JPH11211245A - Air-conditioning equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the load of a compressor when heating operation is started. SOLUTION: Air-conditioning equipment 20 is provided with an outdoor unit 21 where a compressor 25, an outdoor heat exchanger 28, and an outdoor automated inflation valve 29 are connected by an outdoor refrigerant pipe 23 and an indoor unit 22 where an indoor heat exchanger 30 is provided at an indoor refrigerant pipe 24 that can be connected to the outdoor refrigerant pipe. In the air-conditioning equipment 20, a bypass pipe 32 for bypassing at least the outdoor automated inflation valve is connected to the outdoor refrigerant pipe, and a check valve 33 for guiding a high-voltage refrigerant in the outdoor refrigerant pipe reaching the outdoor automated inflation valve through the outdoor heat exchanger from the compressor on operation stop into the outdoor refrigerant pipe at the upstream side on heating operation than the outdoor automated inflation valve is provided at the bypass pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an air conditioner.

[0002]

2. Description of the Related Art As shown in FIG.
An outdoor unit 2 and an indoor unit 3 are provided, and an outdoor refrigerant pipe 4 of the outdoor unit 2 and an indoor refrigerant pipe 5 of the indoor unit 3 are connected to each other. An accumulator 6, a compressor 7, a four-way valve 8, an outdoor heat exchanger 9, and an outdoor electric expansion valve 10 are disposed in the outdoor refrigerant pipe 4. In the indoor refrigerant pipe 5, an indoor heat exchanger 11 and an indoor electric expansion valve 12 are provided.

A switching operation of the four-way valve 8 switches between a cooling operation and a heating operation. During the heating operation, the refrigerant flows inside the outdoor refrigerant pipe 4 and the indoor refrigerant pipe 5 as indicated by the solid arrows, and the indoor heat exchanger 11 cools the room. During the heating operation, the refrigerant flows inside the outdoor refrigerant pipe 4 and the indoor refrigerant pipe 5 as indicated by broken arrows, and the indoor heat exchanger 11 heats the room.

When the heating operation of the air conditioner 1 is stopped, the outdoor electric expansion valve 10 is fully closed so that a large amount of refrigerant is not stored in the outdoor heat exchanger 9 which is in a low temperature state at night. General.

[0005]

However, when the temperature of the outdoor heat exchanger 9 rises due to dawn or morning sun and the liquid refrigerant in the outdoor heat exchanger 9 evaporates, as described above, the outdoor electric expansion valve is used. When the valve 10 is fully closed, the outdoor electric expansion valve 1 from the compressor 7 passes through the four-way valve 8 and the outdoor heat exchanger 9.
The pressure inside the outdoor refrigerant pipe 4 that reaches zero increases. For this reason, the inside of the outdoor refrigerant pipe 4 on the discharge side of the compressor 7 is in a high pressure state, and the load on the compressor 7 increases when the air-conditioning apparatus 1 starts the heating operation.

An object of the present invention is to provide an air conditioner capable of reducing the load on a compressor at the time of starting a heating operation in view of the above circumstances.

[0007]

According to the first aspect of the present invention,
An outdoor unit in which a compressor, an outdoor heat exchanger, and a decompression device are connected by an outdoor refrigerant pipe, and an indoor room in which an indoor heat exchanger is disposed in an indoor refrigerant pipe connectable to the outdoor refrigerant pipe In the air conditioner having a unit, at least a bypass pipe bypassing the pressure reducing device is connected to the outdoor refrigerant pipe, and the outdoor heat pipe is connected to the outdoor heat pipe from the compressor when the operation of the compressor is stopped. A check valve is provided for guiding the high-pressure refrigerant in the outdoor refrigerant pipe that reaches the pressure reducing device via the exchanger to the outdoor refrigerant pipe upstream of the pressure reducing device during the heating operation.

According to a second aspect of the present invention, in the first aspect of the invention, the bypass pipe bypasses only the pressure reducing device.

According to the first aspect of the present invention, the following operation is provided.

At least a bypass pipe bypassing the decompression device is connected to the outdoor refrigerant pipe. When the operation of the compressor is stopped, the bypass pipe is connected to the decompression device via the outdoor heat exchanger from the compressor. Since a check valve that guides the high-pressure refrigerant in the outdoor refrigerant pipe to the outdoor refrigerant pipe on the upstream side during the heating operation from the pressure reducing device in the fully closed state is disposed,
Even if the liquid refrigerant stored in the outdoor heat exchanger and the outdoor refrigerant pipe around it is heated and vaporized by the morning sun or the like and becomes a high-pressure refrigerant during the night, when the heating operation is stopped, this high-pressure refrigerant is stopped. Through the valve, it is guided into the outdoor refrigerant pipe on the upstream side during the heating operation with respect to the pressure reducing device. For this reason, since the discharge side of the compressor does not enter the high pressure state during the stop of the heating operation, the load on the compressor can be reduced at the start of the heating operation.

