JPH04190053A - Multi-chamber type air conditioner - Google Patents

Abstract

PURPOSE:To enable a normal operation pressure state to be always kept even during a heating operation by a method wherein an outdoor device is provided with the second four-way valve, and refrigerant is circulated from an expansion valve of an indoor device toward a heat exchanger at the indoor device during cooling and heating operations. CONSTITUTION:A solenoid four-way valve 13a is inserted into an outlet of a liquid pipe 11 and an outlet of an outdoor device 1. During a heating operation, for example, only an indoor device is operated, the four-way valve 13a is electrically energized,resulting in that gas of high temperature and high pressure passes through conduits 13d and 13c, is heat exchanged at an indoor device heat exchanger 9d, condensed there, passes through a conduit 13e and a conduit 13b. A pressure of the gas is reduced by an expansion valve 5 at the outdoor device and the gas returns to the compressor 2. At this time, since the expansion valves 8a, 8b and 8c at the indoor devices 7a, 7b and 7c are all closed under their stopped conditions, the gas of high temperature and high pressure passed through the conduit 13c is not fed into the heat exchangers 9a, 9b and 9c at the indoor devices. Accordingly, even if the heating conditions are varied, the device can be always operated at a proper operating pressure.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a multi-room air conditioner.

(Prior Art) Regarding a conventional multi-room air conditioner having multiple indoor units, Refrigeration, Vol. 61, No. 708 (October 1986 issue)
The multi-chamber air conditioners shown in Nos. P, 1038 to 1045 will be explained using the configuration diagram in FIG. 2 as an example.

In the figure, an outdoor unit 1 of a multi-room air conditioner includes a compressor 2. Four-way valve 3. Outdoor unit side heat exchanger 4. Outdoor unit side expansion valve 5
and an outdoor unit side fan 6. Further, the plurality of indoor units 7a, 7b, 7c and 7d have indoor unit side expansion valves 8a and 8b, respectively.

8c and 8d, indoor unit side heat exchangers 9a, 9b, 9
c and 9d and indoor unit side fans 10a, 10
b.

It is composed of 10c and 10d. Furthermore, the outdoor unit 1 and the indoor units 7a, 7b, 7c and 7d are connected to the liquid pipe 11.
and are connected in an annular manner by a gas pipe 12 to constitute a refrigerant circuit.

The operation of the multi-room air conditioner configured as above will be explained.

First, to explain the operation during cooling operation, the compressor 2
The high-temperature, high-pressure gas refrigerant that has been adiabatically compressed is branched by a four-way valve 3 and enters the outdoor unit heat exchanger 4, where it is cooled and condensed by the passing outside air by the operation of the outdoor unit fan 6, and becomes a high-pressure liquid refrigerant. , further passes through the outdoor unit side expansion valve 5, becomes a medium-pressure liquid refrigerant, travels through the liquid pipe 11, and is supplied to the plurality of indoor units 7.
a, 7b.

7c and 7d. A plurality of indoor units 7a.

7b, 7c and 7d, indoor unit side expansion valve 8a;

8b, 8c, and 8d expand adiabatically, lowering the pressure and temperature, and forming a mist in the indoor unit side heat exchanger 9a.

9b, 9c and 9d, and the indoor unit side fan IOa.

The operation of 10b, 10c and IOd cools the room, and evaporates through heat exchange to become a low-temperature, low-pressure gas refrigerant, which returns to the compressor 2 through the liquid pipe 11. At this time, if any of the indoor units 7a, 7b, 7c, and 7d is in a stopped state, for example, when the indoor unit 7a is stopped,
The indoor unit-side expansion valve 8a is closed, and no refrigerant flows into the stopped indoor unit 7a.

