JP2018013258A - Heat Pump Water Heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump water heater enabling enhancement of efficiency of a heat pump and improvement of reliability of a compressor.SOLUTION: A heat pump water heater includes: a refrigerant circuit 80 formed by annularly interconnecting a compressor 1, a radiator 4, a decompression device 3 and an evaporator 2 by using refrigerant piping 81; a tank 6 for storing hot water heated by the radiator 4; a discharge temperature sensor 12 for detecting a discharge temperature of a refrigerant from the compressor 1; a tank temperature sensor 10 for detecting a temperature of hot water in the tank 6; an outside air temperature sensor 11 for detecting an outside air temperature; and a control device 13. The radiator 4 is constituted by winding the refrigerant piping 81 around the outer periphery of the tank 6. The decompression device 3 is an electronic expansion valve. The control device 13 controls an opening of the electronic expansion valve so as to reach a target discharge temperature determined by the temperature of the hot water in the tank 6 and the outside air temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat pump water heater.

  Conventionally, as this type of heat pump water heater, a compressor, a radiator, a decompressor, a heat pump that is a refrigerant circuit in which an evaporator is connected in an annular shape with a refrigerant pipe, and a hot water storage tank that stores hot water, a radiator, There is one configured by spirally winding a refrigerant pipe (for example, see Patent Document 1).

  The pressure reducing device uses a temperature automatic expansion valve using a temperature sensitive cylinder.

China Utility Model Notice No. 2014463270

  However, since the conventional configuration can operate only with inherent control characteristics determined from the structure and operating principle of the temperature automatic expansion valve, it is impossible to achieve both high efficiency of the heat pump as a refrigerant circuit and improvement of the reliability of the compressor. It had the problem that.

  This invention solves the said conventional subject, and it aims at providing the heat pump water heater which can implement | achieve coexistence with high efficiency of a heat pump, and the reliability improvement of a compressor.

  In order to solve the above-described conventional problems, a heat pump water heater of the present invention includes a refrigerant circuit in which a compressor, a radiator, a decompression device, and an evaporator are annularly connected by a refrigerant pipe, and hot water heated by the radiator. A tank for storing hot water, a discharge temperature sensor for detecting the discharge temperature of the refrigerant from the compressor, a tank temperature sensor for detecting the hot water temperature in the tank, an outside air temperature sensor for detecting the outside air temperature, and a control device, The radiator is configured by winding the refrigerant pipe around the outer periphery of the tank, the pressure reducing device is an electronic expansion valve, and the control device is configured to control the hot water temperature and the outside air temperature in the tank. The opening degree of the electronic expansion valve is controlled so that the target discharge temperature determined from the above is reached.

  As a result, the refrigerant state sucked into the compressor from the evaporator can be optimized (dryness of 1), the efficiency of the heat pump as the refrigerant circuit can be increased, and the discharge temperature from the compressor is excessive. Can be prevented, and as a result, the reliability of the compressor can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump water heater which can implement | achieve coexistence with high efficiency of a heat pump and the reliability improvement of a compressor can be provided.

1 is a schematic configuration diagram of a heat pump water heater in Embodiment 1 of the present invention.

A first invention includes a refrigerant circuit in which a compressor, a radiator, a decompression device, and an evaporator are annularly connected by a refrigerant pipe, a tank for storing hot water heated by the radiator, and a refrigerant from the compressor A discharge temperature sensor for detecting the discharge temperature of the tank, a tank temperature sensor for detecting the hot water temperature in the tank, an outside air temperature sensor for detecting the outside air temperature, and a control device, wherein the radiator is the refrigerant pipe Is wound around the outer periphery of the tank, the pressure reducing device is an electronic expansion valve, and the control device has a target discharge temperature determined from the hot water temperature in the tank and the outside air temperature. The heat pump water heater is characterized in that the opening degree of the electronic expansion valve is controlled.

  As a result, the refrigerant state sucked into the compressor from the evaporator can be optimized (dryness of 1), the efficiency of the heat pump as the refrigerant circuit can be increased, and the discharge temperature from the compressor is excessive. Can be prevented, and as a result, the reliability of the compressor can be improved.

  In a second aspect of the invention, particularly in the first aspect of the invention, the control device controls at least the opening degree of the electronic expansion valve so that the discharge temperature of the refrigerant from the compressor does not exceed a predetermined temperature. It is a feature.

  As a result, the temperature of the compressor can be protected, and the reliability of the compressor can be improved.

  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 schematic configuration of a heat pump water heater in the present embodiment. As shown in FIG. 1, the heat pump water heater 100 includes a refrigerant circuit 80 in which a compressor 1, a radiator 4, a decompressor 3, and an evaporator 2 are sequentially connected in an annular manner through a refrigerant pipe 81, and a tank for storing hot water. 6 is provided.

