JPH05264110A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a failure such as seizure of compressor by providing a line wherein a solenoid valve is opened to return oil in an oil sump to a compressor at the start of the compressor in such an arrangement wherein the oil separated from refrigerant of an oil separator is returned to the suction side of the compressor. CONSTITUTION:Refrigerant delivered from a compressor 1, after the oil component thereof has been separated at an oil separator 3, flows through a four-way valve 6, outdoor heat exchanger 7, and throttle machanism 8 to an indoor heat exchanger 9, where heat absorption and evaporation is effected and thereafter the refrigerant is returned to the suction side of the compressor 1 via the valve 6 and an accumulator 10, wherein an oil sump 21 is provided in a delivery pipe 2 upstream of the separator 3 so that the oil separated at the separator 3 is drawn out of an oil return line 22 having a capillary 25 to store it in the sump 21. And the sump 21 is connected to the suction side of the compressor 1 through a first and second lines 23, 24 wherein their drawing points are located at different points in the vertical direction and a solenoid valve 26 which is opened at the start of the compressor is provided in the line 23.

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 an improved oil return mechanism.

[0002]

2. Description of the Related Art FIG. 3 is a system diagram of an air conditioner having a conventional oil return mechanism. In the figure, 1 is a compressor, 2 is a discharge pipe of the compressor, 3 is an oil separator connected to the pipe, 4 is the oil separator and the compressor are connected to each other, and oil from the oil separator 3 is supplied to the compressor 1. An oil return circuit for returning, 5 is a capillary provided in the circuit, 6 is a four-way valve connected to the oil separator, 7 is an outdoor heat exchanger connected to the four-way valve, and 8 is connected to the outdoor heat exchanger. Throttle mechanism, 9 is an indoor heat exchanger connected to the same throttle mechanism and to the four-way valve, 1
Reference numeral 0 is an accumulator provided between the four-way valve 6 and the compressor 1.

In this apparatus, during the cooling operation, the refrigerant compressed and discharged by the compressor 1 enters the oil separator 3 via the discharge pipe 2 and then enters the outdoor heat exchanger 7 via the four-way valve 6. Here, heat is radiated and condensed to become a high-pressure liquid refrigerant, which is throttled and decompressed by the throttling mechanism 8 to become a low-pressure liquid gas two-phase refrigerant. The liquid-gas two-phase refrigerant absorbs heat in the indoor heat exchanger 9, evaporates and enters the accumulator 10 via the four-way valve 6. Here, the liquid non-evaporated refrigerant is the same accumulator 10
Of the gas refrigerant collected in the lower part of the above, and returned to the compressor 1.

On the other hand, during the heating operation, the refrigerant compressed and discharged by the compressor 1 enters the oil separator 3, the four-way valve 6 and the indoor heat exchanger 9. Here, heat is radiated and condensed to become a high-pressure liquid refrigerant, which is throttled and decompressed by the throttling mechanism 8 to become a low-pressure liquid gas two-phase refrigerant. The same liquid gas two-phase refrigerant absorbs heat in the outdoor heat exchanger 7, evaporates and enters the accumulator 10 via the four-way valve 6. Here, the liquid non-evaporated refrigerant is accumulated in the lower part of the accumulator 10, and the separated refrigerant is returned to the compressor 1.

Refrigerant and oil are separated in the oil separator 3, and the oil is returned to the compressor 1 through the oil return circuit 4 via the capillary 5. In many cases, when the operation is stopped, the refrigerant and the oil in the compressor 1 are melted and the oil is diluted or lost.

[0006]

In the conventional air conditioner, when the compressor 1 is stopped, the refrigerant and the oil in the compressor 1 are mixed with each other, and the oil is diluted or lost. There were many cases. If the compressor 1 is activated at such a time, seizure may occur.

According to the present invention, when restarting after operation stop, even if oil in the compressor is diluted or oil runs out, oil is replenished so that seizure accident of the compressor does not occur at startup. It is intended to provide an improved air conditioner.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an oil separator is installed on the discharge side of a compressor and the oil separated by the oil separator is returned to the suction side of the compressor. In the air conditioner,
The present invention relates to an air conditioner having the following features.

