JPH09318166A - Refrigerating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the capacity or high pressure of a refrigerating apparatus by means of a simple, inexpensive constitution. SOLUTION: This refrigerating apparatus has a refrigerating circuit comprising a compressor 1, condenser 3, throttling mechanism 5, and evaporator 6 connected in this order and has an oil-returning solenoid valve 11 in an oil- returning circuit 9 by which to return to the suction pipe 8 of the compressor 1 the oil separated by an oil separator 2 set in the discharge pipe 18 of the compressor 1. In this instance the oil-returning circuit 9 is provided with a bypass 13 as an adjunct for bypassing hot gas from the oil separator 2 to the suction pipe 8 of the compressor 1 and a control valve 14 is set in the bypass 13.

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 refrigerating apparatus is shown in FIG. The gas refrigerant discharged from the compressor 1 is discharged from the discharge pipe 18
Enter the cyclone type oil separator 2 installed in
Here, the mist of the lubricating oil contained in the gas refrigerant is separated.

The gas refrigerant from which the oil has been separated flows out from the oil separator 2 and enters the condenser 3 where it radiates heat to the outside to be condensed and liquefied. This liquid refrigerant passes through a receiver 4 and enters a throttling mechanism 5 including an expansion valve and the like, where it is adiabatically expanded by being throttled, and then enters an evaporator 6, where it is evaporated and vaporized by cooling the inside air, In this state, it returns to the compressor 1 through the accumulator 7 and the suction pipe 8.

The oil discharged from the compressor 1 along with the refrigerant in accordance with the operation of the compressor 1 is separated by the oil separator 2 and collected at the bottom of the oil separator 2, and an oil return solenoid valve.
When 11 is opened, the oil in the oil separator 2 is returned to the oil return circuit 9
Further, the oil returns to the compressor 1 via the oil return solenoid valve 11 and the capillary tube 12 which are inserted in the suction pipe 8 and the gas refrigerant flowing through the suction pipe 8.

[0005]

In order to adjust the capacity of the conventional refrigeration system according to the load, the compressor is of a variable discharge type, or the discharge amount is changed by driving the compressor via an inverter. However, there is a problem that the cost is increased because it is necessary to incorporate a special capacity control device.

Further, there is a case where the high pressure abnormally rises at a high outside temperature and the protection mechanism is activated to stop the operation. To prevent this, a special high pressure control mechanism is incorporated to expand the operation range. However, there is a problem that the cost is similarly increased.

[0007]

The present invention has been invented to solve the above problems, and its gist is to connect a compressor, a condenser, a throttle mechanism, and an evaporator in this order. And a solenoid circuit for oil return in an oil return circuit for returning the oil separated by the oil separator installed in the discharge pipe of the compressor to the suction pipe of the compressor. In the refrigerating apparatus, a bypass system passage for bypassing hot gas from the oil separator to the suction pipe side of the compressor is attached to the oil return circuit, and a control valve is provided in the bypass system passage. Located in the freezer.

Another feature is that the control valve is either an electromagnetic valve that is opened or closed according to the detected low pressure, or a constant pressure control valve or a constant pressure expansion valve that keeps the low pressure constant.

Still another feature is that the control valve is either an electromagnetic valve that is opened or closed according to the detected high pressure or a high pressure control valve that keeps the high pressure constant.

Still another feature is that an oil cooler is provided in the oil return circuit on the upstream side of the bypass system passage.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. As shown in FIG. 1, in the oil return circuit 9, a bypass system path 13 that bypasses hot gas from the oil separator 2 to the suction pipe 8 side of the compressor 1 in parallel with the oil return solenoid valve 11 and the capillary tube 12. The bypass valve 13 is provided with a control valve 14.

The control valve 14 is composed of an electromagnetic valve which opens when the low pressure detected by a low pressure sensor (not shown) becomes lower than a set pressure and closes when it becomes higher than the set pressure. Other configurations are the same as those of the conventional one shown in FIG. 4, and corresponding members are designated by the same reference numerals and the description thereof is omitted.

However, when the low pressure becomes lower than the set pressure due to the decrease in the load of the refrigerating apparatus, the control valve 14 opens, and the hot gas in the oil separator 2 is accompanied by the bypass line from the oil return circuit 9. The gas enters the suction pipe 8 through the control valve 13 and the control valve 14, and returns to the compressor 1 with the gas refrigerant flowing therethrough. As a result, the amount of refrigerant circulating in the condenser 3 and the evaporator 6 is reduced, so that the capacity of the refrigeration system is reduced.

When the low-pressure pressure exceeds the set pressure due to the increase in the load of the refrigeration system, the control valve 14 is closed,
Along with this, the entire amount of the refrigerant discharged from the compressor 1 circulates in the condenser 3 and the evaporator 6, so that the capacity of the refrigeration system returns to the rated capacity.

A second embodiment of the present invention is shown in FIG. In the second embodiment, a constant pressure control valve or a constant pressure expansion valve 16 that keeps the low pressure constant by detecting the low pressure and automatically opening and closing the bypass line 13 attached to the oil return circuit 9 is used. Is installed. Other configurations are shown in FIG.
The same members as those of the first embodiment shown in FIG.

