JPH10170078A - Refrigeration equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a large amount of liquid refrigerant from flowing into a refrigerant compressor even in the case that a large amount of liquid refrigerant returns from an evaporator and further to eliminate a disadvantage such as a seizure of a bearing of a refrigerant compressor. SOLUTION: This device is constructed such that a refrigerant compressor 1, and condenser 2, a pressure reducing device 3, an evaporator 4 and a gas- liquid separator 5 or the like are connected in a circuit-form. There are provided a suction pipe 9 for connecting the upper part of the gas-liquid separator 5 with the refrigerant compressor 1 and an oil returning pipe 10 for connecting the lower part of the gas-liquid separator device 5 with the refrigerant compressor 1. In this case, there are provided a solenoid value 11 arranged in the oil returning pipe 10, an oil surface sensor 13 operated when an oil surface in the refrigerant compressor 1 becomes a predetermined level, a suction gas temperature sensing section 12 for sensing a suction gas temperature of the refrigerant compressor 1, and a first control section 14a for closing the solenoid valve 11 until the oil surface in the compressor is decreased lower than a predetermined level when the detected suction gas temperature is less than a predetermined temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus used for, for example, a supermarket showcase, a refrigerator, a freezer, and the like.

[0002]

2. Description of the Related Art FIG. 5 is a refrigerant piping system diagram showing a conventional refrigeration system. In the figure, 1 is a refrigerant compressor, 2 is a condenser, 3 is a decompression device, 4 is an evaporator, and 5 is a gas-liquid separator. This conventional apparatus includes the above-described refrigerant compressor 1, condenser 2,
The depressurizing device 3, the evaporator 4, and the gas-liquid separator 5 are sequentially connected in a circuit form by piping. Further, inside the gas-liquid separator 5, an inlet pipe 6, a U-shaped suction pipe 8 provided with an oil return hole 7 and the like are provided, and the U-shaped suction pipe 8 is provided on the suction side of the refrigerant compressor 1. It communicates with the suction pipe 9 to be connected.

Next, the operation of the conventional apparatus will be described. First, the high-temperature and high-pressure gas refrigerant compressed by the refrigerant compressor 1 is condensed by the condenser 2 and liquefied. The liquid refrigerant passes through a refrigerant pipe (not numbered) and is decompressed by the decompression device 3 to be in a gas-liquid two-phase state. The liquid refrigerant exchanges heat with the outside air in the evaporator 4 and loads in a showcase such as a refrigerator, a freezer, and a supermarket. To cool. The refrigerant that has exchanged heat with the outside air is gasified and flows into the gas-liquid separator 5 via the inlet pipe 6. At this time, the refrigerant compressor 1
A small amount of oil contained in the gas refrigerant discharged from the tank passes through the circuit and accumulates in the gas-liquid separator 5. The gas refrigerant is sucked from the opening 8a at the tip of the U-shaped suction pipe 8 in the gas-liquid separator 5, returns to the refrigerant compressor 1 through the suction pipe 9, and repeats the above cycle. On the other hand, the oil accumulated in the gas-liquid separator 5 is sucked up from the oil return hole 7 at the lower part, returns to the refrigerant compressor 1 through the suction pipe 9, and accumulates in the compressor. The oil level at the bottom of the gas-liquid separator 5 is often disturbed due to the downward direction of the inlet pipe 6 and the momentum due to blowing of the refrigerant or oil.

[0004]

Incidentally, in the conventional refrigeration system, the amount of oil sucked up from the oil return hole 7 of the U-shaped suction pipe 8 is determined by the hole diameter and the opening position of the oil return hole 7. That is, the larger the hole diameter of the oil return hole 7 and the lower the opening position, the larger the amount of oil returning from the gas-liquid separator 5 to the refrigerant compressor 1. On the other hand, when a large amount of liquid refrigerant returns from the evaporator 4 to the gas-liquid separator 5, the oil return hole 7 of the gas-liquid separator 5
A large amount of liquid refrigerant flows into the refrigerant compressor 1 as it is,
This may cause seizure of the bearing of the refrigerant compressor 1 or the like, leading to compressor failure. Therefore, even if a large amount of liquid refrigerant returns from the evaporator 4, the oil return hole 7 is formed so that a large amount of liquid refrigerant does not return to the refrigerant compressor 1 from the gas-liquid separator 5.
It is conceivable to reduce the hole diameter to lower the opening position. However, in such a case, the amount of oil sucked up from the oil return hole 7 becomes excessively small, which leads to a decrease in the oil level in the refrigerant compressor 1. If such a state continues for a long time, oil depletion may lead to serious compressor failure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. Even when a large amount of liquid refrigerant returns from an evaporator to a gas-liquid separator, it is returned to a refrigerant compressor. And ensure that oil is returned to the refrigerant compressor without being affected by turbulence in the oil level in the gas-liquid separator. An object of the present invention is to provide a refrigeration device that does not occur.

