JPS6058377B2 - Air conditioner refrigeration cycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration cycle for an air conditioner, and its purpose is to provide an air conditioner that can operate quietly.

In conventional air conditioners, the high-pressure side and low-pressure side of the refrigeration cycle 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 shorten the pressure difference between the high-pressure side and the low-pressure side. There are some types of air conditioners that reduce the amount of refrigerant in a short amount of time 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 is released into the bypass pipe and the solenoid valve in a short period of time. The problem is that it generates a lot of noise and vibration because it passes through the ground.

Furthermore, this large noise and large vibration propagate to the user-side heat exchanger that allows the refrigerant to flow, resulting in a major drawback of causing discomfort to the user. 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 the 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 compressor cannot be restarted immediately, and the compressor must be restarted before the pressure difference reaches a point where it can be restarted. If you try to do so, you may damage the compressor, and the refrigerant will continue to flow through the throttling device and the heat exchanger on the user side until the pressure difference is completely eliminated, so the long time required for this pressure equilibrium to occur, A major drawback was that refrigerant flow noise was generated from the throttling device and the heat exchanger on the user side, causing discomfort to the user.

The present invention eliminates the above-mentioned conventional drawbacks. Hereinafter, the present invention will be described with reference to the accompanying drawings showing one embodiment thereof.

In the figure, 1 is a compressor, 2 is a discharge muffler, 3 is a heat exchanger on the heat source side, 4 is a throttling device, 5 is a heat exchanger on the user side, and 6 is between the heat source side heat exchanger 3 and the throttling device 4. A high-pressure liquid line 7 indicates a low-pressure gas line between the user-side heat exchanger 5 and the compressor 1, and a refrigeration cycle is constructed by connecting these in an annular manner.

A bypass pipe 8 connects the high-pressure liquid line 6 and the low-pressure gas line 7, and the bypass pipe 8 includes a solenoid valve 9 that closes the passage when energized, and a resistance element for the solenoid valve 9. A series circuit consisting of 11 is provided.

Reference numeral 13 denotes a solenoid valve which is provided between the confluence 10 of the high-pressure liquid line 6 and the bypass pipe 8 and the throttle device 4, and which opens the passage when energized.

The operation in the above configuration will be explained.

First, 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 solenoid valve 13 in the high-pressure liquid line 6,
The gas is depressurized by the expansion device 4, evaporated by the utilization side heat exchanger 5, and returned to the compressor 1 through the low-pressure gas line 7. Here, since the electromagnetic valve 9 in the bypass pipe 8 is energized, the passage is closed, so that the refrigerant does not flow through the bypass pipe 8. 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 regulator or the air conditioner itself is stopped, the supply of electricity to the solenoid valve 9 is stopped at the same time or a little later, and the passage of the solenoid valve 9 is opened.

As a result, 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. Furthermore, at this time, at the same time as the energization to the solenoid valve 9 is stopped, the energization to the solenoid valve 13 is also stopped, so the refrigerant on the high pressure side does not flow through the throttling device 4 to the user side heat exchanger 5 on the low pressure side. . Therefore, the refrigerant in the high-pressure liquid line 6 only passes through the electromagnetic valve 9 and the resistance element 11 in the bypass pipe 8, but does not pass through the throttle device 4. Therefore, the refrigerant noise when the refrigerant passes through the throttle device 4 is reduced. The large noise and vibrations generated by the bypass pipe 8 and the solenoid valve 9 do not enter the heat exchanger on the user side, and when the compressor 1 is stopped, pressure is balanced in the bypass pipe 8, making it possible to restart the compressor 1 in a short time. At the same time, I want to be able to do this on time. No large noise or large vibration is generated from the diaphragm device 4 or the user-side heat exchanger 5.

Next, pressure changes at various parts after the compressor 1 is stopped will be explained with reference to FIG.

In the figure, P day communicates with bypass pipe 8! The pressure of the high pressure liquid line 6, PL is the pressure of the low pressure gas line, P
R indicates the pressure in the high pressure liquid line 6 between the solenoid valve 13 and the throttle device 4.

