JPH102623A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a compressor due to an oil level drop by inserting a solenoid valve opened when an oil level sensor senses a dangerous oil level in a bypass circuit provided in parallel with an expansion valve. SOLUTION: An oil level sensor 20 is provided in a compressor 1. A bypass circuit 14 is provided in parallel with a solenoid valve 16 inserted to an upstream side of an expansion valve 7, and inserted with a solenoid valve 15 opened when the sensor 20 senses a dangerous oil level. When a level of oil 2 stored in a housing 1A of the compressor 1 is lowered and the sensor 20 senses a dangerous oil level, the valve 15 is opened and the valve 16 is closed according to its signal. Thus, high pressure liquid refrigerant liquefied by a condenser 5 is introduced into the housing 1A via a receiver 6, the circuit 14, the valve 15, an evaporator 9, a low pressure tube 10 and an accumulator 9, and a height of the oil level in the compressor 1 is raised. In this manner, since the oil level drop of the compressor 1 can be prevented, the compressor 1 is prevented from being damaged due to a lubricating fault or seizure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A refrigerant circuit of this type of refrigeration system is shown in FIG. Oil 2 is stored in the housing 1A of the low-pressure housing type hermetic electric compressor 1 incorporated in the refrigerant circuit, and the oil 2 is used to lubricate the compressor 1.

When the compressor 1 is operated, the gas refrigerant discharged from the compressor 1 enters the condenser 5, where it is condensed and liquefied, then enters the expansion valve 7 via the receiver 6, where it is throttled. Expand the valve. Next, enter the evaporator 8,
After evaporating here, the compressor 1 is passed through an accumulator 9.
Is sucked into the housing 1A.

The pressure in the temperature-sensitive cylinder 11 attached to the low-pressure pipe 10 at the outlet of the evaporator 8 is led to the expansion valve 7 through the pressure guiding pipe 13 and the capillary tube 12 interposed therebetween, and the The degree of opening of the expansion valve 7 is controlled so that the refrigerant superheat degree becomes constant.

[0005]

In the above-mentioned conventional refrigeration system, when the load is reduced and the compressor 1 repeats the inching operation, oil adheres to the low-pressure pipe 10 and the inner surface of the evaporator 8. As a result, the oil level of the oil 2 in the housing 1A of the compressor 1 may decrease, and the compressor 1 may be damaged due to poor lubrication or seizure based on the lubrication.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its gist is to provide a refrigerant circuit including a compressor, a condenser, an expansion valve, an evaporator, and the like. In the refrigerating apparatus, the compressor is provided with an oil level sensor for detecting an oil level inside the compressor, and a bypass circuit is provided in parallel with the expansion valve. The refrigeration apparatus is provided with an electromagnetic valve that is opened when the refrigeration is detected.

When the oil level inside the compressor becomes a dangerous oil level, the solenoid valve is opened by a command from the oil level sensor that detects the dangerous oil level, and the high-pressure liquid refrigerant flowing out of the condenser is bypassed. Return to the compressor via circuit, solenoid valve, evaporator and low pressure piping.

If the path diameter of the bypass circuit and the electromagnetic valve is substantially equal to the diameter of the liquid refrigerant pipe, the liquid refrigerant flowing out of the condenser flows through the bypass circuit and the electromagnetic valve smoothly.

According to a second aspect of the present invention, in a refrigeration system including a refrigerant circuit including a compressor, a condenser, an expansion valve, an evaporator, and the like, the compressor detects an oil level in the compressor. The refrigerating apparatus is provided with a surface sensor, wherein the expansion valve is an electronic expansion valve, and when the oil level sensor detects a dangerous oil level, the opening degree of the electronic expansion valve is set to a liquid back state.

When the oil level inside the compressor becomes a dangerous oil level, the opening of the electronic expansion valve is in a liquid-back state by a command from the oil level sensor that has detected the dangerous oil level, and has flowed out of the condenser. The liquid refrigerant returns to the compressor via the electronic expansion valve, the evaporator, and the low-pressure pipe.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. The compressor 1 is provided with an oil level sensor 20 for detecting an oil level inside the compressor 1. Further, a bypass circuit 14 is provided in parallel with the expansion valve 7 and a solenoid valve 16 interposed on the upstream side thereof.
An electromagnetic valve 15 that is opened when the unit 12 detects a dangerous oil level is interposed.

Note that the passage diameter of the bypass circuit 11 and the solenoid valve 15 is substantially the same as the diameter of the liquid refrigerant pipe 17. The other configuration is the same as that of the conventional one shown in FIG. 3, and the corresponding members are denoted by the same reference numerals and description thereof will be omitted.