[0006]

In order to achieve the above-mentioned object, a refrigerating apparatus according to the present invention comprises a refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator and the like which are sequentially piped in a circuit form. A refrigeration system that includes a suction pipe that connects the upper part of the gas-liquid separator and the suction side of the refrigerant compressor and an oil return pipe that connects the lower part of the gas-liquid separator and the suction side of the refrigerant compressor. In the device, an electromagnetic valve provided in the oil return pipe, an oil level detector provided in the refrigerant compressor that operates when the oil level in the compressor reaches a predetermined level, and a suction detecting the temperature of the suction gas of the refrigerant compressor A gas temperature detection unit, and a first valve closing the solenoid valve until the oil level in the compressor detected by the oil level detector falls below a predetermined level when the suction gas temperature detected by the suction gas temperature detection unit falls below a predetermined temperature. And a control unit.

In addition, a refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator, and the like are sequentially connected in a pipe form in a circuit, and an upper part of the gas-liquid separator is connected to a suction side of the refrigerant compressor. In a refrigeration apparatus including an intake pipe and an oil return pipe that connects a lower part of the gas-liquid separator and a suction side of the refrigerant compressor,
An electromagnetic valve provided in the oil return pipe, an oil level detector provided in the refrigerant compressor that operates when the oil level in the compressor reaches a predetermined level, and an oil provided in the refrigerant compressor to detect the oil temperature in the compressor A second temperature detection unit, and a second valve closing the solenoid valve until the oil level in the compressor detected by the oil level detector falls below a predetermined level when the oil temperature in the compressor detected by the oil temperature detection unit falls below a predetermined oil temperature. And a control unit.

And a refrigerant compressor, a condenser, a pressure reducing device,
The evaporator, the gas-liquid separator, etc. are sequentially connected in a circuit-like pipe, and the suction pipe connecting the upper part of the gas-liquid separator and the suction side of the refrigerant compressor, and the lower part of the gas-liquid separator and the refrigerant compressor In a refrigerating apparatus including an oil return pipe connecting to the suction side, a throttle valve provided on the oil return pipe and capable of controlling a valve opening degree;
An oil level detector provided in the refrigerant compressor and operating when the oil level in the compressor reaches a predetermined level, an intake gas temperature detector that detects the intake gas temperature of the refrigerant compressor, and an intake gas temperature detector A third control unit that closes the throttle valve by a predetermined opening until the oil level in the compressor detected by the oil level detector falls below a predetermined level when the intake gas temperature falls below a predetermined temperature. It is.

Further, a refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator and the like are sequentially connected in a pipe form in a circuit, and an upper part of the gas-liquid separator is connected to a suction side of the refrigerant compressor. In a refrigeration apparatus including an intake pipe and an oil return pipe that connects a lower part of the gas-liquid separator and a suction side of the refrigerant compressor,
A throttle valve provided in the oil return pipe and capable of controlling the opening degree of the valve, an oil level detector provided in the refrigerant compressor and activated when the oil level in the compressor reaches a predetermined level, and an oil level in the compressor provided in the refrigerant compressor An oil temperature detector that detects the temperature, and a throttle until the oil level in the compressor detected by the oil level detector falls below a predetermined level when the oil temperature in the compressor detected by the oil temperature detector falls below a predetermined oil temperature. A fourth control unit that closes the opening of the valve by a predetermined opening.

