JPH0979672A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a positive returning of oil to a compressor in a freezing cycle in which an oil having a low compatibility with a refrigerant is applied. SOLUTION: There is provided a freezing cycle which is comprised of an evaporator 5, a condenser 3, an adjusting device 4, a compressor 1 fed with a lubricant oil having a low compatibility, an accumulator 6 installed at a refrigerant suction side of the compressor 1, and an oil separator 2 having an oil reservoir installed at a refrigerant discharging side of the compressor 1 and with at least a volume more than that of oil fed into the compressor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a refrigeration cycle using an oil having a low compatibility with a refrigerant.

[0002]

2. Description of the Related Art In a conventional refrigeration cycle of an air conditioner using a refrigerant having HFC-134a as a component and an alkylbenzene-based compressor oil having a low compatibility with the refrigerant, the refrigerant and the oil are the refrigerant and the oil. Since it has good separability, it was compact even if the oil separator doubled as a compressor housing or the oil separator was attached.

FIG. 5 shows a conventional refrigeration cycle provided with an oil separator, 1 is a compressor, 2 is an oil separator, 3 is a condenser, 4 is a throttle device, 5 is an evaporator, and 6 is an accumulator. FIG. 6 shows the structure of the oil separator 2. 13 is a main body, 14 is an inlet pipe, 1
5 is an outlet pipe, 16 is an oil return pipe, and 17 is a partition plate.

The operation of the conventional refrigerating cycle with an oil separator constructed as described above will be described below. The mixed fluid of gas refrigerant and oil discharged from the compressor 1 enters the oil separator 2. Oil separator 2
The mixed fluid flowing in from the inlet pipe 9 enters the space B of the oil separator body 8 directly into the outlet pipe 1
While hitting the partition plate 11 provided so as not to enter 0, the space A is passed through the holes formed in the partition plate 11. In the space A, the flow passage cross-sectional area becomes large, so the flow velocity becomes slow, and the specific gravities of the liquid oil and the gas refrigerant are greatly different, so that they are separated into upper and lower parts. The refrigerant is sucked into the outlet pipe 10 and the oil drops downward and collects at the bottom of the main body 8. The gas refrigerant discharged from the outlet pipe 10 becomes a liquid refrigerant in the condenser 3 and is decompressed by the expansion device 4, becomes a gas refrigerant in the evaporator 5, and enters the accumulator 6. On the other hand, the oil separated by the oil separator 2 and stored in the lower portion of the main body 8 passes through the oil return pipe 7 and the evaporator 5
Is mixed with the refrigerant discharged from the compressor, enters the accumulator 6, and is sucked into the compressor 1.

[0005]

However, in the refrigerating cycle configured as described above, the operation is started at a low temperature for a long time and the operation is stopped in a state where a large amount of refrigerant is accumulated in the compressor. In so-called bed-starting, when the engine is started, the refrigerant evaporates at once and pushes up the oil, and most of the oil may be discharged from the compressor. At this time, most of the oil comes out all at once, so it overflows at the oil separator and goes out to the condenser together with the refrigerant. If the compatibility of the refrigerant and the oil is high, the oil that came out of the refrigeration cycle will return to the compressor relatively quickly to recover the oil level, but if the compatibility is low, it will take a long time to return or the oil will return. In some cases, there was a problem that the lubrication of oil was insufficient and the sliding part of the compressor was damaged.

In view of the above problems, the present invention ensures that the oil and the refrigerant are separated by the oil separator and returned to the compressor to reliably recover the oil level even when the compatibility of the refrigerant and the oil is low. .

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems (achieve the purpose), the present invention relates to a compressor in which a lubricating oil having a low compatibility with an evaporator, a condenser, a throttle device and a refrigerant is injected. A refrigeration cycle having an accumulator installed on the refrigerant suction side of the compressor and an oil separator installed on the refrigerant discharge side of the compressor and having at least an oil reservoir of a volume of oil injected into the compressor are doing.

[0008] Further, a compressor injecting a lubricating oil having a low compatibility with the evaporator, the condenser, the expansion device and the refrigerant, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. Installed at least an oil separator having an oil reservoir having a volume equal to or greater than that of the oil injected into the compressor, and connecting an oil return port of the oil separator to a connecting pipe between the compressor and the accumulator. And a refrigeration cycle having an oil return pipe.

