JPS6054572B2 - Air conditioner refrigeration cycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration cycle for an air conditioner,
The purpose of this is to prevent refrigerant flow noise from being generated from the user-side heat exchanger, etc. when the compressor is stopped.

In conventional air conditioners, the high-pressure side and low-pressure side are connected through a bypass pipe with a solenoid valve, and when the compressor is stopped, the solenoid valve in the bypass pipe is opened to eliminate the pressure difference between the high-pressure side and the low-pressure side in a short time. There are some types of air conditioners that reduce the amount of refrigerant and make it easier to restart the compressor, but in this type of air conditioner, when the solenoid valve is opened, a large amount of refrigerant passes through the bypass pipe and solenoid valve in a short period of time. The drawback was that it generated a lot of noise and vibration.

Furthermore, this noise and vibration propagates to the heat exchanger on the user side, which allows the refrigerant to flow, which causes discomfort to the user, which is a major drawback. In addition, in conventional air conditioners, when the compressor is stopped, the pressure difference between the high pressure side and the low pressure side is reduced by using a throttling device or the heat exchanger itself on the user side, instead of using a bypass pipe as described above. However, with this type of air conditioner, it takes a long time for the pressure difference to become small, so the compressor may not be restarted immediately, or the compressor may not reach a pressure difference that allows it to be restarted. This may damage the compressor that is being restarted before the pressure difference reaches zero, and the refrigerant will continue to flow through the throttling device and the heat exchanger on the user side until the pressure difference becomes completely zero, so the length of time required for this pressure equalization is A major drawback was that the refrigerant flow noise was generated from the throttling device and the user-side heat exchanger for a period of time, causing discomfort to the user.

The present invention eliminates the above-mentioned drawbacks, and will be explained below based on examples thereof.

FIG. 1 shows an embodiment of the refrigeration cycle of an air conditioner according to the present invention, and this refrigeration cycle includes a compressor 1, a discharge muffler 2, a heat source side heat exchanger 3, a throttle device 4, a user side heat exchanger 5 , a bypass pipe 8 connecting the high pressure liquid line 6 between the heat source side heat exchanger 3 and the expansion device 4 and the low pressure gas line 7 between the use side heat exchanger 5 and the compressor 1; A three-way valve 9 having connection ports A, B, and C is provided at the junction between the high-pressure liquid line 6 and the high-pressure liquid line 6, and between the junction 10 between the low-pressure gas line 7 and the bypass pipe 8 and the user-side heat exchanger 5. A check valve 1 is installed in the low-pressure gas line 7 with the confluence section 10 side as the flow blocking side.
It is composed of 1. The operation in the above configuration will be explained. First, when the air conditioner is operating, the refrigerant gas discharged from the compressor 1 passes through the discharge muffler 2, is liquefied in the heat source side heat exchanger 3, and is connected to the high-pressure liquid line 6 and the connection ports A and B of the three-way valve 9. The gas is then depressurized by the expansion device 4, evaporated by the utilization side heat exchanger 5, and returns to the compressor 1 again through the check valve 11 and the low pressure gas line 7. At this time, since the connection port C of the three-way valve 9 is not communicating with the connection ports A and B, the refrigerant on the high pressure liquid line 6 side does not flow through the bypass pipe 8 to the low pressure gas line 7 side. When the compressor 1 of the air conditioner currently being operated in this manner is stopped due to the action of the temperature controller or due to the air conditioner itself being stopped, the three-way valve 9 is switched at the same time or a little later. Connect the connection port A<5C and close the connection port B. Therefore, the refrigerant flows through the bypass pipe 8, and the pressure on the high pressure side and the pressure on the low pressure side are balanced in a short time.
At this time, the connection ports B, A, and C of the three-way valve 9 are not communicating with each other, so the refrigerant on the heat source side heat exchanger 3 side does not flow into the use side heat exchanger 5 on the low pressure side. Rather, the pressure in the low-pressure gas line 7 becomes higher than that in the user-side heat exchanger 5 due to the refrigerant passing through the bypass pipe 8, so the flow of refrigerant is reversed from the low-pressure gas line 7 to the user-side heat exchanger 5 than in normal operation. Head to 5.
Here, the check valve 11 prevents the refrigerant from flowing from the low-pressure gas line to the user-side heat exchanger 5, so it prevents the refrigerant flow noise generated when the refrigerant flows from the low-pressure gas line 7 to the user-side heat exchanger 5. , a three-way valve 9 and . Large noises and vibrations generated in the bypass pipe 8 can be prevented from entering the user-side heat exchanger 5. Further, as mentioned above, the refrigerant on the heat source side heat exchanger 3 side is connected to the connection port A of the three-way valve 9.
, C and the bypass pipe 8 and does not pass through the connection port B of the three-way valve 9, refrigerant noise is generated when passing through the throttling device 4 and the connection ports A and C of the three-way valve 9 and the bypass pipe 8. This prevents large noise and vibration from entering the heat exchanger 5 on the user side.
When the compressor is stopped, pressure is balanced in the bypass pipe, making it possible to restart the compressor in a short time, and at the same time, it has the great effect of not generating loud noise or vibration from the throttling device or heat exchanger on the user side. have. FIG. 2 shows another embodiment of the refrigeration cycle of an air conditioner according to the present invention.
The outdoor unit 101 includes a pole converter compressor 102 having a two-pole motor and a four-pole motor, a discharge muffler 103, a heat source side heat exchanger 104, a liquid receiver 105, a liquid side main pipe 106,
Liquid side branch pipe 107 formed by branching the liquid side main pipe 106 into multiple parts
a, 107b, 107c1 This liquid side branch pipe 107a, 10
Solenoid valves 108a, 108b, 108c1 of a type that open passages when energized are provided in 7b, 107c, respectively.
Sealed connection ports 109a, 109b, 109c1 gas side main pipe 1 provided at the connection portions of liquid side branch pipes 107a, 107b, 107c with indoor units 120a, 120・B, l2Oc
Gas side branch pipes 111a, 111b created by branching 13,
111c1 This gas side branch pipe 111a, 111b, 111
Connection ports 110a, 110b, 110c provided at the connections with the indoor units 120a, 120b, 120c of
6 and the gas side main pipe 113, a bypass pipe 115 is provided at the confluence of the liquid side main pipe 106 and the bypass pipe 115,
Three-way valve 116 with connection ports A, B, and C, gas side main pipe 1
13 and the confluence section 117 of the bypass pipe 115 and the blockade valve 11
2 and a check valve 118 with the merging portion 117 side as the flow blocking side. In addition, the indoor unit 120a,
120b and 120c are user-side heat exchangers 121, respectively.
a, 121b, 121C1 throttle device 122a, 122b
, 122c. This one outdoor unit 101 has multiple indoor units 120a, 120b.
, 120c is called a multi-room air conditioner, and is an air conditioner in which any number of indoor units can be operated individually or simultaneously. The operation will be explained below. The pole change type compressor 102 will be explained before actual operation.