In addition, a refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator, and the like are sequentially connected in a pipe form in a circuit form, and an upper part of the gas-liquid separator is connected to a suction side of the refrigerant compressor. In a refrigeration apparatus including an intake pipe and an oil return pipe that connects a lower part of the gas-liquid separator and a suction side of the refrigerant compressor,
A throttle valve provided in the oil return pipe and whose valve opening can be controlled, an oil level detector provided in the refrigerant compressor that operates when the oil level in the compressor reaches a predetermined level, and detects the intake gas temperature of the refrigerant compressor The throttle valve is opened until the suction gas temperature detected by the suction gas temperature detector falls below a predetermined temperature when the oil level in the compressor detected by the oil level detector falls below a predetermined level. And a fifth control unit for opening the degree by a predetermined opening degree.

And a refrigerant compressor, a condenser, a pressure reducing device,
The evaporator, the gas-liquid separator, etc. are sequentially connected in a circuit-like pipe, and the suction pipe connecting the upper part of the gas-liquid separator and the suction side of the refrigerant compressor, and the lower part of the gas-liquid separator and the refrigerant compressor In a refrigerating apparatus including an oil return pipe connecting to the suction side, a throttle valve provided on the oil return pipe and capable of controlling a valve opening degree;
An oil level detector provided in the refrigerant compressor that operates when the oil level in the compressor reaches a predetermined level, an oil temperature detector provided in the refrigerant compressor to detect the oil temperature in the compressor, and detected by the oil level detector A sixth control unit that opens the throttle valve by a predetermined opening until the oil temperature in the compressor detected by the oil temperature detection unit becomes equal to or lower than the predetermined oil temperature when the detected oil level in the compressor falls below a predetermined level. It is provided.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. Embodiment 1 of the Invention FIG. 1 shows a refrigeration apparatus according to Embodiment 1 of the present invention. In the figure, 1 is a refrigerant compressor, 2 is a condenser, 3 is a decompression device, 4 is an evaporator, 5 is a gas-liquid separator, 9 is an outlet 5a at the upper part of the gas-liquid separator 5 and suction of the refrigerant compressor 1 The suction pipe 10 connecting the sides is connected to the connection 9a of the suction pipe 9 through the oil outlet 5b at the lower part of the gas-liquid separator 5, and the oil return pipe 11 is provided in the middle of the oil return pipe 10 and is fully open. A solenoid valve that is fully closed, 12 is an intake gas temperature detector that detects the intake gas temperature of the refrigerant compressor 1, and 13 is an oil provided in the refrigerant compressor 1 and that operates when the oil level in the compressor reaches a predetermined level. The surface detector 14 a is a first control unit that controls the drive of the solenoid valve 11. First control unit 1
4a is wired and connected to the intake gas temperature detector 12 (input), the oil level detector 13 (input), and the solenoid valve 11 (output), and detects the intake gas temperature detected by the intake gas temperature detector 12. It has a function of controlling opening and closing of the solenoid valve 11 when a predetermined condition is reached. The first control unit 14a includes, for example, a general-purpose arithmetic processing unit (MPU), a memory storing an arithmetic program and control data (both are not shown), and the like. Each of the control units 14b, 14c, 14d, 14e, 1
4f has the same configuration.

The refrigeration apparatus according to the first embodiment is configured as described above. Subsequently, the operation of the refrigeration apparatus will be described. First, the high-temperature and high-pressure gas refrigerant compressed by the refrigerant compressor 1 is condensed and liquefied in the condenser 2,
The evaporator 4 exchanges heat with the outside air to cool the load of a showcase such as a refrigerator, a freezer, and a supermarket. The gasified refrigerant flows into the gas-liquid separator 5, returns to the refrigerant compressor 1 through the suction pipe 9, and repeats the above cycle. At this time, a small amount of oil contained in the gas refrigerant discharged from the refrigerant compressor 1 passes through the condenser 2, the pressure reducing device 3, and the evaporator 4, and accumulates in the gas-liquid separator 5 (hatched portion in the figure). . Further, the oil flows out from the oil outlet 5b of the gas-liquid separator 5, and returns to the refrigerant compressor 1 through the oil return pipe 10 and the solenoid valve 11. Here, when the liquid refrigerant returns to the refrigerant compressor 1 as it is,
That is, when the intake gas temperature detected by the intake gas temperature detection unit 12 falls below a predetermined temperature, the first control unit 14a
Is controlled so that the electromagnetic valve 11 of the oil return pipe 10 is closed so that the liquid refrigerant is not brought into the refrigerant compressor 1 until the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level. Hold in that state. Therefore, even when a large amount of liquid refrigerant returns from the evaporator 4 to the gas-liquid separator 5, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor 1 as it is, and to seize bearings of the refrigerant compressor 1 etc. Such a problem that occurs can be solved.

