JPS6152905B2 - - 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 one of its purposes is to perform quiet heating operation. It is.

In a conventional multi-room air conditioner, when the compressor is running and the indoor unit is in heating operation, if another indoor unit is added to perform heating operation, this added indoor The gas-side solenoid valve and liquid-side solenoid valve that control the flow of refrigerant to the indoor heat exchanger of the unit were opened at the same time. However, before the indoor heat exchanger of this additionally operated indoor unit was operated, the flow of refrigerant was stopped by closing the gas side solenoid valve and the liquid side solenoid valve, 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 suddenly caused high-pressure gas to flow into the low-pressure indoor heat exchanger. This flowing refrigerant causes the indoor unit to make a loud squeak sound, and the check valve, which is installed in parallel with the cooling throttle mechanism in the indoor unit, violently presses against the stopper, causing it to click. This has caused serious problems such as the sound of lunchboxes being generated, and vibrations sometimes being transmitted to the floor and walls on which the indoor unit is installed.

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 a multi-room air conditioner.
Liquid side branch pipes 7a, 7b, 7c formed by branching the liquid side main pipe 6 at the branch point 13; liquid side branch pipes 7a, 7b, 7c
There are the same number of gas side branch pipes 8a, 8b, 8c, a gas side main pipe 9 formed by collecting these gas side branch pipes 8a, 8b, 8c, an accumulator 10, a heating throttle mechanism 11 provided in the liquid side main pipe 6, , a check valve 12 provided in parallel with the heating throttle mechanism 11 to prevent the flow of refrigerant during heating operation, and a check valve 12 provided between the heating throttle mechanism 11 and the branch section 13 of the liquid side main pipe 6. liquid receiver 14, each liquid side branch pipe 7a, 7b, 7c
Bidirectional aperture mechanisms 22a, 22b, 22c inside
A two-way solenoid valve 15a, 1 provided in series with the
5b, 15c, check valves 17a, 17b, 17 whose circulation side is the flow toward the low pressure circuit 20 during heating operation
connection ports 16 between the solenoid valves 15a, 15b, 15c and each indoor unit 30a, 30b, 30c by connecting the solenoid valves 15a, 15b, 15c and the throttles 18a, 18b, 18c in series.
Liquid side branch pipes 7a, 7b between a, 16b, 16c,
Bypass pipes 19a, 19b, 19c connecting 7c and the low pressure circuit 20 during heating operation, gas side branch pipes 8a, 8
It consists of two-way flowable electromagnetic valves 21a, 21b, and 21c, which are provided in the two-way valves 21a, 21b, and 21c, respectively. Further, the indoor units 30a, 30b, and 30c each include indoor heat exchangers 31a, 31b, and 31c, and a blower (not shown).

FIG. 2 shows an embodiment of the electric circuit of a multi-room air conditioner according to the present invention, in which a coil of a solenoid valve 21a is connected in series with a normally open contact R _Das of a delay relay R _Da .
SV _Ga , the coil SV _La of the solenoid valve 15a, the electromagnetic switch M _Ra , and the delay relay R _Da are each connected in parallel to the power supply via the operation switch 40a of the indoor unit 30a, and similarly the delay relay R _Db is connected in parallel to the power supply via the operation switch 40a of the indoor unit 30a. The coil SV _Gb of the solenoid valve 21b connected in series with the normally open contact R _Dbs , the coil SV _Lb of the solenoid valve 15b, the solenoid switch M _Rb and the delay relay R _Db are connected to each other via the operation switch 40b of the indoor unit 30b. A coil of a solenoid valve 21c connected in parallel to the power supply and further connected in series with the normally open contact R _Dcs of the delay relay R _Dc .
SV _Gc , the col SV _Lc of the solenoid valve 15c, the electromagnetic switch M _Rc , and the delay relay R _Dc are each connected in parallel to the power source via the operation switch 40c of the indoor unit 30c.

In addition, the motor MC of the compressor 2 has an electromagnetic switch MR _a ,
The normally open contacts of MR _b and MR _c are connected in series with a circuit in which the normally open contacts MR _as , MR _bs , and MR _cs are connected in parallel and connected to the power supply.
Furthermore, the coil 41 of the four-way valve 4 is connected to a power source via a heating side contact of a heating/cooling switch 42.