Compressors commonly used at present have a two-pole motor, and the rotation speed thereof is 360 revolutions per minute, assuming that there is no vibration during 60 cycles. However, since this pole converter compressor 102 has a two-pole motor and a four-pole motor, assuming there is no vibration after 60 cycles, the rotation speed is 3,600 revolutions per minute when the two-pole motor is operating, and the four-pole motor is 3,600 revolutions per minute. When the motor is operating, the rotation is 1800 revolutions per minute, and when the 4-pole motor is operating, the amount of piston displacement is half that of when the 2-pole motor is operating. Therefore, when the pole number converting compressor 102 has a capacity of 2 when operating a 2-pole motor, its capacity when operating a 4-pole motor becomes 1.
One compressor can have two stages of capacity. This means that when the air-conditioning load is large, the two-pole motor operates to produce a large capacity, and when the air-conditioning load is small, the four-pole motor operates to produce a small capacity, allowing operation commensurate with the load. Moreover, for example, indoor units 120a, 120 of a multi-room air conditioner
A capacity commensurate with the air conditioning load can be obtained by operating a 4-pole motor when operating one of the rooms b and 120c, and operating a 2-pole motor when operating two or three rooms. Things can happen. Now let's explain the operation.

It is now assumed that the indoor units 120a and 120b are being operated and the pole converting compressor 102 is moving with the four-pole motor being energized. At this time, the refrigerant gas discharged from the pole number converting compressor 102 passes through the discharge muffler 103 and then passes through the heat source side heat exchanger 1.
04, the liquid receiver 105, the connection port A of the three-way valve 116, the Bl liquid side main pipe 106, and the liquid side branch pipes 107a, 107b.
Solenoid valves 108a, 108 that are energized and have open passages
b1 sealed connection port 109a, 109b1 indoor unit 12
It is evaporated and gasified in the use side heat exchangers 121a, 121b through the expansion devices 122a, 122b of 0a, 120b, and the connection ports 110a, 110b1 gas side branch pipes 111a, 1
11b1 Blocking valve 112 installed in the gas side main pipe 113
, check valve 118 and accumulator 114 and returns to the pole converter compressor 102 again. In addition, the number of poles converting compressor 1
During the operation of 02, the three-way valve 116 is energized, so the connection port C of the three-way valve 116 does not communicate with the connection ports A and B, so that no refrigerant flows through the bypass pipe 115. In addition, since the indoor unit 120c is not operated, the solenoid valve 108c
is not energized, and no refrigerant flows through the indoor unit 120c. Under these operating conditions, indoor unit 1
As the temperature of the space in which the indoor units 120a and 120b are installed has increased, the indoor units 120a and 120b are required to have even greater capacity, and it becomes necessary to switch from 4-pole motor operation to 2-pole motor operation, which has greater capacity. Ta.

