JPS59210278A - Controller for refrigerant of heat pump type air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention connects a plurality of indoor units to one outdoor unit, and switches the flow of refrigerant between cooling and heating using a four-way valve provided in the outdoor unit. Regarding the heat pump type air conditioner that performs air conditioning and heating,
The purpose is to increase heating capacity during heating and reduce overload when the compressor is overloaded.

In conventional multi-type heat pump air conditioners, refrigerant control is performed as shown in FIG.

That is, in FIG. 1, 51 is an outdoor unit, and 62 is an outdoor unit.
53 is a rotary compressor; 53 is a four-way valve that switches the flow of refrigerant during cooling and heating; 54 is an outdoor heat exchanger that serves as a condenser during cooling and an evaporator during heating; 65a;

ssb is the first capillary tube, 56a, 56b are source side solenoid valves, 57a, 5 are indoor units 58a, 68
a three-way valve connected to b and having a service pulp, 59
a, 59b are second capillary tubes, 60a, 60b
is an indoor heat exchanger that serves as an evaporator for cooling and a condenser for heating; 6
1a and 61b are 3, three-way valves, 62a and e2b are gas side solenoid valves, and 63a.

esb is a check valve through which the refrigerant bypasses the gas-side solenoid valves 62a and 62b during cooling, and is closed during heating, and e4 is 7
#: x-motor, 65a, esb are check valves that constantly send a small amount of refrigerant to the rotary compressor 52 through the injection capillary tube 66 during both cooling and heating; 67 is a check valve during cooling and heating. When abnormally high pressure occurs at any time, the opening degree is adjusted according to the high pressure.
a high-pressure pressure regulating valve for returning the refrigerant to the suction pipe 68 side to lower the temperature and suppressing abnormally high pressure in the compressor 62; 69 is a discharge pipe;
70a and 70b are capillary tubes.

Conventionally, such a refrigerant circuit is configured, and if a small amount of gas-liquid mixed refrigerant flows through the check valve 65a and etsb during heating, (injection capillary tube 66
The refrigerant is returned to the compressor 62 from the injection capillary tube 66 due to the resistance of the indoor unit 7).
It is condensed in the indoor heat exchangers 60a and 60b of 58a and 58b, and the pressure is reduced in the capillary tubes 69a and 59b, and it returns as a gas-liquid mixed refrigerant.The gas-liquid mixture is mainly liquid refrigerant and is compressed in the cylinder in the compressor. In order to alleviate the temperature rise by injecting the air into the gas inside, the heating capacity is reduced. Similarly, when the indoor and outdoor temperatures rise during heating, the compressor 52 becomes overloaded, and the high-pressure pressure regulating valve 67 The refrigerant is returned to the suction pipe 68 side, but since the refrigerant is a gas-liquid mixture, a sufficient amount of refrigerant does not return to the suction pipe side, and the load on the compressor becomes heavy during overload. It had drawbacks such as.

The present invention solves the above-mentioned conventional drawbacks, and an embodiment thereof will be described below based on FIG. 2.

In Figure 2, 1 is an outdoor unit, 2 is a rotary compressor, 3 is a four-way valve for switching the flow of refrigerant during cooling and heating, and 4 is a condenser during cooling and an evaporator during heating. 5 is a first capillary tube for cooling, 6a;

6b is a check valve, 7a and 7b are several solenoid valves that are opened and closed by the operation of the indoor unit, 8a and sb are three-way valves provided in the outdoor unit 1, and 9a and 9b are two-way valves provided on the indoor 5+ unit 10a side. Directional valve 1ob is another indoor unit. 11a and 11b are second capillary tubes for cooling provided in the respective indoor units 10a and 10b, and 12a and 12b are second capillary tubes so that the condensed refrigerant flows to the outdoor unit 1 side during heating and does not flow during cooling. 2
Check valves are provided to bypass the capillary tubes 11a and 11b, 13a and 13b are indoor heat exchangers that act as condensers during heating and evaporators during cooling, 14a and 14b are two-way valves, and 16a and 16b are outdoor units. The three-way valves 16a and 16b provided on the side plate of 1 are indoor unit 10a,
By operating 10b, the gas side solenoid valve opens during heating and closes during cooling. Gas refrigerant flows through 17a and 17b during cooling, does not flow during heating, and bypasses the solenoid valves 16a and 16b during cooling. 18 is an accumulator that vaporizes liquid refrigerant; 19 is a discharge pipe through which high-temperature and high-pressure gas is discharged; 2o is a suction pipe; 21 is a high-pressure pressure regulating valve;
During operation, when the refrigerant discharged from the compressor 2 becomes abnormally high, the pressure inside the pipe 22 becomes high, and a part of the refrigerant is used for the high-pressure pressure regulating valve provided in a part of the outdoor heat exchanger 4. The liquefied refrigerant is liquefied in the heat exchange section 23, flows through the high-pressure pressure regulating valve 21 whose opening degree is adjusted according to the pressure, is bypassed to the suction pipe 20, and by returning a part of the liquid refrigerant, the high-pressure pressure is increased. The amount of refrigerant passing through the regulating valve 21 is increased to reduce the load on the compressor. 24 is a heating electromagnetic valve that is open during heating and closed during cooling; 26a and 2sb are heating pipes through which refrigerant flows only during heating; 26a and 26b are check valves through which refrigerant flows only during heating; 27a and 27b are check valves through which refrigerant flows only during heating; The first capillary tube 28 for heating is always at intermediate pressure (first capillary tube 27a) only during heating.