Next, to explain the operation during heating, the high-temperature, high-pressure gas refrigerant that has been adiabatically compressed by the compressor 2 is branched by the four-way valve 3 and transmitted through the gas pipe 12 to the indoor units 7a, 7b, 7.
c and 7d. In the indoor units 7a, 7b, 7c and 7d, indoor unit side fans 10a and 10 are installed, respectively.
In the operated indoor unit side heat exchangers 9a, 9b, 9c and 9d, the indoor unit side heat exchangers 9a, 9b, 9c and 9d exchange heat with the indoor air for heating and condense into high pressure liquid refrigerant, and further, the indoor unit side expansion valve 8a , 8b.

It passes through 8C and 8d, becomes medium pressure liquid refrigerant, and enters liquid pipe 11.
and returns to outdoor unit 1. Furthermore, in the outdoor unit 1 , it becomes a mist at the outdoor unit side expansion valve 5 , evaporates at the outdoor unit side heat exchanger 4 , and returns to the compressor 2 as a low-temperature, low-pressure gas refrigerant. At this time, if any of the indoor units 7a, 7b, 7c, and 7d is in a stopped state, for example, when the indoor unit 7a is stopped,
The indoor unit side expansion valve 8a is slightly opened, and the indoor unit 7a is stopped.
Almost no refrigerant flows through.

(Problem to be Solved by the Invention) However, in the above configuration, during heating, the gas refrigerant condenses and becomes a liquid refrigerant even in the indoor unit heat exchanger 9a of the indoor unit 7a that is in a stopped state, and the operating state Indoor unit 7 in
There was a problem in which the circulating amount of refrigerant flowing through A decreased, causing both high and low pressure to drop, causing the pressure state to become abnormal and making operation impossible. For example, outdoor unit 1 with 10 horsepower and outdoor unit 1 with 4 horsepower , 3 horsepower.

2 horsepower and 1 horsepower indoor units 7a, 7b, 7c and 7
When using only the 1-horsepower indoor unit 7d for heating in a multi-room air conditioner consisting of the combination d, the indoor unit-side expansion valve 8d of the 1-horsepower indoor unit 7d is set to an opening degree according to the operating conditions. ,
4 horsepower, 3 horsepower and 2 horsepower indoor units 7 in a stopped state
Indoor unit side expansion valves 8a, 8b, and 8C of a, 7b, and 7c are all slightly open. At this time, the high-pressure gas flowing through the indoor units 7a, 7b, and 7c, which are in a stopped state, is condensed in the indoor unit heat exchangers 9a, 9b, and 9c, becomes liquid refrigerant, and expands slightly on the indoor unit side. Valve 8a, 8
However, if the opening degree of the indoor unit-side expansion valve 8d of the 1-horsepower indoor unit 7d becomes smaller due to a change in operating conditions, the 1-horsepower indoor unit 7d The amount of refrigerant flowing through the indoor units 7a, 7b, and 7C, which are in the stopped state, increases.
, 7b, and 7c, the amount of liquid refrigerant condensed increases.

Moreover, the indoor unit 7a is stopped.

The condensation of 7b and 7c increases even if the indoor temperature decreases due to fluctuations.

When these factors overlap, the indoor unit side expansion valve 8a.

The amount of condensation is greater than the amount of refrigerant returning to the outdoor unit 1 from 8b, 8c, and 8d, and the indoor unit 7 soon stops.
Condensed liquid refrigerant begins to accumulate in a, 7b, and 7c. This state continues, and the indoor unit 7a, which is in a stopped state,
When the amount of liquid refrigerant stored in 7b and 7c becomes too large, the amount of refrigerant circulating through the 1-horsepower indoor unit 7d is drastically reduced, and as a result, both the high and low pressures decrease, causing the pressure state to become abnormal and operation to be interrupted. becomes incapable.