  As the refrigerant circulating in the refrigerant circuit 80, a fluorocarbon refrigerant such as R410A, R407C, R134a, and R32, or a natural refrigerant such as carbon dioxide can be used. In the present embodiment, a specification is made such that a fluorocarbon refrigerant is used and the high pressure side pressure of the refrigerant circuit 80 is operated in a subcritical state.

  As the decompression device 3, an electronic expansion valve or a capillary tube whose opening degree can be freely adjusted can be used. In this embodiment, an electronic expansion valve is used.

  In the radiator 4, the refrigerant pipe 81 is spirally wound around the outer periphery of the tank 6 and fixed. The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows through the refrigerant pipe constituting the radiator 4 and dissipates heat to the hot water in the tank 6, so that the hot water in the tank 6 is heated.

  A fan 7 for blowing air to the evaporator 2 is provided in the vicinity of the evaporator 2. The rotational speed of the fan 7 can be freely adjusted.

  An outside air temperature sensor 11 that detects the outside air temperature is provided in the vicinity of the evaporator 2. A discharge temperature sensor 12 that detects the temperature of the refrigerant discharged from the compressor 1 is also provided.

  A water supply pipe 8 that supplies water to the tank 6 and a hot water discharge pipe 9 that discharges hot water in the tank 6 are connected to the tank 6. The water supply pipe 8 is connected to the lower part of the tank 6, and the hot water discharge pipe 9 is connected to the upper part of the tank 6.

In addition, a tank temperature sensor 10 that detects the temperature of hot water in the tank 6 (or the temperature of the outer surface of the tank 6) is disposed at a substantially central portion in the height direction of the tank 6. A plurality of tank temperature sensors 10 may be provided at a predetermined interval in the height direction of the tank 6.

  Next, a method for determining the target discharge temperature of the refrigerant discharge temperature from the compressor 1 will be described. A target discharge temperature set in advance in the control device 13 is determined from the temperature of hot water in the tank 6 detected by the tank temperature sensor 10 and the outside air temperature detected by the outside air temperature sensor 11. The control device 13 controls the opening degree of the electronic expansion valve that is the decompression device 3 so that the detected temperature becomes the target discharge temperature.

  The target discharge temperature set in advance in the control device 13 increases as the temperature of hot water in the tank 6 and the outside air temperature increase, and the target discharge temperature becomes higher at a predetermined temperature or lower. 2 is set so that the state of the refrigerant sucked from 2 is optimum (dryness 1).

  This is because, in the refrigerant circuit 80 having a specification in which the high-pressure side pressure is operated in a subcritical state, the high-pressure side pressure and the temperature of hot water in the tank 6 are correlated with each other. The high pressure side pressure of the refrigerant circuit 80 is estimated, and the optimum target discharge temperature is calculated from the optimum state (dryness 1) of the refrigerant drawn into the compressor 1 from the evaporator 2 and set in advance.

  As a result, the state of the refrigerant sucked into the compressor 1 from the evaporator 2 can be optimized (dryness 1), the efficiency of the refrigerant circuit 80 can be improved, and the refrigerant discharged from the compressor 1 can be increased. An excessive increase in temperature can be suppressed more reliably.

  According to the present invention, since it is possible to achieve both high efficiency of the heat pump and improvement of the reliability of the compressor, it can be applied as a heat pump water heater for home use and business use.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Evaporator 3 Pressure reducing device 4 Radiator 6 Tank 7 Fan 8 Water supply pipe 9 Hot water discharge pipe 10 Tank temperature sensor 11 Outside air temperature sensor 12 Discharge temperature sensor 13 Control device 80 Refrigerant circuit 81 Refrigerant piping 100 Heat pump water heater

Claims (2)

A refrigerant circuit in which a compressor, a radiator, a pressure reducing device, and an evaporator are annularly connected by a refrigerant pipe, a tank for storing hot water heated by the radiator, and a refrigerant discharge temperature from the compressor are detected. A discharge temperature sensor; a tank temperature sensor that detects the temperature of hot water in the tank; an outside air temperature sensor that detects an outside air temperature; and a control device; and the radiator includes the refrigerant pipe on the outer periphery of the tank. The pressure reducing device is an electronic expansion valve, and the control device is configured to control the electronic expansion valve so as to achieve a target discharge temperature determined from the hot water temperature in the tank and the outside air temperature. A heat pump water heater characterized by controlling the opening degree. The heat pump water heater according to claim 1, wherein the control device controls at least an opening degree of the electronic expansion valve so that a discharge temperature of the refrigerant from the compressor does not exceed a predetermined temperature. .

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