Embodiment 2 of the Invention FIG. 2 shows a refrigeration apparatus according to Embodiment 2 of the present invention. In the figure, the configuration of the second embodiment is different from that of the first embodiment in that
An oil temperature detection unit 15 for detecting the oil temperature in the compressor is provided in the refrigerant compressor 1 instead of the intake gas temperature detection unit 12, and a second control unit 14 having a different function is used instead of the first control unit 14a.
b. A detailed description of common components will be omitted. The same applies to the following embodiments. The second control unit 14b includes an oil temperature detection unit 15 (input), an oil level detector 1
3 (input) and the solenoid valve 11 (output). When the oil temperature in the compressor detected by the oil temperature detection unit 15 becomes equal to or lower than a predetermined oil temperature, the second control unit 14b operates until the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level. It has a control function of closing the solenoid valve 11.

The refrigerating apparatus according to the second embodiment is configured as described above. Therefore, when the liquid refrigerant returns to the refrigerant compressor 1 as it is, that is, when the oil temperature in the compressor detected by the oil temperature detection unit 15 becomes equal to or lower than a predetermined oil temperature,
The second control unit 14b controls the solenoid valve 11 of the oil return pipe 10 to close so as not to bring the liquid refrigerant into the refrigerant compressor 1, and the oil level in the compressor detected by the oil level detector 13 is reduced. The state is maintained until the level falls below a predetermined level. Therefore, even when a large amount of liquid refrigerant returns from the evaporator 4 to the gas-liquid separator 5, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor 1 as it is. Thereby, the refrigerant compressor 1
Can be solved.

Embodiment 3 of the Invention FIG. 3 shows a refrigeration apparatus according to Embodiment 3 of the present invention. In the figure, the configuration of the third embodiment is different from that of the first embodiment in that
A throttle valve 16 whose valve opening can be controlled is provided in the oil return pipe 10 instead of the electromagnetic valve 11, and a third control unit 14c having a different function is provided in place of the first control unit 14a. The third control unit 14c is wired and connected to the intake gas temperature detection unit 12 (input), the oil level detector 13 (input), and the throttle valve 16 (output). This third control unit 14c
When the intake gas temperature detected by the intake gas temperature detecting section 12 becomes lower than a predetermined temperature, the opening of the throttle valve 16 is set to a predetermined value until the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level. It has a control function to close only by the opening. The throttle valve 16 is a valve that can obtain an output relatively linear with respect to the input, and is abbreviated as LEV.

The refrigeration apparatus according to the third embodiment is configured as described above. Therefore, as described above, when the intake gas temperature detected by the intake gas temperature detection unit 12 becomes equal to or lower than the predetermined temperature, the third control unit 14c restricts the oil return pipe 10 until the oil level in the compressor falls below a predetermined level. The opening of the valve 16 is controlled to close by a predetermined opening. Therefore, even when a large amount of liquid refrigerant returns from the evaporator 4 to the gas-liquid separator 5, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor 1 as it is, and bearing seizure of the refrigerant compressor 1 can be prevented. Eliminate problems that may occur. Also, compared to the first embodiment,
By finely adjusting the valve opening, the inflow of the liquid refrigerant can be more reliably suppressed.

Embodiment 4 of the Invention FIG. 4 shows a refrigeration apparatus according to Embodiment 4 of the present invention. In the figure, the configuration of the fourth embodiment is different from that of the second embodiment in that
A throttle valve 16 whose valve opening degree can be controlled is provided in the oil return pipe 10 instead of the electromagnetic valve 11, and a fourth control unit 14d having a different function is provided in place of the second control unit 14b. The fourth control unit 14d is connected to the oil temperature detection unit 15 (input), the oil level detector 13 (input), and the throttle valve 16 (output) by wiring. When the oil temperature in the compressor detected by the oil temperature detection unit 15 becomes equal to or lower than a predetermined oil temperature, the fourth control unit 14d operates until the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level. And a control function of closing the opening of the throttle valve 16 by a predetermined opening.

