JPH051957U - Refrigeration equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] A single gas-liquid separator is enough to save space, reduce costs, and prevent compressor failures. [Structure] Refrigerant discharged from the compressor during operation is liquefied by a condenser, decompressed by an expansion valve, evaporated by an evaporator, and then passed through a check valve on the suction side, and then used as gas on both the discharge and suction sides. The liquid refrigerant separated from the gas refrigerant in the separator is returned to the compressor through the first solenoid valve, and when starting after the stop, the refrigerant discharged from the compressor is passed through the three-way valve and the gas-liquid separator suction side check valve. It is characterized in that it is led to a condenser and returned to a compressor via an expansion valve, an evaporator and a second electromagnetic valve. [Effect] It is possible to reduce cost, save space, and prevent damage to the compressor.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a refrigeration system capable of preventing the compressor from being damaged due to a decrease in oil when the refrigeration system using a scroll type compressor is sunk in the refrigerant at startup.

[0002]

[Prior Art]

 FIG. 3 is a refrigerant circuit diagram of a conventional refrigeration system disclosed in, for example, Japanese Utility Model Laid-Open No. 53-35459, in which the number of compressors is one. In FIG. 2, 1 is a compressor, 2 is a discharge pipe, 3 is a discharge side gas-liquid separator, 4 is a discharge pipe, 5 is a condenser, 6 is a liquid pipe, 7 is an expansion valve, 8 is an evaporator, 9 , 11 are suction pipes, 10 is a gas-liquid separator on the suction side, which constitute a refrigeration cycle. Further, 12 is an oil return pipe, and 13 is a solenoid valve.

Next, the operation will be described. The refrigerant compressed in the compressor 1 passes through the discharge pipe 2 to separate the oil in the discharge side gas-liquid separator 3, is liquefied in the condenser 5 via the discharge pipe 4, and is liquefied in the condenser 6 via the pipe 6. It is decompressed, evaporated in the evaporator 8, and sucked into the compressor 1 through the suction pipe, the suction side gas-liquid separator 10 and the suction pipe 11. The oil accumulated in the discharge side gas-liquid separator 3 returns to the compressor 1 from the suction pipe 11 through the oil return pipe 12 and this solenoid valve 13 by opening the solenoid valve 13.

The liquid refrigerant lies in the compressor 1 during the stop, and a mixture of the liquid refrigerant and oil is discharged at the time of start, and the oil in the compressor 1 is taken out, so that the gas-liquid separator 3 on the discharge side is discharged. To separate the oil-liquid refrigerant and return it to the compressor. Although the amount of oil rising during operation will drop to 0.5 wt% or less due to the performance improvement of the compressor 1, the stagnation during stoppage has not been solved.

The gas-liquid separator 10 on the suction side prevents a liquid bag {due to a failure of the expansion valve 7, a blower (not shown) of the evaporator 8 is stopped, etc.) during operation.

[0006]

[Problems to be solved by the device]

 Since the conventional refrigeration system is configured as described above, it is necessary to provide a gas-liquid separator on the discharge side and the suction side, which requires a large installation space, and the device cannot be made compact. There is a problem that the cost becomes high and the compressor 1 fails because the oil does not return to the compressor 1 when the solenoid valve fails.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a refrigerating apparatus which requires only one gas-liquid separator, has a small mounting space, and can be made compact. ..

[0008]

[Means for Solving the Problems]

 The refrigerating apparatus according to the present invention comprises a gas-liquid separator provided for both the discharge side and the suction side of the compressor, and the refrigerant discharged from the compressor during normal operation, guided to the condenser side, and stopped. Refrigerant switching means for switching the refrigerant discharged from the compressor to the gas-liquid separator side at the time of subsequent startup, and the first solenoid valve that opens during normal operation and closes at startup after shutdown. A second electromagnetic valve is provided which is closed during normal operation and opened during startup after stop.