Further, a compressor into which a lubricating oil having a low compatibility with the evaporator, the condenser, the expansion device and the refrigerant is injected, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. Refrigeration having an oil separator installed and having at least an oil reservoir having a volume equal to or greater than the volume of oil injected into the compressor, and an oil return pipe communicating from an oil return port of the oil separator to a return pipe of the accumulator It has a cycle.

Further, a compressor in which lubricating oil having a low compatibility with the evaporator, the condenser, the expansion device, and the refrigerant is injected, an accumulator installed on the refrigerant suction side of the compressor, and a refrigerant discharge side of the compressor. An oil separator installed and having at least an oil reservoir having a volume equal to or larger than that of the oil injected into the compressor, and an oil return port of the oil separator are connected to a connecting pipe between the compressor and the accumulator. A refrigeration cycle having an oil return pipe and a valve provided in the middle of the oil return pipe is provided.

[0011]

The operation of the above means is as follows.

According to the present invention, since the oil sump in the oil separator is larger than the volume of the oil injected into the compressor, even if the oil is discharged from the compressor at a stretch, the oil does not overflow into the refrigeration cycle. You can prevent it from going out.

Furthermore, since the oil return pipe of the oil separator is connected between the compressor and the accumulator, the oil separated by the oil separator is directly mixed with the refrigerant sucked into the compressor, so that the oil is separated in the accumulator. It is possible to surely return to the compressor quickly without accumulating once.

Furthermore, since the oil return pipe of the oil separator communicates with the return pipe of the accumulator, the structure for attaching the accumulator to the compressor is not changed, only the accumulator is changed, and the intake port of the compressor is complicated. You have lost the remodeling.

Further, a valve is provided in the middle of the oil return pipe to close the valve when the operation is stopped, and when the refrigerant is not flowing during the operation stop, the oil flows into the compressor suction port to restart the compressor. Inhaling a large amount of oil prevents it from locking or breaking.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 is a refrigeration cycle diagram of one embodiment of the present invention. This refrigeration cycle uses HFC- as a refrigerant.
134a is enclosed, 1 is a variable rotation speed compressor filled with an alkylbenzene oil having low compatibility with a refrigerant as a lubricating oil, 2 is an oil separator, 3 is a condenser, 4
Is an expansion device, 5 is an evaporator, 6 is an accumulator, and 7 is an oil return pipe for guiding the oil separated by the oil separator 2 to the low pressure side.

FIG. 2 is a structural view of an oil separator 2 according to one embodiment of the present invention, in which 8 is a main body, 9 is an inlet pipe,
10 is an outlet pipe, 7 is an oil return pipe, 11 is a partition plate, and the volume of the space A to the tip of the outlet pipe 10 is larger than the volume of the oil filled in the compressor 1.

The operation of the refrigeration cycle configured as described above will be described below. The mixed fluid of gas refrigerant and oil discharged from the compressor 1 enters the oil separator 2. The mixed fluid flowing from the inlet pipe 9 in the oil separator 2 is stored in the space B of the oil separator body 8.
Entering into the space A through the holes formed in the partition plate 11 while hitting the partition plate 11 provided so as not to enter directly into the outlet pipe 10. In the space A, the flow passage cross-sectional area becomes large, so the flow velocity becomes slow, and the specific gravities of the liquid oil and the gas refrigerant are greatly different, so that they are separated into upper and lower parts. The refrigerant is sucked into the outlet pipe 10 and the oil drops downward and collects at the bottom of the main body 8. The gas refrigerant discharged from the outlet pipe 10 becomes a liquid refrigerant in the condenser 3 and is decompressed by the expansion device 4, becomes a gas refrigerant in the evaporator 5, and enters the accumulator 6. On the other hand, oil separator 2
The oil separated by the above and accumulated in the lower part of the main body 8 is mixed with the refrigerant flowing out of the evaporator 5 through the oil return pipe 7, enters the accumulator 6 and returns to the compressor 1. In this refrigeration cycle, in the so-called start-up that starts the operation at a low temperature for a long time when the operation is stopped, in order to improve the start-up of the air conditioning, the number of rotations of the compressor 1 is increased after the start to operate. Therefore, the refrigerant in the compressor 1 evaporates at once and pushes up the oil, and most of the oil is discharged from the compressor 1. At this time, most of the oil comes out all at once, and the oil separator 2
Although it collects in the space A therein, since the space A is larger than the oil volume filled in the compressor 1, it does not overflow into the outlet pipe 10.