As a countermeasure to this problem, it is possible to increase the opening degree of the indoor unit expansion valves 8a, 8b, and 8c of the 4 horsepower, 3 horsepower, and 2 horsepower indoor units 7a, 7b, and 7c that are in a stopped state. Conversely, since the amount of circulation to the 1-horsepower indoor unit 7d that is in operation is reduced, the desired heating capacity cannot be obtained, and it becomes necessary to increase the amount of refrigerant sealed. This is not appropriate because it causes a difference in the amount of refrigerant that is appropriate for cooling.

Moreover, as another measure, the indoor unit side heat exchanger 9a.

A second indoor unit expansion valve is provided on the opposite side of indoor unit expansion valves 8a, 8b, and 8C, sandwiching 9b and 9C, and during cooling, the second indoor unit expansion valve is fully closed and in a stopped state. Although it is possible to eliminate condensation within the indoor units 7a, 7b, and 7C, this method eliminates condensation within all the indoor units 7a, 7b, and 7C.
It is necessary to provide a second indoor unit side expansion valve for each of 7c and 7d, which significantly increases cost and is not appropriate.

The present invention solves the above problems, and provides a multi-room air conditioner with a simple configuration that does not become inoperable even during heating and always maintains an appropriate operating pressure state. .

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a second four-way valve in the outdoor unit and supplies the refrigerant to the indoor unit side expansion valves 8a, 8b, 8c during both cooling and heating. And from 8d, it is circulated in the direction of indoor unit side heat exchangers 9a, 9b, 9c and 9d.

(Function) With the above configuration, the indoor units 7a and 7b stop during heating.
Since the indoor unit-side expansion valves 8a, 8b, and 8C of 7c can be fully closed, the operation can always maintain an appropriate operating pressure state regardless of changes in indoor and outdoor load conditions.

(Example) An embodiment of the present invention will be described using the configuration diagram of FIG.

In the same figure, the difference between this embodiment and the conventional example shown in FIG. The first conduit 13b is connected to the liquid pipe 11 connected to the outdoor unit expansion valve 5, and the second conduit 13c is connected to the indoor units 7a, 7b.
, 7c and 7d, the outgoing pipe 14 is connected to the indoor unit side expansion valves 8a, 8b, 8c and 8d, the third conduit +3d is the gas pipe 12 connected to the four-way valve 3, and the fourth conduit 13e is connected to the indoor unit side expansion valve 8a, 8b, 8c and 8d. The points where 7a, 7b, 7c and 7d are connected to the return pipes 15 connected to the indoor unit side heat exchangers 9a, 9b, 9c and 9d, respectively, and the indoor unit 7a, 7b, 7c
and 7d indoor unit side expansion valves 8a, 8b, 8c and 8
The point is that an electric expansion valve is adopted for d, making it possible to fully close the valve.

Since the rest is the same as the conventional example, the same components are given the same reference numerals and their explanations will be omitted.

In addition, in this embodiment, the outdoor unit side heat exchanger 4 has a power of 10 horsepower,
The indoor unit side heat exchangers 9a, 9b, 9c, and 9d were set to 4 horsepower, 3 horsepower, 2 horsepower, and 1 horsepower, respectively, and the compressor 2 was variable between 2 and 10 horsepower.

The operation of the multi-room air conditioner configured as described above will be explained.

During cooling, the electromagnetic four-way valve 13a is not energized, and the first conduit 13b and the second conduit! 3c, the third conduit 13d, and the fourth conduit 13e are in communication with each other, so that the refrigerant circuit configuration is the same as that of the conventional refrigerant circuit, and the same cooling operation as the conventional one is performed.

A case will be described in which, for example, only the indoor unit 7d (1 horsepower) is operated during heating. When the electromagnetic four-way valve 13a is energized, the first conduit 13b and the fourth conduit 13e are connected to the second conduit 1.
3c and the third conduit 13d communicate with each other.

