JPS5914703B2 - Refrigeration circuit of multi-room air conditioner - 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. This is one of the purposes.

In a conventional multi-room air conditioner, when the indoor unit is in heating operation with the compressor running,
When adding another indoor unit for heating operation, the gas-side solenoid valve and source-side solenoid valve that control the flow of refrigerant to the indoor heat exchanger of the indoor unit that is being operated for additional heating are opened at the same time. .

However, in the indoor heat exchanger of the indoor unit that was subjected to this additional heating operation, the gas side solenoid valve and the source side solenoid valve were closed before the heating operation was started, and the flow of refrigerant was stopped. Since it was connected to a low-pressure circuit, the pressure was almost the same as the suction pressure of the compressor.

For this reason, if the gas side solenoid valve and the source side solenoid valve are opened simultaneously, high pressure gas will flow into the low pressure indoor heat exchanger at high speed, and this flowing refrigerant will generate a loud impact sound on the gas side. By violently moving the pilot valve part of the solenoid valve, the sound of the lunch box clinking was generated.

These impact noises and lunch box 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 source-side 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 source side main pipe. 6,
Source side main pipe created by branching source side main pipe 6 at branch point 13? a
, 7b, 7c1 There are the same number of gas side branch pipes 8a, 7b, and 7c as the liquid branch pipes 7a, 7b, and 7c.

The gas side main pipe 9 made by collecting 8b and 8c, the accumulator 10, the heating coarse throttle 9 isostructure 11 provided in the source side main pipe 6, and the refrigerant in parallel with the heating rough throttle 9 isostructure 11 and during heating operation. Check valve 12 provided to block the flow of water, heating throttle mechanism 11 of source side main pipe 6 and source side branch pipes 7a, 7by7c
A liquid receiver 14 provided between the branch part 13 and each source side branch pipe 7
Bidirectional throttling mechanism 22a, 22 during at7bt7c
b.

A two-way solenoid valve 15a is provided in series with 22c.

15b, 15c, each solenoid valve 15a, 15b, 15
Each source side branch pipe 7a between c and the heating rough throttle 9 isostructure 11.

7b, 7c or source side main pipe 6 and each indoor unit 30
Utilization side heat exchanger 31a of a y 30 b, 30 c
.

31b, 31c and each gas side solenoid valve 21a-21b.

Bypass pipes 23 a * 23 b, 23 c- connect gas side branch pipes 8 a, 8 b, and 8 c between gas side branch pipes 21 c, respectively.
The bypass pipes 23a, 23by23c are provided in the bypass pipes 23a and 23by23c so that the valve can be closed even if there is a pressure difference between the front and rear in the two-flow direction when the current is not energized, and the flow is allowed in the two-flow direction when the power is energized. Direct-acting bypass solenoid valve 25a with bidirectional flow.

25b, 25c, a check valve 17a provided in a direction that allows refrigerant to flow toward the low-pressure circuit 20 during heating operation;

The electromagnetic valve 15a is formed by connecting the throttles 17b, 17c and the throttles 18a, 18b, 18c in series, respectively.

15b, 15c and each indoor unit 30a, 30b.

Bypass pipes 19a, I9b, 19c connect the source side branch pipes 7 a t 7 b t 7 c between the connection ports 16 a, 16 b, 16 c with the 30 c and the low pressure circuit 20 during heating operation.

These are bidirectional solenoid valves 21a, 21b, and 21c provided in the gas side branch pipes 8a, 8b, and 8c, respectively.

Note that the outdoor unit 1 includes an air blower that blows air to the heat source side heat exchanger 5.

In addition, the indoor units 30a, 30b, and 30c each include user-side heat exchangers 31a, 31b, and 31c, and an indoor blower that sends the air heat-exchanged by each user-side heat exchanger 31a=31bt31c into the room. .

Next, the direct acting solenoid valve 25 will be explained with reference to FIG.

In FIG. 2, a bidirectional direct-acting electromagnetic valve 25 is pulled up by an inlet pipe a1, an outlet pipe, a valve body 50 whose position is fixed, and an electromagnetic coil 51, and is pulled up by a tip end 52. The plunger valve 54 has a valve hole 53, and a cylindrical body 56 houses a spring 55 for pushing down the plunger valve 54.

Here, the operation of the bidirectional solenoid valve 25 will be explained.

Assuming that the electromagnetic coil 51 is in a non-energized state and the pressure Pa inside the inlet pipe a is higher than the pressure Pb inside the outlet pipe, the thinner tip 52 of the plunger valve 54 is on the side of the inlet pipe a. As a result, the tip 52 of the plunger valve 54 is pushed in the direction of Pd by the force toward the outlet pipe.
The left side of the valve body 50 is firmly pressed down and the inlet pipe a
There is no leakage from the outlet pipe to the plunger valve 5.
4 and the right side of the valve body 50, the pressure Pc in the space between the cylindrical body 56, the plunger valve 54, and the valve body 50 becomes the same as the pressure Pa in the inlet pipe a section.

