JPH01263472A - Heat pump with air heating source - Google Patents

Abstract

PURPOSE:To enable a heating operation to be carried out even during a defrosting operation by a method wherein a hot coolant liquid after a coolant tank is flowed in an air heat exchanger to perform a defrosting operation, a pressure is reduced by an expansion valve, an accumulated heat of a thermal accumulation tank is absorbed to evaporate and gasify the coolant. CONSTITUTION:Gas becomes gas of high temperature and high pressure through a coolant compressor 1, enters a water heat exchanger 2 and heats water. The heated water passes through a pipe 7, enters an air conditioner 6 to heat air. The heated air is used for heating a room. The gas of high temperature and high pressure is condensed, and liquefied by the water heat exchanger 2 and enters a coolant tank 4. High-temperature coolant liquid after the tank 4 passes through a pipe 11 and enters air heat exchanger 3 so as to melt adhered frost. With this arrangement, the coolant liquid which is slightly over-cooled is reduced by an expansion valve 5 for its pressure, the liquid is evaporated, gasified with an accumulated heat being applied as a heating source. The gasified gas is sucked into a coolant compressor 1. In case that a defrosting operation is carried out, the coolant liquid is evaporated and gasified with an accumulated heat being applied as a heating source, so that a heating operation can be continued without reducing capacity even during defrosting operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an air heat source heat pump that is capable of efficient heating operation even during defrosting.

[Conventional technology] As shown in FIG. 3, in heating using an air source heat pump, gas that has become high temperature and high pressure in a refrigerant compressor 1 is condensed and liquefied in a water side heat exchanger 2, and then transferred to a refrigerant tank 4. After being stored, the refrigerant is depressurized by the expansion valve 5, is evaporated and vaporized by the air side heat exchanger 3, and is sucked into the refrigerant compressor 1, and the cycle is repeated.

At this time, the hot water heated by the water-side heat exchanger 2 passes through the water pipe 7 and exchanges heat with air in the air conditioner 6 to heat the room. During heating operation, the air side heat exchanger becomes a refrigerant evaporator, so when the outside air temperature is low (approximately 5°C or less), the evaporation temperature becomes 0°C or less, and the heat transfer surface of the air side heat exchanger Moisture in the air condenses and forms frost. If frost adheres to the heat transfer surface, heat exchange with the air will be inhibited, and heating capacity will not be significantly reduced. Therefore, it is necessary to periodically remove the accumulated frost, and the following methods have been used. (Refer to pages 203-206 of "Automatic Control Equipment for Refrigeration" published by the Japan Refrigeration Association, S, 60.6.30) (1) Hola L-Cass Method This is a system that transfers high-temperature, high-pressure scum discharged from the compressor to the evaporator. This method uses the heat of condensation of the refrigerant gas to flow into the heat tube and melt the frost that forms on the surface of the heat transfer tube from inside the heat transfer tube of the evaporator. When defrosting during heating operation, the refrigerant piping is switched to cooling operation mode and defrosted.

2) Water sprinkling method This method does not melt the frost by directly spraying water onto the frosted evaporator using a spray nostle or the like.

3) One-way electric heater method This method involves inserting a pipe-type sheathed heater into the evaporator and defrosting it by electric heating.

[Problems to be Solved by the Invention] In the hot gas method, heating operation must be interrupted and cooling operation performed in order to defrost, so heating cannot be performed during defrosting. Especially on days when the outside temperature is low and frost is likely to form.
If you have to defrost frequently, the heating won't work as expected. The watering method takes time to defrost. If the water temperature is too high, a mist will form, which will condense on the blower and cause ice formation (fan lock) during cooling, causing motor burnout and other problems. You will also need a sprinkler system and power to keep it running. A single electric heater requires a large amount of power. There is a problem.

[Means for Solving the Problems] The present invention aims to solve the above problems by introducing the high temperature refrigerant liquid after the water side heat exchanger into the air side heat exchanger, and removing the discharged refrigerant from the water side heat exchanger. A pipeline that returns the liquid to the piping in front of the expansion valve, a bypass pipe of the expansion valve, a heat storage tank heat transfer tube connected to the pipeline after the expansion valve, a heat storage tank that accommodates the heat transfer tube, and the heat storage tank. A second pipe installed in the pipeline between the heat exchanger tube and the air side heat exchanger
The present invention is an air source heat pump characterized by comprising an expansion valve and a bypass pipe for the second expansion valve.

[Operation] When defrosting is not required, the high temperature refrigerant liquid after the refrigerant tank is sent to the heat storage tank heat transfer tube through the bypass pipe of the expansion valve, and after heating the heat storage tank liquid, the pressure is reduced by the second expansion valve. By using a circuit that evaporates and vaporizes in the air side heat exchanger, heat can be stored in the heat storage tank and heating can be performed. In addition, when defrosting, a circuit is used that passes the high temperature refrigerant liquid after the refrigerant tank through the air side heat exchanger, defrosts it, reduces the pressure with an expansion valve, absorbs the heat stored in the heat storage tank, and evaporates and vaporizes it. By doing so, heating can be performed without reducing the heating capacity.