The refrigeration apparatus according to Embodiment 4 is configured as described above. Therefore, as described above, when the oil temperature in the compressor detected by the oil temperature detection unit 15 becomes equal to or lower than the predetermined oil temperature, the fourth control unit 14d restricts the oil return pipe 10 until the oil level in the compressor falls below a predetermined level. The opening of the valve 16 is controlled to close by a predetermined opening. Therefore, even when a large amount of liquid refrigerant returns from the evaporator 4 to the gas-liquid separator 5, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor 1 as it is. As a result, problems such as bearing seizure of the refrigerant compressor 1 can be solved. Further, as compared with the second embodiment, the inflow of the liquid refrigerant can be more reliably suppressed by finely adjusting the valve opening.

Embodiment 5 of the Invention FIG. 3 shows a refrigeration apparatus according to Embodiment 5 of the present invention. In the figure, the configuration of the fifth embodiment differs from that of the third embodiment in that
Fifth control unit 1 having a different function instead of third control unit 14c
4e (indicated by parentheses in the figure). When the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level, the fifth control unit 14e operates until the suction gas temperature detected by the suction gas temperature detection unit 12 becomes equal to or lower than the predetermined temperature. It has a control function to open the throttle valve 16 by a predetermined opening.

The refrigeration apparatus according to Embodiment 5 is configured as described above. Therefore, when the oil level in the gas-liquid separator 5 is significantly disturbed and oil cannot be properly sent to the refrigerant compressor 1, that is, when the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level. , The fifth control unit 14e,
The opening degree of the throttle valve 16 of the oil return pipe 10 is controlled to be opened by a predetermined opening degree so that oil is sent to the refrigerant compressor 1, and the state is maintained until the suction gas temperature becomes equal to or lower than the predetermined temperature. Therefore, the oil accumulated in the gas-liquid separator 5 can be reliably returned to the refrigerant compressor 1 without being affected by the turbulence of the oil level, and the oil level becomes low due to a decrease in the oil level in the compressor. Can be eliminated.

Embodiment 6 of the Invention FIG. 4 shows a refrigeration apparatus according to Embodiment 6 of the present invention. In the figure, the configuration of the sixth embodiment is different from that of the fourth embodiment in that
Sixth control unit 1 having a different function instead of fourth control unit 14d
4f (indicated by parentheses in the figure). When the oil level in the compressor detected by the oil level detector 13 falls below a predetermined level, the sixth control unit 14f operates until the oil temperature in the compressor detected by the oil temperature detection unit 15 becomes equal to or lower than the predetermined temperature. It has a control function to open the throttle valve 16 by a predetermined opening.

The refrigeration apparatus according to Embodiment 6 is configured as described above. Therefore, when the oil level in the compressor detected by the oil level detector 13 falls below the predetermined level as described above, the sixth control unit 14f controls the oil return pipe 10 until the oil temperature in the compressor becomes equal to or lower than the predetermined oil temperature. The opening of the throttle valve 16 is controlled to open by a predetermined opening. Therefore, the oil accumulated in the gas-liquid separator 5 can be removed without being affected by the turbulence of the oil level.
It can be reliably returned to the refrigerant compressor 1. This allows
It is possible to eliminate a problem that the oil level of the refrigerant compressor 1 is reduced and oil is depleted.

[0024]

Since the present invention is configured as described above, it has the following effects. That is, in the present invention, when the detected intake gas temperature becomes equal to or lower than the predetermined temperature, the first control unit closes the solenoid valve provided in the oil return pipe until the oil level in the compressor falls below the predetermined level. Therefore, even when a large amount of liquid refrigerant returns from the evaporator to the gas-liquid separator, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor. Therefore, it is possible to solve the problem that the seizure of the bearing of the refrigerant compressor or the like occurs.

When the detected oil temperature in the compressor becomes equal to or lower than the predetermined oil temperature, the electromagnetic valve provided in the oil return pipe is closed by the second control unit until the oil level in the compressor falls below the predetermined level. Therefore, even when a large amount of liquid refrigerant returns from the evaporator to the gas-liquid separator, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor. Therefore, it is possible to solve the problem that the seizure of the bearing of the refrigerant compressor or the like occurs.