[0009]

[Action]

 In this invention, during normal operation, the refrigerant discharged from the compressor is guided to the condenser side by the refrigerant switching means, the first solenoid valve is opened, and the second solenoid valve is closed, so Refrigerant from the liquid separator is returned to the compressor through the first solenoid valve, and when starting after stop, the first solenoid valve is closed, the second solenoid valve is opened, and the refrigerant switching means Is switched to the gas-liquid separator side to guide the refrigerant discharged from the compressor to the gas-liquid separator, and the refrigerant in the gas-liquid separator returns to the compressor via the condenser and the second electromagnetic valve.

[0010]

Embodiment An embodiment of the refrigerating apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a refrigerant circuit diagram showing the configuration of the embodiment. In the description of the configuration in FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals to avoid redundant description, and the parts different from those in FIG. 3 will be mainly described. As is apparent from a comparison of FIG. 1 with FIG. 3, the portions denoted by reference numerals 1, 2, 4 to 11 in FIG. 1 are the same as those in FIG. 3, and the portions described below are different from those in FIG. This is a characteristic part of the embodiment shown in FIG.

That is, 14 is a three-way valve provided in the discharge pipe 2 as a refrigerant switching means, which connects the discharge pipes 2 and 4 during normal operation, and discharge pipe 2 and pipe 15 at the time of start-up after stoppage. To communicate.

As is apparent from FIG. 2 showing the structure of the gas-liquid separator 10, this pipe 15 is connected to the inlet pipe 10 a of the gas-liquid separator 10 and is sucked via a suction side check valve 19. It is connected to the pipe 9. The inlet pipe 10a is connected to the body portion of the gas-liquid separator 10. The suction pipe 9 is connected between the bypass pipe 17 and the outlet side of the evaporator 8. The bypass pipe 17 branches off from the suction pipe 9 and is connected to the inlet side of the compressor 1. A solenoid valve 18 is provided in the middle of the pipe 17.

A condenser 5 is provided between the discharge pipe 4 connected to the three-way valve 14 and the liquid pipe 6, and the condenser 5 is connected to the evaporator 8 via the liquid pipe 6. The liquid pipe 6 is provided with an expansion valve 7.

Further, the suction side of the compressor 1 and the gas-liquid separator 10 are connected by a suction pipe 11, and the suction pipe 11 is provided with a solenoid valve 16. A discharge side bypass pipe 20 is connected between the electromagnetic valve 16 and the suction pipe 11 on the outlet side of the gas-liquid separator 10 and is connected to the discharge pipe 4. A discharge-side check valve 21 is provided midway. Reference numeral 22 is a thin tube (for example, 6.35D) from the gas-liquid separator 10.

Next, the operation will be described. Generally, when the refrigerant stagnates in the compressor 1, it is discharged in the form of oil and refrigerant liquid or liquid. As the structure of the gas-liquid separator in this case, as shown in FIG. 2, which is adopted in the suction-side gas-liquid separator, the direction of the inlet pipe 10a is changed to the body part of the gas-liquid separator 10. The method of connecting to the wall surface is effective. The structure of such a gas-liquid separator 10 is the same for both discharge and suction.

During operation of the refrigeration system, the three-way valve 14 is switched so that the discharge pipes 2 and 4 communicate with each other, the solenoid valve 16 is opened, and the solenoid valve 18 is closed. The high temperature refrigerant discharged from the compressor 1 in this state is introduced into the condenser 5 through the discharge pipe 2-three-way valve 14-discharge pipe 4, is liquefied in the condenser 5, and then passes through the liquid pipe 6. The pressure is reduced by the expansion valve 7, evaporated by the evaporator 8, passes through the suction pipe 9 through the suction side check valve 19, enters the gas-liquid separator 10 through the inlet pipe 10a of the gas-liquid separator 10, and the gas-liquid separator At 10, the refrigerant liquid is separated from the gas cooling medium, and returns from the gas-liquid separator 10 to the compressor 1 through the suction pipe 11 and the solenoid valve 16.

The gas-liquid separator 10 separates the refrigerant liquid against the malfunction of the expansion valve 7 during operation, the malfunction of the blower (not shown) of the evaporator 8 or the liquid bag such as hot gas defrost (not shown). Then, the liquid bag is protected.

