JP2001289519A - Refrigerating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigerating apparatus in which a refrigerating-machine oil in a compressor is prevented from being diluted even in a liquid-back operation, and a compression fracture does not result. SOLUTION: In the refrigerating apparatus, a variation in the oil-level of low-pressure shell compressors 1, 2 can be absorbed by using mechanical oil regulators 6, 7. The refrigerating apparatus is provided with a supply tube which supplies, through a solenoid valve 14, the refrigerating machine oil accumulated in an oil tank 5 to an accumulator 12, a float switch 12 detecting a level of the accumulator 12, and a valve controller 15. The controller 15 controls the solenoid valve 14 by opening it, when the float switch 12 detects the accumulator 12 full of the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system used for a supermarket showcase, a refrigerator, a thermostat, and the like, and more particularly to a refrigeration system capable of preventing dilution of refrigeration oil in a compressor during a liquid-back operation. It is.

[0002]

2. Description of the Related Art FIG. 7 is a diagram showing a configuration of a conventional refrigeration system. In FIG. 7, two low-pressure shell compressors 1,
2 are connected in parallel, compress the refrigerant gas, and output the refrigerant gas and the refrigerating machine oil to the oil separators 3 and 4, respectively. The oil separators 3 and 4 separate the refrigerant gas from the refrigerating machine oil and output the separated refrigerant gas to the condenser 8. The condenser 8 condenses the refrigerant gas and sends it to the expansion device 9. The expansion device 9 expands the refrigerant and sends the refrigerant to the evaporator 10. The evaporator 10
The refrigerant evaporates and accumulates in the accumulator 12. A refrigeration cycle is performed in which the refrigerant is again input from the accumulator 12 to the two low-pressure shell-type compressors 1 and 2.

On the other hand, the refrigerating machine oil separated by the oil separators 3 and 4 is output to an oil tank 5. The oil tank 5 temporarily stores the input refrigerating machine oil. The oil tank 5 is connected to an accumulator 12 via a pressure regulating valve 11.
And is maintained at an intermediate pressure having a constant pressure difference with the low pressure side. The mechanical oil regulators 6 and 7 are attached to the low-pressure shell compressors 1 and 2, respectively. When the oil level in each of the low-pressure shell compressors 1 and 2 drops below a certain height, the oil tank 5 is opened. Utilizing the differential pressure, the refrigerating machine oil stored in the oil tank 5 is supplied to each of the low-pressure shell-type compressors 1,
2 to adjust the oil level of each of the low-pressure shell-type compressors 1 and 2 to be constant.

[0004]

In the above-described conventional refrigeration system, the refrigerating machine oil held by each of the low-pressure shell-type compressors 1 and 2 is discharged during operation, and the low-pressure shell-type compressors 1 and 2 are discharged. Although the oil level should decrease, the liquid refrigerant overflowing from the accumulator 12 is always supplied to each of the low-pressure shell-type compressors 1 and 2 while the refrigeration apparatus is in the liquid-back operation. The oil levels of the shell-type compressors 1 and 2 increase, and the mechanical oil regulators 6 and 7 recognize that the refrigerating machine oil is sufficiently supplied. It is no longer supplied to the machines 1 and 2. That is, during the liquid back operation of the refrigeration system, the mechanical oil regulators 6 and 7 do not perform their original normal functions.

In this case, the refrigerating machine oil held by each of the low-pressure shell compressors 1 and 2 is diluted by the liquid refrigerant supplied from the accumulator 12. As the dilution of the liquid refrigerant proceeds, each of the low-pressure shell-type compressors 1, 2
In such a case, there is a problem that an oil film that should be originally formed on a metal contact portion such as a tooth tip is not formed, contact resistance increases, and as a result, compression is broken.

It is conceivable to stop the corresponding unit in response to the compression failure of each of the low-pressure shell-type compressors 1 and 2. However, some users who use the refrigerating apparatus demand that the corresponding unit be not stopped. There are cases.

The present invention has been made in view of the above, and an object of the present invention is to provide a refrigerating apparatus that prevents dilution of refrigerating machine oil in a compressor even during a liquid back operation and does not cause compression breakage.

[0008]

In order to achieve the above object, a refrigeration apparatus according to the present invention comprises a refrigeration cycle in which a condenser, a throttle device, an evaporator, an accumulator, a compressor, and an oil separator are sequentially connected. Provide an oil regulator that detects the oil level of the compressor and supplies refrigerating machine oil to the compressor, and communicates with the accumulator through a pressure adjustment valve,
A refrigerating apparatus having an oil level fluctuation absorbing function for supplying the refrigerating machine oil to the compressor via the oil regulator from an oil tank for temporarily storing the refrigerating machine oil separated by the oil separator. A supply pipe for supplying the refrigerating machine oil stored in the oil tank to the accumulator, a float switch for detecting a liquid level of the accumulator, and the solenoid valve when the float switch detects that the accumulator is full. And valve control means for controlling the opening of the valve.

According to the present invention, when the float switch detects that the accumulator is full, the valve control means opens the solenoid valve, supplies the refrigerating machine oil stored in the oil tank to the accumulator, and supplies the refrigerating machine oil together with the liquid refrigerant. Is supplied to the compressor to prevent compression breakdown due to oil dilution by the liquid refrigerant in the compressor during the liquid back operation.