At the current time T1, the solenoid valve 13 simultaneously stops the compressor 1.
The passage of the solenoid valve 9 is closed and the passage of the solenoid valve 9 is opened (then the pressure PH of the high pressure liquid line 6 communicating with the bypass pipe 8 starts to decrease rapidly, and at the same time, refrigerant starts flowing from the high pressure liquid line 6. The pressure P of the low-pressure gas line 7 increases, and at time T2, the pressure PH and the pressure P become the same.However, the pressure PR of the high-pressure liquid line 6 in the part sandwiched between the solenoid valve 13 and the throttle device 4 is , when the compressor 1 stops and the passage of the solenoid valve 13 closes, the pressure can only be reduced through the throttle device 4 which has a high resistance value, so the pressure drop is slower than the drop in pressure PH, and the pressure decreases at time T3. PH,
It becomes the same value as P. Therefore, during pressure drop, PR>P
H, the refrigerant between the solenoid valve 13 and the throttle device 4 will push up the valve in the solenoid valve Jl3 and flow through the solenoid valve 13 toward the confluence 10 of the high-pressure liquid line 6 and bypass pipe 8. shall be.

Next, the internal structure of the solenoid valve 13 will be explained with reference to FIG.

In the figure, the solenoid valve 13 includes an inlet pipe 150 and an outlet pipe 1.
A cylinder 1 that houses a valve body 153 to which a valve 51 is fixed, a plunger 154 that is pulled up by a coil 156, and a spring 155 that pushes down this plunger 154.
It is closer to 52 mag.

The operation will be explained here. Assuming that the coil 156 is not energized now, there is a slight gap between the cylinder 152 and the plunger 154, so the pressure PH inside the inlet pipe 150
The pressure PT in the space created by the cylinder 152 and the surface of the plunger 154 in contact with the spring 155 becomes equal. Now, the area of the surface where the plunger 154 contacts the spring 155 is Ap, the cross-sectional area of the hole 157 of the valve body 153 is Av, and the force of the spring 155 is F, the plunger 154
When the own weight of the plunger 154 is Fp, the force F1 pushing down the plunger 154 becomes F1=Fs+Fp+ApPH. On the other hand, the force F2 that tries to push the plunger 154 upward is F
2=AVPR. Generally, since Ap>Av, at least when PH>PR, the hole 157 of the valve body 153 is closed by the plunger 154 which is pressed down.
When the coil 156 is energized from this state, the coil 156
Due to the pulling force FO of the plunger 154 due to F1
F2+FO, the plunger 154 is pulled upward, and the hole 157 of the valve body 153 communicates the outlet pipe with the inlet pipe. Furthermore, even when the coil 156 is de-energized, the outlet pipe 151
When the pressure PR inside the inlet pipe 150 becomes larger than the pressure PH inside the inlet pipe 150 to a certain extent, a state of F2>F1 occurs, and the plunger 154 is pushed upward. Now, the solenoid valve 13 has its inlet pipe 150 connected to the junction 10 side of the high-pressure liquid line 6 and the bypass pipe 8, and its outlet pipe 151 connected to the throttle device 4 side.

As shown in FIG. 2, when the compressor 1 is stopped, the outlet pipe 1
Since the pressure PR on the 51 side becomes higher than the pressure PH on the inlet pipe 150 side, a phenomenon appears in which the plunger 154 is pushed up. However, since the amount of refrigerant in the high-pressure liquid line 6 between the solenoid valve 13 and the throttle device 4 is not so large, when the plunger 154 is pushed up, some of the refrigerant is released to the inlet pipe 150 side, and the pressure PR decreases slightly. and becomes PRl. Then, the pressure becomes PRl - PH temporarily, and it is the turn of the plunger 154 to be pushed down again, but while the plunger 154 is being pushed down, the pressure PH also decreases slightly due to the action of the bypass pipe, and becomes PHl. Then PRl again
PHL and the plunger 154 is pushed up, the vertical movement of the plunger 154 is repeated violently in a short period of time, and the large plunger 15 is released from the solenoid valve 13.
4 will be generated. However, in the case of this embodiment, the resistance element 11 is provided in the bypass pipe 8 with a resistance value selected such that the pressure of PR-PH=ΔP does not push up the plunger 154.
Refrigerant does not flow from the outlet pipe 151 of the solenoid valve 13 to the inlet pipe 150, and as a result, the refrigerant flows from the solenoid valve 13 to the plunger 15.
It does not generate the humming noise of 4.

Further, the resistance element 11 has the effect of absorbing noise and vibration generated by the solenoid valve 13. The solenoid valve 13 is provided so that when the compressor 1 is stopped and the compressor 1 is bypassed using the bypass pipe 8, noise and vibration during the bypass and refrigerant sound caused by the throttling device 4 are not emitted from the heat exchanger 5 on the user side. Therefore, generating large noise from itself is a big problem, and being able to eliminate that problem is extremely effective in achieving completely low noise and vibration. In addition, when the refrigerant passes through the resistance element 11 in the bypass pipe 8, the pressure of the refrigerant is reduced, so that the liquid refrigerant is easily gasified by adiabatic expansion, making it difficult for the liquid refrigerant to return to the compressor 1, and compressing the refrigerant. This also has the effect of not damaging the compressor 1 when the machine 1 is restarted.

