JPH05306839A - Refrigerating machine - Google Patents

Abstract

PURPOSE:To prevent temperature of discharged refrigerant from excessively rising due to delay of supplying liquid refrigerant by interposing a check valve for preventing flow of the liquid refrigerant toward a condenser in a tube from an outlet of the condenser to a connecting position of one end of a liquid refrigerant bypass tube. CONSTITUTION:Refrigerant discharged from a compressor 1 is sequentially circulated through a condenser 2, a check valve 12, a receiver 3, an evaporator 5 and an accumulator 6 in this order during operation of the compressor 1, and tubes from the outlet of the condenser 2 to the inlet of a solenoid valve 7 and to the inlet of an expansion valve 4 are fully filled with liquid refrigerant. When the compressor 1 is stopped, and tubes for coupling the valves 12, 7, 4 are closed by these valves. The liquid refrigerant in the tube is prevented from being discharged to the other thereby to be retained as it is. When the compressor 1 is started, temperature of the discharged gas refrigerant is raised to a set value and the valve 7 is opened, the residual liquid refrigerant is input to the compressor through a bypass tube 9, the valve 7 and a tube 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating device such as an air conditioner, a refrigerator and a water heater.

[0002]

2. Description of the Related Art An example of a refrigerant circuit of a conventional refrigeration system is shown in FIG.
Is shown in. In FIG. 5, 1 is a compressor, 2
Is a condenser, 3 is a receiver, 4 is an expansion valve, 5 is an evaporator, 6 is an accumulator, 9 is a liquid refrigerant bypass pipe,
Reference numeral 7 is a solenoid valve, 8 is a capillary tube, 10 is a temperature sensor, and 11 is a temperature sensing cylinder.

The refrigerant discharged from the compressor 1 is condensed and liquefied by the condenser 2, non-condensed gas is separated by the receiver 3, decompressed by the expansion valve 4, evaporated and vaporized by the evaporator 5, and then passed through the accumulator 6 and the compressor. 1 is inhaled and the above is repeated.

When the temperature of the refrigerant gas discharged from the compressor 1 rises and reaches a preset set value,
The electromagnetic valve 7 is opened by a signal from the temperature sensor 10 that detects this, and the liquid refrigerant is replaced by the liquid refrigerant bypass pipe 9, the electromagnetic valve 7,
It is supplied to the compressor 1 via the capillary tube 8 to prevent the temperature of the discharged gas refrigerant from rising excessively.

The degree of superheat of the gas refrigerant at the outlet of the evaporator 5 is detected by the temperature sensing tube 11, and the signal from the temperature sensing tube 11 adjusts the opening degree of the expansion valve 4 to adjust the flow rate of the refrigerant flowing through it. By doing so, the degree of superheat of the gas refrigerant at the outlet of the evaporator 5 is maintained at a predetermined value.

[0006]

In the above refrigerating apparatus, when the operation is restarted after the stop, the liquid refrigerant may not exist at the inlet of the solenoid valve 7. In this case, as shown by the broken line in FIG. 2, after the solenoid valve 7 is opened, the solenoid valve 7 is opened.
There is a problem that the temperature of the gas refrigerant discharged from the compressor 1 excessively rises during the time B before the liquid refrigerant cannot be supplied to the compressor 1 until the time B before the liquid refrigerant is supplied to the inlet of the. ..

[0007]

The present invention has been invented to solve the above-mentioned problems, and the gist of the present invention is that the refrigerant discharged from the compressor includes a condenser, an expansion valve and an evaporator in this order. These are connected via a pipe so as to circulate through, and one end of the liquid refrigerant bypass pipe is connected to the inlet side pipe of the expansion valve and the other end is connected to the inlet side pipe of the compressor, and is discharged from the compressor. In a refrigeration system in which a solenoid valve that opens when the temperature of the refrigerant gas rises and reaches a set value is installed in the liquid refrigerant bypass pipe, a connection from the outlet of the condenser to one end of the liquid refrigerant bypass pipe In the refrigerating apparatus, a check valve for preventing the flow toward the condenser is provided in the pipe reaching the position.

[0008]

In the present invention, because of the above configuration, the liquid refrigerant is sealed in the pipes from the check valve to the solenoid valve and the expansion valve when the refrigeration system is stopped. Therefore, when the operation of the refrigeration system is restarted, if the electromagnetic valve is opened, the liquid refrigerant is immediately supplied to the compressor via the liquid refrigerant bypass pipe.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the invention is shown in FIG. When the condenser 2 and the receiver 3 are located higher than the expansion valve 4 and the solenoid valve 7, a check valve 12 that blocks the flow toward the condenser 2 is provided in the pipe from the outlet of the condenser 2 to the receiver 3. There is. Other configurations are shown in FIG.
It is similar to the conventional one shown, and corresponding members are designated by the same reference numerals.