A refrigeration apparatus according to the next invention is characterized in that a refrigeration cycle in which a condenser, a throttling device, an evaporator, an accumulator, a compressor, and an oil separator are connected in sequence to detect the oil level of the compressor and perform the compression. An oil regulator that supplies refrigerating machine oil to the machine, and communicates with the accumulator via a pressure regulating valve to temporarily store the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function of supplying the refrigerating machine oil to a machine, having a solenoid valve,
A supply pipe for supplying the refrigerating machine oil stored in the oil tank to the accumulator, a temperature detecting unit for detecting a temperature on a discharge side of the compressor, and the electromagnetic unit when the temperature detecting unit detects a predetermined temperature or lower. Valve control means for performing control to open the valve.

According to this invention, when the temperature detecting means provided on the discharge side of the compressor detects a temperature equal to or lower than a predetermined temperature corresponding to the liquid back operation, the valve control means opens the electromagnetic valve and sets the oil By supplying the refrigerating machine oil accumulated in the tank to the accumulator and supplying the refrigerating machine oil to the compressor together with the liquid refrigerant, the compression failure due to oil dilution by the liquid refrigerant in the compressor during the liquid back operation is prevented.

[0012] A refrigeration apparatus according to the next invention is characterized in that a refrigeration cycle in which a condenser, a throttle device, an evaporator, an accumulator, a compressor, and an oil separator are sequentially connected, detects an oil level of the compressor and performs the compression. An oil regulator that supplies refrigerating machine oil to the machine, and communicates with the accumulator via a pressure regulating valve to temporarily store the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function of supplying the refrigerating machine oil to a machine, having a solenoid valve,
A supply pipe for supplying refrigerating machine oil accumulated in the oil tank to the accumulator, a temperature detecting unit for detecting an oil temperature of the compressor, and the solenoid valve when the temperature detecting unit detects a predetermined temperature or lower. And valve control means for performing control to open.

According to the present invention, when the temperature detecting means for detecting the oil temperature of the compressor detects a temperature equal to or lower than a predetermined temperature corresponding to the liquid back operation, the valve control means opens the solenoid valve, and the oil tank is opened. By supplying the refrigerating machine oil accumulated in the compressor to the accumulator and supplying the refrigerating machine oil to the compressor together with the liquid refrigerant, the compression failure due to the oil dilution by the liquid refrigerant in the compressor during the liquid back operation is prevented.

[0014] A refrigeration apparatus according to the next invention is characterized in that a refrigeration cycle in which a condenser, a throttle device, an evaporator, an accumulator, a compressor, and an oil separator are connected in sequence to detect the oil level of the compressor and perform the compression. An oil regulator that supplies refrigerating machine oil to the machine, and communicates with the accumulator via a pressure regulating valve to temporarily store the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function of supplying the refrigerating machine oil to a machine, having a solenoid valve,
A supply pipe for supplying the refrigerating machine oil stored in the oil tank to the accumulator, a temperature detecting unit for detecting a temperature on a suction side of the compressor, and the solenoid valve when the temperature switch detects a predetermined temperature or lower. And valve control means for controlling the opening of the valve.

According to this invention, when the temperature detecting means provided on the suction side of the compressor detects a temperature equal to or lower than the predetermined temperature corresponding to the liquid back operation, the valve control means opens the solenoid valve, and the oil valve is opened. By supplying the refrigerating machine oil accumulated in the tank to the accumulator and supplying the refrigerating machine oil together with the liquid refrigerant, compression breakage due to oil dilution by the liquid refrigerant in the compressor during the liquid back operation is prevented.

A refrigeration apparatus according to the next invention is characterized in that, in the above invention, a capillary tube is provided on the supply pipe between the solenoid valve and the accumulator.

According to the present invention, the refrigerating machine oil supplied from the oil tank to the accumulator is gradually supplied by the capillary tube provided on the supply pipe between the solenoid valve and the accumulator, and the tooth of the compressor is adjusted. The oil film at the metal contact portion such as the tip is continuously formed for a long time to prevent compression failure.

A refrigeration apparatus according to the next invention is characterized in that, in the above invention, a strainer is provided on the supply pipe between the solenoid valve and the oil tank.

According to the present invention, the strainer provided on the supply pipe between the solenoid valve and the oil tank includes:
Even if the refrigerating machine oil supplied from the oil tank to the accumulator is filtered and, for example, an HFC-based refrigerant that easily generates sludge is used, the supply pipe is not blocked. When a capillary tube is provided downstream of the solenoid valve,
The supply pipe is more likely to be clogged, but even in this case, the supply pipe can be prevented from being clogged.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a refrigeration apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 1 of the present invention. The refrigerating apparatus shown in FIG. 1 further includes a float switch 13 for detecting whether or not the inside of the accumulator 12 is full, in the accumulator 12 in the refrigerating apparatus shown in FIG. Further, a supply pipe is provided for communicating between the oil tank 5 and the accumulator 12 via the electromagnetic valve 14. Also, based on the detection result of the float switch 13,
A valve control unit 15 that controls opening and closing of the solenoid valve 14 is provided. Other configurations are the same as those of the refrigeration apparatus shown in FIG. 7, and the same components are denoted by the same reference numerals.