On the other hand, the indoor unit expansion valve 8d is set to an opening degree according to the operating conditions, and the indoor unit expansion valves 8a, 8b, and 8C of the indoor units 7a, 7b, and 7c that are in a stopped state are fully closed. The high-temperature, high-pressure gas compressed by the compressor 2 passes through the four-way valve 3 to the third
The refrigerant passes through the conduit 13d and the second conduit 13c, exchanges heat with indoor air in the indoor unit heat exchanger 9d via the indoor unit side expansion valve 8d, and condenses to become a high-pressure liquid refrigerant.
It passes through the conduit 13b, is depressurized by the outdoor unit side expansion valve 5, evaporates in the outdoor unit side heat exchanger 4, becomes low temperature, low pressure gas, and returns to the compressor 2. At this time, is the indoor unit in a stopped state? a, 7b
Since the indoor unit side expansion valves 8a, 8b and 8C of 7C are fully closed, the high temperature and high pressure gas passing through the second conduit 13c does not flow into the indoor unit side heat exchangers 9a, 9b and 9C. . Therefore, the phenomenon that occurs in the past, where the amount of refrigerant circulating through the 1-horsepower indoor unit 7d is drastically reduced, resulting in the pressure state becoming abnormal and making operation impossible, does not occur, and even if the heating conditions change, the system is always maintained properly. It is possible to operate at operating pressure.

In this embodiment, the electromagnetic four-way valve 13a is de-energized during heating, and the first conduit 13b is connected to the four-way valve 3 as shown in FIG. 1(b).
And the second conduit 13c is the indoor unit side expansion valve 8a.

8b, 8c, and 8d, the third conduit 13d is the outdoor unit side expansion valve 5, and the fourth conduit 13e is the indoor unit side heat exchanger 9a.

Connect to 9b, 9c, and 9d, respectively, and the power is off! 111f23b and the second conduit f13c are the third conduit 1
3d and the fourth conduit 13e are in communication with each other, and when energized, the electromagnetic four-way valve 13a is switched so that the first conduit 13b and the fourth conduit 13e are in communication with each other, and the second conduit 13c and the third conduit 13d are in communication with each other. Needless to say, it's a good thing.

In addition, although a four-way valve was used for the refrigerant flow switching device 13,
It goes without saying that similar effects can be obtained by configuring a similar refrigerant circuit by combining three-way valves and the like.

(Effects of the Invention) As explained above, according to the present invention, even if the operating conditions change during heating, liquid refrigerant does not accumulate in the indoor unit when it is stopped.
A multi-chamber air conditioner that can always maintain an appropriate operating pressure state is obtained.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are a block diagram of a multi-chamber air conditioner according to the present invention and a block diagram of its essential parts, and FIG. 2 is a block diagram of a conventional multi-chamber air conditioner. 1...Outdoor unit, 2...Compressor, 3...
Four-way valve, 4...Outdoor unit side heat exchanger, 5...Outdoor unit side expansion valve, 6...Outdoor unit side fan, 7a,
7b, 7c, 7d--Indoor unit, 8a, 8b
, 8c, 8d-=indoor unit side expansion valve, 9a,
9b, 9c, 9d-=indoor unit side heat exchanger, 10a,
Job, 10c, 10d--Indoor unit side fan,
DESCRIPTION OF SYMBOLS 11...Liquid pipe, 12...Gas pipe, 13...Refrigerant flow switching device,] 3a...Solenoid four-way valve, 13b...
First conduit, 13c...Second conduit, 13d...Third conduit, 13e...Fourth conduit, 14...Outgoing pipe, 15.
・Return pipe.

Claims (1)

[Claims] In a multi-room air conditioner in which an outdoor unit consisting of a compressor, a four-way valve, a heat exchanger, and an expansion valve is connected to a plurality of indoor units consisting of expansion valves and heat exchangers to form a ring-shaped refrigerant circuit, A multi-room air conditioner characterized in that the outdoor unit is provided with a refrigerant flow switching means to circulate the refrigerant from the expansion valve to the heat exchanger in the indoor unit both during cooling and heating.