JPS6250737B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit, and its purpose is to enable quiet heating operation. It is to be one.

In a conventional multi-room air conditioner, when an indoor unit whose compressor is running is in heating operation, when another indoor unit is added to perform heating operation, this additional heating operation is performed. The gas-side solenoid valve and liquid-side solenoid valve that control the flow of refrigerant to the indoor heat exchanger of the indoor unit were opened at the same time.

However, before heating operation was started, the indoor heat exchanger of the indoor unit subjected to additional heating operation had the gas side solenoid valve and liquid side solenoid valve closed, thereby stopping the flow of refrigerant, and the pressure was low. Since the pressure was almost the same as the suction pressure of the compressor, opening the gas-side solenoid valve and the liquid-side solenoid valve at the same time caused high-pressure gas to flow into the low-pressure indoor heat exchanger at high speed. It will flow into
This flowing refrigerant generates a loud impact sound, and the sudden movement of the pilot valve portion of the gas-side solenoid valve generates a clicking sound. These impact noises and lunchbox noises are amplified by the indoor unit, creating a serious problem in that they generate large noises and vibrations from the floor and walls on which the indoor unit is installed. Furthermore, these drawbacks similarly occur even when only the liquid-side solenoid valve is opened in the same state.

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

FIG. 1 is a refrigeration cycle diagram of an embodiment of the multi-chamber air conditioner according to the present invention, in which the outdoor unit 1 includes a compressor 2, a discharge muffler 3, a four-way valve 4, a heat source side heat exchanger 5, and a liquid side main pipe 6. , liquid side branch pipes 7a and 7b formed by branching the liquid side main pipe 6 at the branch point 13, and the liquid side branch pipe 7
The same number of gas side branch pipes 8a and 8b as a and 7b,
A gas side main pipe 9, an accumulator 10, and a liquid side main pipe 6 formed by collecting these gas side branch pipes 8a and 8b.
A heating throttle mechanism 11 provided therein, a check valve 12 provided in parallel with the heating throttle mechanism 11 and on the side that blocks the flow of refrigerant during heating operation, and a heating throttle mechanism for the liquid side main pipe 6. 11, and liquid side branch pipes 7a, 7b
A liquid receiver 14 provided between the branch part 13 of Flowable solenoid valves 21a, 21b are formed by connecting in series check valves 17a, 17b and throttles 18a, 18b with the low pressure circuit 20 side as the flow blocking side during heating operation, and the solenoid valves 15a, 15b and each room Connection ports 16a, 1 of units 30a, 30b
Bypass pipes 19a, 19b connecting the liquid side branch pipes 7a, 7b between 6b and the low pressure circuit 20 during heating operation,
Check valves 22a and 22b on the gas side branch pipes 8a and 8b side, which are on the flow blocking side, and solenoid valves 23a and 23b are connected in series, respectively, and the solenoid valve 2 is connected from the liquid side main pipe 6.
Bypass pipe 24a, which connects the gas side branch pipes 8a, 8b on the indoor units 30a, 30b side of 1a, 21b;
It consists of 24b. Also, indoor units 30a, 30b
are the user-side heat exchangers 31a, 31b, the cooling throttle mechanisms 32a, 32b, and the non-return check installed in parallel with the cooling throttle mechanisms 32a, 32b to prevent the flow of refrigerant during cooling operation. valve 33
It consists of a and 33b. In addition, the indoor unit 30a,
30b and gas side piping 35a, 35b.

FIG. 2 shows an embodiment of the electric circuit of the multi-room air conditioner according to the present invention, in which the coil 15a' of the solenoid valve 15a, the coil 21a' of the solenoid valve 21a, and the solenoid switch coil 2a are connected to the indoor unit 30a. The operation switch 40a and the relay contact 45a are connected in parallel to the power supply 50 through a series-connected circuit, and similarly, the coil 15b' of the solenoid valve 15b, the coil 21b' of the solenoid valve 21b, and the solenoid switch 2b are each connected to an indoor unit. The motor 2' of the compressor 2 is connected in parallel to the power supply 50 through a circuit in which the operation switch 40b and the relay contact 45b of the compressor 30b are connected in series. connected in series with the connected circuit and connected to the power supply 50,
Further, a line in which the relay contact 46a and the coil 23a' of the solenoid valve 23a are connected in series and the solenoid valve 23b
The line in which the coil 23b' of the four-way valve 4 is connected in series, the coil 4' of the four-way valve 4, a microcomputer, etc. are used to turn the operation switches 40a and 40b ON and OFF.
By detecting the relay contacts 45a, 45
A control device 44 for controlling the air conditioners b, 46a, and 46b is connected in parallel to a power source 50 through a heating side contact 48 of a heating/cooling changeover switch 42, respectively. Here, the control device 44 is composed of a microcomputer, etc., and controls each solenoid valve 15a, 15b, 21a, 21b, 23a, 2 of the two indoor units 30a, 30b.
Controls the opening and closing of 3b. Specifically, the solenoid valve 15a of one of the indoor units 30a that was operated first,
21a, a time switch means that opens the solenoid valve 23b of the bypass pipe 24b for a predetermined time when the other indoor unit 30b is added, and a solenoid valve of the bypass pipe 24b after the predetermined time elapses. 23b and opens the solenoid valves 15b and 21b of the additionally operated indoor unit 30b.