In FIG. 1, two low-pressure shell-type compressors 1 and 2 are connected in parallel, compress refrigerant gas, and output refrigerant gas and refrigerating machine oil to oil separators 3 and 4, respectively. The oil separators 3 and 4 separate the refrigerant gas from the refrigerating machine oil and output the separated refrigerant gas to the condenser 8. The condenser 8 condenses the refrigerant gas and sends it to the expansion device 9. The expansion device 9 expands the refrigerant and sends the refrigerant to the evaporator 10. Evaporator 10
Causes the refrigerant to evaporate and accumulate in the accumulator 12. A refrigeration cycle is performed in which the refrigerant is again input from the accumulator 12 to the two low-pressure shell-type compressors 1 and 2.

On the other hand, the refrigerating machine oil separated by the oil separators 3 and 4 is output to an oil tank 5. The oil tank 5 temporarily stores the input refrigerating machine oil. The oil tank 5 is connected to an accumulator 12 via a pressure regulating valve 11.
Through the pressure relief valve 11 to release the pressure,
It is maintained at an intermediate pressure with a constant pressure difference from the low pressure side. The mechanical oil regulators 6 and 7 are attached to the low-pressure shell compressors 1 and 2, respectively. When the oil level in each of the low-pressure shell compressors 1 and 2 drops below a certain height, the oil tank 5 is opened. Utilizing the pressure difference, the refrigerating machine oil stored in the oil tank 5 is supplied to each of the low-pressure shell-type compressors 1 and 2 so that the height of the oil level of each of the low-pressure shell-type compressors 1 and 2 is kept constant. I do.

When the liquid refrigerant in the accumulator 12 becomes full, the float switch 13 sends a signal indicating that the liquid refrigerant is full to the valve control unit 15. That is, the start of the liquid back is detected. The valve control unit 15 closes the solenoid valve 14 and does not cause the refrigerating machine oil to be sent from the oil tank 5 to the accumulator 12 unless a signal indicating that the liquid is full is input from the float switch 13.
On the other hand, when a signal indicating that the liquid is full is input from the float switch 13, the valve control unit 15
Is opened to send the refrigerating machine oil from the oil tank 5 to the accumulator 12.

Thus, each low-pressure shell compressor 1,
The dilution of the refrigeration oil 2 is suppressed. That is, when the accumulator 12 becomes full, the accumulator 12
The liquid refrigerant inside is sent to each of the low-pressure shell-type compressors 1 and 2,
The proportion of the refrigerating machine oil in the liquid refrigerant in the low-pressure shell-type compressors 1 and 2 is reduced and diluted. At the same time, the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 via the electromagnetic valve 14. Therefore, the refrigerating machine oil is sent from the accumulator 12 to the low-pressure shell compressors 1 and 2 together with the liquid refrigerant, and dilution of the refrigerating machine oil in the low-pressure shell compressors 1 and 2 is suppressed.

According to the first embodiment, the float switch 13 detects the start of liquid back by detecting that the accumulator 12 is full, and sends the refrigerating machine oil in the tank 5 to the accumulator 12 at this time. Since the refrigerating machine oil is supplied together with the liquid refrigerant from the accumulator 12, dilution of the refrigerating machine oil in each of the low-pressure shell-type compressors 1 and 2 due to the liquid back operation can be prevented, the compression breakage can be eliminated, and the corresponding unit is stopped. The refrigeration apparatus can be operated continuously without performing this operation.

Embodiment 2 FIG. Next, a second embodiment of the present invention will be described. In the first embodiment described above,
A float switch 13 is provided in the accumulator 12,
Although the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 when the float switch 13 detects a full level, in the second embodiment, the discharge side of each of the low-pressure shell-type compressors 1 and 2 is discharged. Is provided with a discharge gas temperature switch, and when the temperature of the discharge temperature switch becomes equal to or lower than a predetermined temperature, the refrigerating machine oil in the oil tank 5 is supplied to the accumulator 12.
To be sent to.

FIG. 2 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 2 of the present invention. The refrigeration system shown in FIG. 2 is provided with discharge gas temperature switches 21 and 22 on the discharge side of each of the low-pressure shell compressors 1 and 2, instead of the float switch 13 of the refrigeration system shown in FIG. Valve control unit 23
Corresponds to the valve control unit 15 shown in FIG. 1, and when the discharge gas temperature switches 21 and 22 detect below a certain temperature,
Control for opening the solenoid valve 14 is performed. Other configurations are the same as those of the refrigeration apparatus shown in FIG. 1, and the same components are denoted by the same reference numerals.