The second aspect of the present invention has the following operation.

Since the bypass pipe in which the check valve is provided bypasses only the pressure reducing device, as described above, during the heating operation stop, the compressor is connected to the fully closed pressure reducing device via the outdoor heat exchanger. When the refrigerant in the refrigerant pipe (outdoor refrigerant pipe) is in a high pressure state, the high pressure refrigerant is discharged through the bypass pipe to reduce the load on the compressor at the time of starting the heating operation, and to perform the cooling operation. At times, the refrigerant exceeding the capacity of the decompression device in the open operation state can be discharged to the indoor heat exchanger side (downstream during the cooling operation from the decompression device) to the decompression device, so that the safety of the decompression device is improved. Can be secured.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

[A] First Embodiment FIG. 1 is a refrigerant circuit diagram showing a first embodiment of an air conditioner according to the present invention.

As shown in FIG. 1, the air conditioner 20 comprises
It has an outdoor unit 21 and an indoor unit 22,
The outdoor refrigerant pipe 23 of the outdoor unit 21 and the indoor refrigerant pipe 24 of the indoor unit 22 are connected to each other.

The outdoor unit 21 is installed outdoors, and a compressor 25 is provided in an outdoor refrigerant pipe 23.
5 has an accumulator 26 on the suction side and a four-way valve 2 on the discharge side.
The outdoor heat exchanger 28 and the outdoor electric expansion valve 29 as a pressure reducing device are sequentially connected to the four-way valve 27 via the outdoor refrigerant pipe 23. A fan (not shown) that blows air toward the outdoor heat exchanger 28 is disposed adjacent to the outdoor heat exchanger 28.

The outdoor electric expansion valve 29 has its opening adjusted to reduce the pressure of the refrigerant during the heating operation of the air conditioner 20, and is fully closed when the heating operation of the air conditioner 20 is stopped. If the outdoor electric expansion valve 29 is fully opened when the air-conditioning apparatus 20 stops heating operation, the outdoor heat exchanger 28 is cooled at night, and the outdoor refrigerant in the outdoor heat exchanger 28 and the outdoor refrigerant around the outdoor heat exchanger 28 are cooled. The inside of the pipe 23 is in a low pressure state, and a large amount of liquid refrigerant in the outdoor refrigerant pipe 23 and the indoor refrigerant pipe 24 is stored in the outdoor refrigerant pipe 23 around the outdoor heat exchanger 28 including the outdoor heat exchanger 28. Therefore, when the heating operation of the air conditioner 20 is stopped, the outdoor heat exchanger 28
As described above, in order to prevent a large amount of liquid refrigerant from accumulating in the outdoor refrigerant pipe 23 around the outdoor heat exchanger 28 including
When the heating operation is stopped, the outdoor electric expansion valve 29 is fully closed.

On the other hand, the indoor unit 22 is installed indoors, and an indoor heat exchanger 30 is disposed in the indoor refrigerant pipe 24.
An indoor electric expansion valve 31 is provided near the indoor heat exchanger 30 through which the liquid refrigerant flows during the heating operation in the indoor refrigerant pipe 24. The degree of opening of the indoor electric expansion valve 31 is adjusted according to the air conditioning load. Further, a fan (not shown) for blowing air to the indoor heat exchanger 30 is arranged adjacent to the indoor heat exchanger 30.

In the above-described air conditioner 20, by switching the four-way valve 27, the flow of the refrigerant flowing in the outdoor refrigerant pipe 23 and the indoor refrigerant pipe 24 is changed, and the cooling operation or the heating operation is performed.

When the air conditioner 20 is switched to the cooling side, the refrigerant flows through the outdoor refrigerant pipe 23 and the indoor refrigerant pipe 24 as shown by the solid arrows in FIG.
Becomes a condenser, and the indoor heat exchanger 30 becomes an evaporator to be in a cooling operation state, and the indoor heat exchanger 30 cools the room.

When the four-way valve 27 is switched to the heating side, the refrigerant flows in the outdoor refrigerant pipe 23 and the indoor refrigerant pipe 24 as indicated by the broken arrows in FIG.
Is a condenser, and the outdoor heat exchanger 28 is an evaporator to be in a heating operation state, and the indoor heat exchanger 30 heats the room.