When the detected intake gas temperature becomes equal to or lower than a predetermined temperature, the opening of the throttle valve provided in the oil return pipe is adjusted by the third control unit until the oil level in the compressor falls below a predetermined level. Since only the liquid refrigerant is closed, even when a large amount of liquid refrigerant returns from the evaporator to the gas-liquid separator, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor.
Therefore, it is possible to eliminate the problem that the bearing of the refrigerant compressor is seized.

Further, when the detected oil temperature in the compressor becomes equal to or lower than the predetermined oil temperature, the opening of the throttle valve provided in the oil return pipe is adjusted by the fourth control unit until the oil level in the compressor falls below the predetermined level. Since the opening is closed only by the opening, even if a large amount of liquid refrigerant returns from the evaporator to the gas-liquid separator, it is possible to prevent a large amount of liquid refrigerant from flowing into the refrigerant compressor. Therefore, it is possible to solve the problem that the seizure of the bearing of the refrigerant compressor or the like occurs.

If the detected oil level in the compressor falls below a predetermined level, the fifth control unit adjusts the opening of the throttle valve provided in the oil return pipe until the intake gas temperature falls below the predetermined temperature. Because it is opened only, the oil accumulated in the gas-liquid separator can be reliably returned to the refrigerant compressor without being affected by the disturbance of the oil level. Therefore, it is possible to solve the problem that the oil level of the refrigerant compressor is reduced and oil is depleted.

If the detected oil level in the compressor falls below a predetermined level, the sixth control unit adjusts the opening of the throttle valve provided in the oil return pipe until the oil temperature in the compressor falls below the predetermined oil temperature. Since the valve is opened only by the opening, the oil accumulated in the gas-liquid separator can be reliably returned to the refrigerant compressor without being affected by the turbulence of the oil level. Therefore, it is possible to solve the problem that the oil level of the refrigerant compressor is reduced and oil is depleted.

[Brief description of the drawings]

FIG. 1 is a refrigerant piping system diagram showing a refrigeration apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a refrigerant piping system diagram showing a refrigeration apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a view showing a third embodiment or a fifth embodiment of the present invention;
It is a refrigerant | coolant piping system diagram which shows the refrigerating apparatus which concerns on.

FIG. 4 is a view showing a fourth embodiment or a sixth embodiment of the present invention;
It is a refrigerant | coolant piping system diagram which shows the refrigerating apparatus which concerns on.

FIG. 5 is a refrigerant piping system diagram showing a conventional refrigeration apparatus.

[Explanation of symbols]

Reference Signs List 1 refrigerant compressor, 2 condenser, 3 decompression device, 4 evaporator, 5 gas-liquid separator, 5a outlet of gas-liquid separator, 5b
Oil extraction section, 9 suction pipe, 9a connection section, 10 oil return pipe, 11 solenoid valve, 12 suction gas temperature detection section,
13 oil level detector, 14a first control unit, 14b second
Control unit, 14c third control unit, 14d fourth control unit, 14
e 5th control part, 14f 6th control part, 15 oil temperature detection part, 16 throttle valve.

Claims (6)

