JPH0131114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacity control device for an air conditioner, and in particular, it reduces power consumption by controlling the capacity according to the load of an air conditioner having a plurality of indoor heat exchangers. The purpose of the present invention is to provide an air conditioner that reduces energy consumption and does not impair comfort.

Conventionally, the refrigeration cycle in this type of separate air conditioner was constructed as shown in FIG. 4, and its control circuit was constructed as shown in FIG. 5.

That is, the compressor 102 of the outdoor unit 101
is the indoor unit 11 along with the outdoor blower 104.
Normally open contact 118a of relay coil 117a of 3a
Similarly, relay coil 1 of indoor unit 113b
17b is connected to the outdoor power source 126 via an OR circuit of the normally open contact 118b. In this case, the compressor 102 operates at full output when either the normally open contact 118a or 118b is turned on, which has the disadvantage of wasting power when the load on the indoor unit 113a or 113b is light.
In addition, in FIGS. 4 and 5, 106, 107
is a solenoid valve, 115a, 115b is an indoor blower, 1
03 is an outdoor heat exchanger, 114a, 114b are indoor heat exchangers, 109, 110, 111 are capillary tubes, 119a, 119b are relay contacts, 1
27a and 127b are indoor power supplies.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to control compressor capacity in response to load fluctuations due to changes in the number of operating indoor units and load fluctuations in an air-conditioned space.

In order to achieve the above object, the present invention configures a refrigeration cycle by one variable capacity compressor, an outdoor heat exchanger, a capillary tube, and a plurality of indoor heat exchangers, and further A plurality of thermostats that stop the operation of the compressor when the indoor temperature reaches a set value, and a capacity control device that changes the capacity of the compressor are provided, and the capacity control device is configured to adjust the capacity of the compressor. a first timer that operates from when the compressor is stopped and outputs an output after a first set time has elapsed; and operating the capacity variable means in the capacity reduction direction by a second timer that outputs after a second set time has elapsed, the output of the first timer, and the OFF operation of the plurality of thermostats;
The output of the second timer and the ON operation of any one of the thermostats operate the capacity variable means in the direction of increasing the capacity, and the ON operation of the plurality of thermostats operates the first thermostat. and switching means for canceling the output of the second timer and operating the capacity variable means in the direction of increasing the capacity.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings showing one embodiment thereof.

First, the refrigeration cycle will be explained with reference to FIG.

In the figure, 1 is an outdoor unit, which includes a variable capacity compressor 2 having a bypass circuit 2a, an outdoor heat exchanger 3, an outdoor blower 4 for cooling the outdoor heat exchanger 3, and a bypass circuit for the compressor 2. An electromagnetic three-way valve (switching means) 5 that controls the circuit 2a, an electromagnetic two-way valve 6, 7, 8, and capillary tubes 9, 10,
11 and 12, respectively. 13a,1
3b is the indoor heat exchanger 14a, 14b and the indoor blower 1 for the indoor heat exchanger 14a, 14b, respectively.
5a and 15b, each of which is connected via piping in parallel to the outdoor unit 1. Here, the variable capacity compressor 2 may have a conventionally well-known structure, and in the case of this embodiment, when the electromagnetic three-way valve 5 is operated to communicate with the bypass circuit 2a, high pressure is applied to the bypass circuit 2a. Depending on the refrigerant pressure, a variable capacity discharge port that opens into a compression space (not shown) inside the compressor 2 is closed via a valve, and all of the compressed refrigerant is transferred to the outdoor heat exchanger 3.
When the three-way electromagnetic valve 5 operates to cut off the bypass circuit 2a, the variable capacity discharge port opens, and a part of the compressed refrigerant flows to the compressor via the back circuit 2b. A structure is adopted in which the refrigerant flows into the return pipe of No. 2 and the flow rate of the refrigerant to the outdoor heat exchanger 3 decreases, resulting in a decrease in capacity. Since the structure is not directly related to the gist of the present invention, detailed description and illustration thereof will be omitted.

Next, the control circuit of the air conditioner will be explained with reference to FIG. Here, the same numbers as those in FIG. 1 are given the same numbers, and the description thereof will be omitted.