Furthermore, if the resistance element 11 is provided downstream of the solenoid valve 9, the refrigerant cooled by passing through the resistance element 11 will not cool the solenoid valve 9, so that the coil etc. of the solenoid valve 9 will not be cooled due to cooling. Since it is not exposed to dew, it has the effect of extending the life of the coil, etc. Next, another embodiment will be described with reference to FIG.

In the figure, the outdoor unit 101 has a two-pole motor C.
Pole change type compressor 102 having 2 and 4 pole motor C4
, discharge muffler 103, heat source side heat exchanger 104, liquid receiver 1
05, liquid side main pipe 106, liquid side branch pipes 107a, 107b, 107c formed by branching the liquid side main pipe 106 into a plurality of parts. Solenoid valve 108a
, 108b, 108c1 liquid side branch pipe 107a, 107b,
Indoor units 120a, 120b, 120c of 107c
Sealed connection ports 109a, 109b, 1 provided at the connection with
09c1 Gas side branch pipes 111a, 111b, 111c1 formed by branching the gas side main pipe 113 This gas side branch pipe 1
11a, 111b, 111c indoor unit 120a,
Connection port 110a provided at the connection part with 120b and 120c
, 110b, 110c1 A blocking valve 112 provided in the gas side main pipe 113, an accumulator 114, a solenoid valve 116 of the type that closes the passage when energized, and a resistance element 119 are arranged to connect the liquid side main pipe 106 and the gas side main pipe 113. Bypass pipe 1
It consists of 15.

In addition, the indoor units 120a, 120b, 120c have user-side heat exchangers 121a, 121b, 121c1, respectively.
It is composed of aperture 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.

The compressor currently in common use has a two-pole motor, and its rotational speed is 3,600 revolutions per minute, assuming no vibration after 60 cycles. However, since this pole converter compressor 102 has a two-pole motor C2 and a four-pole motor C4, assuming that there is no rotation during 60 cycles, the rotation speed is 3600 revolutions per minute when the two-pole motor C2 is operating. When the 4-pole motor C4 is operating, the rotation is 1800 revolutions per minute, and when the 4-pole motor C4 is operating, the piston displacement is half that of the 2-pole motor C2 operating. Therefore, when the capacity of this pole converter compressor 102 is 2 when the 2-pole motor C2 is operating, the capacity when the 4-pole motor C4 is operating is 1, and one compressor has two levels of capacity. I can do it. This means that when the air-conditioning load is large, the two-pole motor C2 operates to produce a large capacity, and when the air-conditioning load is small, the four-pole motor C4 operates to produce a small capacity, allowing operation commensurate with the load. In addition, for example, indoor units 120a and 120b of a multi-room air conditioner
, 120c, when one room is operating, the four-pole motor C4 is operated, and when two or three rooms are operating, the two-pole motor C2 is operated, thereby increasing the capacity commensurate with the air conditioning load. Obtainable. Now let's explain the operation.

It is assumed that the indoor units 120a and 120b are operated and the pole converter compressor 102 is powered by the four-pole motor C4. At this time, the refrigerant gas discharged from the pole conversion type compressor 102 passes through the discharge muffler 103 and is liquefied in the heat source side heat exchanger 104, and is liquefied in the liquid receiver 105, the liquid side main pipe 106, and the liquid side branch pipes 107a and 107b. Solenoid valves 108a, 108b1 that are energized and have open passages; closed connection ports 109a, 1;
09b1 Throttling device 1 of indoor units 120a, 120b
22a, 122b to the user side heat exchangers 121a, 12
1b and is evaporated into gas, connecting ports 110a and 110b.
1 Gas side branch pipes 111a, 111b1 Gas side main pipes 113 are provided with a blockage valve 112 and an accumulator 114, and then return to the re-pole number converting compressor 102. Note that while the pole converter compressor 102 is in operation, the electromagnetic valve 116 in the bypass pipe 115 is energized, so the passage is closed and no refrigerant is allowed to flow. 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, when the temperature of the space in which the indoor units 120a and 120b are installed increases, the indoor units 120a and 120b
0b is required to have even greater capacity, and it becomes necessary to switch to the two-pole motor C2 operation, which has a greater capacity than the four-pole motor C4 operation.