During operation of the compressor 1, however, the refrigerant discharged from the compressor 1 circulates through the condenser 2, the check valve 12, the receiver 3, the expansion valve 4, the evaporator 5, and the accumulator 6 in this order, The inside of the pipe from the outlet of the condenser 2 to the inlet of the solenoid valve 7 and the inlet of the expansion valve 4 is filled with liquid refrigerant.

When the compressor 1 is stopped, the check valve 12,
The pipes connecting the electromagnetic valve 7 and the expansion valve 4 are closed by these valves, and the liquid refrigerant in the pipes is prevented from flowing out to the other and remains as it is. Although the gas refrigerant also exists in the receiver 3, the liquid refrigerant remains at the inlet of the electromagnetic valve 7 because the electromagnetic valve 7 and the expansion valve 4 are located at low positions.
When the compressor 1 is started and the temperature of the gas refrigerant discharged from the compressor 1 rises to a set value and the electromagnetic valve 7 is opened, the liquid refrigerant remaining at the inlet of the electromagnetic valve 7 becomes liquid refrigerant bypass pipe 9,
It is immediately supplied to the compressor 1 via the solenoid valve 7 and the capillary tube 8.

FIG. 2 shows changes in discharge refrigerant temperature and pressure when the refrigeration system is restarted. After the compressor 1 is started, the discharge refrigerant temperature rises and the electromagnetic valve 7 opens, and at the same time, the liquid refrigerant is supplied to the compressor 1. Therefore, the discharge refrigerant temperature changes as shown by the solid line in FIG. As is clear from the conventional one shown, the discharged refrigerant temperature does not rise excessively.

A second embodiment of the present invention is shown in FIGS. In the second embodiment, the check valve 12 is provided in the pipe from the outlet of the receiver 3 to the expansion valve 30,
A relief function is added to the expansion valve 30. As shown in FIG. 4, the expansion valve 30 includes a needle valve 31 and a spring 32 that pushes the needle valve 31 toward a valve seat.
The superheat degree of the refrigerant gas at the outlet of the evaporator 5 is maintained at the set value by controlling the flow rate of the refrigerant flowing through the refrigerant.

Then, when the compressor 1 stops,
The liquid refrigerant in the pipes from the check valve 12 to the solenoid valve 7 and the expansion valve 30 is sealed. Then, when the discharge refrigerant temperature rises due to the restart of the compressor 1 and the solenoid valve 7 opens, the liquid refrigerant is immediately supplied to the compressor 1.

When the temperature of the pipes from the check valve 12 to the solenoid valve 7 and the expansion valve 30 rises while the compressor 1 is stopped, the pressure of the liquid refrigerant sealed inside this rises. In this case, The needle valve 31 springs due to the pressure of the liquid refrigerant.
By opening the valve against the pressing force of 32, the pressure of the liquid refrigerant is prevented from rising excessively. A safety valve may be used instead of the expansion valve 30 to perform the relief function.

[0016]

According to the present invention, since the check valve for blocking the flow toward the condenser is provided in the pipe from the outlet of the condenser to the connection position of the one end of the liquid refrigerant bypass pipe,
When the refrigeration system is stopped, the liquid refrigerant is sealed in the piping from the check valve to the solenoid valve and the expansion valve. Accordingly, when the operation of the refrigeration system is restarted, the liquid refrigerant is immediately supplied to the compressor via the liquid refrigerant bypass pipe if the solenoid valve is opened.
It is possible to prevent the discharge refrigerant temperature from rising excessively due to the supply delay of the liquid refrigerant.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing temporal changes in discharged refrigerant temperature and pressure in the above embodiment.

FIG. 3 is a refrigerant circuit diagram showing a second embodiment of the present invention.

FIG. 4 is a sectional view of an expansion valve according to a second embodiment.

FIG. 5 is a refrigerant circuit diagram of a conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Receiver 4 Expansion valve 5 Evaporator 7 Solenoid valve 9 Liquid refrigerant bypass pipe 12 Check valve

Claims (1)

[Claims] 1. A condenser, an expansion valve, and an evaporator are connected through a pipe so that the refrigerant discharged from the compressor circulates through the condenser, the expansion valve, and the evaporator in this order, and one end of the liquid refrigerant bypass pipe is connected to the inlet side pipe of the expansion valve. The liquid refrigerant bypass pipe is equipped with a solenoid valve that is connected and the other end is connected to the inlet side pipe of the compressor, and opens when the temperature of the refrigerant gas discharged from the compressor rises and reaches a set value. In the refrigerating apparatus as described above, a check valve that blocks a flow toward the condenser is provided in a pipe from an outlet of the condenser to a connection position of one end of the liquid refrigerant bypass pipe.