In the figure, the second timer of outdoor unit 1
_T2 is connected to the compressor 2 and the outdoor blower 4 through the timer contact 24 of the first timer _T1 , and the solenoid two-way valve 8 and the solenoid three-way valve 5 are connected to the compressor 2 and the outdoor blower 4, respectively, through the timer contact 23 of the first timer _T1 . At the same time, the relay coils 17a, 17 of the indoor units 13a, 13b
It is connected to an outdoor power source 26 via an OR circuit of relay contacts 18a and 18b. Further, the relay coils 17a and 17b are connected to the thermostats 16a and 16b of the indoor units 13a and 13b, respectively.
are connected to indoor power supplies 27a, 27b together with indoor blowers 15a, 15b, respectively.
Further, the first timer _T1 is connected to an outdoor power source 26 via a NOR circuit consisting of relay contacts 21a and 21b of relay coils 17a and 17b,
In addition, a relay contact 20a is connected in parallel with the NOR circuit.
A self-holding circuit consisting of a NAND circuit 20b, a timer contact 22 of the first timer _T1, and a timer contact 25 of the second timer _T2 is connected to the outdoor power supply 26.
connected to. Further, the electromagnetic two-way valves 6 and 7 are connected to the relay contacts 19a and 1 of the relay coils 17a and 17b.
It is connected to the outdoor power source 26 via 9b.

In the above configuration, the indoor units 13a, 13
Both thermostats 16a and 16b of b are ON.
In this state, that is, in the state of two-chamber operation, both relay coils 17a and 17b are turned on, and the respective relay contacts 18a, 18b, 19a, and 19
b becomes ON, relay contacts 20a, 20b, 2
1a and 21b are turned off. Therefore, the compressor 2, the outdoor blower 4, and the two-way electromagnetic valves 6, 7, and 8 are turned on, respectively, to cool the indoor heat exchangers 14a, 14b of the indoor units 13a, 13b. here,
When the electromagnetic three-way valve 5 is in the ON state, the bypass circuit 2a of the compressor 2 is set to be in the OFF state, so the compressor 2 operates at full output. Further, during this two-chamber operation, the first timer _T1 does not turn on because the relay contacts 20a, 20b, 21a, and 21b are all open. Therefore, the second timer
_T2 also does not turn on.

Meanwhile, the indoor temperature drops and compressor 2 stops,
Relay coil 17 of indoor units 13a, 13b
When both a and 17b are OFF, the relay contacts 21a and 21b are closed, the first timer _T1 is energized, and after the set time _t1 of the first timer _T1 , the timer contact 22 is closed and the relay contacts 20a and 20b are turned off.
The first timer T ₁ is self-maintained through the NAND circuit of and the timer contact (normally closed) 25 of the second timer T ₂ . Note that if either the thermostat 16a or 16b of the indoor units 13a or 13b is turned on within the set time _t1 of the first timer _T1 , the self-holding of _the first timer _T1 will not occur; After the self-holding of the indoor units 13a, 1
3b either thermostat 16a, 16b
It is clear that even if T1 is turned on, the first timer _T1 continues to hold its true value.

In the case of single-room operation where the first timer T ₁ is ON (self-holding) and either indoor unit 13a or 13b is turned ON again due to a temperature rise, the first timer T 1 is turned on at the same time as the compressor 2 and outdoor blower 4 are turned ON. ₁ , the timer contact 24 is turned on, so the second timer _T2 is also energized. Furthermore, the electromagnetic three-way valve 5 and the electromagnetic two-way valve 8 are in the OFF state because the timer contact 23 of the first timer _T1 is open, and the electromagnetic three-way valve 5 turns on the bypass circuit of the compressor 2, and together with the capillary tube 12. This reduces the load on the compressor 2, reducing output and power consumption.

During operation with the output of the compressor 2 reduced, one of the indoor units 13a, 13b may be damaged due to some reason.
If the cooling load increases, the compressor 2 will have to operate for a long time with insufficient capacity, which is undesirable. To prevent this, the indoor unit 13
A second timer T ₂ is provided to temporally detect changes in the load conditions of a and 13b.
Therefore, after the set time _t2 of the second timer _T2 ,
The timer contact 25 is opened, and the first timer T ₁
Self-holding is released and the first timer _T1 is turned OFF.
As a result, the timer contact 23 is closed, so the electromagnetic three-way valve 5 and the electromagnetic two-way valve 8 are turned ON, and the bypass circuit 2a of the compressor 2 is turned OFF, causing the compressor to operate at full output.

