JPH0120703B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an air conditioner equipped with a heat medium heating device and having a bypass circuit for reducing the difference between the discharge pressure and suction pressure of a compressor. be.

(Configuration of conventional example and its problems) Conventionally, in air conditioners that use a compressor, provide heating capacity with a heat medium heating device, and can also perform cooling operation with the same compressor, it is difficult to increase the cooling capacity. If a compressor is selected to ensure high heat transfer, the amount of heat medium discharged from the compressor during heating operation will be excessive, and the pressure difference between the discharge side and the suction side will be too large, resulting in an overload condition of the compressor and an increase in electrical input. Therefore, a bypass circuit was installed from the discharge side to the suction side of the compressor to reduce the pressure difference and make it possible to suck in a heat medium with an appropriate degree of heating.

However, even in this case, the amount of circulating heat medium discharged from the compressor is two to three times that of normal cooling operation, so the refrigerating machine oil (hereinafter referred to as oil) in the compressor
Excess amount of oil was discharged together with the heat medium, and the amount of oil remaining inside the compressor fell below the specified level, causing wear and seizure inside the compressor and causing failure.

(Object of the Invention) The present invention solves the above-mentioned conventional problems, and includes an oil separator provided on the discharge side of the compressor, an outlet of the heat medium oil connected to a bypass circuit, and the oil separator installed on the discharge side of the compressor. The purpose of this is to prevent oil from circulating to the compressor and to immediately return the oil to the compressor to maintain an appropriate amount of oil inside the compressor and prevent wear and seizure inside the compressor.

(Structure of the Invention) In order to achieve the above object, the air conditioner of the present invention includes a compressor, a four-way valve three indoor heat exchanger, a two-way valve,
A refrigeration cycle is constructed by connecting the heat medium heating devices in an annular manner through piping, and connecting an outdoor heat exchanger in parallel to the two-way valve and the heat medium heating device, and connecting the outlet pipe of the compressor and the four-way An oil separator is provided between the valve and the inlet pipe of the compressor and a lower part of the oil separator are connected to provide a bypass circuit having a pressure reducer, and the refrigerant is removed from the compressor by switching the four-way valve. The bypass circuit is provided with a two-way valve that is opened when the oil separator, the four-way valve, the indoor heat exchanger, the two-way valve, and the heat medium heating device are sequentially flowed.

(Description of an Embodiment) An embodiment of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an indoor unit, which is equipped with an indoor heat exchanger 2 and an indoor blower 3. 4
is an outdoor unit, which includes a compressor 5, an oil separator 6, a bypass circuit 7, two-way valves 8, 9, check valves 10, 11,
It is equipped with pressure reducers 12, 13, 14, an outdoor heat exchanger 15, an outdoor blower 16, a four-way valve 17, a heat medium heating device 18, etc., and the pressure reducers 13, 14 are for adjusting the heat medium circulation amount. , bypass circuit 7
It is possible to omit the heat medium if a balance is maintained between the four-way valve 17 and the heat exchange section.The solid line indicates the flow of the heat medium in the four-way valve 17 during heating operation, and the broken line indicates during cooling operation.

During cooling operation, the two-way valves 8 and 9 are closed.
The heat medium flows from the compressor 5 to the oil separator 6, the four-way valve 17, the outdoor heat exchanger 15, the pressure reducer 12, the check valve 11, the pressure reducer 14, the indoor heat exchanger 2, and the four-way valve 1.
7 shows a normal refrigeration cycle in which the air passes through the check valve 10 and returns to the compressor 5.

During heating operation, two-way valves 8 and 9 are open.
The flow of the heat medium enters the oil separator 6 from the compressor 5, where the heat medium and oil are separated, and a part of the heat medium and the oil enter the bypass circuit 7, pass through the two-way valve 8, the pressure reducer 13, and the compressor. Return to 5. The heat medium that does not contain oil passes from the oil separator 6 through the four-way valve 17, the indoor heat exchanger 2, the pressure reducer 14, the two-way valve 9, and the heat medium heating device 18, where it is heated, and then heated by the compressor 5. Return to Note that the check valves 10 and 11 are for preventing the heat medium from flowing into the outdoor heat exchanger 15.

Here, the internal structure of the oil separator 6 and the flow of the heat medium and oil will be explained with reference to FIG. Yes, it hits Batsuful 6b. And since oil is a liquid component, Batsuful 6
b, the oil drips and accumulates at the bottom of the oil separator 6, and goes to the bypass circuit 7 through the oil outlet 6c. Since the heat transfer medium is a gas component, after hitting the Batsuful 6b, some of the oil component has disappeared.
From the gap b, the heat medium goes to the four-way valve 17 from the heat medium outlet 6d, and the heat medium containing a part of the oil component flows through the oil outlet 6c.
It then goes to the bypass circuit 7 and returns to the compressor 5.

Therefore, the oil is discharged to the heat exchange section and does not remain there, so that the amount of oil remaining in the compressor is maintained at an appropriate level, and wear and seizure of the compressor can be prevented.

(Effect of the invention) As described above, the structure of the air conditioner of the present invention is as follows:
Since an oil separator is installed at the branch inlet of the bypass circuit, the oil from the compressor will not come back even if it is discharged during heating operation, eliminating wear and seizure inside the compressor. Since the oil does not flow into the heat exchanger, no oil film is formed on the inner wall of the heat exchanger, which improves heat exchange and increases efficiency.Furthermore, when heated by the heat medium heating device, the temperature of the heat exchanger decreases. Even if the temperature rises, there is no oil, so oil decomposition can be prevented. Furthermore, since the oil separator is installed at the inlet of the bypass circuit, it can also be used as a branch pipe of the bypass circuit, resulting in effects such as cost reduction.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner equipped with a heat medium heating device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the internal structure of an oil separator in the air conditioner. 2... Indoor heat exchanger, 5... Compressor, 6... Oil separator, 7... Bypass circuit, 15... Outdoor heat exchanger, 17... Four-way valve, 18... Heat medium heating device.

Claims (1)

[Claims] 1 A compressor, a four-way valve, an indoor heat exchanger, a two-way valve, and a heat medium heating device are each connected in a ring with piping, and an outdoor heat exchanger is connected in parallel to the two-way valve and the heat medium heating device. a bypass comprising a refrigeration cycle, an oil separator being provided between the outlet pipe of the compressor and the four-way valve, connecting the inlet pipe of the compressor to a lower part of the oil separator, and having a pressure reducer. A circuit is provided, and the circuit is opened when the four-way valve is switched to cause the refrigerant to flow in order from the compressor to the oil separator, the four-way valve, the indoor heat exchanger, the two-way valve, and the heat medium heating device. An air conditioner in which a two-way valve is provided in the bypass circuit.