JPS6314270B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-type separate air conditioner in which a plurality of indoor units are connected to one outdoor unit. The purpose is to reduce the noise of the refrigerant flowing into the stopped indoor unit when the indoor unit is stopped.

Conventionally, in a multi-type separate air conditioner, when any one indoor unit is stopped during cooling, for example, when three indoor units are being operated simultaneously, refrigerant flow noise is generated from the stopped indoor unit. In the conventional gas circuit configuration of this type of indoor unit, the expansion valve for cooling the indoor unit is provided on the inlet side of the heat exchanger, and the temperature sensing part of this expansion valve is provided on the outlet side of the heat exchanger. ing. Furthermore, a circuit is provided to bypass the expansion valve, and check valves are provided in the bypass circuit in the flow direction during heating and in the stop direction during cooling. However, the reason why the flow noise is emitted from the indoor unit on the stopped side during cooling is because the refrigerant flowing from the stopped outdoor unit to the indoor unit in liquid form is installed on the outlet side and reaches its maximum temperature due to the temperature rise of the temperature sensing part. It is drawn to the low pressure side through the opened expansion valve, and at that time it becomes flash gas and generates a flow noise.

In addition, the above-mentioned circulation noise mainly occurs when the indoor unit is stopped from operation, but even during operation, if there is a shortage of refrigerant in any of the indoor units when three rooms are operating simultaneously, the flush gas This caused the refrigerant flow noise to be generated in the vicinity of the expansion valve, which had the disadvantage of being harsh to the ears.

The present invention solves the above-mentioned conventional drawbacks,
An example of this will be explained below based on the drawings.

In the figure, 1 is the outdoor unit, 2, 3, and 4 are 1
These are indoor units No. 3 to 3. The outdoor unit 1 includes a four-way valve 6 from the compressor 5, an outdoor heat exchanger 7, a heating expansion valve 8, and a check valve provided in the refrigerant flow direction during cooling at a position that bypasses the heating expansion valve 8. 9. A flow path is formed via the receiver 10 to the liquid side solenoid valve 11 of the No. 1 indoor unit 2, the liquid side solenoid valve 12 of the No. 2 indoor unit 3, and the liquid side solenoid valve 13 of the No. 3 indoor unit 4. has been done. In addition, pressure equalizing capillary tubes 18, 19, which are in parallel with the liquid side solenoid valves 11, 12, 13,
A pressure equalizing pipe 17 is connected to 20, and the other end of this pressure equalizing pipe 17 is connected to a pipe 21 which becomes a low pressure side during heating. Furthermore, in the outdoor unit 1,
A flow path is formed from the gas side solenoid valves 14, 15, 16 to the compressor 5 via the four-way valve 6.

On the other hand, each indoor unit 2, 3, 4 is provided with an indoor heat exchanger 22, 23, 24, and an expansion valve 25 for cooling is provided on the inlet side of each indoor heat exchanger 22, 23, 24 during cooling. , 26, 27 are provided,
The temperature sensing parts 25a, 26a, 27a are provided on the outlet side of the indoor heat exchangers 22, 23, 24 during cooling. The opening degrees of the expansion valves 25, 26, and 27 are adjusted by sensing the temperature on the outlet side. Each of the cooling expansion valves 25, 2
At bypass positions 6 and 27, check valves 27b, 28, and 2 are installed in the direction of flow toward the outdoor unit 1 during heating.
There are 9. And cooling expansion valve 25,2
6, 27, that is, near the front side of the expansion valve during cooling, short capillary tubes 30, 3 are installed to temporarily relieve the flow of refrigerant.
1 and 32 are provided. This thin tube 30, 31, 3
2 is the connection point 3 of the bypass pipes 33, 34, 35
The tubes are arranged closer to the expansion valves 25, 26, and 27 than the expansion valves 6, 37, and 38, and have no relation to the arrangement during heating, and are short enough to have no effect on the cooling capacity during cooling.

In the above configuration, when the No. 1 indoor unit 2, the No. 2 indoor unit 3, and the No. 3 indoor unit 4 are operated simultaneously during cooling, the compressor 5, the four-way valve 6,
Outdoor heat exchanger 7, check valve 9, receiver 10, liquid side solenoid valves 11, 12, 13, thin tubes 30, 31, 3
2, expansion valves 25, 26, 27, indoor heat exchanger 2
2, 23, 24, gas side solenoid valve 14, 15, 1
6, the four-way valve 6, and the compressor 5 in this order, three-chamber simultaneous operation is performed. During this operation, for example, if No. 1 indoor unit 2 is stopped,
Although the liquid-side solenoid valve 11 is closed, the liquid refrigerant remaining in the pipe piped from the liquid-side solenoid valve 11 to the indoor side passes through the thin tube 30. At this time, in the temperature sensing section 25a, the indoor heat exchanger 2, which was being cooled until then,
2, the temperature gradually increases on the outlet side (temperature sensing part 25a side), so the expansion valve 25 gradually becomes fully open, the refrigerant is slightly depressurized in the thin tube 30, and the flash gas generated by this slight depressurization causes the expansion to fully open. The gas side solenoid valve 14 passes through the valve 25 slowly.
It flows to the side.

As described above, the present invention provides a cooling system between the cooling expansion valve and the liquid-side solenoid valve provided in each indoor unit, and near the expansion valve side, to the extent that the cooling capacity during cooling operation is not affected. As a result of providing a short tubule,
When the indoor unit is stopped, the expansion valve is fully opened to allow the refrigerant to flow at a slow rate, so the flow noise is significantly reduced and is no longer annoying to the ears, which is a practical effect.

[Brief explanation of the drawing]

The drawing is a circuit diagram of a separate air conditioner according to an embodiment of the present invention. 1... Outdoor unit, 2, 3, 4... Indoor unit, 25, 26, 27... Cooling expansion valve, 3
0,31,32...tubule.

Claims (1)

[Claims] 1. A plurality of indoor units are connected to one outdoor unit, and a cooling expansion valve is connected to the liquid side pipe inside the outdoor unit or inside the indoor unit, and the cooling expansion valve is connected to the cooling expansion valve. A separate air conditioner comprising a temperature-sensing section provided on the outlet side of the indoor heat exchanger, and a short thin tube that does not affect the cooling capacity during cooling operation near the piping of the cooling expansion valve. Machine.