FIG. 3 is a refrigeration cycle diagram of another embodiment of the present invention. Reference numeral 12 is a suction pipe that connects the accumulator 6 and the suction port of the compressor 1. The oil return pipe 7 of the oil separator 2 is connected to the suction pipe 12, that is, the downstream side of the accumulator 6.

The operation of the refrigerating cycle configured as described above will be described below. The mixed fluid of gas refrigerant and oil discharged from the compressor 1 is separated into gas refrigerant and oil by the oil separator 2, and the gas refrigerant is condensed by the condenser 3 and decompressed by the expansion device 4. The depressurized refrigerant is the evaporator 5
Is evaporated in the accumulator 6 and separated into gas and liquid.
Is sucked into. On the other hand, the oil separated by the oil separator 2 passes through the oil return pipe 7, enters the suction pipe 12, is mixed with the gas refrigerant discharged from the accumulator 6, and returns to the compressor 1.

In this way, the oil discharged all at once at the time of starting to sleep is separated by the oil separator 2 and can be surely returned to the compressor quickly without passing through the accumulator 6.

FIG. 4 is a refrigeration cycle diagram of another embodiment of the present invention, and FIG. 5 is a structural diagram of an accumulator. 6 '
Is an accumulator body, 13 is an inlet pipe connected to the evaporator 5, 14 is a baffle fixed to the body 6 ', 1
Reference numeral 5 is a return pipe connected to the suction port of the compressor 1, and the oil return pipe 7 penetrates into the accumulator body 6 ′ and is inserted into the upper inlet of the return pipe 15.

The operation of the refrigeration cycle configured as described above will be described below. The mixed fluid of gas refrigerant and oil discharged from the compressor 1 is separated into gas refrigerant and oil by the oil separator 2, and the gas refrigerant is condensed by the condenser 3 and decompressed by the expansion device 4. The depressurized refrigerant is the evaporator 5
At this point, the gas refrigerant is evaporated, enters the accumulator 6, and is separated into gas and liquid. On the other hand, the oil separated by the oil separator 2 enters the oil return pipe 7 into the accumulator 6, is directly sent to the return pipe 15, is mixed with the gas refrigerant, and returns to the compressor 1.

As described above, the oil separated by the oil separator 2 can surely return to the compressor 1 quickly, and the refrigeration cycle can be constructed without changing the positional relationship between the accumulator and the compressor. .

FIG. 6 is a refrigeration cycle diagram of another embodiment of the present invention. A solenoid valve 17 is provided in the oil return pipe 7 of the oil separator 2.

The operation of the refrigerating cycle configured as described above will be described below. When the compressor 1 is in operation, the electromagnetic valve 17 is open, the mixed fluid of gas refrigerant and oil discharged from the compressor 1 is separated into gas refrigerant and oil by the oil separator 2, and the gas refrigerant is condensed by the condenser 3 And the pressure is reduced by the expansion device 4. The depressurized refrigerant is the evaporator 5
Then, the gas refrigerant is evaporated into the accumulator 6, and the gas refrigerant is separated into gas and liquid, and is sucked into the compressor 1 through the suction pipe 12. On the other hand, the oil separated by the oil separator 2 passes through the oil return pipe 7, enters the suction pipe 12, is mixed with the gas refrigerant discharged from the accumulator 6, and returns to the compressor 1. Next, when the operation of the compressor 1 is stopped, immediately after the operation is stopped, the inside of the oil separator 2 is higher than the intake port of the compressor 1, and the oil accumulated in the oil separator 2 is transferred to the intake port of the compressor 1 due to this pressure difference. I try to flow.
At this time, the solenoid valve 17 is closed to prevent oil from flowing to the suction port of the compressor 1.

In this way, oil is prevented from collecting on the suction side of the compressor while the refrigerant is not flowing, and the compressor is prevented from being damaged by liquid compression when the compressor is restarted.

In each of the present embodiments, the refrigerant flow is a unidirectional refrigeration cycle, but the same effect can be obtained even in a refrigeration cycle in which a reverse cycle using a four-way valve is performed.

[0030]

As is apparent from the above embodiments, in the air conditioner of the present invention, the compressor and the refrigerant in which the lubricating oil having low compatibility with the evaporator, the condenser, the expansion device, and the refrigerant is injected. Since it has a refrigeration cycle having an accumulator installed on the suction side and an oil separator installed on the refrigerant discharge side of the compressor and having an oil reservoir of at least the volume of the oil injected into the compressor, Even if the oil is discharged from the compressor all at once, it is possible to prevent the oil from flowing into the refrigeration cycle without overflowing the oil in the oil receiver.