[Example] An example of the present invention will be described below based on the drawings. 1st
2 to 2 are circuit diagrams of an air source heat pump according to an embodiment of the present invention. The air heat source heat pump of the present invention has a refrigerant tank 4 in the circuit of a conventional air heat source heat pump.
A pipe line 11 for feeding and discharging the high-temperature refrigerant liquid into the air-side heat exchanger 3 is connected to a pipe line 10 between the refrigerant tank 4 and the expansion valve 50, a bypass pipe line 12 of the expansion valve 5, and the expansion valve. The heat storage tank heat transfer tube 8 connected to the pipe line after 5, the heat storage tank 9 that accommodated the heat storage tank heat transfer tube 8, and the second An expansion valve 14 and a bypass pipe 15 for the second expansion valve 14 are provided.

-5= Next, a method of using the air source heat pump of the present invention will be explained. The flow when defrosting is not performed is shown in bold lines in FIG. The scum enters the water side heat exchanger 2 as high temperature and high pressure scum from the refrigerant compressor 1, and heats water. The heated water enters the air conditioner 6 through the pipe "#I7" and warms the air.
The warmed air is used to heat the room. The high temperature and high pressure gas is condensed and liquefied in the water side heat exchanger 2 and then sent to the refrigerant tank 4.
to go into. The high-temperature refrigerant liquid enters the heat storage tank heat transfer tube 8 through the bypass pipe 2, heats water, etc. in the heat storage tank 9, and exits the pipe 13. Thereby, heat is stored in the heat storage tank. Conduit 13
The high-temperature refrigerant liquid that comes out is depressurized by the second expansion valve, enters the air-side heat exchanger 3, evaporates and vaporizes, becomes a gas, and is sucked into the refrigerant compressor 1.

When defrosting is not performed in this manner, heat is stored in the heat storage tank 9 at the same time as heating is performed.

In FIG. 1, the flow when defrosting is shown by a thick line. The scum enters the water side heat exchanger 2 as high temperature and high pressure scum from the refrigerant compressor 1, and heats water. The heated water passes through the pipe 7 and enters the air conditioner 6 to warm the air, and the warmed air is used to heat the room. The high temperature and high pressure waste is condensed and liquefied in the water side heat exchanger 2 and enters the refrigerant tank 11. The high-temperature refrigerant liquid after the refrigerant tank 4 enters the air-side heat exchanger 3 through the pipe line 1 and does not melt the frost that has adhered thereto. The refrigerant liquid, which has been slightly supercooled by this, is depressurized by the expansion valve 5 and is evaporated and vaporized using the heat stored in the heat storage tank heat transfer tube 8 as a heat source, and the vaporized residue is sucked into the refrigerant compressor 1.

When defrosting in this way, the refrigerant liquid is evaporated and vaporized using the heat stored when defrosting is not being performed as a heat source.
Heating can be continued without reducing capacity even during defrosting.

[Effects of the Invention] With the above configuration, the present invention can perform heating operation even during defrosting. During defrosting operation, the refrigerant liquid is evaporated using the heat stored in the heat storage tank as a heat source. Since it is vaporized, there is no reduction in heating capacity.Also, there is no problem of time-consuming defrosting as with the water spray method, and there is no need for a large amount of electricity as with the electric heater method. There is.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the heat storage flow of an air source heat pump according to an embodiment of the present invention, Fig. 2 is a circuit diagram showing a defrosting flow of an air heat source heat pump according to an embodiment of the present invention, and Fig. 3 is a conventional circuit diagram. FIG. 2 is a circuit diagram showing an air source heat pump. ]... Refrigerant compressor, 2... Water side heat exchanger, 3 - Air side heat exchanger, 5... Expansion valve, 8... Heat storage tank heat exchanger tube, 9
- Heat storage tank, 12... Bypass pipe line, 14... Second expansion valve, 15 - Bypass pipe line.

Claims (1)

[Claims] A pipe line that introduces the high temperature refrigerant liquid after the water side heat exchanger to the air side heat exchanger and returns the discharged refrigerant liquid to the piping in front of the expansion valve;
A bypass pipe of the expansion valve, a heat storage tank heat transfer tube connected to a pipe line after the expansion valve, a heat storage tank housing the heat transfer tube, and a pipe line between the heat storage tank heat transfer tube and the air side heat exchanger. An air source heat pump characterized by comprising: a second expansion valve provided in the second expansion valve; and a bypass pipe for the second expansion valve.