[Claims] 1. A refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator, and the like are sequentially connected in a pipe-like manner, and an upper part of the gas-liquid separator and a suction side of the refrigerant compressor are connected. In a refrigerating apparatus including a suction pipe to be connected, and an oil return pipe connecting a lower part of the gas-liquid separator and a suction side of the refrigerant compressor, an electromagnetic valve provided in the oil return pipe; An oil level detector provided in the compressor and operating when the oil level in the compressor reaches a predetermined level; an intake gas temperature detector that detects the intake gas temperature of the refrigerant compressor; and an intake gas temperature detector that detects the intake gas temperature. A first control unit that closes the solenoid valve until the oil level in the compressor detected by the oil level detector falls below the predetermined level when the detected intake gas temperature falls below a predetermined temperature. Refrigeration equipment. 2. A refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator and the like are sequentially connected in a pipe-like manner, and an upper part of the gas-liquid separator and a suction side of the refrigerant compressor are connected. In a refrigerating apparatus including a suction pipe to be connected, and an oil return pipe connecting a lower part of the gas-liquid separator and a suction side of the refrigerant compressor, an electromagnetic valve provided in the oil return pipe; An oil level detector provided in the compressor and operating when the oil level in the compressor reaches a predetermined level; an oil temperature detector provided in the refrigerant compressor for detecting the oil temperature in the compressor; and an oil temperature detector. A second control unit that closes the solenoid valve until the oil level in the compressor detected by the oil level detector falls below the predetermined level when the detected oil temperature in the compressor falls below a predetermined oil temperature. A refrigeration apparatus characterized by the above-mentioned. 3. A refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator and the like are sequentially connected in a pipe-like manner, and an upper part of the gas-liquid separator and a suction side of the refrigerant compressor are connected. In a refrigerating apparatus including a suction pipe to be connected, and an oil return pipe connecting a lower part of the gas-liquid separator and a suction side of the refrigerant compressor, a throttle provided in the oil return pipe and capable of controlling a valve opening degree. A valve, an oil level detector provided in the refrigerant compressor that operates when an oil level in the compressor reaches a predetermined level, an intake gas temperature detection unit that detects an intake gas temperature of the refrigerant compressor, When the temperature of the intake gas detected by the temperature detection unit falls below a predetermined temperature, the opening of the throttle valve is closed by a predetermined opening until the oil level in the compressor detected by the oil level detector falls below the predetermined level. Refrigeration characterized by providing a third control unit apparatus. 4. A refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator, and the like are sequentially connected in a pipe-like manner, and an upper part of the gas-liquid separator and a suction side of the refrigerant compressor are connected. In a refrigerating apparatus including a suction pipe to be connected, and an oil return pipe connecting a lower part of the gas-liquid separator and a suction side of the refrigerant compressor, a throttle provided in the oil return pipe and capable of controlling a valve opening degree. A valve, an oil level detector provided in the refrigerant compressor that operates when an oil level in the compressor reaches a predetermined level, an oil temperature detector provided in the refrigerant compressor to detect an oil temperature in the compressor, When the oil temperature in the compressor detected by the oil temperature detection unit falls below a predetermined oil temperature, the opening of the throttle valve is opened by a predetermined amount until the oil level in the compressor detected by the oil level detector falls below the predetermined level. A refrigeration apparatus comprising: a fourth control unit that closes only once. 5. A refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator and the like are sequentially connected in a pipe-like manner, and an upper part of the gas-liquid separator and a suction side of the refrigerant compressor are connected. In a refrigerating apparatus including a suction pipe to be connected, and an oil return pipe connecting a lower part of the gas-liquid separator and a suction side of the refrigerant compressor, a throttle provided in the oil return pipe and capable of controlling a valve opening degree. A valve, an oil level detector provided in the refrigerant compressor that operates when an oil level in the compressor is at a predetermined level, an intake gas temperature detector that detects an intake gas temperature of the refrigerant compressor, and an oil level detector. When the oil level in the compressor detected by the detector falls below the predetermined level, the opening of the throttle valve is opened by a predetermined opening until the suction gas temperature detected by the suction gas temperature detection unit becomes equal to or lower than a predetermined temperature. A refrigeration unit provided with a fifth control unit; Place. 6. A refrigerant compressor, a condenser, a decompression device, an evaporator, a gas-liquid separator and the like are sequentially connected in a pipe-like manner, and an upper part of the gas-liquid separator and a suction side of the refrigerant compressor are connected. In a refrigerating apparatus including a suction pipe to be connected, and an oil return pipe connecting a lower part of the gas-liquid separator and a suction side of the refrigerant compressor, a throttle provided in the oil return pipe and capable of controlling a valve opening degree. A valve, an oil level detector provided in the refrigerant compressor that operates when an oil level in the compressor reaches a predetermined level, an oil temperature detector provided in the refrigerant compressor to detect an oil temperature in the compressor, When the oil level in the compressor detected by the oil level detector falls below the predetermined level, the opening of the throttle valve is opened by a predetermined amount until the oil temperature in the compressor detected by the oil temperature detection unit becomes equal to or lower than the predetermined oil temperature. A refrigeration apparatus comprising a sixth control unit that opens only once.