JPS6144259A - 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 Application of the Invention] The present invention relates to an air conditioner, and particularly to an air conditioner for heating and cooling multiple rooms, which is constructed by sequentially connecting a plurality of indoor units in parallel to one outdoor unit. It is related to.

[Background of the invention]

Conventionally, in air conditioners for multi-room heating and cooling, the appropriate amount of refrigerant in the refrigeration cycle is different for single-room operation and multi-room operation. The refrigeration cycle cannot be operated efficiently, and the liquid refrigerant remains in the heat exchanger when the operation is stopped, resulting in a refrigerant shortage. In order to solve these problems, it is known that pressure equalization pipes are attached to each indoor unit (
% Kaisho 58-8959. Utility Model 179076 (1976).

However, when each indoor unit is provided with a pressure equalizing pipe, there are problems that need to be improved, such as a complicated structure and an increase in the amount of control.

[Purpose of the invention]

The present invention improves the problems of the prior art described above, and provides an air conditioner that has a simple structure and always maintains an appropriate amount of refrigerant in the refrigeration cycle, regardless of whether it is operated in a single room or in multiple rooms. This is the purpose.

[Summary of the invention]

The configuration of the air conditioner according to the present invention includes at least a compressor, a four-way switching valve, and a branch point on the compressor side of a pipe extending from the four-way switching valve of an outdoor unit having an outdoor heat exchanger;
At least an indoor heat exchanger,
In an air conditioner formed by sequentially connecting a plurality of indoor units having pressure reducers in parallel, a solenoid valve is provided in the middle of an indoor heat exchanger.

More specifically, a solenoid valve for flow control during heating operation is provided in the middle of the indoor heat exchanger, and during heating operation, excess refrigerant from the stopped indoor unit is transferred to a liquid between the branch point and the solenoid valve. It is designed to be retained as a refrigerant.

[Embodiments of the invention]

Hereinafter, the present invention will be explained by examples.

FIG. 1 is a cycle configuration diagram of an air conditioner according to a first embodiment of the present invention.

In FIG. 1, 1 is a compressor 4 whose rotation speed can be changed according to its capacity. Four-way switching valve that switches between cooling and heating operation by switching the flow direction of refrigerant 5. This is an outdoor unit consisting of an outdoor heat exchanger 6. Reference numeral 2 denotes an indoor heat exchanger consisting of a first indoor heat exchanger A7 and a second indoor heat exchanger A9, which are provided with a solenoid valve hole 8 at an intermediate position (details will be described later).

A reversible expansion valve A for a pressure reducer that can arbitrarily change the throttle from fully open to fully closed, allowing refrigerant to flow from both directions.
This is an indoor unit A consisting of IO.

3, a solenoid valve B12 is provided at an intermediate position (details will be described later),
First indoor heat exchanger Bll and second indoor heat exchanger 8
1.3, an indoor unit consisting of a reversible expansion valve (B14) associated with a pressure reducer that can optionally change the aperture from fully open to fully closed and allow refrigerant to flow from both directions. .

15 is a pipe coming out of the four-way switching valve 5, 17 is a pipe coming out of the outdoor heat exchanger 6, and a branch point 168 on the compressor side.
and the outdoor heat exchanger side branch point 18a.
The indoor units) B3 are connected in parallel between the compressor side branch points 1 and 6b and the outdoor heat exchanger side branch point 18b.

1.52 is the four-way switching valve 5 and the indoor unit A2.
Pipes a and 15b connecting with are connected to pipe al 5a,
Piping b1 connecting indoor unit A2 and indoor unit B3
17a is a pipe a' that connects the indoor unit A2 and the outdoor heat exchanger 6, and 17b is a pipe b' that is connected to the pipe a'17a and connects the indoor unit A2 and the indoor unit B3.

To explain the intermediate positions where the solenoid valves A and 8 (the same goes for solenoid valve B 1.2) are installed, when the solenoid valve A8 is closed, the amount of refrigerant that is approximately equal to the amount of refrigerant during heating operation is transferred to the solenoid. It is provided at an intermediate position where it can be retained between the valve hole 8 and the compressor side branch point 16a.

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

A case will be described in which two air-conditioned rooms in which indoor unit A2 and indoor unit B3 are placed are simultaneously cooled. In this case, set the four-way switching valve 5 to the cooling operation side, and set the solenoid valve A8 to the cooling operation side.
and set solenoid valve B12 open. When the air conditioner is turned on here, the throttles of the expansion valves AIO and B14 are adjusted according to the required cooling capacity of each air-conditioned room, and the rotation speed of the compressor 4 is adjusted to the cooling load of the double-wave air-conditioned room. It is operated while changing depending on the situation. As a result, the high temperature and high pressure gas refrigerant discharged from the compressor 4 is transferred to the four-way switching valve 5.
through the outdoor heat exchanger 6, where the heat is radiated to the outside air and condensed. This condensed drip refrigerant passes through the pipes aJ and 7a, and part of it is sent to the expansion valve AIO, and the rest passes through the pipe b'17b and is sent to the expansion valve B14. The refrigerant that has become low pressure in the expansion valves 1 and 10 and the expansion valve B14 absorbs heat from the air-conditioned room, becomes a gas refrigerant, is sent to the four-way switching valve 5 through the pipe a15a and the pipe b15b, and is then returned to the compressor 4. Return to

In addition, if cooling of one of the air-conditioned rooms is no longer necessary,
The indoor unit of the air-conditioned room that is no longer needed, for example, the expansion valve AIO of the indoor unit A2, is fully closed, and the solenoid valve A8 is opened to operate. By doing this, the first. Second indoor heat exchange A7. A, the pressure inside 9 becomes low pressure,
It becomes a gas refrigerant, and there is no longer any stagnation of liquid refrigerant.

