JPS6054575B2 - 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, in this type of air conditioner, it takes a long time for the pressure difference to become small, so the compression bar cannot be restarted immediately, or the pressure difference becomes such that the compressor can be restarted. Attempting to restart the compressor previously may damage the compressor, and the long time required for this pressure equilibrium to occur, as the refrigerant continues to flow through the throttling device and the heat exchanger on the user side until the pressure difference becomes completely zero. During this period, a major drawback was that refrigerant flow noise was generated from the expansion device and the user-side heat exchanger, causing discomfort to users.

The present invention is intended to eliminate the above-mentioned drawbacks, and one embodiment thereof will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the refrigeration cycle of an air conditioner according to the present invention. , 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 usage side heat exchanger 5 and the compressor 1; and connection ports A, B, and C provided at the confluence with the low-pressure liquid line 7.
The three-way valve 9 has a three-way valve 9. The operation in the above configuration will be explained.

During operation of the air conditioner, refrigerant gas discharged from the compressor 1 passes through the discharge muffler 2, is liquefied in the heat source side heat exchanger 3, passes through the high-pressure liquid line 6, is depressurized by the expansion device 4, and is sent to the user side. It is evaporated in the heat exchanger 5 and connected to the connection ports A and B of the three-way valve 9.
and returns to the compressor 1 again. 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 to the low pressure gas line 7 side. The compressor 1 of the air conditioner currently being operated in this way is
When the air conditioner is stopped due to the operation of the temperature controller or the air conditioner itself is stopped, the three-way valve 9 is switched at the same time or a little later to connect the connection ports C and B and close the connection port A. 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 resistance value of the throttling device 4 is much larger than that of the bypass pipe 8 and the three-way valve 9 that communicates with the connection ports B and C, so the refrigerant on the high pressure side passes through the throttling device 4 and passes through the use side heat exchanger 5 on the low pressure side. There is almost no flow into it. 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, connection port AI:. The communicating three-way valve 9 of C prevents the flow of refrigerant from the low pressure gas line 7 to the user side heat exchanger 5.
The refrigerant flow noise generated when the refrigerant flows from the low-pressure gas line 7 to the heat exchanger 5 on the user side, and the large noise and vibrations generated in the bypass pipe 8 and three-way valve 9 that come along with the flow of this refrigerant, are generated on the user side. Intrusion into the heat exchanger 5 can be prevented. Furthermore, as mentioned above, since the resistance value of the throttle device 4 is much larger than that of the bypass pipe 8 and the three-way valve 9, most of the refrigerant in the high-pressure liquid line 6 passes through the bypass pipe 8 and the three-way valve 9, and the resistance value of the throttle device 4 is much larger than that of the bypass pipe 8 and the three-way valve 9. The compressor 1 When the compressor 1 is stopped, the pressure is balanced in the bypass pipe 8 and the compressor 1 is restarted. This has the great effect of not only making it possible in a short period of time, but also preventing the generation of large noises and vibrations from the heat exchanger 5 on the user side of the expansion device 4 during this time. Further, FIG. 2 shows another embodiment of the refrigeration cycle of an air conditioner according to the present invention, in which an outdoor unit 101
, 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 10, a liquid receiver 105, a liquid side main pipe 106, and a liquid side main pipe 106 branched into multiple parts. Liquid side branch pipes 107a, 107b, 107 made by
c1 Solenoid valves 108a, 108b, 108c provided in the liquid side branch pipes 107a, 107b, 107c, respectively, which open passages when energized.1 Liquid side branch pipes 107a, 1.
07b, 107c indoor units 120a, 120b,
Sealed connection ports 109a and 10 provided at the connection with 120c
9b, 109c1 Gas side branch pipes 111a, 111b, 111c1 created by branching the gas side main pipe 113 Indoor unit 120 of these gas side branch pipes 111a, 111b, 111c
Connection port 11 provided at the connection part with a, 120b, 120c
0a, 110b, 110c1 Blocking valve 112 provided in gas side main pipe 113, accumulator 114, liquid side main pipe 10
6 and the gas side main pipe 113, and a three-way valve 117 having connection ports A, B, and C provided at the junction of the gas side main pipe 113 and the bypass pipe 115. In addition, indoor units 120a, 120b, 12
0c are the user side heat exchangers 121a, 121b,
121c1 is composed of diaphragm devices 122a, 122b, and 122c. A system in which multiple indoor units 120a, 120b, 120c are connected to one outdoor unit 101 is called a multi-room air conditioner, and an air conditioner that can operate any number of indoor units independently or simultaneously. It is a harmonizing machine. The operation will be explained below. Before the actual operation, the pole change type compressor 102 will be explained.

Compressors commonly used at present have a two-pole motor, and the rotation speed thereof is 3600 per minute assuming no vibration during 60 cycles. However, since this pole number variable compressor 102 has a 2-pole motor and a 4-pole motor, assuming there is no vibration after 60 cycles, the number of revolutions is 3600 per minute when the 2-pole motor is operating, and 1 per minute when the 4-pole motor is operating. minute 18
00, and when the 4-pole motor is operating, the amount of piston displacement is half that of the 2-pole motor operating. Therefore, in this pole converting type compressor 102, if the capacity when operating a two-pole motor is 2, the capacity when operating a four-pole motor is 1, and one compressor can have two levels 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. Also, for example, indoor units 120a, 120b, 120c of a multi-room air conditioner.
When operating one of the rooms, the 4-pole motor is operated.
When operating 2 or 3 rooms, the capacity commensurate with the air conditioning load can be obtained by operating the 2-pole motor.
Now let's explain the operation.

