JPS6152913B2 - - 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, the indoor heat exchanger of the indoor unit that was subjected to this additional heating operation stopped the flow of refrigerant by closing the gas side solenoid valve and the liquid side solenoid valve before the heating operation was started. Since it was connected to a connected circuit, the pressure was at a low level, almost the same as the suction pressure of the compressor. For this reason,
If the gas-side solenoid valve and the liquid-side solenoid valve are opened at the same time, high-pressure gas will flow into the low-pressure indoor heat exchanger at high speed, and this flowing refrigerant may generate a loud impact noise or damage the pilot valve section of the gas-side solenoid valve. By moving the lunch box rapidly, a clicking sound can be generated. 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. Further, these drawbacks similarly occur even when only the liquid measuring solenoid valve is opened in the same state.

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 is a refrigeration cycle diagram of an embodiment of a multi-room air conditioner according to the present invention, in which an 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, 7b, 7c created by branching the liquid side main pipe 6 at the branch point 13, gas side branch pipes 8a, 8b, 8c, which have the same number as the liquid side branch pipes 7a, 7b, 7c, and these gas side Branch pipe 8a,
A heating throttle mechanism 11 provided in the gas side main pipe 9, the accumulator 10, and the liquid side main pipe 6, which are made by collecting 8b and 8c, is parallel to the heating throttle mechanism 11 and prevents the flow of refrigerant during heating operation. A check valve 12 provided so as to be on the side, a liquid receiver 14 provided between the heating throttle mechanism 11 of the liquid side main pipe 6 and the branch part 13 of the liquid side branch pipes 7a, 7b, 7c, and each liquid side branch pipe. 7a, 7
Bidirectional aperture mechanisms 22a, 22 in b, 7c
bidirectional flow solenoid valves 15a, 15b, 15c provided in series with b, 22c, each solenoid valve 15a, 15
Bypass pipes 23, 24 connecting each liquid side branch pipe 7a, 7b between b, 15c and connection ports 16a, 16b, 16c and between 7b, 7c, bidirectional pipes provided in these bypass pipes 23, 24 Flowable bypass solenoid valves 25, 26, check valves 17a, 17b, 17c and throttles 18a, 18b provided in a direction that allows refrigerant to flow toward the low pressure circuit 20 during heating operation.
The solenoid valves 15a, 15b, 15c and each indoor unit 30 are connected in series with each other.
Connection ports 16a, 16b with a, 30b, 30c,
Bypass pipe 19a, which connects the liquid side branch pipes 7a, 7b, 7c between 16c and the low pressure circuit 20 during heating operation.
19b, 19c, bidirectional flow solenoid valves 21a provided in the gas side branch pipes 8a, 8b, 8c, respectively.
It consists of 21b and 21c. In addition, outdoor unit 1
is equipped with an air blower that blows air to the heat source side heat exchanger 5. In addition, the indoor units 30a, 30b, 30c
are the user side heat exchangers 31a, 31b, 31, respectively.
c and each user side heat exchanger 31a, 31b, 31c
It consists of an indoor blower that blows the heat-exchanged air into the room.

FIG. 2 shows an embodiment of the electric circuit of the multi-room air conditioner according to the present invention, in which the coil SV _La of the solenoid valve 15a is shown.
and the coil SV _Ga of the solenoid valve 21a and the relay contact 46
The circuit in which A is connected in series with the electromagnetic switch MR _a is,
Each operation switch 40 of the indoor unit 30a
Similarly, the coil SV _Lb of the solenoid valve 15b and the coil of the solenoid valve 21b are connected in parallel to the power supply 45 via a.
The circuit in which SV _Gb and relay contact 46b are connected in series and the electromagnetic switch MR _b are connected to the indoor unit 30, respectively.
b is connected in parallel to the power supply 45 via the operation switch 40b, and similarly the coil of the solenoid valve 15c.
The circuit in which the SV _Lc , the coil SV _Gc of the solenoid valve 21c, and the relou contact 46c are connected in series, and the solenoid switch MR _c are respectively connected to the operation switch 4 of the indoor unit 30c.
It is connected in parallel to the power supply 45 via 0c.
In addition, the motor MC of the compressor 2 has an electromagnetic switch MR _a ,
The normally open contacts MR _as , MR _bs , and MR _cs of MR _b and MR c are connected in series to the power supply 45, and the bypass solenoid valve 25 is _further connected in parallel.
A circuit consisting of a relay 43 connected in series with the 26 coils V _{a to b} and V _{b to c} and a coil 41 of the four-way valve 4 is connected to a power source 45 via a heating side contact 48 of a cooling/heating changeover switch 42. , and an operation switch 40a, which is made up of a microcomputer, etc.
A control device 44 that controls the relay contacts 43, 46a, 46b, 46c by detecting ON, OFF, etc. of 40b, 40c is connected to a power source 45. Here, in the control device 44, the operation switches 40a, 40b, 40c are the switch means and the first
The relay contact 43 corresponds to a second opening means for controlling the opening and closing of the bypass solenoid valves 25 and 26, and the relay contacts 46a, 46b, and 46c control the opening and closing of the solenoid valves 21a, 21b, and 21c. This corresponds to the third opening means. Further, the control device 44
has a timer function, and is equipped with a delay means for activating the third opening means with a delay after the first and second opening means are activated.