Therefore, in the non-energized state, the inlet pipe a and the outlet pipe A do not communicate with each other, and when the electromagnetic coil 51 is energized from this state, the pulling force F1 of the plunger valve 54 of the electromagnetic coil 51 is
As, the force Fs of the spring 55 and the plunger valve 5
4 and the force Ff that moves the tip 52 of the plunger valve 54 pressed against the valve body 50 in the direction perpendicular to the force acting in the direction between the inlet pipe a and the outlet pipe a. Fortunately, the plunger valve 53 can be immediately pulled up with a small force generated by the electromagnetic coil 51.

This is exactly the same even when the pressure Pb inside the outlet pipe is larger than the pressure Pa inside the inlet pipe a, Pb>Pa, and the pressures Pa and Pb inside the inlet pipe a and the outlet pipe a are larger than the pressure Pa inside the inlet pipe a.
Even if there is a large difference in , that is, Pa≧Pb, Pa
<: This means that the valve can be opened and closed even at P b.

Also, here, the inlet pipe a1 is the outlet pipe.
Although a distinction is made between the inlet pipe and the outlet pipe, either one may be the inlet pipe or the outlet pipe.

FIG. 3 shows an embodiment of the electric circuit of the multi-room air conditioner according to the present invention, showing the coil 5VLa of the solenoid valve 15a and the solenoid valve 21.
The circuit in which the coil 5VGa of a and the relay contact 46a are connected in series and the electromagnetic switch MRa are both indoor units)
The circuit connected in parallel to the power supply 45 via the operation switch 40a of 30a, and similarly connected in series with the coil 5VLb of the solenoid valve 15b, the coil 5VGb of the solenoid valve 21b, and the relay contact 46b, and the solenoid switch MRb are each an indoor unit. The coil SV of the solenoid valve 15c is connected in parallel to the power supply 45 via the operation switch 40b of the solenoid valve 30b.
I, c, coil 5VGC of solenoid valve 21c and relay contact 4
6c connected in series and the electromagnetic switch MRc are each connected in parallel to the power source 45 via the operation switch 40c of the indoor unit 30c.

In addition, the motor MC of the compressor 2 is an electromagnetic switch MRa y M.
Rb 1MRc normally open contacts MRas, MRbs.

The power supply 45 is connected in series with the circuit in which MRcs are connected in parallel.
A bypass solenoid valve 25 connected to the tl further connected in parallel.
Coils Va, vb of a, 25b, 25c.

Relays 43a each connected in series with Vc.

43 b s 43 c and the coil 41 of the four-way valve 4 are connected in parallel to a power source 45 via the heating side contact 48 of the cooling/heating changeover switch 42, and further connected to a power supply 45 such as a microcomputer or the like.
By detecting ON, OFF, etc. of 40 b y 40 c, the relay contacts it 3 , 46 a, 46 b.

The control devices 44 that control the 46c are each connected to a power source 45.

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, with the cooling/heating selector switch 42 set to the heating side contact 48 side, the operation switch 40 of the indoor unit 30a
If compressor a is turned on, the control device 44 consisting of a microcomputer etc. detects that the indoor unit 30a has issued the first signal to rotate the motor MC of the compressor 2, which has been stopped. Selective solenoid valve 21a
coil 5vLa, electromagnetic switch MRa and control device 44
A voltage is applied to the coil 5VGa of the solenoid valve 15a through the relay contact 46a, which is closed due to the action of the solenoid valve 15.
a and 21a are simultaneously opened to open the normally open contact M of the electromagnetic switch MRa.
Close Ras and rotate the motor MC of the compressor 2.

At this time, as mentioned earlier, the control device 44 is an indoor unit)
Since it is detected that the motor 30a has issued the first control signal to rotate the motor MC of the compressor 2 which had been stopped, the normally open contacts of the relay contacts 43a, 43b, and 43c are kept open. Coil Va of double-flow directional bypass solenoid valves 25a, 25b, 25c
Since the coil 41 of the four-way valve 4 is energized, the refrigerant gas discharged from the compressor 2 flows through the four-way valve 4 through the energized gas side main pipe 9 and gas side branch pipe 8.
The heat is radiated and liquefied through the as solenoid valve 21a to the indoor heat exchanger 31a of the indoor unit 30a, and then the connection
6a1 Solenoid valve 15a1 Liquid side branch pipe 7a1 Throttle device 22a1
It passes through the branch point 13 and 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 6, passes through the four-way valve 4 again, and passes through the accumulator 10. A refrigeration cycle is formed in which the air returns to the compressor 2, and the indoor unit 30a performs heating operation.