When the oil level sensor 20 detects a dangerous oil level due to a decrease in the oil level of the oil 2 stored inside the housing 1A of the compressor 1, the solenoid valve 15 receives a signal from the oil level sensor 20 to detect a dangerous oil level. Is opened and the solenoid valve 16 is closed at the same time.

Thus, the high-pressure liquid refrigerant condensed and liquefied by the condenser 5 enters the housing 1A of the compressor 1 through the receiver 6, the bypass circuit 14, the solenoid valve 15, the evaporator 8, the low-pressure pipe 10, and the accumulator 9, and In this process, evaporator 8 and low pressure pipe
The oil adhering and staying on the inner surface of the pipe 10 returns to the housing 1A of the compressor 1 with the liquid refrigerant, whereby the oil level inside the compressor 1 increases.

The compressor 1 is opened by opening the solenoid valve 15.
If the oil level inside rises and returns to the normal oil level, the solenoid valve
15 is closed, the solenoid valve 16 is opened, and the refrigeration system returns to the normal operation. However, if the oil level in the compressor 1 does not return to the normal oil level even after a predetermined time, for example, 1 minute, elapses. In this case, the refrigerator is stopped abnormally.

Thus, the oil level inside the compressor 1 can be prevented from lowering below the dangerous oil level, so that the compressor 1 can be prevented from being damaged due to poor lubrication or seizure.

A second embodiment of the present invention is shown in FIG. In the second embodiment, the expansion valve is an electronic expansion valve 21. When the oil level sensor 20 detects a dangerous oil level, the opening of the electronic expansion valve 21 is increased by a predetermined amount to increase the liquid back. It is in a state. The other configuration is the same as that of the conventional one shown in FIG. 3, and the corresponding members are denoted by the same reference numerals and description thereof will be omitted.

When the oil level sensor 20 detects a dangerous oil level, the opening of the electronic expansion valve 21 is increased by a predetermined amount in response to a signal from the oil level sensor 20. In response, the liquid refrigerant is supplied to the electronic expansion valve 20.
And flows into the evaporator 8 without being throttled.

Thus, the oil adhering to the evaporator 8 or the inner surface of the low-pressure pipe 10 and staying therewith is accompanied by the liquid refrigerant and the compressor 1
When the oil level inside the compressor 1 rises and returns to the normal oil level, the electronic expansion valve 20 returns to the normal opening degree. If it does not return to the oil level, the refrigeration system stops abnormally.

[0020]

According to the first aspect of the present invention,
When the oil level inside the compressor becomes a dangerous oil level, the solenoid valve is opened by a command from the oil level sensor that detects this, and the high-pressure liquid refrigerant flowing out of the condenser is bypassed,
Returning to the compressor through the solenoid valve, evaporator, and low-pressure piping, it is possible to prevent the oil level inside the compressor from dropping below the dangerous oil level, and therefore the compressor is damaged by poor lubrication or seizure Can be prevented from occurring.

If the path diameter of the bypass circuit and the solenoid valve is substantially equal to the diameter of the liquid refrigerant pipe, the liquid refrigerant passes through the bypass circuit,
The fluid can flow smoothly through the solenoid valve.

According to the second aspect of the present invention, when the oil level inside the compressor becomes a dangerous oil level, the electronic expansion valve is brought into a liquid back state by a command from an oil level sensor that detects this. Since the liquid refrigerant flowing out of the condenser returns to the compressor via the electronic expansion valve, the evaporator, and the low-pressure pipe, the same effects as those of the first invention can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a system diagram showing a second embodiment of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 5 Condenser 7 Expansion valve 8 Evaporator 20 Oil level sensor 14 Bypass circuit 15, 16 Solenoid valve

Claims (3)

[Claims] 1. A refrigerating apparatus having a refrigerant circuit including a compressor, a condenser, an expansion valve, an evaporator, and the like, wherein the compressor is provided with an oil level sensor for detecting an oil level inside the compressor, and the expansion valve is provided on the expansion valve. A refrigerating apparatus comprising a bypass circuit provided in parallel with the bypass circuit, and an electromagnetic valve that opens when the oil level sensor detects a dangerous oil level is interposed in the bypass circuit. 2. The refrigeration system according to claim 1, wherein the passage diameter of the bypass circuit and the solenoid valve is substantially equal to the diameter of the liquid refrigerant pipe. 3. A refrigeration system having a refrigerant circuit including a compressor, a condenser, an expansion valve, an evaporator, etc., wherein the compressor is provided with an oil level sensor for detecting an oil level inside the compressor, and the expansion valve is provided with the oil level sensor. An electronic expansion valve, wherein the opening of the electronic expansion valve is set to a liquid back state when the oil level sensor detects a dangerous oil level.