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 that the cooling/heating selector switch 42 is turned to the heating side, voltage is applied to the coil 41 of the four-way valve 4, and the operation switch 40 of the indoor unit 30a is turned on.
Since contact a is closed, electromagnetic switch MR _a
The contact MR _as closes, the motor MC of the compressor 2 rotates, and since voltage is applied to the coils SV _Ga and SV _La , the passages of the solenoid valves 21a and 15a are opened, and only the indoor unit 30a is operated for heating. Suppose that

The refrigeration cycle in this case will be explained next. First, the refrigerant discharged from the compressor 2 passes through the discharge muffler 3, the four-way valve 4, and the gas side branch pipes 8a,
8b and 8c. Here, the passage of the solenoid valve 21a is opened and the passages of the other solenoid valves 21b and 21c are closed, so the refrigerant is sent only to the indoor unit 30a and enters the outdoor unit 1 again through the indoor heat exchanger 31a. , the solenoid valve 1 in the liquid side sub-tube 7a
5a, throttle mechanism 22a, branch point 13, liquid receiver 14
The air is depressurized by the heating throttle mechanism 11, evaporated by the outdoor heat exchanger 5, returns to the compressor 2 through the four-way valve 4, and the accumulator 10. In addition, solenoid valves 21b, 21c and 15 control the refrigerant flow in the indoor units 30b and 30c whose operation is stopped.
b, 15c are closed, solenoid valve 21b
Refrigerant does not flow into the refrigeration circuit that is closed by the solenoid valve 15b and includes the indoor heat exchanger 13b, and the refrigeration circuit that is closed by the solenoid valve 21c and the solenoid valve 15c and includes the indoor heat exchanger 31c. However, in reality, the solenoid valves 21a, 21b, 21c, 15
A, 15b, 15c, etc. cannot completely stop the flow of refrigerant and there is a leak. Therefore, the indoor heat exchangers 31b, 31c of the indoor units 30b, 30c that are stopped
Refrigerant will gradually accumulate inside.
However, when a large amount of refrigerant accumulates in the indoor heat exchangers 31b and 31c, the indoor unit 30 during operation
The amount of refrigerant flowing through the indoor heat exchanger 31 a decreases, resulting in a decrease in heating capacity and causing damage to the compressor 2 . Therefore, one end of the bypass pipe 19 is connected to the low pressure circuit 20 during heating operation.
Indoor heat exchangers 31b, 31c by b, 19c
This is to extract the refrigerant that has accumulated inside.
Therefore, the refrigerant pressure in the indoor heat exchangers 31b, 31c of the indoor units 30b, 30c that are stopped is at the same low pressure state as in the low pressure circuit 20 during heating operation.

Under these circumstances, when the other indoor unit 30b is operated for additional heating, the conventional control method opens the solenoid valves 21b and 15b at the same time. The refrigerant was flowing in and causing loud noises and vibrations.

Therefore, in the case of the present invention, when the operation switch 40b of the indoor unit 30b is turned on, the coil
Voltage is applied to SV _Lb and solenoid valve 1 in liquid side branch pipe 7b
By opening the passage 5b, part of the high-pressure refrigerant that has been flowing through the indoor heat exchanger 31a of the indoor unit 30a that has been in operation to the solenoid valve 15a, the branch point 13, and the liquid receiver 14 is removed. It is sent from the branch point 13 to the indoor heat exchanger 31b through the throttle mechanism 22b and the electromagnetic valve 15b, thereby bringing the indoor heat exchanger 31b into a high pressure state. Here, since the throttle mechanism 22b has a large resistance, the pressure inside the indoor heat exchanger 31b gradually increases, and no noise or vibration is generated. In particular, since the throttle mechanism 22b is located inside the outdoor unit 1, the refrigerant noise generated by the throttle mechanism 22b is not carried over to the indoor unit 30b, so that no noise or vibrations are generated from the indoor unit 30b. do not have. In this way, when the pressure inside the indoor heat exchanger 31b becomes almost the same as the refrigerant pressure in the gas side main pipe 9, the normally open contact R _Dbs of the delay relay R _Db , which is energized at the same time as the coil SV _Lb , closes. A voltage is applied to the coil SV _Gb to open the solenoid valve 21b and allow the refrigerant to pass through the indoor unit 30b. Therefore, this method has the great effect of eliminating the need to generate refrigerant noise that occurs when the indoor unit 30b is additionally operated using the conventional method. In particular, in recent years, electronic control such as a microcomputer has enabled fine control, and solenoid valves 15a, 15b, 15
c, 21a, 21b, 21c, etc. are also being opened and closed frequently, so the conventional method would constantly generate noise and vibration, so the effects of the present invention are particularly expected. Furthermore, the aperture mechanism 22b
Since no check valve is connected in parallel with the check valve, there are effects such as no valve hitting noise from the check valve.

In addition, in this embodiment, the solenoid valve 15a in the liquid side branch pipe,
The opening timing of 15b and 15c is determined by the solenoid valve 21.
Normally open contacts R of delay relays R _Da , R _Db , R _Dc are used to delay the opening timing of a, 21b, and 21c.
_Das , R _Dbs , R _Dcs and solenoid valves 21a, 21b, 21
The coils SV _Ga , SV _Gb , and SV _Gc of c are connected in series, respectively, but the normally open contacts R _Das , R _Dbs , and R _Dcs of the delay relays R _Da , R _Db , and R _Dc are replaced by pressure SW contacts. indoor units 30a, 30b, 30
When the pressure inside the indoor heat exchangers 31a, 31b, 31c of c rises to a certain value, the solenoid valves 21a, 21
The passages b and 21c may be left open.