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 with the cooling/heating changeover switch 42 turned 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. By detecting that the first signal for rotating the motor MC of the compressor 2 has been issued, the relay contact 46a is closed by the action of the coil SV _La of the solenoid valve 21a, the solenoid switch MR _a , and the control device 44. A voltage is applied to the coil SV _Ga of the solenoid valve 15a through the solenoid valve 1.
5a and 21a at the same time, the normally open contact MR _as of the electromagnetic switch MR _a is closed, and the motor MC of the compressor 2 is rotated. 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 MC of the compressor 2, which had been stopped, so the relay contact 4
The normally open contacts of No. 3 are kept open, and the coils V _{a - b} of the bypass solenoid valves 25 and 26 are
V _{b - c} are not energized. Since the coil 41 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, and the solenoid valve 21a, and enters the indoor unit 30a. The heat is radiated and liquefied to the inner heat exchanger 31a, and further to the connection port 16a and the solenoid valve 15.
a, liquid side branch pipe 7a, throttle device 22a, branch point 1
3. Passes through 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 is compressed via the accumulator 10. A refrigeration cycle is formed in which the air returns to the air conditioner 2, and the indoor unit 30a performs heating operation. Note that in this case, it goes without saying that the outdoor blower and the indoor blower in the indoor unit 30a are operating. Also, this indoor unit 30
During heating operation of unit a, other indoor units 30b, 3
0c, the contacts of the operation switches 40b and 40c are open, so heating operation is not performed, and the solenoid valve 15 is closed.
Coils SV _Lb of b, 21b, 15c, 21c,
Since SV _Gb , SV _Lc , and SV _Gc are not energized, the solenoid valves 15b, 21b, 15c, and 21c close their passages. Therefore, the refrigeration circuit 32b including the indoor heat exchanger 31b is closed by the solenoid valve 21b and the solenoid valve 15b, and the indoor heat exchanger 31c is closed by the solenoid valve 21c and the solenoid valve 15c.
The refrigerating circuit 32c including the refrigerant is in a state where no refrigerant flows. However, in reality, the solenoid valves 21a, 21b, 21
c, 15a, 15b, 15c, etc. cannot completely stop the flow of refrigerant and there is some leakage, so refrigerant gradually accumulates in the indoor heat exchangers 31b, 31c of the indoor units 30b, 30c that are stopped. It's going to get complicated. However, the indoor heat exchanger 31b, 3
If a large amount of refrigerant accumulates in the compressor 1c, the amount of refrigerant flowing through the indoor heat exchanger 31a of the indoor unit 30a during operation will decrease, resulting in a decrease in the heating capacity and damage to the compressor 2. A problem arises.

Therefore, the refrigerant accumulated in the indoor heat exchangers 31c, 31b is extracted by bypass pipes 19b, 19c, one end of which is connected to the low pressure circuit 20 during heating operation. Therefore, the indoor heat exchangers 31b, 31c of the indoor units 30b, 30c that are stopped
The pressure of the refrigerant inside 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, when the operation switch 40b of the indoor unit 30b is turned on, as shown in the valve operation timing chart in FIG. The operation switch 40b detects that the motor MC of the compressor 2 is turned on while it is in operation, keeps the relay contact 46b open, closes the normally open relay contact 43, and closes the bypass solenoid valves 25 and 26. When a voltage is applied to the coils V _{a to b} and V _{b to c} , the refrigerant circuit 32 a in which voltage liquid is flowing and the refrigeration circuits 32 b and 32 c, which have been stopped and have a low pressure until now, are communicated through bypass pipes 23 and 24. As the liquid refrigerant enters, the pressure in the refrigeration circuits 32b and 32c gradually increases. Here, since the refrigerant flowing into the refrigeration circuit 32b through the bypass pipe 24 is in liquid form, the inflow speed is slow and no impact noise is generated. Also, at the same time as the coils SV _{a to b} and SV _{b to c} of the solenoid valves 25 and 26 are energized, the indoor unit 3 that is additionally operated is
Since the coil SV _Lb of the liquid-side electromagnetic valve 15b for 0b is also energized, the high-pressure liquid refrigerant in the liquid-side main pipe 6 also flows into the indoor heat exchanger 31b through the refrigeration circuit 32b. Therefore, the indoor heat exchanger 31
It is possible to quickly increase the pressure inside b. Therefore, the pressure inside the indoor heat exchanger 31b can be rapidly increased without generating impact noise.