Incidentally, in this case, it goes without saying that the outdoor blower and the indoor blower in the indoor unit 30a are operating.

Also, when this indoor unit 30a is in heating operation, the other indoor units) 30b and 30c are operated by the operation switch 40 b s
Since the contact point of 40c is open, heating operation is not performed, and solenoid valve 15b.

2 l b m 15 c s 21 c coil S
V I, b t S V G b tS V L C
tS VG o is not energized, so solenoid valve 15
a, 21b, 15c, and 21c close the passages.

Therefore, the refrigerant flows through the refrigeration circuit 32b that is closed by the solenoid valves 21b and 15b and includes the indoor heat exchanger 31b, and the refrigeration circuit 32c that is closed by the solenoid valves 21c and 15c and includes the indoor heat exchanger 31c. There is no state.

However, in reality, the solenoid valves 21a, 21b, and 2jc.

15a, 15b, 15c, etc. cannot completely stop the flow of refrigerant and there is some leakage, so please use indoor units (indoor units that are stopped) 30
b, indoor heat exchanger 31b of 30c.

The refrigerant will gradually accumulate in 31c.

However, when a large amount of refrigerant accumulates in the indoor heat exchangers 31b and 31c, the amount of refrigerant flowing through the indoor heat exchanger 31a of the operating indoor unit 30a decreases, resulting in a decrease in heating capacity. A problem arises in which the compressor 2 is imitated with horizontal lines.

Therefore, the indoor heat exchangers 31c, 3 are connected to the bypass pipes 19b, 19c, one end of which is connected to the low pressure circuit 20 during heating operation.
The refrigerant accumulated in 1b is extracted.

Therefore, the indoor heat exchangers 31b of the indoor units 30b and 30c are stopped.

The refrigerant pressure in 31c is in the same low pressure state as in the low pressure circuit 20 during heating operation.

Under these circumstances, when additionally operating another indoor unit 30b, the conventional control method
5b was open at the same time, so the indoor heat exchanger 3 was at low pressure.
Due to the pressure difference, high-pressure refrigerant gas flows into the refrigerant 1b at high speed, causing large refrigerant impact noises, vibrations, and intense solenoid valve 21b punching noises.

Therefore, in the case of the present invention, the operation switch 40b of the selective indoor unit 30b shown in the valve operation timing chart of FIG.
When the motor MC of the compressor 2 is turned on, the control device 44 consisting of a microcomputer etc. switches the operation switch 40b to the motor MC of the compressor 2 since the operation switch 40a has already been turned on.
It is detected that the relay is turned on during operation, and the relay contact 46b
When the contact of the relay contact 43b is left open and the normally open contact of the relay contact 43b is closed to apply voltage to the coil vb of the bypass solenoid valve 25b, the source side branch pipe 22a and the source side main pipe 6, through which high-pressure liquid is flowing, are stopped. The refrigeration circuit 32b, which had a low pressure due to the refrigeration, is communicated with the bypass pipe 23b, and the pressure of the refrigeration circuit 32b gradually increases as the liquid refrigerant enters.

Here, since the refrigerant flowing into the refrigeration circuit 32b through the bypass pipe 23b is in liquid form, the inflow speed is slow and no impact noise or the like is generated.

Also, at the same time as the coil vb of the solenoid valve 25b is energized, the liquid solenoid valve 15b for the indoor unit 30b which is additionally operated.
Since the coil 5VLb of
1b, so the indoor heat exchanger 31b
Therefore, the pressure inside the indoor heat exchanger 31b can be rapidly increased without generating impact noise.

In this way, the pressure inside the refrigeration circuits 32b and 32c increases to a certain extent, and when the solenoid valve 21b is opened, the indoor heat exchanger 31
When the pressure difference between the refrigerant pressure flowing into the refrigerant pipe 8b and the pressure inside the gas side branch pipe 8b is thought to have become small, the control device 44 opens the relay contact 43b and closes the normally closed contact of the relay 46b, thereby shutting down the indoor unit. ) 30b through the coil 5VGb of the solenoid valve 21b in the refrigeration circuit 32b that supplies refrigerant to the refrigeration circuit 32b.
Since the passage of the exposed solenoid valve 21b is opened, the solenoid valve 21
The refrigerant flowing through b flows into the refrigeration circuit 32 with a small pressure difference.
Since it is inside b, no impact noise or vibration is generated.

Also, since the solenoid valve 21b is not violently bent, the valve will not be damaged.

Also, a direct acting solenoid valve 25a as shown in FIG.

The valve portions 25b and 25c are closed when not energized.

Therefore, even if the pressure on the gas side branch pipes 8a, 8b, 8c side is higher than the pressure on the liquid side main pipe 6 side, the flow of refrigerant can be prevented.

Therefore, the refrigerant may flow through the direct acting electromagnetic valves 25a, 25b, 25c and the capacity of the indoor unit during operation may be reduced.In addition, in this embodiment, the bypass pipes 23a, 23b.

