JPS633151A - Multiple chamber type heat pump system 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 Field of Industrial Application The present invention relates to a so-called multi-room heat pump air conditioner in which a plurality of indoor units are connected to one outdoor unit.

Conventional technology In conventional multi-room heat pump air conditioners, the liquid side pipes and gas side pipes that connect the outdoor unit and indoor unit are branched for the number of indoor units, and the indoor unit is used as an inlet for refrigerant during cooling. An electric expansion valve that reduces the pressure of the refrigerant is installed on the liquid side branch pipe that is the outlet during heating, and a bidirectional solenoid valve is installed on the gas side branch pipe that is the outlet during cooling and the inlet during heating. During cooling, the refrigerant is controlled by opening a bidirectional solenoid valve regardless of whether the indoor unit is running or stopping, and during heating, by opening a solenoid valve installed in the operating indoor unit. Units are stopped individually.

An example of the conventional multi-chamber heat pump type air conditioner mentioned above will be described below with reference to the drawings. FIG. 2 shows a refrigeration cycle of a conventional multi-chamber heat pump air conditioner. In FIG. 2, an outdoor unit 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, and a heating pressure reducing valve 5.
, a check valve 6 that bypasses the heating pressure reducing valve 5 during cooling;
It consists of an accumulator, a liquid pipe 8, a gas pipe 9, etc.

In addition, the liquid pipe 8 and the gas pipe 9 are the liquid side main pipe 1Q that connects the indoor and outdoor areas,
Liquid side branch pipes 12a, 12b, 12c branched from the gas side main pipe 11 by the number of indoor units; gas side branch pipes 13a;
Indoor units 14 connected to 13b and 13c, respectively
a, 14b, and 14c are indoor heat exchangers 15a and 1, respectively.
5b, 15c.

Gas side branch pipes 13a, 13b, 13c and indoor coil 15a
, 15b, 15c, two-way solenoid valves 16a, 1θb, 16c, liquid side branch pipes 12a, 1, respectively.
2b, 12c and indoor coil 15a.

An electric expansion valve 18a is interposed between the expansion valves 15b and 15C and whose opening degree is adjusted by the control device 17.

18b, 18C, etc.

The operation of the multi-chamber heat pump air conditioner configured as above will be described below. First, it is assumed that only the indoor air conditioner 14a is being operated for cooling. The refrigerant gas discharged from the compressor 2 passes through the four-way valve 3, condenses and liquefies in the outdoor heat exchanger 4, passes through the check valve 6, liquid pipe 8, liquid side pipe 1Q, and liquid side branch pipe 12a, and is sent to the control device. 17i
The pressure is reduced by the electric expansion valve 18a whose opening degree is adjusted from C, and the pressure is evaporated by the indoor heat exchanger 15a, and the bidirectional solenoid valve 16
a, gas side branch pipe 13a, gas side pipe 11, gas pipe 9, four-way valve 3, accumulator 7 and returns to compressor 2. At this time, the indoor units 14b and 14C are stopped, the electric expansion valves 18b and 18C are fully closed by the control device 17, and the indoor unit 14b is closed.

There is no refrigerant supply to 14c. Moreover, the indoor unit 14a
, 14b, and 14Q are all operated, the electric expansion valves 18b and 18C are adjusted in opening degree, and the liquid is diverted from the liquid side pipe 1o to the liquid side branch pipes 12b and 12C, and the bidirectional solenoid valves 1eb and 1ec are also opened. Refrigerant will be supplied to three indoor units.

On the other hand, during heating operation, the refrigerant is discharged from the compressor 2 and the four-way valve 3
, gas pipe 9, gas side pipe 11, and gas side branch pipe 13a.
, 13b, and 13c. Here, the indoor unit 14a,
Assuming that three units 14b and 14Q are in operation, two-way solenoid valves 16a and 16b.

16c is an open indoor heat exchanger 15a, 15b.

The refrigerant is liquefied and condensed in step 15c, and the liquefied and condensed refrigerant is passed through the electric expansion valves 18a and 1, which are fully opened by the control device 17.
sb, 18c, liquid side branch pipes 12a, 12b.