In the air conditioner 20 described above, a bypass pipe 32 bypassing the outdoor electric expansion valve 29 is connected to the outdoor refrigerant pipe 23 of the outdoor unit 21.
A check valve 33 is provided in the bypass pipe 32.
That is, one end of the bypass pipe 32 is connected to the outdoor heat exchanger 28.
And the other end is connected to the outdoor refrigerant pipe 23 upstream of the outdoor electric expansion valve 29 during the heating operation.

The check valve 33 is connected to an outdoor refrigerant pipe from the compressor 25 to the outdoor electric expansion valve 29 (fully closed state) via the four-way valve 27 and the outdoor heat exchanger 28 when the operation of the air conditioner 20 is stopped. When the temperature of the refrigerant inside the outdoor heat exchanger 23 rises due to the morning sun shining on the outdoor heat exchanger 28 and becomes high-pressure refrigerant, the high-pressure refrigerant is placed upstream of the outdoor electric expansion valve 29 in the fully closed state during the heating operation. The refrigerant flows in a direction leading to the inside of the outdoor refrigerant pipe 23. Therefore, when the air conditioner 20 performs the cooling operation, when a refrigerant having a capacity equal to or larger than the outdoor electric expansion valve 29 flows from the outdoor heat exchanger 28 to the outdoor electric expansion valve 29, the check valve 33 Partially bypass piping 3
2, it is also possible to flow into the outdoor refrigerant pipe 23 downstream of the outdoor electric expansion valve 29 during the cooling operation.

As described above, according to the air conditioner 20 of the above embodiment, the following effects and advantages can be obtained.

A bypass pipe 32 bypassing the outdoor electric expansion valve 29 is connected to the outdoor refrigerant pipe 23, and is connected to the outdoor heat exchanger 28 from the compressor 25 when the operation of the air conditioner 20 is stopped. The high-pressure refrigerant in the outdoor refrigerant pipe 23 reaching the outdoor electric expansion valve 29 in the fully closed state via
Since the check valve 33 that guides the inside of the outdoor refrigerant pipe 23 on the upstream side during the heating operation with respect to the outdoor electric expansion valve 29 in the fully closed state is provided, the outdoor heat exchanger 2 can be used during the night when the heating operation is stopped.
Even if the liquid refrigerant stored in the outdoor refrigerant pipe 23 and its surroundings is heated and vaporized by the morning sun or the like to become a high-pressure refrigerant, the high-pressure refrigerant passes through the check valve 33 and passes through the outdoor electric expansion valve 29. Outdoor refrigerant pipe 2 on the upstream side during heating operation
It is led into 3. For this reason, even if the outdoor heat exchanger 28 is heated by the morning sun etc. during the heating operation stop, the outdoor heat expansion valve 29 (fully closed state) is reached from the compressor 25 via the four-way valve 27 and the outdoor heat exchanger 28. The pressure in the outdoor refrigerant pipe 23 on the discharge side of the compressor 25 is balanced with the pressure in the outdoor refrigerant pipe 23 on the upstream side during the heating operation with respect to the outdoor electric expansion valve 29 in the fully closed state. Since the inside of 23 does not become a high pressure state, the load on compressor 25 can be reduced at the time of starting the heating operation.

The bypass pipe 3 provided with the check valve 33
2 bypasses only the outdoor electric expansion valve 29, so that the load on the compressor 25 at the start of the heating operation can be reduced as described above, and the outdoor electric expansion valve in the open operation state during the cooling operation. Since the refrigerant exceeding the capacity of 29 can be discharged to the downstream side during the cooling operation of the outdoor electric expansion valve 29, the safety of the outdoor electric expansion valve 29 can be ensured.

[B] Second Embodiment FIG. 2 is a refrigerant circuit diagram showing a second embodiment of the air conditioner according to the present invention. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the air conditioner 40 shown in FIG.
A bypass pipe 41 provided with a check valve 42 is connected to the outdoor refrigerant pipe 23 bypassing the outdoor heat exchanger 28 and the outdoor electric expansion valve 29. That is, the bypass pipe 41
Has one end connected to the outdoor refrigerant pipe 23 between the compressor 25 and the outdoor heat exchanger 28, and the other end connected to the outdoor electric expansion valve 2.
9, the outdoor refrigerant pipe 23 on the upstream side during the heating operation.
Connected to. Similarly to the check valve 33, when the heating operation of the air conditioner 40 is stopped, the check valve 42 also discharges the liquid refrigerant stored in the outdoor heat exchanger 28 and in the outdoor refrigerant pipe 23 around the outdoor heat exchanger 28. When the temperature of the heat exchanger 28 rises due to the rising sun and becomes high-pressure refrigerant, the high-pressure refrigerant is
The refrigerant flows in a direction leading to the outdoor refrigerant pipe 23 on the upstream side during the heating operation from the outdoor electric expansion valve 29 (fully closed state).