29 is a pipe through which gas refrigerant flows from above the separator 28 to the injection circuit of the compressor 2 during heating; 30 is a check valve; 31 is a second capillary tube for heating, and in this second capillary tube 31 the pressure is changed from intermediate pressure to low pressure, and the air is evaporated in the outdoor heat exchanger 4 and returned to the compressor 2 via the four-way valve 3. 32 is a heating injection capillary tube through which the liquid refrigerant stored below the separator 28 passes, 33 and 34 are injection piping connected to the inside of the cylinder of the compressor 2, and 35 is a cooling injection capillary tube. During cooling, the length of the capillary tube is selected so that a portion of the liquid refrigerant condensed in the outdoor heat exchanger 4 can flow into the cylinder of the compressor in an amount sufficient to cool the gas being compressed. .

36a and 36b are piping 37a taken out between the gas side solenoid valves 16a and 16b and the three-way valves 1eia and 15b.

37b, and these pressure equalizing capillary tubes 36a and 36b are connected to the suction pipe 2o.
When either indoor unit 10a or 10b is stopped, the pressure of the condensed refrigerant in the indoor heat exchanger of the stopped indoor unit is made equal to the pressure on the suction pipe side, and the high-pressure liquid refrigerant is gradually removed. It was established for the purpose of collecting waste.

In the above configuration, normal refrigeration cycle operation is performed during cooling. That is, the gas refrigerant compressed by the compressor 2 is
Four-way valve 3. An outdoor heat exchanger 4, where it is condensed, a first capillary tube 5 for cooling (a part of the liquid refrigerant passes through an injection capillary tube 35 for cooling), an inverted one-way valve ea, 6b,.

Gas side electric double valve ya, 7J three-way valve sa, sb (at this time, the heating solenoid valve 24 is closed, so the check valve 26a).

26b), indoor unit 1oa.

10b(7) Second capillary tube 11a, 1
13 indoor heat exchangers 13a, 13b, three-way valves 15a, 1
The refrigerant circuit includes the sJ check valves 17a and 17b, the four-way valve 3, and the accumulator 18. When the high pressure becomes abnormally high, the high pressure regulating valve 21 opens and the liquid refrigerant condensed in the heat exchange section 23 is transferred to the suction pipe. 20 to reduce the load on the compressor. Next, during heating, the gas refrigerant compressed by the compressor 2 is transferred to the four-way valve 3, the gas side solenoid valves 16a, 16b, the three-way valve 15a,
15b, indoor heat exchanger 1 of indoor units 10a, 10b
3a.

13b, check valve 12a, 12J three-way valve sa,
Since it is stopped by the check valves ea and sb, it passes through the check valves 26a and 26b and reaches the first heating capillary tube 27a, 27b, the heating solenoid valve 24, and the separator 28. In this separator 28, the main circuit is that the liquid refrigerant is connected to the check valve 30,
The heating circuit includes the second capillary tube 31, the outdoor heat exchanger 4, and the four-way valve 3. A part of the liquid refrigerant flows through the piping 34 and the heating injection capillary tube 32 and is depressurized, while the gas refrigerant A part of the refrigerant flows through the pipe 29, and a gas-liquid mixed refrigerant, which is a mixture of liquid refrigerant and gas refrigerant,
It flows through the pipe 33 and is injected into the cylinder of the compressor 2.

At this time, most of the gas-liquid mixed refrigerant is gas refrigerant from the pipe 29, and only a small amount of liquid refrigerant is from the capillary tube 32. Furthermore, when the indoor temperature or outdoor temperature rises and the compressed high-temperature, high-pressure refrigerant becomes abnormally high, resulting in an overload condition, the pressure in the pipe 22 also rises, causing the high-pressure pressure regulating valve 2 to rise.
1 begins to open, the liquid refrigerant condensed in the heat exchange section 23 flows through the high-pressure pressure regulating valve 21, flows into the suction pipe 2o, and returns to the accumulator 18, reducing the load on the compressor 2. Next, also during heating, the indoor unit 10a.