(1) An oil sump capable of heat exchange is provided on the discharge pipe between the compressor and the oil separator, an oil return circuit from the oil separator is connected to the oil sump, and the oil sump is connected from the bottom of the oil sump. A first circuit for returning oil to the suction side of the compressor via a solenoid valve; and a second circuit connected to the oil reservoir at a position higher than the first circuit for returning the oil to the suction side of the compressor Was it.

(2) A first circuit for returning oil from the bottom of the oil separator to the suction side of the compressor via an electromagnetic valve, and a throttle mechanism connected to the oil separator at a position higher than the first circuit. A second circuit for returning oil to the suction side of the compressor.

[0011]

(1) The refrigerant compressed by the compressor and discharged is circulated in the refrigerant cycle as in the prior art. Refrigerant and oil are separated in the oil separator during the refrigerant cycle,
The oil is stored in the oil sump via the cavity and the oil return circuit. The oil discharged from the compressor is stored in the oil sump,
Since it exchanges heat with the hot discharge gas, it becomes almost oily.
When the compressor is operated and the oil is excessively accumulated in the oil sump to cause an overflow, the oil returns to the suction side of the compressor via the second circuit. However, when the compressor is started, there may be no oil in the compressor or the oil may be diluted. At that time, the solenoid valve is opened and the oil stored in the oil sump is changed to the first circuit. Return to the compressor via.

(2) The refrigerant compressed by the compressor circulates in the refrigerant cycle as in the prior art. In the oil separator body container during the refrigerant cycle, the refrigerant and oil are separated,
Returned to the suction side of the compressor. When the liquid level of the oil in the oil separator body container is higher than the tip of the opening of the second circuit in the oil separator body container, the oil returns to the compressor through the throttle mechanism. At the time of starting the compressor, when there is no oil in the compressor or it is diluted,
Return oil to the compressor through the solenoid valve.

[0013]

1 is a system diagram of a first embodiment of the present invention.
In the figure, 21 is an oil sump provided on the discharge pipe 2,
Reference numeral 22 is an oil return circuit that connects the oil separator 3 and the top of the oil sump 21, and 23 is the bottom of the oil sump 21 and the compressor 1
Circuit for returning oil to the suction side of the compressor 1, a second circuit for returning oil from a position higher than the opening of the first circuit of the oil sump 21 to the suction side of the compressor 1, and 25 for returning the oil. The capillaries and 26 provided on the circuit 22 are the first circuit 2 described above.
3 is a solenoid valve provided on the reference numeral 27, and 27 is the second circuit 2
4 is a diaphragm mechanism. The parts other than the above are the same as those of the conventional technique (FIG. 3), and thus the description thereof will be omitted.

In this apparatus, the refrigerant compressed by the compressor 1 and discharged is circulated in the refrigerant cycle as in the conventional system. The refrigerant and oil are separated in the oil separator 3 during the refrigerant cycle, and the oil is stored in the oil sump 21 via the oil return circuit 22 having the capillary 25. The oil sump 2
In No. 1, the high-temperature discharge gas discharged from the compressor 1 and the accumulated oil exchange heat with each other, so that almost only oil is left. When the compressor 1 is operated and the oil is excessively accumulated in the oil sump 21 to cause an overflow, the oil returns to the suction side of the compressor 1 via the second circuit 24. At the time of starting the compressor 1, when there is no oil in the compressor 1 or when the oil is diluted, the solenoid valve 26 is opened to set the oil sump 21.
The oil stored in the compressor 1 is passed through the first circuit 23 to the compressor 1
Return to.

In this embodiment, when the oil in the compressor is diluted by the refrigerant when stopped or runs out, the oil previously stored in the oil sump is returned to the compressor, so that the compressor burns. Accidents can be prevented.