In this way, the pressure in the refrigerant circuits 32b, 32c increases to a certain extent, and at a point when it is thought that there will be no significant pressure difference between the pressure of the refrigerant flowing into the indoor heat exchanger 31b when the solenoid valve 21b is opened, the control device 44 closes the relay contact 43. When the contact of the relay 46b is opened and the normally closed contact of the relay 46b is closed, the coil of the solenoid valve 21b in the refrigeration circuit 32b supplies refrigerant to the indoor unit 30b.
Since SV _Gb is energized and the passage of the solenoid valve 21b is opened, the refrigerant flowing through the solenoid valve 21b enters the refrigeration circuit 32b with a small pressure difference, so that no impact noise or vibration is generated. Also, the solenoid valve 21b does not suddenly hit the valve, so the valve will not be damaged. Bypass solenoid valves 25 and 26 provided in this refrigeration circuit are used to operate the refrigeration circuit from the refrigeration circuit 32a side in the bypass pipe 24, for example, since it is not known which indoor unit is being operated and which indoor unit will be additionally operated. Since it may flow from the refrigeration circuit 32b side to the refrigeration circuit 32a side, or from the refrigeration circuit 32b side to the refrigeration circuit 32a side, the solenoid valve must be bidirectional. Further, in this embodiment, only two bypass pipes 23 and 24 are provided, but if necessary, a third bypass pipe connecting the refrigeration circuits 32a and 32c is provided, and a bidirectional solenoid valve is installed in this bypass pipe. may also be provided.

Moreover, the position of the bypass pipe is also the same as that of the solenoid valves 15a, 15b,
Liquid side branch pipes 7a, 7b, 7c between 15c and connection ports 16a, 16b, 16c are connected,
When the flow resistance of the solenoid valves 15a, 15b, 15c and the bypass solenoid valves 25, 26 is small, the throttle devices 22a, 22b, 22c and the solenoid valves 15a, 15
Liquid side branch pipes 7a, 7b, 7c between connecting b, 15c
It goes without saying that even if they are tied together, the same effect can be expected.

Furthermore, in this embodiment, when operating the indoor unit 30c while the indoor unit 30a is operating, it is necessary to open both the bypass solenoid valves 25 and 26;
When operating 0b, the electric circuit may be configured such that only the bypass solenoid valve 25 is opened. Furthermore, in the electric circuit shown in FIG.
A temperature controller is installed in series with 0a, 40b, and 40c, and when other indoor units are in operation and compression operation is in progress,
It goes without saying that if similar control is performed when the operating switch is turned on and the temperature regulator is reset, the same effect can be obtained. Further, the opening time of the bypass solenoid valves 25 and 26 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, when other indoor units are to be brought into additional heating operation or returned to operation by a thermostat, etc., bypass the liquid side branch pipes on the indoor unit side from the throttle device. In addition, the liquid side solenoid valve in the additional heating operation room is opened to increase the pressure in the indoor heat exchanger of the indoor unit that has been inactive, and then the gas side solenoid valve is opened. It has great effects such as quiet heating operation without refrigerant impact noise or vibration, and the ability to prolong the life of the gas side solenoid valve without causing severe gas side solenoid valve punching.

[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, and Fig. 3 is the operation of the solenoid valve. It is a timing chart diagram. 1... Outdoor unit, 7a, 7b, 7c... Liquid side branch pipe, 15a, 15b, 15c... Solenoid valve, 1
9a, 19b, 19c...Bypass pipe (liquid drain pipe), 21a, 21b, 21c...Solenoid valve, 22
a, 22b, 22c... diaphragm device, 23, 24...
...Bypass pipe, 25, 26...Bypass solenoid valve,
30a, 30b, 30c...indoor unit, 44
...control device, 43, 46a, 46b, 46c...
...Relay contact, MC...Compressor motor, SV _La ,
SV _Lb , SV _Lc ... Solenoid valves 15a, 15b, 15c
coils, SV _Ga , SV _Gb , SV _Gc ...Solenoid valve 21
Coils a, 21b, 21c, V _{a - b} ... Coils of the solenoid valve 25, V _{b - c} ... Coils of the solenoid valve 26.

Claims (1)

[Claims] 1. A plurality of indoor units pipe-connected to one outdoor unit, a throttling device installed in series in the liquid side branch pipes created by branching the liquid side main pipe of the outdoor unit to the number of indoor units, and a liquid-side solenoid valve, a bypass pipe that communicates each of the liquid-side branch pipes between each of the throttle devices and the indoor heat exchanger of each of the indoor units, and a bypass solenoid valve that connects and disconnects the bypass pipes. , a gas side solenoid valve installed in a gas side branch pipe created by branching the gas side main pipe of the outdoor unit to the number of indoor units, and a pipe line that becomes low pressure during heating operation with each of the liquid side branch pipes. and a switch means for returning or additionally heating the other indoor unit when one of the indoor units is in the heating operation, and a switch means that connects the other indoor unit to the other indoor unit when the switch means is turned on. a first opening means for opening a liquid-side solenoid valve corresponding to the unit; and the bypass pipe that communicates the liquid-side branch pipe corresponding to the indoor unit in heating operation with the liquid-side branch pipe corresponding to the other indoor unit. a second opening means for opening the bypass solenoid valve provided in the second indoor unit; a third opening means for opening the gas side solenoid valve in the gas side branch pipe corresponding to the other indoor unit; A multi-room air conditioner comprising a delay device that operates the third opening means after a predetermined period of time has elapsed after the second opening means is activated.