12c, passing through the liquid side pipe 10 and liquid pipe 8, and heating pressure reducing valve 5
It is depressurized and evaporated in the outdoor heat exchanger 4, passes through the four-way valve 3 and the accumulator 7, and returns to the compressor.

If one or two of the three indoor units are stopped, for example, if the indoor unit 14a is stopped, the bidirectional solenoid valve 16a and the electric expansion valve 18& are fully closed, and the indoor unit 14a is stopped. Stop supplying refrigerant to.

Problems to be Solved by the Invention However, in the above configuration, each indoor unit is provided with two-way solenoid valves 16a, 1e5b.

16c is required, and the configuration of the refrigerant cycle becomes extremely complicated, resulting in high costs, increased piping resistance, and reduced capacity.

Also, when one or two indoor units are stopped during heating operation, the solenoid valve and electric expansion valve are fully closed, which may cause refrigerant to accumulate in the indoor unit, causing the operating indoor units to shut down. This method has the disadvantage that the amount of refrigerant to be circulated is reduced and a proper refrigeration cycle cannot be formed.

The present invention provides a multi-chamber heat pump type air conditioner that eliminates the above-mentioned conventional drawbacks.

Means for Solving the Problems In order to solve the above problems, the multi-room heat pump air conditioner of the present invention provides a plurality of indoor units with electric expansion valves, and operates the electric expansion valves during cooling. Indoor units are depressurized, indoor units that are stopped are fully closed, and indoor units that operate during heating are fully opened.
It is equipped with an electric expansion valve control device that opens the indoor unit slightly when it is stopped.

Function: In the multi-room heat pump air conditioner of the present invention, the control device for the electric expansion valve controls each electric expansion valve to perform a depressurization action in the indoor unit that operates during cooling, and to perform a depressurization action in the indoor unit that is stopped. By closing, the supply of refrigerant is stopped to the indoor unit that is to be stopped, and by fully opening the indoor unit that operates during heating and slightly opening the indoor unit that is stopping, refrigerant does not accumulate in the indoor unit that is stopping. This is how it was done.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows a refrigeration cycle diagram of the present invention.

In Fig. 1, an outdoor unit 1 includes a compressor 2, a four-way valve 3
, an outdoor heat exchanger 4, a pressure reducing valve for heating 6, a reverse valve 6 that bypasses the pressure reducing valve for heating 5 during cooling, an accumulator 7,
It consists of a liquid pipe 8, a gas pipe 9, etc. In addition, the liquid pipe 8 and the gas pipe 9 are connected to a liquid side main pipe 10 and a gas side main pipe 11 that connect the indoor and outdoor areas, and liquid side branch pipes 12a branched by the number of indoor units.
12b.

12C1 Indoor UNISO (indoor unit) connected to gas side branch pipes 13a, 13b, 13c, respectively) 14a, 14b.

14c are indoor heat exchangers 15a and 15b, respectively.

15C1 gas side branch pipes 13a, 13b, 13c, liquid side branch pipes 12a, 12b, 12c and indoor coil 15a.

Electric expansion valves 17a and 17b are interposed between the expansion valves 15b and 15c, respectively, and have their opening degrees adjusted by the control device 16.

17c etc.

The operation of the multi-chamber heat pump air conditioner configured as above will be described below. First, it is assumed that only the indoor unit 14a is being operated for cooling. The refrigerant gas discharged from the compressor 2 is condensed and liquefied in the outdoor heat exchanger 4 that passes through the four-way valve 3, passes through the check valve e, the liquid pipe 8, the liquid side pipe 10, and the liquid side branch pipe 12a, and is sent to the control device. The pressure is reduced by the electric expansion valve 17a whose opening degree is adjusted by 16, and the gas side branch pipe 13a is evaporated by the indoor heat exchanger 15a.

It passes through the gas side pipe 11, gas pipe 9, four-way valve 3, and accumulator 7, and returns to the compressor 2. At this time, indoor unit l-1
4b and 14C are stopped, and the electric expansion valve 1 completed b,
17C is completely closed by the control device 16, and no refrigerant is supplied to the indoor units 14b and 14C. Moreover, when all three indoor units 14a, 14b, and 14c are operated, the electric expansion valve 17b.