Furthermore, although this embodiment has been explained in the case where additional heating operation is performed, the same effects can be obtained when an indoor unit whose heating operation is suspended due to the temperature controller is restarted by the temperature controller. Needless to say.

Next, the cooling operation will be briefly explained. now,
Assuming that only the indoor unit 30a is operating, the refrigerant is discharged from the compressor 2, discharge muffler 3, four-way valve 4, outdoor heat exchanger 5, check valve 12,
Liquid receiver 14, throttle mechanism 22a, solenoid valve 15a, indoor heat exchanger 31a, solenoid valve 21a, four-way valve 4,
It passes through the accumulator 10 and returns to the compressor 2.
Note that at this time, the solenoid valves 15b and 15c are closed,
The solenoid valves 21b and 21c are open. That is, during cooling operation, the solenoid valves 15a, 15b, 1
5c, 21a, 21b, 21c are controlled by an electric circuit completely different from the electric circuit shown in FIG. solenoid valve 2 is opened and the others are closed.
1a, 21b, and 21c are all left open. Therefore, during cooling operation, refrigerant does not accumulate in any of the indoor heat exchangers 31a, 31b, and 31c.

In addition, in order to prevent refrigerant from accumulating in the indoor heat exchanger during cooling operation, instead of opening all the solenoid valves 21a, 21b, 21c as described above, each solenoid valve 21a, 21b, A check valve that allows the refrigerant to flow from the indoor heat exchanger to the four-way valve 4 may be provided in parallel with 21c. In any case, the indoor heat exchanger is connected to the low-pressure circuit of the refrigeration cycle during cooling operation, and liquid refrigerant does not accumulate in the indoor heat exchanger. Note that while the indoor unit is in a low pressure state when it is stopped during cooling operation, the pressure on the upstream side of the liquid side solenoid valve is also low, so even when the second and third indoor units are operated, there is almost no pressure difference. Since there is no noise or vibration, there is no noise or vibration.

As mentioned above, the multi-chamber air conditioner according to the present invention has the following features:
When one or more indoor units are in heating operation and the compressor is running, when operating a stopped indoor unit, first open the solenoid valve in the liquid side branch pipe,
After a certain period of time has elapsed, or when the pressure in the circuit including the indoor unit rises to a certain level, the solenoid valve in the gas side branch pipe is opened and the refrigerant is passed through a bidirectional throttling mechanism installed in the outdoor unit. Since the pressure inside the indoor unit is gradually increased through the indoor unit, no noise or vibration is generated from the operating indoor unit, making extremely quiet heating operation possible.At the same time, there is no need for check valves, which reduces costs. It also has the great effect of being cheaper.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of a multi-chamber air conditioner according to an embodiment of the present invention, and FIG. 2 is an electrical circuit diagram of the same multi-chamber air conditioner during heating. 1...Outdoor unit, 7a, 7b, 7c...Liquid side branch pipe, 8a, 8b, 8c...Gas side branch pipe, 15
a, 15b, 15c...Solenoid valve, 19a, 19
b, 19c...Bypass pipe, 21a, 21b, 2
1c... Solenoid valve, 22a, 22b, 22c... Bidirectional throttle mechanism, 30a, 30b, 30c...
Indoor unit, 31a, 31b, 31c...Indoor heat exchanger, 41...Coil, R _Da , R _Db , R _Dc
...Delay relay, R _Das , R _Dbs , R _Dcs ... Contact of delay relay, SV _La , SV _Lb , SV _Lc ... Solenoid valve 15
Coils a, 15b, 15c, SV _Ga , SV _Gb ,
SV _Gc ...Coil of solenoid valves 21a, 21b, 21c.

Claims (1)

[Claims] 1. A plurality of indoor units are connected to one outdoor unit, and a throttle device and a liquid are installed in each outdoor unit of the liquid side branch pipes formed by branching from the main liquid side pipe of the outdoor unit according to the number of indoor units. A series circuit consisting of side solenoid valves is provided, and a gas side solenoid valve is provided in each gas side branch pipe formed by branching from the gas side main pipe according to the number of indoor units, and furthermore, a series circuit consisting of each of the liquid side solenoid valves and each of the abovementioned indoor units is provided. Bypass pipes are connected between each indoor heat exchanger of the indoor unit to the pipes that have low pressure during heating operation, and to these bypass pipes, the flow of refrigerant from the refrigerant pipes that have low pressure during heating to the liquid side branch pipe is connected. A check valve and a resistor are installed in series to prevent this from happening, and when one or more indoor units is in heating operation and another indoor unit is in additional heating operation or restart heating operation with a temperature controller, etc., the other indoor unit is an electric control circuit that opens the gas side solenoid valve that controls the flow of refrigerant to the other indoor unit after a certain period of time has elapsed after opening the liquid side solenoid valve that controls the flow of refrigerant to the other indoor unit; Multi-room air conditioner.