A dual-flow directional solenoid valve 25a for bypass in 23c.
, 25b, 25c, . However, in order to reduce the cost, only one solenoid valve 25 is provided, and the bypass sound 23 is reduced.
a * 23 b - 23 c may be attached to a common part where they are combined into one.

Furthermore, in the electric circuit of FIG. 3, the operation switch 40a
, 40b, 40c, and if the same control is performed when the operation switch is turned on and the temperature controller is restarted while other indoor units are operating and compression operation is in progress, exactly the same effect can be obtained. It goes without saying that this can be obtained.

Furthermore, there is a bi-directional bypass solenoid valve 25a.

The opening times of 25b and 25c may be calculated and determined each time by a microcomputer, taking various conditions into consideration.

That is, the various conditions include various factors such as the number of units in the operating room, thermostat temperature, and thermostat OFF time.

Alternatively, the bidirectional flow bypass solenoid valve may be controlled by a pressure switch or the like.

In addition, the wood ash flow type variable resistance valve has a coil Va g vbt
If Vc is not energized, the valve can be closed even if the pressure difference between before and after is red in both directions, and flow is allowed in both directions when energized, so this is used during heating or cooling operation. It can also be used as a bypass for the indoor heat exchanger for overload, low temperature, capacity control, etc., as a bypass when the cooling cycle is activated during de-ice, and for promoting pressure balance when the compressor is stopped. , Noise countermeasures during heating operation are not in vain, and many controls can be performed at the same time.

As described above, in the multi-room air conditioner according to the present invention, when the compressor is running and at least one indoor unit is heating, when the other indoor units are put into additional heating operation or restarted by the thermostat, etc. A dual-flow directional direct-acting type direct-acting type that can be opened and closed at high pressure differences in the bypass pipe connecting the pipe between the gas-side solenoid valve and the gas-side solenoid valve and the pipe between the gas-side solenoid valve and the indoor unit. Open the dynamic solenoid valve and open the liquid side solenoid valve in the additional heating operation room to increase the pressure in the indoor heat exchanger of the indoor unit that was inactive, then open the gas side solenoid valve. This allows for quiet heating operation without refrigerant impact noise or vibration from the indoor unit, and also eliminates the occurrence of severe gas-side solenoid valve sagging, extending the life of the gas-side solenoid valve. It has great effects and can be used for control on various refrigeration circuits.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram of an embodiment of a multi-room air conditioner according to the present invention, Fig. 2 is a cross-sectional view of a direct-acting solenoid valve with dual flow directionality that constitutes the circuit, and Fig. 3 is the same. FIG. 4 is an electrical circuit diagram of an embodiment of a multi-room air conditioner, and FIG. 4 is an operation timing chart of a solenoid valve. 1...Outdoor unit), 7 a p 7 b
t 7 c...Liquid branch pipe, 15a, 1 s
b, 15c = solenoid valve, 19a, 19b, 19c...
...Bypass pipe (liquid drain pipe), 21a*21bt2
1c"" Solenoid valve, 22a. 22 b, 22 c=throttle device, 23a, 23b. 23 c = bypass pipe, 25a, 25b, 25c...
...Double-flow directional bypass solenoid valve, 30a. 30 b * 30 c...Indoor unit, 4
4...Control device, 43, 46a, 46b, 46
c = relay contact, MC...compressor motor, S
V(, a, 5Vjb. SVL c "" Coil of solenoid valves 15a, 15b, 15c, 5VGa, 5vQbtSVGC"" Coil of solenoid valve 21a. 21 b, 21 C, Va, Vb,
Vc ”--Coil of solenoid valves 25a, 25b, 25c.

Claims (1)

[Claims] In a multi-room air conditioner in which multiple indoor units are connected to 11 outdoor units through connection piping, source-side branch pipes created by branching the source-side main pipes of the outdoor units to the number of indoor units. A source-side solenoid valve is provided in each of the source-side solenoid valves in the source-side branch pipes, and a gas-side solenoid valve is provided in each of the gas-side branch pipes created by branching the gas-side main pipe into the number of indoor units, and the source-side solenoid valve in the source-side branch pipe and the outdoor unit are connected to each other. A throttling device is provided between the heat source side heat exchanger of the unit, and a pipe line between each source side solenoid valve in each of the source side branch pipes and the throttling device in the source side main pipe is provided. A bypass pipe is provided between the gas-side solenoid valve of each indoor unit and the usage-side heat exchanger of each indoor unit that communicates with the respective gas-side branch pipe, and each of the bypass pipes has a pressure across the valve in both flow directions when no current is applied. A refrigeration circuit for a multi-room air conditioner equipped with a bidirectional flow solenoid valve that can close the valve even if the difference is small and allows flow in both directions when energized.