In FIG. 2, two low-pressure shell-type compressors 1 and 2 are connected in parallel, compress refrigerant gas, and output refrigerant gas and refrigerating machine oil to oil separators 3 and 4, respectively. The oil separators 3 and 4 separate the refrigerant gas from the refrigerating machine oil and output the separated refrigerant gas to the condenser 8. The condenser 8 condenses the refrigerant gas and sends it to the expansion device 9. The expansion device 9 expands the refrigerant and sends the refrigerant to the evaporator 10. Evaporator 10
Causes the refrigerant to evaporate and accumulate in the accumulator 12. A refrigeration cycle is performed in which the refrigerant is again input from the accumulator 12 to the two low-pressure shell-type compressors 1 and 2.

On the other hand, the refrigerating machine oil separated by the oil separators 3 and 4 is output to an oil tank 5. The oil tank 5 temporarily stores the input refrigerating machine oil. The oil tank 5 is connected to an accumulator 12 via a pressure regulating valve 11.
Through the pressure relief valve 11 to release the pressure,
It is maintained at an intermediate pressure with a constant pressure difference from the low pressure side. The mechanical oil regulators 6 and 7 are attached to the low-pressure shell compressors 1 and 2, respectively. When the oil level in each of the low-pressure shell compressors 1 and 2 drops below a certain height, the oil tank 5 is opened. Utilizing the pressure difference, the refrigerating machine oil stored in the oil tank 5 is supplied to each of the low-pressure shell-type compressors 1 and 2 so that the height of the oil level of each of the low-pressure shell-type compressors 1 and 2 is kept constant. I do.

Here, when the liquid refrigerant in the accumulator 12 becomes full, the liquid refrigerant in the accumulator 12 is sent out to each of the low-pressure shell-type compressors 1 and 2. At this time, the temperature on the discharge side of each of the low-pressure shell compressors 1 and 2 decreases. The discharge gas temperature switches 21 and 22 are disposed on the discharge side of each of the low-pressure shell-type compressors 1 and 2 to detect the temperature of the discharge gas,
When a temperature equal to or lower than a certain temperature is detected, a signal indicating a temperature decrease is output to the valve control unit 23. In other words, the discharge gas temperature switches 21 and 22 determine the start of the liquid back by the valve control unit 23.
Notify.

The valve controller 23 is provided with a discharge gas temperature switch 2
If a signal indicating that the temperature exceeds a certain temperature is received by the solenoid valves 14 and 22, the solenoid valve 14 is closed, and the refrigerating machine oil is not sent from the oil tank 5 to the accumulator 12. On the other hand, when the discharge gas temperature switches 21 and 22 detect a temperature below a certain temperature, the valve control unit 23 opens the solenoid valve 14 and
The refrigerating machine oil is sent from the oil tank 5 to the accumulator 12. The valve control unit 23 opens the solenoid valve 14 when one of the discharge gas temperature switches 21 and 22 detects a temperature below a certain temperature. The solenoid valve 14
May be opened. Further, the valve control unit 23
Only the temperature information may be received, and the electromagnetic valve 14 may be opened when the average temperature falls below a certain temperature.

Thus, each low-pressure shell compressor 1,
The dilution of the refrigeration oil 2 is suppressed. That is, the timing corresponding to the time when the accumulator 12 becomes full is detected by the discharge gas temperature switches 21 and 22, and the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 via the electromagnetic valve 14 at the time of this detection. . For this reason, the refrigerating machine oil and the liquid refrigerant are sent from the accumulator 12 to each of the low-pressure shell-type compressors 1 and 2, and each of the low-pressure shell-type compressors 1, 2
The dilution of the refrigerating machine oil inside is suppressed.

According to the second embodiment, the discharge gas temperature switches 21 and 22 detect the start of the liquid back by detecting the time corresponding to the liquid full state in the accumulator 12, and at the time of the detection, the discharge in the tank 5 is performed. Since the refrigerating machine oil is sent to the accumulator 12 and the refrigerating machine oil is supplied from the accumulator 12 together with the liquid refrigerant to each of the low-pressure shell-type compressors 1 and 2, each of the low-pressure shell-type compressors 1 and 2 by the liquid back operation.
It is possible to suppress the dilution of the refrigerating machine oil inside, to eliminate the compression breakage, and to continuously operate the refrigerating apparatus without stopping the corresponding unit.

Embodiment 3 FIG. Next, a third embodiment of the present invention will be described. In the first embodiment described above,
A float switch 13 is provided in the accumulator 12,
Although the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 when the float switch 13 detects a full state, in the third embodiment, the oil temperature of each of the low-pressure shell-type compressors 1 and 2 is increased. Is provided, and when the temperature of the oil temperature switch falls below a certain temperature, the refrigerating machine oil in the oil tank 5 is supplied to the accumulator 12.
To be sent to.

FIG. 3 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 3 of the present invention. The refrigeration system shown in FIG. 3 is provided with oil temperature switches 31 and 32 for detecting the oil temperature of each of the low-pressure shell-type compressors 1 and 2, instead of the float switch 13 of the refrigeration system shown in FIG. Valve control unit 33
Corresponds to the valve control unit 15 shown in FIG. 1, and performs control to open the solenoid valve 14 when the oil temperature switches 31 and 32 detect a certain temperature or lower. Other configurations are the same as those of the refrigeration apparatus shown in FIG. 1, and the same components are denoted by the same reference numerals.