In the second embodiment, when the low pressure falls below the set pressure, the constant pressure control valve or the constant pressure expansion valve 16
Is opened and the hot gas is bypassed, so that the capacity of the refrigeration system can be reduced. Further, since the low pressure can be maintained constant regardless of the fluctuation of the load of the refrigeration system, the constant pressure control valve or the constant pressure expansion valve which can avoid the repeated operation / stop of the compressor 1, that is, the inching operation and is inexpensive. Since 16 is used, the cost can be reduced.

A third embodiment of the invention is shown in FIG. In this third embodiment, the bypass line 13
An oil cooler 10 is interposed in the oil return circuit 9 on the upstream side of the. The oil cooler 10 is attached to and integrated with the condenser 3. Another configuration is the first configuration shown in FIG.
This embodiment is similar to the embodiment described above, and the corresponding members are designated by the same reference numerals and the description thereof is omitted.

In the third embodiment, the compressor 1
Since the oil and the hot gas returning to the above can be cooled by the oil cooler 10, the temperature rise of the motor coil built in the compressor 1 and the housing thereof can be suppressed. Although not shown, even if an oil cooler is provided in the oil return circuit 9 of the second embodiment shown in FIG. 2, the same effect as described above can be obtained.

In the above-described embodiment, the capacity control of the refrigeration system can be easily realized by using the oil return circuit 9. However, the high pressure control of the refrigeration system can be performed by using the oil return circuit 9. It can be easily realized. The embodiment will be described below.

In the refrigerating apparatus shown in FIG. 1, if the control valve 14 is constructed as an electromagnetic valve which is opened when the high pressure detected by a high pressure sensor (not shown) is higher than a set pressure and is closed when the pressure is lower than the set pressure, When high pressure rises due to high outside temperature in summer, hot gas can be detected and bypassed.Therefore, it is possible to prevent the protection mechanism from operating due to abnormal rise of high pressure, resulting in operation stop. The operating range of the refrigeration system can be expanded.

Further, in place of the constant pressure control valve or the constant pressure expansion valve 16 shown in FIG. 2, if a high pressure control valve is used which keeps the high pressure constant by detecting the high pressure and automatically opening and closing, the high pressure can be kept constant. Since the temperature can be maintained, the operating range of the refrigeration system at the time of high outside air temperature in summer can be expanded similarly to the above. It goes without saying that the same can be applied to the refrigerating apparatus having the oil cooler 10 shown in FIG.

[0022]

According to the present invention, the control valve provided in the bypass passage provided in the oil return circuit is opened to allow hot gas from the oil separator to pass through the oil return circuit and the bypass passage, and the suction pipe of the compressor. By bypassing to the side,
Utilizing the oil return circuit, it is possible to realize capacity control or high pressure control of the refrigeration system with an extremely simple and inexpensive configuration. As a result, frequent operation / stop of the refrigeration system can be prevented to suppress fluctuations in the temperature to be cooled, or the durability and reliability of the refrigeration system can be improved.

If the control valve is either an electromagnetic valve that opens and closes according to the detected low pressure, or a constant pressure control valve that keeps the low pressure constant, or a constant pressure expansion valve, the low pressure will be maintained regardless of fluctuations in the load of the refrigeration system. Can be maintained constant and the cost can be reduced by using a constant pressure control valve or a constant pressure expansion valve.

If the control valve is either an electromagnetic valve that opens and closes according to the detected high pressure, or a high pressure control valve that keeps the high pressure constant, the high pressure is maintained constant regardless of fluctuations in the load of the refrigeration system. Therefore, the operating range of the refrigeration system at high outside air temperature can be expanded, and the cost can be reduced by using the high pressure control valve.

If an oil cooler is provided in the oil return circuit on the upstream side of the bypass passage, the oil returning to the compressor via the oil return circuit and the hot gas returning to the compressor via the bypass passage are cooled by the oil cooler. Therefore, the temperature rise of the compressor can be prevented.

[Brief description of drawings]

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

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

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

FIG. 4 is a refrigerant circuit diagram of a conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 18 Discharge pipe 8 Suction pipe 2 Oil separator 3 Condenser 4 Receiver 5 Throttling mechanism 6 Evaporator 7 Accumulator 9 Oil return circuit 11 Oil return solenoid valve 12 Capillary tube 13 Bypass passage 14 Capacity control valve

Claims (4)

[Claims] 1. A compressor is provided with a refrigerant circuit in which a compressor, a condenser, a throttle mechanism, and an evaporator are connected in this order, and oil separated by an oil separator installed in a discharge pipe of the compressor is used as the compressor. A refrigeration system in which an oil return solenoid valve is inserted in an oil return circuit for returning to the suction pipe of the compressor, a bypass system for bypassing hot gas from the oil separator to the suction pipe side of the compressor in the oil return circuit. A refrigeration system having a passage and a control valve provided in the bypass passage. 2. The control valve is any one of a solenoid valve that is opened and closed according to the detected low pressure, a constant pressure control valve that keeps the low pressure constant, or a constant pressure expansion valve. Refrigeration equipment. 3. The refrigerating apparatus according to claim 1, wherein the control valve is either an electromagnetic valve that is opened or closed according to the detected high pressure or a high pressure control valve that keeps the high pressure constant. 4. The refrigerating apparatus according to claim 1, wherein an oil cooler is provided in the oil return circuit on the upstream side of the bypass system passage.