That is, as shown by A in FIG.
If the compressor 2 is restarted within the set time t ₁ of the first timer T ₁ after the compressor 2 is stopped, the indoor temperature rise rate per unit time is high, so high-capacity operation is performed to quickly cool the room. . Furthermore, as shown by B in the figure, when the compressor 2 is restarted due to single-room operation (thermostat 16a ON) after the set time _t1 of the first timer _T1 has elapsed after the compressor 2 was stopped. ,
The first timer _T1 determines that the load is small because the indoor temperature has not risen to the restart temperature of the compressor 2 after the elapse of the set time _t1 of the first timer T1.
T ₁ turns off the electromagnetic three-way valve 5 at the set time t ₁ and switches the capacity of the compressor 2 to a small capacity. Therefore, in the case of B, when the compressor 2 is restarted, the compressor 2 operates at a low capacity to slowly cool the room. Further, as shown by C in the same figure, the restart of the compressor 2 starts after the set time t ₁ after the compressor 2 is stopped, and even after the set time t ₂ of the second timer T ₂ has elapsed, the compressor 2 continues to be restarted.
is operating, it is determined that the load is large because the capacity is insufficient in low-capacity operation, and when the set time _t2 has elapsed, the solenoid three-way valve 5 is turned ON, and the compressor 2 is switched to high-capacity operation. Switch. In addition, when changing from one room small capacity operation to two room operation, the first timer
Since T ₁ and the second timer T ₂ are canceled (OFF), the compressor 2 switches to high capacity operation.

The above operations, that is, the operation controls A, B, and C according to the load, or a combination of these operation controls, result in the operation control according to the load each time.

Therefore, when the load decreases, the capacity (output) of compressor 2 is automatically reduced to reduce power consumption, not only during single-room operation but also during two-room operation when one room is stopped for a certain period of time. Furthermore, even if the load increases midway through, the capacity is automatically switched to a larger capacity, so the cooling effect will not be reduced. Also, unnecessary power consumption can be prevented.

In this embodiment, the capacity of the compressor 2 is controlled by the bypass circuit 2a, the back circuit 2b, and the electromagnetic three-way valve 5. However, the present invention is not limited to this. It can be similarly implemented using means such as phase control and current control. That is, the pole number changeover switch, phase control switch, current control switch, etc. corresponding to the electromagnetic three-way valve 5 may be switched in the same manner using the first and second timers T ₁ and T ₂ .

As is clear from the above embodiments, the capacity control device for an air conditioner according to the present invention is effective when the compressor is restarted within the first set time or when the compressor is operated at a low capacity. When the compressor does not stop even when the load is high, operate the compressor at high capacity, and when restarting the compressor,
Due to the low capacity operation, unnecessarily high capacity operation can be prevented as much as possible, reducing power consumption, and the compressor capacity can be switched according to the load.
Since the comfort of the cooling effect is not compromised, and the control circuit on the indoor side does not need to be changed, existing air conditioners can be used for capacity control by replacing only the outdoor side. spread, etc.
It has various advantages.

[Brief explanation of drawings]

FIG. 1 is a piping circuit diagram of a separate air conditioner equipped with a control device according to an embodiment of the present invention, FIG. 2 is a control circuit diagram of the same separate air conditioner, and FIG. 3 is a compression circuit diagram of the same control device. 4 and 5 are a piping circuit diagram and a control circuit diagram, respectively, of a separate type air conditioner showing conventional examples. 2...Compressor, 2a, 2b...Bypass circuit and back circuit (capacity variable means), 3...Outdoor heat exchanger, 5...Solenoid three-way valve (switching means), 9,1
0, 11, 12... Capillary tube, 14
a, 14b...Indoor heat exchanger, _T1 ...First timer (control device), _T2 ...Second timer (control device).

Claims (1)

[Claims] 1 A refrigeration cycle is composed of one compressor with variable capacity, an outdoor heat exchanger, a capillary tube, and multiple indoor heat exchangers, and an indoor heat exchanger corresponding to each indoor heat exchanger is constructed. The unit is equipped with a thermostat installed in the unit and a capacity control device that varies the capacity of the compressor, and when any one of the indoor units is in operation, T ₁ -OFF within the time of the first timer is as follows: The operation of the first timer is prohibited by the ON signal of the thermostat, and the switching means is turned on, and the capacity variable means of the compressor is operated to the capacity increasing side to achieve high capacity operation, and the time of the first timer is changed. After T ₁ −ON is the first
The timer maintains itself and operates the second timer, and at the same time prohibits the operation of the switching means and operates the capacity variable means to the capacity reduction side to achieve low capacity operation, and after the time of the second timer T ₂ −ON. The second timer cancels the self-holding of the first timer to perform high-capacity operation, and when multiple indoor units are operated simultaneously, the thermostats of the multiple units are activated.
capacity variable means for turning off the first timer and the second timer to achieve high capacity operation in response to an ON signal;
A capacity control device for an air conditioner consisting of a switching means.