It is assumed that the indoor units 120a and 120b are operated and the pole converting compressor 102 is powered by the four-pole motor and is moving. At this time, the refrigerant gas discharged from the pole number converting compressor 102 passes through the discharge muffler 103 to the heat source side heat exchanger 10.
4, the electromagnetic valves 108a, 108b1, which are energized and have open passages, are liquefied in the liquid receiver 105, the liquid side main pipe 106, and the liquid side branch pipes 107a, 107b.The closed connection ports 109a, 109
Throttle device 122 of b1 indoor units 120a, 120b
a, 122b to the user side heat exchangers 121a, 121b
The connection ports 110a, 110b1, the gas side branch pipes 111a, 111b1, the blocking valve 112 disposed in the gas side main pipe 113, and the connection ports A, Bl of the three-way valve 117.
It passes through the accumulator 114 and returns to the pole change type compressor 1.
Return to 02. Note that while the pole converter compressor 102 is operating, the three-way valve 117 is energized, so the connection port C of the three-way valve 117 does not communicate with the connection ports A and B, so the bypass pipe 1
No refrigerant flows through 15. Further, since the indoor unit 120c is not operated, the solenoid valve 108c is not energized, and no refrigerant flows through the indoor unit 120c. In this operating state, the temperature of the space where the indoor units 120a and 120b are installed has increased, so the indoor unit 1
20a and 120b have come to be required to have even greater capacity, and it has become necessary to switch from 4-pole motor operation to 2-pole motor operation, which has greater capacity. 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.
While the pole-changing compressor 102 is stopped during this pressure equilibrium, the indoor units 102a and 102b are not air-conditioned. It is inconvenient to have to stop the However, in order to protect the pole-changing compressor 102, the pole-changing compressor 102 is temporarily stopped at this time, and during this time, the pressure on the high pressure side and the pressure on the low pressure side are quickly balanced, and the new switch is started 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 117 is de-energized and the connection ports C and B of the three-way valve 117 are closed.
is communicated with the bypass pipe 115 so that the refrigerant flows 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 can be restarted immediately, so that the indoor units 120a and 120b need to be stopped for an extremely short time. . In this case, as in the case of the refrigeration cycle of the air conditioner according to the present invention shown in FIG. Almost no gas flows through the expansion devices 122a, 122b to the low-pressure side heat exchangers 121a, 121b. Also, the solenoid valve 1 provided in the liquid side branch pipes 107a, 107b which guide the refrigerant to the indoor units 120a, 120b during communication between the connection ports C and B of this three-way valve 117.
If the passages 08a and 108b are closed, the throttle device 122
Since refrigerant does not flow into the indoor units 120a and 120b from the sides a and 122b, the large noise and vibrations generated in the bypass pipe 115 and the three-way valve 117 are transmitted to the indoor unit 12.
It is not propagated to 0a and 120b. On the other hand, the pressure in the gas side main pipe 113 becomes higher than that in the use side heat exchangers 121a and 121b due to the refrigerant passing through the bypass pipe 115.
” to the user-side heat exchangers 121a, 121b. However, since the connection port A.15C of the three-way valve 117 is not communicating, the three-way valve 117 of the gas-side main pipe 113 allows the refrigerant to flow to the user-side heat exchangers 121a, 121b. In order to prevent the flow from the bypass pipe 115 to the utilization side heat exchanger 121a,
The refrigerant flow noise generated by the refrigerant flowing to the refrigerant 121b and the bypass pipe 115 that comes along with this refrigerant flow.
It is also possible to prevent large noises and vibrations generated by the three-way valve 117 from entering the user-side heat exchangers 121a and 121b. As mentioned above, in a multi-room air conditioner, operation switching between the two-pole motor and the four-pole motor of the pole converter compressor 102 is performed depending on load changes in each space in which the indoor unit is installed, and the user This occurs many times when the number of driver's cabs is changed according to the will of the driver.

Furthermore, in addition to stopping at the time of switching the pole number, 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 in reducing 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 also serves as a bypass solenoid valve and a refrigerant backflow control valve to the heat exchanger on the user side, so it can achieve the above-mentioned effects at a low cost.Furthermore, since the refrigerant flowing through the bypass pipe starts from high-pressure liquid refrigerant, The flow resistance is small, and therefore pressure equilibrium can 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 according to an embodiment of the present invention, and FIG. 2 is a refrigerant circuit diagram of a refrigeration cycle of an air conditioner according to another embodiment of the invention. 1...Compressor, 3...Heat source side heat exchanger, 5...Using side heat exchanger, 8...Bypass pipe, 9...Three sides Valve, 108a, 108b, 108c
, 116... Solenoid valve, 114... Accurator, 1
17... Three-way 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 a low-pressure confluence between the bypass pipe and the low-pressure gas line. A three-way valve is provided to switch the flow from the heat exchanger on the user side to the compressor side, and at the same time or almost simultaneously when the compressor is stopped, the flow of refrigerant from the high pressure liquid line is transferred from the bypass pipe to the compressor side. A refrigeration cycle for an air conditioner, the refrigeration cycle of an air conditioner being configured to operate the three-way valve so that the flow is to the side.