In FIG. 3, two low-pressure shell-type compressors 1 and 2 are connected in parallel, compress refrigerant gas, and output refrigerant gas and refrigerating machine oil to oil separators 3 and 4, respectively. The oil separators 3 and 4 separate the refrigerant gas from the refrigerating machine oil and output the separated refrigerant gas to the condenser 8. The condenser 8 condenses the refrigerant gas and sends it to the expansion device 9. The expansion device 9 expands the refrigerant and sends the refrigerant to the evaporator 10. Evaporator 10
Causes the refrigerant to evaporate and accumulate in the accumulator 12. A refrigeration cycle is performed in which the refrigerant is again input from the accumulator 12 to the two low-pressure shell-type compressors 1 and 2.

On the other hand, the refrigerating machine oil separated by the oil separators 3 and 4 is output to the oil tank 5. The oil tank 5 temporarily stores the input refrigerating machine oil. The oil tank 5 is connected to an accumulator 12 via a pressure regulating valve 11.
Through the pressure relief valve 11 to release the pressure,
It is maintained at an intermediate pressure with a constant pressure difference from the low pressure side. The mechanical oil regulators 6 and 7 are attached to the low-pressure shell compressors 1 and 2, respectively. When the oil level in each of the low-pressure shell compressors 1 and 2 drops below a certain height, the oil tank 5 is opened. Utilizing the pressure difference, the refrigerating machine oil stored in the oil tank 5 is supplied to each of the low-pressure shell-type compressors 1 and 2 so that the height of the oil level of each of the low-pressure shell-type compressors 1 and 2 is kept constant. I do.

Here, when the liquid refrigerant in the accumulator 12 becomes full, the liquid refrigerant in the accumulator 12 is sent out to each of the low-pressure shell-type compressors 1 and 2. At this time, the oil temperature of each of the low-pressure shell-type compressors 1 and 2 decreases. The oil temperature switches 31 and 32 detect the oil temperature in each of the low-pressure shell-type compressors 1 and 2, and output a signal indicating a temperature decrease to the valve control unit 33 when detecting a temperature lower than a certain temperature. That is,
The oil temperature switches 31 and 32 notify the valve control unit 33 of the start of the liquid back.

The valve control unit 33 includes oil temperature switches 31 and 3
If a signal indicating that the temperature exceeds the predetermined temperature is received, the solenoid valve 14 is closed, and the refrigerating machine oil is not sent from the oil tank 5 to the accumulator 12. On the other hand, when the oil temperature switches 31 and 32 detect a temperature below a certain temperature, the valve control unit 33 opens the solenoid valve 14 and causes the refrigerating machine oil to be sent from the oil tank 5 to the accumulator 12. The valve control unit 33 includes the oil temperature switches 31, 3
The solenoid valve 14 is opened when either one of them detects a temperature below a certain temperature, but when both become below a certain temperature, the solenoid valve 14 is opened. Is also good. Further, the valve control unit 33 may receive only the temperature information, and open the solenoid valve 14 when the average temperature becomes equal to or lower than a certain temperature.

Thus, each low-pressure shell compressor 1,
The dilution of the refrigeration oil 2 is suppressed. That is, the timing corresponding to the time when the accumulator 12 becomes full is detected by the oil temperature switches 31 and 32, and the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 via the electromagnetic valve 14 at the time of this detection. Therefore, the accumulator 1
From 2, the refrigerating machine oil is sent together with the liquid refrigerant to each of the low-pressure shell-type compressors 1 and 2, and the dilution of the refrigerating machine oil in each of the low-pressure shell-type compressors 1 and 2 is suppressed.

According to the third embodiment, the start of liquid back is detected by detecting the timing when the oil temperature switches 31 and 32 correspond to the liquid full state in the accumulator 12, and
At the time of this detection, the refrigerating machine oil in the tank 5 is supplied to the accumulator 1
2 and the refrigerating machine oil is supplied from the accumulator 12 together with the liquid refrigerant to each of the low-pressure shell-type compressors 1 and 2,
The dilution of the refrigerating machine oil in each of the low-pressure shell-type compressors 1 and 2 due to the liquid back operation can be suppressed, and the compression breakage can be eliminated.
The refrigeration system can be operated continuously without stopping the corresponding unit.

Embodiment 4 FIG. Next, a fourth embodiment of the present invention will be described. In the first embodiment described above,
A float switch 13 is provided in the accumulator 12,
Although the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 when the float switch 13 detects that the liquid is full, in the fourth embodiment, the suction side of each of the low-pressure shell-type compressors 1 and 2 is used. A suction gas temperature switch for detecting a temperature is provided, and when the temperature of the suction gas temperature switch falls below a certain temperature, the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12.

FIG. 4 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 4 of the present invention. The refrigeration apparatus shown in FIG. 4 is replaced with the float switch 13 of the refrigeration apparatus shown in FIG. 1, and the intake gas temperature switches 41, 42 for detecting the intake gas temperature on the intake side of each of the low-pressure shell compressors 1, 2. Is provided. The valve control unit 43 corresponds to the valve control unit 15 shown in FIG. 1, and performs control to open the solenoid valve 14 when the intake gas temperature switches 41 and 42 detect a certain temperature or lower. Other configurations are the same as those of the refrigeration apparatus shown in FIG. 1, and the same components are denoted by the same reference numerals.