Therefore, the air conditioner 40 also has the following effects similar to the above effects.

A bypass pipe 41 bypassing the outdoor electric expansion valve 29 and the outdoor heat exchanger 28 is connected to the outdoor refrigerant pipe 23.
Is connected to the bypass pipe 41. When the heating operation of the air conditioner 40 is stopped, the high pressure inside the outdoor refrigerant pipe 23 from the compressor 25 via the outdoor heat exchanger 28 to the outdoor electric expansion valve 29 in the fully closed state is connected. The refrigerant is supplied to the outdoor refrigerant pipe 2 on the upstream side during the heating operation from the outdoor electric expansion valve 29 in the fully closed state.
Since the check valve 42 for guiding into the inside 3 is provided, the liquid refrigerant stored in the outdoor heat exchanger 28 and the surrounding outdoor refrigerant pipe 23 rises in temperature during the night and during the stoppage of the heating operation due to the morning sun and the like. Even if the high-pressure refrigerant is vaporized and becomes a high-pressure refrigerant, the high-pressure refrigerant is guided through the check valve 42 into the outdoor refrigerant pipe 23 upstream of the outdoor electric expansion valve 29 during the heating operation. For this reason, even if the outdoor heat exchanger 28 is heated by the morning sun etc. during the heating operation stoppage, the compressor 25 passes through the four-way valve 27 and the outdoor heat exchanger 28 to the outdoor electric expansion valve 29 (fully closed state). The pressure in the outdoor refrigerant pipe 23 reaching the upstream side of the outdoor electric expansion valve 29 in the fully closed state and the pressure in the outdoor refrigerant pipe 23 on the upstream side during the heating operation are balanced. Since the inside of 23 does not become a high pressure state, the load on compressor 25 can be reduced at the time of starting the heating operation.

Although the present invention has been described based on one embodiment, the present invention is not limited to this. For example, the present invention may be applied to an air conditioner in which a compressor, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger are sequentially connected.

[0032]

As described above, according to the air conditioner of the present invention, at least the bypass pipe bypassing the pressure reducing device is connected to the outdoor refrigerant pipe, and the bypass pipe is connected to the compressor when the operation is stopped. A check valve that guides the high-pressure refrigerant in the outdoor refrigerant pipe from the outdoor heat exchanger to the decompression device into the outdoor refrigerant pipe on the upstream side during the heating operation from the decompression device is provided. When the heating operation is stopped, even if the pressure reducing device is fully closed and the outdoor heat exchanger is heated, the operation of the bypass pipe and the check valve causes
The pressure in the outdoor refrigerant pipe from the compressor to the decompression device via the outdoor heat exchanger and the pressure in the outdoor refrigerant pipe on the upstream side during the heating operation with respect to the decompression device are balanced, and compression at the start of the heating operation is performed. The load on the machine can be reduced.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing a first embodiment of an air conditioner according to the present invention.

FIG. 2 is a refrigerant circuit diagram illustrating a second embodiment of the air-conditioning apparatus according to the present invention.

FIG. 3 is a refrigerant circuit diagram showing a conventional air conditioner.

[Explanation of symbols]

 Reference Signs List 20 air conditioner 21 outdoor unit 22 indoor unit 23 outdoor refrigerant pipe 24 indoor refrigerant pipe 25 compressor 28 outdoor heat exchanger 29 outdoor electric expansion valve (outdoor decompression device) 30 indoor heat exchanger 32 bypass pipe 33 check valve 40 air Conditioner 41 Bypass pipe 42 Check valve

Claims (2)

[Claims] An indoor heat exchanger is provided in an outdoor unit in which a compressor, an outdoor heat exchanger, and a decompression device are connected by an outdoor refrigerant pipe, and in an indoor refrigerant pipe connectable to the outdoor refrigerant pipe. In an air conditioner having an indoor unit configured as described above, at least a bypass pipe bypassing the pressure reducing device is connected to the outdoor refrigerant pipe.
When the operation of the compressor is stopped, the high-pressure refrigerant in the outdoor refrigerant pipe from the compressor via the outdoor heat exchanger to the decompression device, the outdoor refrigerant pipe on the upstream side during the heating operation from the decompression device. An air conditioner, characterized in that a check valve for guiding into the inside is provided. 2. The air conditioner according to claim 1, wherein the bypass pipe bypasses only a pressure reducing device.