  Next, when the bath temperature falls below the set temperature of the remote controller or the bath heating operation is selected by the remote controller and the operation of the heat pump hot water supply device is started, the bath circulation pump 49 and the fan 35 are operated, and the bath temperature sensor 53 is operated. The bath water temperature flowing from the bath 13 into the bath heating heat exchanger 48 is measured, the outdoor air temperature sensor 55 measures the outdoor air temperature, the discharge temperature sensor 56 measures the discharge refrigerant temperature of the compressor 31, and the bath water temperature. The operating frequency of the compressor 31 and the initial opening P1 of the pressure reducing device 33 are selected and determined from a preset table according to the outdoor air temperature and the bath target temperature, and the operation of the compressor 31 and the circulation pump 43 is started. .

  The high-temperature and high-pressure refrigerant discharged from the compressor 31 flows into the hot water supply heat exchanger 32 where it heats and exchanges heat with the water sent from the circulation pump 43. Then, the refrigerant becomes a medium temperature and high pressure, and after being decompressed by the decompression device 33, flows into the evaporator 34, where it exchanges heat with the outside air blown by the fan 35, evaporates and returns to the compressor 31.

  On the other hand, the hot water supplied by the circulation pump 43 is heated by the hot water heat exchanger 32, and the three-way valve 44 is controlled so as to connect the hot water heat exchanger 32 and the bypass circuit 47, and flows into the bypass circuit 47. It returns to the circulation pump 43 through the bath heating heat exchanger 48. At this time, the circulation pump 43 controls the flow rate so that the temperature becomes a certain value (for example, 10 degrees) higher than the bath target temperature. In the bath heating heat exchanger 48, the hot water heated by the refrigerant circuit and the hot water are exchanged to heat the hot water. When the bath water temperature becomes equal to or higher than the bath target temperature, it is determined that the bath heating is completed, the operation of the compressor 31, the circulation pump 43, the bath circulation pump 49, and the fan 35 is stopped, and the bath heating operation is completed.

  As a result, the hot water storage tank can be obtained by heating the hot water in the bathtub 50 with a heat pump without adding new components to the conventional device, without heating the bath using the hot water of the hot water tank. The temperature of the hot water in 41 is not lowered. Moreover, since the water temperature rise at the lower part of the hot water tank can be prevented, a heat pump with higher energy efficiency can be performed with a heat pump.

  In the present embodiment, the radiator is described as the bath heating heat exchanger 48, but a heating heat exchanger used for a floor heater or the like may be used.

  As described above, the heat pump hot water supply apparatus according to the present invention can perform hot water supply operation with high energy efficiency, and thus can be applied to uses such as an air conditioner using high-temperature hot water.

The block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention Configuration diagram of conventional heat pump water heater

Explanation of symbols

12 Bath Circulation Pump 13 Bathtub 31 Compressor 32 Heat Exchanger for Hot Water Supply 33 Depressurization Device (Throttle Device)
34 Evaporator 35 Fan 41 Hot water storage tank 42 Water intake port at the bottom of the hot water storage tank 43 Circulation pump 44 Three-way valve 45 Hot water return port at the top of the hot water storage tank 46 Hot water supply circuit 47 Bypass circuit 48 Bath heating heat exchanger 49 Bath circulation pump 50 Bathtub 51 Incoming water temperature Sensor 52 Hot water temperature sensor 53 Bath temperature sensor 54 Bath return temperature sensor 55 Outdoor air temperature sensor 56 Discharge temperature sensor 57 Evaporator outlet temperature sensor 58 Control device

Claims (2)

A refrigerant circuit in which a compressor, a hot water supply heat exchanger, a decompression device, and an evaporator are sequentially connected, a circulation pump, a hot water supply circuit that heats water in the hot water tank through the hot water supply heat exchanger, and the hot water supply circuit A three-way valve provided on the downstream side of the hot water heat exchanger, and a bypass circuit connecting the three-way valve and the upstream side of the circulation pump of the hot water supply circuit, and provided heat dissipation means in the bypass circuit. A heat pump water heater characterized by The heat pump hot water supply apparatus according to claim 1, wherein carbon dioxide gas is used as the refrigerant.

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