Further, a compressor in which lubricating oil having a low compatibility with the evaporator, the condenser, the expansion device and the refrigerant is injected, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. An oil separator installed and having at least an oil reservoir having a volume equal to or larger than that of the oil injected into the compressor, and an oil return port of the oil separator are connected to a connecting pipe between the compressor and the accumulator. Since the refrigerating cycle having the oil return pipe is provided, the oil separated by the oil separator is mixed with the refrigerant directly sucked into the compressor, so that the oil can surely return to the compressor quickly.

Further, a compressor in which a lubricating oil having a low compatibility with the evaporator, the condenser, the expansion device and the refrigerant is injected, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. Refrigeration having an oil separator installed and having at least an oil reservoir having a volume equal to or greater than the volume of oil injected into the compressor, and an oil return pipe communicating from an oil return port of the oil separator to a return pipe of the accumulator Since it is equipped with a cycle, the oil separated by the oil separator can be reliably returned to the compressor, and the structure for attaching the accumulator to the compressor does not change, only the accumulator needs to be changed. Eliminating complicated modifications.

Further, a compressor in which lubricating oil having a low compatibility with the evaporator, the condenser, the expansion device and the refrigerant is injected, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. An oil separator installed and having at least an oil reservoir having a volume equal to or larger than that of the oil injected into the compressor, and an oil return port of the oil separator are connected to a connecting pipe between the compressor and the accumulator. Since a refrigeration cycle having an oil return pipe and a valve provided in the middle of the oil return pipe is provided, the valve provided in the middle of the oil return pipe is closed when the operation is stopped, and the refrigerant in the operation stop is Prevents oil from flowing into the compressor intake when it is not flowing, and prevents the compressor from inhaling a large amount of oil and locking or breaking it when restarted. They are out.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner according to a first embodiment.

FIG. 2 is a structural diagram of an oil separator according to the first embodiment.

FIG. 3 is a refrigeration cycle diagram of the air conditioner of the second embodiment.

FIG. 4 is a refrigeration cycle diagram of the air conditioner of the third embodiment.

FIG. 5 is a structural diagram of an accumulator according to a third embodiment.

FIG. 6 is a refrigeration cycle diagram of the air conditioner of the fourth embodiment.

FIG. 7 is a refrigeration cycle diagram of a conventional air conditioner.

FIG. 8 is a structural diagram of a conventional oil separator.

[Explanation of symbols]

 1 Compressor 2 Oil separator 3 Condenser 4 Throttling device 5 Evaporator 6 Accumulator 7 Oil return pipe 12 Suction pipe

Claims (4)

[Claims] 1. A compressor injecting a lubricating oil having a low compatibility with an evaporator, a condenser, a throttle device and a refrigerant, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. An air conditioner provided with a refrigeration cycle having an oil separator installed and having at least an oil reservoir having a volume equal to or greater than the volume of oil injected into the compressor. 2. A compressor into which lubricating oil having a low compatibility with an evaporator, a condenser, a throttle device and a refrigerant is injected, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. An oil separator installed and having at least an oil reservoir having a volume equal to or larger than that of the oil injected into the compressor, and an oil return port of the oil separator are connected to a connecting pipe between the compressor and the accumulator. An air conditioner equipped with a refrigeration cycle having an oil return pipe. 3. A compressor injecting a lubricating oil having a low compatibility with an evaporator, a condenser, a throttle device and a refrigerant, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. Refrigeration having an oil separator installed and having at least an oil reservoir having a volume equal to or greater than the volume of oil injected into the compressor, and an oil return pipe communicating from an oil return port of the oil separator to a return pipe of the accumulator An air conditioner equipped with a cycle. 4. A compressor injecting a lubricating oil having a low compatibility with an evaporator, a condenser, a throttle device and a refrigerant, an accumulator installed on the refrigerant suction side of the compressor and a refrigerant discharge side of the compressor. An oil separator installed and having at least an oil reservoir having a volume equal to or larger than that of the oil injected into the compressor, and an oil return port of the oil separator are connected to a connecting pipe between the compressor and the accumulator. An air conditioner comprising a refrigeration cycle having an oil return pipe and a valve provided in the middle of the oil return pipe.