However, in order to protect the motor and mechanical parts, the pole converter compressor 102 instantly switches from the 4-pole motor C4 to the 2-pole motor C4.
2 or vice versa, it is not possible to switch from the 2-pole motor C2 to the 4-pole motor C. In other words, in order to protect the motor and mechanical parts, change the number of poles after the pressure on the high pressure side and the pressure on the low pressure side are balanced, or after the pressure difference between the high pressure side and the low pressure side has become small enough to not adversely affect the mechanical parts or motor. The compressor 102 must be restarted. During this pressure equilibrium, the time during which the pole change compressor 102 is stopped;
Since the indoor units 120a and 120b are not being air-conditioned, it is inconvenient that the pole change type compressor 102 has to be stopped at a time when there is a demand for increased capacity.

However, in order to protect the pole-changing compressor 102, the pole-changing compressor 102 is temporarily stopped, and during this time the pressure on the high pressure side and the pressure on the low pressure side are quickly balanced, and the pressure on the high pressure side and the low pressure side are quickly balanced. In order to be able to operate the pole converter compressor 102 with the switched two-pole motor C2, the bypass pipe 115 is
The energization of the solenoid valve 116 inside is stopped and the passage of the solenoid valve 116 is opened to allow 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 can be restarted immediately, so that the shutdown time of the indoor units 120a and 120b can be extremely short. In this case, as in the case of Figure 1,
While the passage of the solenoid valve 116 for bypass is open, the liquid side branch pipe 107 guides the refrigerant to the indoor units 120a, 120b.
Solenoid valves 108a, 10 provided in a, 107b
Since the passage of 8b is closed, the throttle devices 122a, 122
The refrigerant on the high pressure side passes through the b side and enters the indoor units 120a, 1.
20b, and the large noise and vibrations generated by the bypass pipe 115 and the solenoid valve 116 are transmitted to the indoor unit 120.
a, 120b.

Also, similar to what was explained in Figures 1, 2, and 3,
When the compressor 102 is stopped, the passages of the solenoid valves 108a and 108b are closed, thereby reducing the throttle devices 122a and 122b.
Solenoid valve 108a caused by refrigerant that accumulates between
, 108b plunger buzzing sound is generated by solenoid valve 1.
08a, 108b can be stopped by a resistance element 119 selected not to push up the plunger. It also has the effect that the resistance element 119 can absorb noise and vibration generated when the refrigerant passes through the electromagnetic valve 116. The same applies to the protection of the solenoid valve 116 and the pole convertible compressor 102.

As mentioned above, in a multi-room air conditioner, operation switching between the two-pole motor C2 and the four-pole motor C4 of the pole converter compressor 102 is performed depending on load changes in each space where the indoor unit is installed. This happens many times when the number of driver's cabs is changed according to the user's will.

Furthermore, in addition to the stoppage when the number of poles is switched, the operation of the pole number converting type compressor 102 becomes unnecessary because the load request of each indoor unit is 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 convertible compressor, there are more opportunities to temporarily stop the pole convertible compressor. Therefore, this embodiment is highly effective as a measure against refrigerant, noise, vibration, and solenoid valve beat in such cases. As is clear from the above embodiments, the refrigeration cycle of the air conditioner according to the present invention enables early restart of the compressor by performing pressure balance using the bypass pipe when the compressor is stopped, and at the same time, when the pressure is equalized, the indoor unit , No noise or vibration is generated from the outdoor unit, no humming noise is generated from the solenoid valve installed in the high-pressure pipeline, and the bypass solenoid valve is closed when the compressor is operating.
The amount of refrigerant flowing to the user heat exchanger does not decrease,
It has great effects such as no reduction in heat exchange capacity.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram of an air conditioner according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing pressure changes on the high pressure side and low pressure side in the refrigeration cycle, and Fig. 3 is an electromagnetic diagram in the refrigeration cycle. A sectional view of the valve 13 and FIG. 4 are a refrigeration cycle diagram of an air conditioner in another embodiment of the present invention.

Claims (1)

[Claims] 1 A refrigerant circulation circuit is constituted by a compressor, a heat source side heat exchanger, a throttle device, and a usage side heat exchanger, and a bypass line is provided to connect a high pressure pipe and a low pressure line in this refrigerant circulation circuit, and the above-mentioned A bypass solenoid valve and a resistance element are provided in the bypass line, and an electromagnetic on-off valve is provided in the high-pressure line between the junction of the high-pressure line and the bypass line and the throttle device, and the compressor A refrigeration cycle for an air conditioner configured to open the bypass solenoid valve and close the solenoid on-off valve when the air conditioner stops.