JPS5845456A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a refrigeration system equipped with a liquid injection circuit for a rotary compressor.

Normally, in a refrigeration system that uses a rotary compressor to form a refrigeration cycle, the compressed high-temperature, high-pressure refrigerant gas is once discharged into the compressor's sealed container. Exposure to high temperatures can cause insulation breakdown of motors and deterioration of lubricating oil.

This may even lead to seizure accidents due to poor lubrication. For this reason, it is common to install a liquid injection circuit that cools the motor and lubricating oil by introducing a portion of the liquid refrigerant condensed in the condenser into a sealed container and exchanging heat with the compressed high-pressure, high-temperature gas. .

However, the flow rate of refrigerant flowing through this liquid injection circuit is determined by the auxiliary capillary tape installed in this circuit, and it is controlled to the maximum flow rate under all conditions in response to load fluctuations and power supply voltage frequency fluctuations. However, since the specifications of the auxiliary capillary tape were determined to meet one condition, there was a drawback that the refrigeration cycle could not be maintained optimally.

In the present invention, a part of the discharged high-temperature and high-pressure refrigerant gas is mixed into the liquid injection circuit while adjusting the flow rate.

By controlling the liquid refrigerant flow rate in the liquid injection circuit, it is possible to deal with load fluctuations, power supply voltage, and frequency fluctuations.
The object of the present invention is to provide a refrigeration system that can maintain the liquid injection flow rate at an optimum flow rate under most conditions and obtain an optimum refrigeration cycle.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, 1 is a rotary compressor, which is connected to a condenser 2, a cavity chamber 3, and an evaporator 4 in an annular manner. Reference numeral 5 denotes a liquid injector circuit, which is connected from a liquid pipe 6 between the condenser 2 and the capillary cheese 3 to the closed container of the rotary compressor 1 via an auxiliary cavillary cheese 7. ing.

Reference numeral 8 designates a bypass gas circuit which runs from a high-temperature, high-pressure gas pipe 9 between the rotary compressor 1 and the condenser 2 to the liquid pipe 6 and the auxiliary capillary chest 7. It communicates with the upstream Q'I of 7 via a flow control valve 10. This flow rate control valve 10 has a high temperature and high pressure gas pipe 9.
It has a temperature detection section 11 that detects the temperature of the air, and adjusts the degree of throttling (the amount of refrigerant flowing) according to this temperature.

In the above configuration, the high-pressure refrigerant gas compressed by the rotary compressor 1 is guided to the condenser 2 and becomes liquid-cooled as shown by the arrow in FIG.
Most of the remaining part is led to the capillary tube 3. The liquid refrigerant introduced into the capillary tube 3 absorbs heat and evaporates in the evaporator 4 and returns to the rotary compressor 1 as superheated gas.

On the other hand, the liquid refrigerant led to the liquid injection extraction circuit 5 is controlled in flow rate to some extent by the auxiliary capillary tube 7 and returned to the discharge side of the single-rotation compressor 1.
At this time, the opening degree of the flow rate control valve °10 is adjusted so that the temperature of the high-pressure refrigerant gas detected by the temperature detection unit 11 of the flow rate control valve 10 of the bypass circuit 8 is constant, and the high-pressure refrigerant gas is supplied from the bypass circuit 8. Part of the gas is transferred to liquid injection circuit 6
lead to.

When there are load fluctuations and fluctuations in power supply voltage and frequency, for example, considering load fluctuations, when the load on the evaporator 4 decreases and the temperature of the high-pressure refrigerant gas discharged from the rotary compressor 1 decreases, the temperature detection unit 11 immediately detects this, opens the flow rate control valve 10 in the opening direction, and changes the bypass circuit 8.
The flow rate of the high-pressure refrigerant gas in the liquid injection circuit 5 is increased, and the flow rate of the liquid refrigerant in the liquid injection circuit 5 is restricted. Therefore, a decrease in the temperature of the high-pressure refrigerant gas discharged from the rotary compressor 1 is restricted, an optimum amount of liquid injection refrigerant is maintained, and an optimum refrigeration cycle can be maintained. Conversely, if the load on the evaporator 5 increases.

Similarly, the temperature detection unit 11 detects this and throttles the flow rate control valve 8 to increase the flow rate of liquid refrigerant in the liquid injection circuit 5 to maintain a constant temperature of the high-pressure refrigerant gas discharged from the single-rotation compressor 1, and optimize the temperature. It is possible to maintain a constant refrigeration cycle.

As is clear from the above explanation, the refrigeration system of the present invention is
A bypass circuit connects the liquid injection circuit and a high pressure gas pipe on the discharge side of the rotary compressor, and a flow rate adjustment valve is provided in the bypass circuit to control the temperature of the high pressure gas pipe,
Load fluctuation and power supply voltage.

This is because the amount of liquid refrigerant in the liquid refrigerant circuit is controlled according to fluctuations in frequency, etc.

The amount of liquid refrigerant in the liquid injection circuit is maintained in response to fluctuations in load, power supply voltage, frequency, etc., and the optimal refrigeration cycle can be maintained at all times, thereby reducing the burden on the single-rotation compressor. It is something.

1...Rotary compressor, 2...Condenser,
6・6+++l+a liquid injector circuit, 7.
,,,,Auxiliary capillary tube,8,,,,,,,
Bypass circuit, 10...'・Flow control valve.

Claims (1)

[Claims] A rotary compressor, a condenser, a cavillary cheese, and an evaporator are sequentially connected in an annular manner, and a liquid pipe between the condenser and the capillary cheese and the compressor are connected to a liquid injection circuit having an auxiliary capillary tube. The high-pressure gas pipe between the compressor and the condenser and the upstream liquid pipe of the auxiliary cavity pipe of the liquid injection circuit are operated by detecting the discharge gas temperature of the compressor. The refrigeration system is connected to a bypass circuit having a flow rate control valve, and the amount of refrigerant flowing through the liquid injection circuit is controlled by the flow rate control valve.