17c is connected from the liquid side pipe 10 to the liquid side branch pipe 12b with the opening degree adjusted.
, 12c, and the refrigerant is supplied to the three indoor units.

Next, heating operation will be explained. The refrigerant gas discharged from the compressor 2 passes through the four-way valve 3, the gas pipe 9, and the gas side pipe 11, and reaches the gas side branch pipes 13a, 13b, and 13c. Here, assuming that all three indoor units 14a, 14b, and 14c are in operation, the gas side branch pipes 13a, 13b,
The refrigerant gas branched to the indoor heat exchanger 15a,
It is condensed and liquefied in 15b and 15c. This liquid refrigerant flows through the electric expansion valve 17a, which is fully opened by the control device 16;
17b and 17c, and liquid side branch pipes 12a and 12b.
, 12c, the liquid side pipe 10, and the liquid pipe 8, the pressure is reduced by the heating pressure reducing valve 5, evaporated in the outdoor heat exchanger 4, and returned to the compressor 1 via the four-way valve 3 and the accumulator 7.

Next, when the indoor unit 14a is stopped, the electric expansion valve 17a is closed by the control device 16, but it is not fully closed, but slightly opened (for example, % of fully open). With this operation, the amount of refrigerant diverted to the gas side branch pipe 13a is reduced and flows into the liquid pipe 10 through the slightly open electric expansion valve 17a. For this reason, when heating the indoor unit 7
Even if a solenoid valve is not provided in the gas side branch pipe 13a that serves as the inlet of 4a, the refrigerant will not stagnate, and an appropriate amount of refrigerant to be circulated to the indoor units 14b and 14C can be secured, resulting in an appropriate refrigeration cycle. is sustained.

The same applies when the indoor unit 14b or 14c is stopped.

As described above, the indoor unit that operates during cooling has a depressurizing effect, the indoor unit that is stopped is fully closed and refrigerant supply is stopped, the indoor unit that is operated during heating is fully opened, and the indoor unit that is stopped is completely closed, and the indoor unit that is stopped is slightly closed. By controlling the electric expansion valve so as to keep it open and prevent refrigerant from accumulating, the configuration of the refrigeration cycle becomes extremely simple, and a decrease in capacity due to an increase in pressure loss can be prevented. In addition, since the refrigerant is flowing little by little and the indoor heat exchanger is preheated in the 22-K, which stops during heating, there is also the advantage that warm air will be blown out immediately when it is restarted.

Effects of the Invention As described above, the present invention provides electric expansion valves in each of a plurality of indoor units, performs a depressurizing action in the indoor units operating during cooling, completely closes the units to stop the supply of refrigerant, and Fully open the indoor unit for heating operation.
Indoor uni stops.

By providing a control device that controls the electric expansion valve so that the refrigerant does not stagnate and flows little by little by opening it slightly at the end, the refrigeration cycle becomes extremely simple and a reduction in capacity due to an increase in pressure loss is prevented. be.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of a multi-chamber heat pump type air conditioner showing an embodiment of the present invention, and FIG. 2 is a refrigeration cycle diagram of a conventional multi-chamber heat pump type air conditioner. 1...Outdoor unit, 2...Compressor,
4...Outdoor heat exchanger, 14a, 14b, i4c
...Indoor unit, 15a, 15b, 15c.
...Indoor heat exchanger, 16--Control device, 17
a, 17b, 17C...Electric expansion valve.

Claims (1)

[Claims] One outdoor unit with a compressor and an outdoor heat exchanger,
A plurality of indoor units are connected to the outdoor unit and each have an electric expansion valve and an indoor heat exchanger, and each of the electric expansion valves is controlled, and during cooling, the operating indoor unit performs a depressurizing action and the indoor unit is stopped. A multi-room heat pump air conditioner equipped with an electric expansion valve control device that completely closes the unit, fully opens the operating indoor unit during heating, and slightly opens the indoor unit that stops.