However, the pole converter compressor 102 cannot instantly switch from a 4-pole motor to a 2-pole motor, or vice versa, to protect the motor and mechanical parts. In order to protect the motor and mechanical parts, the pole change type compressor 102 must be restarted after the pressure on the high pressure side and the pressure on the low pressure side are balanced. During the time when the pole change type compressor 102 is stopped for this pressure equilibrium, the indoor unit 12
0a and 120b are not being air-conditioned, and it is inconvenient that the pole change type compressor 102 has to be stopped at this time when there is a request for capacity increase. However, in order to protect the pole-changing compressor, the pole-changing compressor 102 was temporarily stopped, and during this time, the pressure on the high pressure side and the pressure on the low pressure side were quickly balanced, and a new switch was made within a short time. In order to be able to operate the pole converter compressor 102 with a two-pole motor, the three-way valve 116 is de-energized and the three-way valve 1 is turned off.
16 connection port A (5C) is connected to allow the refrigerant to flow into the bypass pipe 115. In this way, the pressure on the high pressure side and the pressure on the low pressure side are balanced in a short time, and the pole change type compressor 102 is immediately turned off. The indoor unit 120 can be restarted.
The stop time of a and 120b is extremely short. Also, the connection port A of this three-way valve 116. Since the connecting port B of l5C is not communicating with the connecting ports A and C, the throttle device 122a
Since refrigerant does not flow into the indoor units 120a, 120b from the , 122b side, large noises and vibrations generated at the bypass pipe 115 and the connection ports A, C of the three-way valve 116 are not propagated to the indoor units 120a, 120b. There is no.
On the other hand, the pressure in the gas side main pipe 113 becomes higher than that in the user side heat exchangers 121a and 121b due to the refrigerant passing through the bypass pipe 115, so the flow of the refrigerant is reversed from the normal operation, from the gas side main pipe 113 to the user side heat exchanger. Head to the containers 121a and 121b. Here, the check valve 118 prevents the refrigerant on the confluence section 117 side of the gas side main pipe 113 from flowing to the utilization side heat exchangers 121a, 121b. Refrigerant flow noise generated when refrigerant flows to 121a and 121b. and the bypass pipe 115 and three-way valve 1 that lead to this refrigerant flow.
The large noise and vibration generated in 16 are transmitted to the user side heat exchanger 121a
, 121b can be prevented. As mentioned above, in a multi-room air conditioner, the pole number conversion L-type compressor 10
Operation switching between the 2-pole motor and the 4-pole motor described in 2.2 occurs many times due to changes in the load in each space where the indoor unit is installed, or when the number of operating rooms is changed at the user's will. .

In addition to stopping at the time of pole number switching, the pole number changing type compressor 102 may no longer need to be operated because the load requirements of each indoor unit are satisfied, and the pole number changing type compressor 102 may be stopped. Therefore, compared to the operation of a single general air conditioner, in the case of a multi-room air conditioner using a pole converting compressor, there are more opportunities to temporarily stop the pole converting compressor. The present invention is highly effective as a countermeasure against noise and vibration in such cases. As has been described so far, the air conditioner refrigeration cycle according to the present invention performs pressure equalization using the bypass pipe when the compressor is stopped, thereby enabling early restart of the compressor, and at the same time, when the pressure is equalized, the air conditioner refrigeration cycle performs pressure equalization using the bypass pipe. It has the great effect of not generating noise or vibration.

In addition, the three-way valve doubles as the bypass pipe solenoid valve and the refrigerant inflow control valve to the user-side heat exchanger, so it is inexpensive.
There is also the great effect of being able to exhibit the effects mentioned above. Furthermore, since the refrigerant flowing through the bypass pipe is a high-pressure liquid refrigerant, the flow resistance is small, and pressure equilibrium can therefore be achieved in a short time.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram showing a refrigeration cycle of an air conditioner in one embodiment of the present invention, and FIG. 2 is a refrigerant circuit diagram showing a refrigeration cycle of an air conditioner in another embodiment of the invention. 1... Compressor, 3... Heat source side heat exchanger, 5... Utilization side heat exchanger, 8... Bypass pipe, 9... Three-way valve, 11...Check valve, 1
08a, 108b, 108c...Solenoid valve, 11
5... Bypass pipe, 116... Three-way valve, 11
8...Check valve.

Claims (1)

[Claims] 1 A compressor, a heat source side heat exchanger, a throttle device, and a user side heat exchanger are connected in a ring to form a refrigeration cycle, and a high pressure liquid line is formed between the heat source side heat exchanger and the expansion device;
A low-pressure gas line formed between the user-side heat exchanger and the compressor is connected by a bypass pipe, and a flow of refrigerant is directed from the bypass pipe to the compressor side at the confluence of the bypass pipe and the high-pressure liquid line. A three-way valve is provided to switch between the flow from the heat exchanger on the heat source side and the flow from the heat exchanger on the heat source side to the expansion device side. A check valve is provided so that the flow to the compressor is in the forward direction, and the three-way valve is set so that the refrigerant from the heat source side heat exchanger flows from the throttling device side to the bypass pipe at the same time or almost simultaneously when the compressor is stopped. Refrigeration cycle of an air conditioner configured to operate.