Next, the operation at the time of starting after the stop will be described. In this case, the three-way valve 14 serving as the refrigerant switching means is switched so that the discharge pipe 2 and the pipe 15 are communicated with each other, the solenoid valve 16 is closed, and the solenoid valve 18 is opened.

In this state, the liquid refrigerant and oil sunk in the compressor 1 are mixed and discharged (liquid) to the discharge pipe 2 at the time of start-up, and the three-way valve 14 passes through the pipe 15 from the inlet pipe 10a to separate gas and liquid. Enter vessel 10. At this time, the suction side check valve 19 is closed by the reverse pressure.

The liquid refrigerant and oil that have entered the gas-liquid separator 10 collide with the wall surface inside the gas-liquid separator 10, and the liquid refrigerant accumulates in the lower part of the gas-liquid separator 10. The gas refrigerant is sent from the suction pipe 11 to the condenser 5 through the bypass pipe 20, the discharge side check valve 21, and the discharge pipe 4. Thereafter, in the same manner as in the above-mentioned normal operation, the refrigerant liquefied in the condenser 5 is decompressed by the expansion valve 7 via the liquid pipe 6, evaporated in the evaporator 8, and sucked in the pipe 9, the bypass pipe 17, the solenoid valve. After passing through 18, the separated mixture of oil and liquid refrigerant returns to the compressor 1 due to the pressure difference (the pressure difference between the high pressure of the gas-liquid separator 10 and the low pressure on the suction side of the compressor 1), and the inside of the compressor 1 To prevent the oil level from dropping. Since this operation stabilizes in about 1 to 3 minutes, the three-way valve 14 and the solenoid valves 16 and 18 are switched during the normal operation, and the normal operation is performed.

Further, in the above-mentioned embodiment, the embodiment in which the three-way valve 14 is used has been illustrated, but as the cooling medium switching means, two two-way valves may be used instead of the three-way valve 14.

Further, instead of the solenoid valve 16 of the suction pipe, a thin pipe (depending on the output of the compressor) may be used. Further, the solenoid valve 16 is closed for about 1 minute at the start, and the suction valve It is also possible to stop the refrigerant of No. 3 and operate only with the sleeping refrigerant.

[0023]

[Effect of the device]

 As described above, according to the present invention, since the gas-liquid separator for discharging and suctioning the compressor is constituted by one unit, the mounting space is reduced and the device is not only compact but also A solenoid valve is not required for the thin tube from the liquid separator, so there is no risk of oil shortage due to a failure, and the cost will be reduced.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigerating apparatus according to an embodiment of the present invention.

2 is a structural explanatory view of a gas-liquid separator in the refrigerating apparatus of FIG.

FIG. 3 is a refrigerant circuit diagram of a conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 2,4 Discharge pipe 5 Condenser 7 Expansion valve 8 Evaporator 10 Gas-liquid separator 14 Three-way valve 16,18 Solenoid valve 19 Suction side check valve 21 Discharge side check valve

Claims (1)

[Claims for utility model registration] Claims: 1. A gas-liquid separation pipe for separating the refrigerant into a liquid refrigerant and a gas refrigerant, which is provided for both the suction side and the discharge side of the compressibility, and the discharge piping of the compressor. In operation, a refrigerant switching unit that guides the refrigerant discharged from the compressor to the condenser and switches to guide the refrigerant discharged from the compressor to the gas-liquid separator at the time of start after stop, An evaporator that decompresses the refrigerant liquefied by the condenser after it is decompressed by an expansion valve and an evaporator that opens during the operation and evaporates by the evaporator, and compresses the liquid refrigerant stored in the gas-liquid separator. First solenoid valve that is guided to the machine and closes at the time of startup after the stop, a suction side check valve that guides the refrigerant discharged from the evaporator to the gas-liquid separator only during the operation, and a start after the stop Refrigerant introduced into the gas-liquid separator through the refrigerant switching means only at times A discharge-side check valve that leads from the gas-liquid separator to the condenser, and a valve that is closed during the operation and opened at the time of startup after the stop to return the refrigerant that exits from the evaporator to the compressor. Refrigerating device equipped with the solenoid valve.