When either of the indoor heat exchangers 10a and 10b is stopped, the gas side solenoid valves 1ea and 16b are closed to prevent liquid refrigerant from accumulating in the stopped indoor heat exchanger 1. The one that stops is closed, and the pipe 37a
, 37b, and further a pressure equalizing capillary tube 36
The refrigerant gradually flows through the stopped side of a and 36b and flows into the suction pipe 20, and the refrigerant is recovered while dropping the high pressure circuit of the stopped side to the suction pipe 20 side pressure.

Also, for example, when indoor unit (10a) is operating, indoor unit (10b) is simultaneously operated for a short time, and when indoor unit (10a) is stopped and only indoor unit (10b) is in operation, the gas side electromagnetic The valve 16a is closed, and the refrigerant in this system flows through the pipe 37a1 and the pressure equalization capillary tube 3.
6a and is gradually collected into the suction pipe 20, and the second capillary tube 31 via the first heating capillary tube 27a, the heating solenoid valve 24, the separator 28, and the check valve 3o. Since the refrigerant in the stopped pipe is recovered by the intermediate pressure and circulated to the indoor unit 10b which is in operation, the refrigerant circulation amount in the machine 2 is temporarily insufficient. There is no possibility that the temperature will rise to 11- and put a burden on the compressor.

According to the present invention, during cooling operation, the separator 2
8 is separated from the main cooling circuit, so that no refrigerant accumulates in the separator 18. On the other hand, during heating operation, the injection refrigerant returned to the piping 33 is mainly gas refrigerant coming out from above the separator 28. The gas refrigerant flowing through the piping 29, the liquid refrigerant coming out from below the separator 28, and the liquid refrigerant flowing through the piping 34 and the injection capillary tube 32 for heating combine to form a gas-liquid mixed refrigerant mainly containing gas refrigerant. Since the refrigerant is injected into the cylinder of the compressor 2, the discharge temperature can be increased and the heating capacity can be improved compared to the conventional injection of mainly liquid refrigerant. Furthermore, in the heat exchange section 23, the liquid refrigerant, which is mostly liquefied, is returned to the heat exchange section 23 under high pressure regulation, compared to the conventional method that mainly returns a gas-liquid mixture of liquid refrigerant even in the event of an overload. Since the refrigerant is allowed to flow through the valve 21, the refrigerant volume can be increased to obtain a large amount of refrigerant flow, and the load on the compressor can be reduced. Furthermore, through injection from intermediate pressure during heating,
Compared to the conventional method that recovers liquid refrigerant in a stopped indoor heat exchanger, the present invention improves the height difference between the gas side solenoid valve and the three-way valve so that the pressure is equalized from the high pressure side during heating. By attaching a refrigerant, the refrigerant can be recovered quickly and the rate at which liquid refrigerant accumulates in the indoor unit is reduced.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant control circuit diagram of a conventional heat pump type air conditioner/heater, and FIG. 2 is a refrigerant control circuit diagram of a heat pump type air conditioner/heater according to an embodiment of the present invention. 2...Compressor, 3...Four-way valve, 4...
...Outdoor heat exchanger, 7a, 7b =----
Source side solenoid valve, 15a, 15b... Three-way valve, 16a
, 16b...Mountain/gas side solenoid valve, 20...Suction pipe, 21...High pressure regulating valve, 24...
Heating solenoid valve, 26a, 26b... River check valve, 27a
, 27b...first capillary tube for mountain heating;
28... Separator, 29... Piping,
32... Injection capillary tube, 13 36a, 36b... Pressure equalization capillary tube.

Claims (1)

[Claims] Compressor, four-way valve, outdoor heat exchanger, capillary tube,
Equipped with a heat pump type air conditioner/heater equipped with an indoor heat exchanger, etc., when the air conditioner is overloaded, the refrigerant discharged from the compressor is liquefied in a part of the outdoor heat exchanger, and heat is supplied to the suction pipe side through a high-pressure pressure regulating valve. circuit, a check valve that flows only during heating between the three-way valve of the outdoor unit and the source-side solenoid valve, a first capillary tube for heating, and a heating solenoid valve that opens when heating and closes when cooling. a circuit through which the gas refrigerant flows through the separator to the compressor, and a circuit through which liquid refrigerant flows from the separator through a capillary tube for heating injection to join the piping. A refrigerant control device for a heat pump type air conditioner/heater, further comprising a gas side solenoid valve and a pressure equalizing capillary tube connected to a suction pipe from between the three-way valve.