Here, the operation of the multi-room air conditioner according to the present invention in the above configuration during heating operation will be explained.

Now, if the operation switch 40a of the indoor unit 30a is turned on while the cooling/heating changeover switch 42 is turned on to the heating side contact 48 side, the control device 44 consisting of a microcomputer etc. will detect that the indoor unit 30a is stopped. The coils 15a', 21 of the solenoid valves 15a, 21a detect that the motor 2' of the compressor 2 issues the first signal to rotate, and keep the relay contact 45a closed.
A' and a voltage is applied to the electromagnetic switch coil 2a to open the passages of the electromagnetic valves 15a and 21a, close the normally open contact 2a' of the electromagnetic switch coil 2a, and rotate the motor 2' of the compressor 2. At this time, as mentioned earlier, the control device 44 detects that the indoor unit 30a has issued the first control signal to rotate the motor 2' of the compressor 2, which had been stopped, so it opens the relay contact 46a. The coil 23a' of the bypass solenoid valve 23a is not energized. Since the coil 4' of the four-way valve 4 is energized in this way, the refrigerant gas discharged from the compressor 2 passes through the four-way valve 4, the gas side main pipe 9, the gas side branch pipe 8a, the solenoid valve 21a,
The gas passes through the gas side pipe 35a to the indoor heat exchanger 31a of the indoor unit 30a, where it liquefies, and then the check valve 33a, the liquid side pipe 34a, the solenoid valve 15a, the liquid side branch pipe 7a, the branch point 13, and the liquid receiver. 14, is depressurized by the heating throttle mechanism 11, passes through the low pressure circuit 20 during heating operation, evaporates in the heat source side heat exchanger 5, passes through the four-way valve 4 again, and returns to the compressor 2 via the accumulator 10. A cycle is formed, and the indoor unit 30a performs heating operation. Also, during heating operation of this indoor unit 30a, other indoor units 30a
Since the contact point of the operation switch 40b is open, heating operation is not performed and the solenoid valves 15b and 21b are closed.
Since the coils 15b', 21b' are not energized, the solenoid valves 15b, 21b close the passages.

Therefore, the refrigeration circuit 34 including the indoor heat exchanger 31b is closed by the solenoid valve 21b and the solenoid valve 15b.
b is in a state where the refrigerant does not flow.

However, in reality, the solenoid valves 21a, 21b, 15
A, 15b, etc. cannot completely stop the flow of refrigerant and there is some leakage, so if the indoor unit 30 is stopped,
The refrigerant gradually stays in the indoor heat exchanger 31b. However, when a large amount of refrigerant accumulates in the indoor heat exchanger 31b, the indoor heat exchanger 31a of the indoor unit 30a during operation
Since the amount of refrigerant flowing through the compressor 2 decreases, there is a problem that the heating capacity decreases and the compressor 2 burns out.

Therefore, the indoor heat exchanger 31 is connected to the bypass pipe 19b whose one end is connected to the low pressure circuit 20 during heating operation.
b The refrigerant that has accumulated inside the tank is removed. Therefore, the refrigerant pressure in the indoor heat exchanger 31b of the indoor unit 30b that is stopped is at the same low pressure state as in the low pressure circuit 20 during heating operation.

Under these circumstances, other indoor units 3
When 0b is additionally operated, the conventional control method opens the solenoid valves 21b and 15b at the same time, which causes high-pressure refrigerant gas to flow at high speed into the low-pressure indoor heat exchanger 31b due to the pressure difference, resulting in loud refrigerant impact noise and Vibrations, intense noise from the electromagnetic valve 21b, etc. were occurring.