In FIG. 4, two low-pressure shell-type compressors 1 and 2 are connected in parallel, compress refrigerant gas, and output refrigerant gas and refrigerating machine oil to oil separators 3 and 4, respectively. The oil separators 3 and 4 separate the refrigerant gas from the refrigerating machine oil and output the separated refrigerant gas to the condenser 8. The condenser 8 condenses the refrigerant gas and sends it to the expansion device 9. The expansion device 9 expands the refrigerant and sends the refrigerant to the evaporator 10. Evaporator 10
Causes the refrigerant to evaporate and accumulate in the accumulator 12. A refrigeration cycle is performed in which the refrigerant is again input from the accumulator 12 to the two low-pressure shell-type compressors 1 and 2.

On the other hand, the refrigerating machine oil separated by the oil separators 3 and 4 is output to the oil tank 5. The oil tank 5 temporarily stores the input refrigerating machine oil. The oil tank 5 is connected to an accumulator 12 via a pressure regulating valve 11.
Through the pressure relief valve 11 to release the pressure,
It is maintained at an intermediate pressure with a constant pressure difference from the low pressure side. The mechanical oil regulators 6 and 7 are attached to the low-pressure shell compressors 1 and 2, respectively. When the oil level in each of the low-pressure shell compressors 1 and 2 drops below a certain height, the oil tank 5 is opened. Utilizing the pressure difference, the refrigerating machine oil stored in the oil tank 5 is supplied to each of the low-pressure shell-type compressors 1 and 2 so that the height of the oil level of each of the low-pressure shell-type compressors 1 and 2 is kept constant. I do.

Here, when the liquid refrigerant in the accumulator 12 becomes full, the liquid refrigerant in the accumulator 12 is sent out to each of the low-pressure shell-type compressors 1 and 2. At this time, the suction-side temperatures of the low-pressure shell compressors 1 and 2 decrease. The intake gas temperature switches 41 and 42 are connected to the low-pressure shell compressors 1 and 2, respectively.
If the temperature of the suction gas on the suction side of No. 2 is detected and a temperature equal to or lower than a certain temperature is detected, a signal indicating a temperature decrease is output to the valve control unit 43. That is, the intake gas temperature switch 4
1 and 42 notify the valve control unit 43 of the start of the liquid back.

The valve control unit 43 is provided with the intake gas temperature switch 4
If a signal indicating that the temperature exceeds a certain temperature is received from the oil tanks 1 and 42, the solenoid valve 14 is closed, and the supply of the refrigerating machine oil from the oil tank 5 to the accumulator 12 is not performed. On the other hand, when the intake gas temperature switches 41 and 42 detect a temperature below a certain temperature, the valve control unit 43 opens the solenoid valve 14 and
The refrigerating machine oil is sent from the oil tank 5 to the accumulator 12. The valve control unit 43 opens the solenoid valve 14 when either one of the intake gas temperature switches 41 and 42 detects a temperature below a certain temperature, but both of them become below a certain temperature. The solenoid valve 14
May be opened. In addition, the valve control unit 43
Only the temperature information may be received, and the electromagnetic valve 14 may be opened when the average temperature falls below a certain temperature.

Thus, each low-pressure shell compressor 1,
The dilution of the refrigeration oil 2 is suppressed. That is, the timing corresponding to the time when the accumulator 12 becomes full is detected by the intake gas temperature switches 41 and 42, and at this time, the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 via the electromagnetic valve 14. . For this reason, the refrigerating machine oil and the liquid refrigerant are sent from the accumulator 12 to each of the low-pressure shell-type compressors 1 and 2, and each of the low-pressure shell-type compressors 1, 2
The dilution of the refrigerating machine oil inside is suppressed.

According to the fourth embodiment, the suction gas temperature switches 41 and 42 detect the start of the liquid back by detecting the time corresponding to the liquid full state in the accumulator 12. Since the refrigerating machine oil is sent to the accumulator 12 and the refrigerating machine oil is supplied from the accumulator 12 together with the liquid refrigerant to each of the low-pressure shell-type compressors 1 and 2, each of the low-pressure shell-type compressors 1 and 2 by the liquid back operation.
It is possible to suppress the dilution of the refrigerating machine oil inside, to eliminate the compression breakage, and to continuously operate the refrigerating apparatus without stopping the corresponding unit.

Embodiment 5 FIG. Next, a fifth embodiment of the present invention will be described. In the above-described first to fourth embodiments, when the float switch 13 directly or indirectly detects the full state, the refrigerating machine oil in the oil tank 5 is sent to the accumulator 12 at a stretch. In the fifth embodiment, a capillary tube is provided on the downstream side of the solenoid valve 14 to adjust an optimal oil supply amount to the accumulator 12 and supply refrigerating machine oil to each of the low-pressure shell-type compressors 1 and 2 for a long time. An oil film is continuously formed on a metal contact portion such as a tooth tip without proceeding with dilution.