FIG. 2 is a system diagram of the second embodiment of the present invention. In the figure, 31 is a first circuit for returning oil from the oil separator 3 to the suction side of the compressor 1, 32 is a second circuit for returning oil from the oil separator 3 to the suction side of the compressor 1, 3
3 is an electromagnetic valve provided on the first circuit 31, 34 is a throttle mechanism provided on the second circuit 32, 35 is an opening in the oil separator 3 of the first circuit 31, 36 Is an opening in the oil separator 3 of the second circuit 32. The opening 35 of the first circuit 31 is provided close to the bottom of the oil separator 3, and the opening 36 of the second circuit 32 is the opening 3 of the first circuit 31.
It is installed at a position higher than 5. The parts other than the above are the same as those of the conventional technique (FIG. 3), and thus the description thereof is omitted.

Also in this apparatus, the compressor 1 compresses,
The discharged refrigerant circulates in the refrigerant cycle as in the conventional system. In the main body container of the oil separator 3, the refrigerant and the oil are separated. When the liquid level in the main body container of the oil separator 3 is at a position higher than the opening tip portion 36 of the second circuit 32, the oil returns to the compressor via the throttle mechanism 34.
Further, when the compressor 1 is started up and there is no oil in the compressor 1, or when the oil is diluted, the solenoid valve 33 is opened and the oil accumulated in the main body container of the oil separator 3 is transferred to the compressor 1. return.

In this embodiment, when the oil in the compressor is diluted with the refrigerant or runs out when the compressor is stopped, the oil previously accumulated in the oil separator is returned to the compressor. It is possible to prevent the seizure accident of the compressor.

[0019]

In the air conditioner of the present invention, an oil sump capable of heat exchange is provided on the discharge pipe between the compressor and the oil separator, and an oil return circuit from the oil separator is connected to the oil sump. , A first circuit that returns oil from the bottom of the oil sump to the suction side of the compressor via a solenoid valve, and a position higher than the first circuit that is connected to the oil sump and returns the oil to the suction side of the compressor A second circuit, or returning the oil from the bottom of the oil separator to the suction side of the compressor via a solenoid valve
And a second circuit which is connected to the oil separator at a position higher than the first circuit and returns the oil to the suction side of the compressor through the throttle mechanism. In the above, it is possible to prevent an accident such as seizure due to dilution of oil in the compressor or lack of oil.

[Brief description of drawings]

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

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

FIG. 3 is a system diagram of a conventional air conditioner.

[Explanation of symbols]

 1 Compressor 2 Discharge piping 3 Oil separator 4 Oil return circuit 5 Capillary 6 Four-way valve 7 Outdoor heat exchanger 8 Throttling mechanism 9 Indoor heat exchanger 10 Accumulator 21 Oil sump 22 Oil return circuit 23 First circuit 24 Second circuit 25 Capillary 26 Solenoid Valve 31 First Circuit 32 Second Circuit 33 Solenoid Valve 34 Throttle Mechanism 35 Opening of First Circuit 36 Opening of Second Circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumi Honma 1 Takamichi, Iwatsuka-cho, Nakamura-ku, Nagoya-shi Mitsubishi Heavy Industries, Ltd. Nagoya Research Laboratory

Claims (2)

[Claims] 1. An air conditioner in which an oil separator is installed on the discharge side of the compressor, and the oil separated by the oil separator is returned to the suction side of the compressor. A heat-exchangeable oil sump is installed on the discharge pipe of the oil separator, an oil return circuit from the oil separator is connected to the oil sump, and oil is returned from the bottom of the oil sump to the suction side of the compressor via a solenoid valve. An air conditioner comprising: a first circuit; and a second circuit connected to an oil sump at a position higher than the first circuit to return oil to the suction side of the compressor. 2. An air conditioner in which an oil separator is installed on the discharge side of the compressor and the oil separated by the oil separator is returned to the suction side of the compressor, and a solenoid valve is installed from the bottom of the oil separator. A first circuit for returning the oil to the suction side of the compressor via the first circuit, and a second circuit connected to the oil separator at a position higher than the first circuit for returning the oil to the suction side of the compressor via the throttle mechanism. An air conditioner characterized by being equipped with.