Therefore, in the case of the present invention, as shown in the valve timing chart in FIG.
a is already turned on, the operation switch 40b detects that the motor 2' of the compressor 2 is turned on while the motor 2' of the compressor 2 is in operation, opens the relay contact 45b, closes the relay contact 46b, and closes the electromagnetic bypass valve 2.
When voltage is applied to the coil 23b' of 3b, the refrigeration circuit 6 in which high-pressure liquid is flowing and the refrigeration circuit 35b, which has been stopped and has been at low pressure, are connected to the bypass pipe 2.
As the liquid refrigerant enters the refrigeration circuit 35b, the pressure in the refrigeration circuit 35b gradually increases.
Liquid refrigerant accumulates in the gas side pipe 34b. Here, since the refrigerant flowing into the refrigeration circuit 35b through the bypass pipe 24b is liquid, the inflow speed is slow;
No impact noise etc. will be generated. In this way, the refrigeration circuit 35b
When the internal pressure rises to a certain extent and there is no significant pressure difference between the refrigerant pressure flowing into the indoor heat exchanger 31b when the solenoid valve 21b is opened, the control device 44 opens the relay contact 46b, and the relay contact 45b Solenoid valves 21 in the refrigeration circuits 35b and 34b supply refrigerant to the indoor unit 30b when closed.
The coils 21b' and 15b' of the coils 21b and 15b are energized, and the passages of the solenoid valves 21b and 15b are opened. At this time, the refrigerant flowing through the solenoid valve 21b enters the refrigeration circuit 34b with a small pressure difference and enters the gas side piping 35.
Since there is a large amount of refrigerant in b, much of the energy due to the pressure difference is changed into kinetic energy, so no impactor or vibration occurs. Also, the solenoid valve 21b does not undergo sudden valve punching, so the valve will not be damaged. Further, when the bypass solenoid valves 23a, 23b are opened, the solenoid valves 15a, 15b may be opened in order to promote pressure rise in the refrigeration circuits 34a, 34b, which have been stopped up to now.

Furthermore, in the electric circuit shown in FIG. 2, it is conceivable to provide a temperature controller in series with the operation switches 40a, 40b in order to adjust the room temperature. However, even in that case, the same effects can be obtained by performing the same control in conjunction with turning on the operation switch on the side where operation is to be started or restarted later and turning on the temperature controller. Needless to say.

Furthermore, the opening time of the bypass solenoid valves 23a, 23b may be calculated and determined each time by a microcomputer, taking various conditions into account. That is, the various conditions include various factors such as the number of units in the driver's room, thermostat temperature, thermostat OFF time, and the like. Alternatively, the bypass solenoid valve may be controlled by a pressure switch or the like.

As mentioned above, the multi-chamber air conditioner according to the present invention has the following features:
When the compressor is running and at least one indoor unit is in heating operation, and other indoor units are to be put into additional heating operation or returned to operation by a thermostat, etc., between the gas side solenoid valve and the indoor unit from the liquid side pipe. By bypassing the high-pressure refrigerant to the gas side branch pipe of the indoor unit and increasing the pressure inside the indoor heat exchanger of the indoor unit that was inactive, the gas side solenoid valve and liquid side solenoid valve are opened. Completely quiet heating operation is possible with no refrigerant impact noise or vibration emitted from the unit, and the life of the gas side solenoid valve can be significantly extended without causing severe valve hitting of the gas side solenoid valve. Furthermore, the refrigerant that has passed through the indoor units that are already in operation flows into the additionally operated indoor units for a predetermined period of time before forming the predetermined refrigeration cycle, so the amount of refrigerant flowing through the indoor units that are already in operation decreases. As a result, the capacity of the indoor unit does not drop suddenly, and reasonable countermeasures against refrigerant impact noise and vibration can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram of an embodiment of the multi-chamber air conditioner according to the present invention, Fig. 2 is an electric circuit diagram of an embodiment of the multi-chamber air conditioner according to the present invention, and Fig. 3 is a solenoid valve. This is an operation timing chart. 1... Outdoor unit, 15a, 15b... Solenoid valve, 21a, 21b... Solenoid valve, 24a, 24b
... Solenoid valve, 30a, 30b ... Indoor unit,
44...control device, 40a, 40b, 45a, 4
5b, 46a, 46b...Relay.

Claims (1)

[Claims] 1. In a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit by connection piping, liquid side branch pipes formed by branching to the number of indoor units are connected to the liquid side main pipe of the outdoor unit. death,
A liquid-side solenoid valve is provided in each of these liquid-side branch pipes, and gas-side branch pipes branched as many times as the number of indoor units are connected to the gas-side main pipe, and a gas-side solenoid valve is provided in each gas-side branch pipe. , a pressure reducing device is provided between the liquid side main pipe and the outdoor heat exchanger of the outdoor unit, and a pipe connecting the liquid side solenoid valve and the pressure reducing device is connected to the gas side solenoid valve and each indoor unit. A bypass pipe is provided which communicates with the branch pipe between the heat exchanger of each indoor unit, a bypass solenoid valve is provided in each of the bypass pipes, and a bypass solenoid valve is provided between each of the liquid side solenoid valves and each of the indoor heat exchangers of each of the indoor units. A liquid drain pipe is connected from the liquid side branch pipe in between to each pipe line which becomes low pressure during heating operation, and a control device is provided to control the opening and closing of the liquid side solenoid valve, the gas side solenoid valve, and the bypass solenoid valve. The control device includes a time switch means for opening the bypass solenoid valve on the side to be additionally operated for a predetermined time when the other indoor unit is operated in addition to the one indoor unit being operated;
A multi-room air conditioner comprising a switch means for opening a liquid-side solenoid valve and a gas-side solenoid valve to be additionally operated after the predetermined period of time has elapsed.