FIG. 5 is a diagram showing a partial configuration inside a refrigeration apparatus according to Embodiment 5 of the present invention. In FIG. 5, a capillary tube 51 is provided downstream of the solenoid valve 14, that is, between the solenoid valve 14 and the accumulator 12. Since the capillary tube 51 is a thin and long tube, the refrigerating machine oil is decompressed and gradually stored in the accumulator 12.
Will be supplied. This capillary tube 5
By providing 1, it is possible to adjust and secure the optimal refueling amount with respect to the maximum liquid back amount estimated from the maximum refrigerant amount. The tooth tips of the low-pressure shell-type compressors 1 and 2 can continue to form an oil film for a long time, and do not cause compression failure. Note that, for other configurations, any of the configurations of Embodiments 1 to 4 shown in FIGS. 1 to 4 are applied.

According to the fifth embodiment, since the capillary tube 51 is provided downstream of the solenoid valve 14,
Since the amount of the refrigerating machine oil supplied from the oil tank 5 to the accumulator 12 is adjusted appropriately and supplied gradually, the tip of each of the low-pressure shell-type compressors 1 and 2 can continue to form an oil film for a long time. In addition, it is possible to eliminate compression breakage, and to continuously operate the refrigeration apparatus without stopping the corresponding unit.

Embodiment 6 FIG. Next, a sixth embodiment of the present invention will be described. In the above-described first to fifth embodiments, it is assumed that an HCFC-based refrigerant is used. However, in this embodiment, even if an HFC-based refrigerant is used, the refrigerating machine oil can be supplied to the accumulator 12 without any trouble. Like that. The HCFC-based refrigerant is H
CFC22 (CHClF ₂ ) and HCFC123 (CHC
l ₂ CF ₃₎ a CFC refrigerant such as, HFC based refrigerant _{is, HFC32 (CH 2 F 2)} , HFC125 (CHF 2
_{CF 3), HFC134a (CH 2} FCF 3) is a chlorofluorocarbon refrigerants such as.

FIG. 6 is a diagram showing a partial configuration inside a refrigeration apparatus according to Embodiment 6 of the present invention. In FIG. 6, a strainer 52 is provided on the upstream side of the electromagnetic valve 14, that is, between the electromagnetic valve 14 and the oil tank 5.

Since the HFC-based refrigerant is more likely to generate sludge than the HCFC-based refrigerant, it is filtered by the strainer 52 to prevent the sludge from blocking the supply pipe. In particular, since the capillary tube 51 shown in FIG. 5 is thin and long, the blockage can be effectively prevented.
Note that, for other configurations, any of the configurations of Embodiments 1 to 5 shown in FIGS. 1 to 5 are applied.

According to the sixth embodiment, since the strainer 52 is provided on the upstream side of the solenoid valve 14, even if an HFC-based refrigerant that easily generates sludge is used, blockage on the supply pipe is effectively prevented. And reliability can be improved. In particular, it is effective when the capillary tube 51 is provided on the downstream side of the electromagnetic valve 14.

[0058]

As described above, according to the present invention, when the float switch detects that the accumulator is full, the valve control means opens the solenoid valve and supplies the refrigerating machine oil accumulated in the oil tank to the accumulator. Supply and supply the refrigerating machine oil to the compressor together with the liquid refrigerant from the accumulator, and stop the refrigerating device accompanying the liquid backing operation because the compression breakage due to dilution of the refrigerating machine oil in the compressor during the liquid backing operation is prevented. This has the effect of enabling continuous operation without the need.

According to the next invention, when the temperature detecting means provided on the discharge side of the compressor detects a temperature lower than a predetermined temperature corresponding to the liquid back operation, the valve control means opens the solenoid valve, The refrigerating machine oil stored in the oil tank is supplied to the accumulator, and the refrigerating machine oil is supplied to the compressor together with the liquid refrigerant from the accumulator, so that compression breakage due to dilution of the refrigerating machine oil in the compressor during the liquid back operation is prevented.
There is an effect that the continuous operation can be performed without stopping the refrigeration apparatus accompanying the liquid back operation.

According to the next invention, when the temperature detecting means for detecting the oil temperature of the compressor detects a temperature equal to or lower than a predetermined temperature corresponding to the liquid back operation, the valve control means opens the solenoid valve and sets the oil valve to The refrigerating machine oil stored in the tank is supplied to the accumulator, and the refrigerating machine oil is supplied to the compressor together with the liquid refrigerant from the accumulator, thereby preventing compression breakdown due to dilution of the refrigerating machine oil in the compressor during the liquid back operation. There is an effect that continuous operation can be performed without stopping the refrigeration apparatus during operation.

According to the next invention, when the temperature detection means provided on the suction side of the compressor detects a temperature equal to or lower than a predetermined temperature corresponding to the liquid back operation, the valve control means opens the solenoid valve, The refrigerating machine oil stored in the oil tank is supplied to the accumulator, and the refrigerating machine oil is supplied to the compressor together with the liquid refrigerant from the accumulator, so that compression breakage due to dilution of the refrigerating machine oil in the compressor during the liquid back operation is prevented.
There is an effect that the continuous operation can be performed without stopping the refrigeration apparatus accompanying the liquid back operation.

