JPS5913574Y2 - Air conditioning equipment - Google Patents

Description

[Detailed description of the invention] During defrosting, this invention creates a defrosting cycle by exchanging heat between the discharged gas and the suction liquid, thereby always achieving stable defrosting operation, shortening the defrosting time, and reducing the Increases durability, prevents liquid return, and prevents cold trough.

Conventionally, the defrosting method for air source heat pumps uses a four-way valve to switch the flow of refrigerant, with the outdoor heat exchanger acting as a condenser and the indoor heat exchanger acting as an evaporator, performing reverse cycle operation to prevent frost formation. Reverse cycle defrosting methods are commonly used.

However, in practical use, many problems remained in terms of shortening the defrosting time, preventing liquid return, and preventing cold drafts.

The present invention aims to improve such problems, and as a configuration for that purpose, the present invention has a compressor, a first four-way valve, a user-side heat exchanger, an air-conditioning/heating main capillary tube, and a liquid receiver connected in series. Furthermore, a cooling auxiliary capillary tube, a heat source side heat exchanger, and an accumulator are connected in series to the liquid receiver via a parallel body of a heating capillary tube and a check valve to form a heat pump refrigerant circuit in which the whole is connected in a ring. , an auxiliary coil is buried in the liquid receiver, and this auxiliary coil is connected to a second four-way valve installed at an appropriate position in the piping connecting the first four-way valve and the heat source side heat exchanger, and the high-pressure liquid of the refrigerant circuit is connected to the second four-way valve. A bypass pipe is provided which connects a part of the pipe to the low pressure side via a solenoid valve, and the solenoid valve is opened during defrosting.

The present invention will be explained below with reference to the drawings showing one embodiment thereof.

1 is an indoor unit, 2 is an outdoor unit, and 3 is a refrigerant piping unit.

In the indoor unit 1, 4 is a compressor, 5 is a first four-way valve, 6 is an indoor heat exchanger, and 7 is a gas provided at one end of each of a plurality of divided circuits that divide the refrigerant flowing through the indoor heat exchanger 6. A side branch pipe, 8 is a cooling/heating main capillary tube directly connected to the other end of each of the plurality of divided circuits of the indoor heat exchanger 6, 9 is a filter, and 10 is a bypass pipe with a solenoid valve 11 that is opened only during defrosting. It is connected to the suction side of the compressor 4 through the compressor 4.

12 is an accumulator, 13 is a joint, and 14 is an indoor fan.

In the outdoor unit 2, 15 is an outdoor heat exchanger;
Reference numeral 6 indicates gas side branch pipes 17 provided at one end of each of the outdoor heat exchangers 15 that provide a plurality of divided circuits similarly to the indoor heat exchanger 6;
18 is a filter, 19 is a check valve, and 20 is a heating capillary tube directly connected to the other end of each of the plurality of divided circuits, and these check valves 19 and the heating capillary tube 20 are are parallel.

21 is a liquid receiver, 22 is an auxiliary coil embedded in the liquid receiver 21, which functions as an evaporator using the heat source of discharged gas during defrosting, 23 is a second four-way valve, 24 is a joint, 25
is an outdoor fan.

The feature of the refrigerant circuit configuration of the present invention as described above is that when the outdoor heat exchanger 15 is frosted or the outside temperature is low, the first four-way valve 5, When the second four-way valve 23 is operated to switch to the defrosting circuit, the high-temperature, high-pressure gas refrigerant discharged from the compressor 4 is transferred to the first four-way valve 5, the joint 13, the refrigerant piping unit 3, the joint 24, and the second four-way valve. Via the valve 23,
The refrigerant, which is guided through the auxiliary coil 22 buried in the liquid receiver 21 and partially liquefied by heat transfer to the refrigerant in the liquid receiver 21, passes through the second four-way valve 23 and the gas side branch pipe 16 to the outdoor heat source. Exchanger 1
Enter 5.

In the outdoor heat exchanger 15, the frost adhering to the fan is heated from the inside, melted and removed, and the completely condensed and liquefied refrigerant is depressurized in the cooling/heating auxiliary capillary tube 17 and passed through the filter 1.
8, check valve 19, liquid is guided to receiver 21, gasified by heat exchange with discharged gas, joint 24, refrigerant piping unit 3, joint 13, bypass pipe 10, solenoid valve 1
1. A defrosting cycle is formed for the accumulator 12 and the compressor 4, and when the amount of frost gradually decreases, the outdoor heat exchanger 15
The amount of liquefied refrigerant flowing out also gradually decreases, and the temperature difference between the refrigerant at the entrance and exit of the outdoor heat exchanger 15 disappears, resulting in a defrosting refrigerant circuit that completes defrosting.

In other words, since the discharge gas is used as a heat source and heat exchange is performed between the discharge gas and the suction refrigerant, the compressor suction refrigerant completely evaporates, completely preventing liquid return and liquid compression. Stable defrosting operation is possible, and frost formation on the indoor heat exchanger 6 can be prevented by forming a defrost cycle with a refrigerant circuit that bypasses the indoor heat exchanger 6 during defrosting. It is something.

As is clear from the above embodiments, according to the air conditioning system of the present invention, the refrigerant sucked into the compressor is completely gasified by the discharged gas, and compression of the liquid return can be completely prevented, and stable defrosting operation is always possible. In addition, since the defrost cycle is operated in a refrigerant circuit that bypasses the indoor heat exchanger, it is possible to prevent frost formation on the indoor heat exchanger. and can prevent cold drafts.

[Brief explanation of the drawing]

The drawing is a refrigerant circuit diagram of a heating and cooling device showing an embodiment of the present invention. 4... Compressor, 5... First four-way valve, 6
...Indoor heat exchanger (user side heat exchanger), 8.
...Heating and cooling main capillary tube, 10...
...Bypass pipe, 11... Solenoid valve, 12...
... Accumulator, 15 ... Outdoor heat exchanger (heat source side heat exchanger), 17 ... Air conditioning auxiliary capillary tube, 20 ... Air conditioning dedicated capillary tube, 21 ...Liquid receiver, 22...
...Auxiliary coil, 23...Second four-way valve.

Claims (1)

[Scope of utility model registration request] The compressor, the first four-way valve, the heat exchanger on the user side, the main capillary tube for cooling/heating, and the liquid receiver are connected in series, and the liquid receiver is connected to the cooling/heating auxiliary via a parallel body of a heating capillary tube and a check valve. A heat pump refrigerant circuit is constructed by piping a capillary tube, a heat source side heat exchanger, and an accumulator in series and connecting the whole in an annular manner, and an auxiliary coil is embedded in the liquid receiver, and this auxiliary coil is used as a heat source side heat exchanger, A bypass pipe is provided which connects the first four-way valve to a second four-way valve provided at an appropriate position in the pipe, and connects a part of the high-pressure liquid pipe of the refrigerant circuit to the low-pressure side via a solenoid valve, and the solenoid valve is an air conditioning system that is opened during defrosting.