[0062] According to the next invention, the refrigerating machine oil supplied from the oil tank to the accumulator is gradually supplied by the capillary tube provided on the supply pipe between the solenoid valve and the accumulator. Since the oil film on the metal contact part such as the tooth tip is continuously formed for a long time to prevent compression breakage, there is no need to stop the refrigeration system due to the liquid back operation, and the effect that continuous operation becomes possible To play.

According to the next invention, the strainer provided on the supply pipe between the solenoid valve and the oil tank filters the refrigerating machine oil supplied from the oil tank to the accumulator, and for example, sludge is easily generated. Even when an HFC-based refrigerant is used, the supply pipe is not blocked. Further, when a capillary tube is provided downstream of the solenoid valve, the supply pipe is more likely to be clogged. Even in this case, the supply pipe can be prevented from being clogged. Refrigeration oil can be supplied with high reliability, and as a result, there is an effect that the stoppage of the refrigeration apparatus due to the liquid back operation is eliminated and continuous operation becomes possible.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 3 of the present invention.

FIG. 4 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 4 of the present invention.

FIG. 5 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 5 of the present invention.

FIG. 6 is a diagram showing a configuration of a refrigeration apparatus according to Embodiment 6 of the present invention.

FIG. 7 is a diagram showing a configuration of a conventional refrigeration apparatus.

[Explanation of symbols]

1,2 low pressure shell type compressor, 3,4 oil separator, 5
Oil tank, 6, 7 mechanical oil regulator, 8
Condenser, 9 expansion device, 10 evaporator, 11 pressure regulating valve, 12 accumulator, 13 float switch,
14 solenoid valve, 15, 23, 33, 43 valve control unit, 2
1, 22 discharge gas temperature switch, 31, 32 oil temperature switch, 41, 42 intake gas temperature switch, 51
Capillary tube, 52 strainer.

Claims (6)

[Claims] 1. A refrigerating cycle in which a condenser, a throttling device, an evaporator, an accumulator, a compressor, and an oil separator are sequentially connected, and the refrigerating machine oil is supplied to the compressor by detecting the oil level of the compressor. An oil regulator is provided, and the refrigerating machine oil is supplied to the compressor via the oil regulator from an oil tank which communicates with the accumulator via a pressure regulating valve and temporarily stores the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function, comprising: a supply pipe having an electromagnetic valve to supply refrigerating machine oil stored in the oil tank to the accumulator; a float switch for detecting a liquid level of the accumulator; Valve control means for performing control to open the solenoid valve when the float switch detects that the accumulator is full. Refrigeration apparatus, characterized in that. 2. A refrigerating cycle in which a condenser, a throttling device, an evaporator, an accumulator, a compressor, and an oil separator are sequentially connected, and the refrigerating machine oil is supplied to the compressor by detecting the oil level of the compressor. An oil regulator is provided, and the refrigerating machine oil is supplied to the compressor via the oil regulator from an oil tank which communicates with the accumulator via a pressure regulating valve and temporarily stores the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function, comprising a solenoid valve, a supply pipe for supplying refrigerating machine oil stored in the oil tank to the accumulator, and a temperature for detecting a temperature on a discharge side of the compressor. Detecting means; and valve control means for performing control to open the solenoid valve when the temperature detecting means detects a predetermined temperature or lower. Apparatus. 3. A refrigerating cycle in which a condenser, a throttle device, an evaporator, an accumulator, a compressor, and an oil separator are sequentially connected, and the refrigerating machine oil is supplied to the compressor by detecting the oil level of the compressor. An oil regulator is provided, and the refrigerating machine oil is supplied to the compressor via the oil regulator from an oil tank which communicates with the accumulator via a pressure regulating valve and temporarily stores the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function, comprising: a supply pipe having an electromagnetic valve for supplying refrigerating machine oil accumulated in the oil tank to the accumulator; and temperature detecting means for detecting an oil temperature of the compressor. And a valve control means for performing control to open the electromagnetic valve when the temperature detection means detects a predetermined temperature or less. 4. A refrigerating cycle in which a condenser, a throttling device, an evaporator, an accumulator, a compressor, and an oil separator are sequentially connected, and the refrigerating machine oil is supplied to the compressor by detecting an oil level of the compressor. An oil regulator is provided, and the refrigerating machine oil is supplied to the compressor via the oil regulator from an oil tank which communicates with the accumulator via a pressure regulating valve and temporarily stores the refrigerating machine oil separated by the oil separator. A refrigerating apparatus having an oil level fluctuation absorbing function, comprising: a supply pipe for supplying refrigerating machine oil accumulated in the oil tank to the accumulator, having a solenoid valve, and a temperature for detecting a temperature on a suction side of the compressor. Detecting means; and valve control means for performing control to open the solenoid valve when the temperature switch detects a temperature lower than a predetermined temperature. Apparatus. 5. The refrigeration apparatus according to claim 1, wherein a capillary tube is provided on the supply pipe between the solenoid valve and the accumulator. 6. The refrigeration apparatus according to claim 1, wherein a strainer is provided on the supply pipe between the solenoid valve and the oil tank.