Next, a case will be described in which two air-conditioned rooms are heated at the same time. In this case, the four-way switching valve 5 is set to the heating operation side, and the solenoid valve hole 8 and solenoid valve B12 are set to open. When the air conditioner is turned on here, the expansion valve A10. It is operated while controlling the throttle of the expansion valve B14 and the rotation speed of the compressor 4. As a result, contrary to the cooling operation, the high-temperature, high-pressure gas refrigerant leaving the compressor 4 passes through the pipes a15a and b15b to the respective indoor heat exchangers A7. The heat is sent to A9, Bll, and B13, and is radiated to the air-conditioned room and condensed, and the expansion valve A10°B14
The refrigerant becomes a low pressure, passes through the pipes a'l7a and b'17b, absorbs heat from the outside air in the outdoor heat exchanger 6, becomes a gas refrigerant, and returns to the compressor 4 through the four-way switching valve 5.

Further, when heating of one of the air-conditioned rooms is no longer necessary, for example when heating of the indoor unit A2 is no longer necessary, the solenoid valve A8 is closed and the expansion valve AIO is fully opened for operation. As a result, the inside of the first indoor heat exchanger A7 in the indoor unit A2 is not on the high pressure side, the refrigerant is condensed, and the liquid refrigerant is retained. On the other hand, in the second indoor heat exchanger A9, the cam refrigerant evaporates on the low pressure side and becomes a gas refrigerant. By the way, if the solenoid valve hole 8 is closed, the first indoor heat exchanger A7
Set the position of the solenoid valve hole 8 so that the amount of liquid refrigerant that stays in the area (between the compressor side branch point 162 and the solenoid valve hole 8) is the same as the amount of refrigerant in A2 of the indoor unit during heating operation. Therefore, the amount of refrigerant in the refrigeration cycle becomes appropriate even during the heating partial operation in which only one air-conditioned room is heated, making it possible to perform highly efficient heating operation.

According to the first embodiment described above, the structure is simple because there is no need to provide pressure equalization pipes, and the amount of refrigerant during heating operation can be controlled to an appropriate value regardless of single-room or multi-room heating. This has the effect of being able to provide an air conditioner that has a high efficiency refrigeration cycle and can save power.

Although the above-mentioned embodiments relate to a two-unit air conditioner for heating and cooling, the present invention can also be applied to an air conditioner for heating and cooling multiple rooms in a royal room or above.

FIG. 2 is a cycle configuration diagram of an air conditioner according to a second embodiment of the present invention.

In FIG. 2, the same numbers as in FIG. 1 indicate the same parts. 19 is a cooling capillary tube A120 related to a pressure reducer, and a cooling solenoid valve A121 is,
The heating capillary tube A122 related to the pressure reducer is the heating check valve A123, the cooling capillary tube B124 related to the pressure reducer is the cooling solenoid valve B125, and the heating capillary tube B126 related to the pressure reducer is the heating check valve. B
It is.

The operation of the air conditioner constructed in this way according to FIG. 2 will be explained.

During cooling operation, in the case of dual cooling, solenoid valve A8. Solenoid valve B12. Cooling solenoid valve A20. Open the cooling solenoid valve B24. By operating in this manner, a part of the sweat refrigerant condensed in the outdoor heat exchanger 6 is transferred to the pipe a'17a,
The cooling solenoid valve A20 is passed through υ, and the remaining liquid refrigerant is piped b'1.
7b, the cooling solenoid valve B24 is passed through each cooling capillary tube A19. The pressure is reduced at B23, and the indoor heat exchanger A7. A9. Heat is absorbed from the air-conditioned room at Bl 1 ' and Bl 3.

In addition, when cooling of one of the air-conditioned rooms is no longer necessary, for example, when cooling of the air-conditioned room on the side of the indoor unit A2A is no longer necessary, the cooling solenoid valve A20 is closed.

By operating with the solenoid valve A8 open, the insides of the first indoor heat exchanger A7 and the second indoor heat exchanger A9 become low-pressure, and the refrigerant evaporates, leaving only gas refrigerant. Therefore, no liquid refrigerant remains in the indoor unit A2A.

On the other hand, during heating operation, in the case of dual heating, solenoid valve A8.
Open the solenoid valve B1'2 and close the cooling solenoid valve A20° and the cooling solenoid valve B24. By operating in this manner, the high temperature gas refrigerant that has exited the compressor 4 is transferred to the pipe a 15.
a and pipe b15b to the indoor heat exchanger A7. A9, Bll, and B13 radiate heat to the air-conditioned room and condense it, and each heating capillary tube A21. B2
5. Heating check valve A22. B26 is passed through and sent to the outdoor heat exchanger 6, where it absorbs heat from the outside air, passes through the gas refrigerant and potash, and returns to the compressor 4 through the four-way switching valve 5.

If the heating of one air-conditioned room is no longer necessary, for example, the indoor unit) A, 2 If the heating of the A side is no longer necessary, close the solenoid 8 and turn the cooling solenoid valve A20. Drive with it open. As a result, similarly to the first embodiment, the first indoor heat exchanger A7 becomes a high-pressure side and liquid refrigerant accumulates, and the second indoor heat exchanger A9 becomes a low-pressure side and gas It becomes a refrigerant and can always be operated with the appropriate amount of refrigerant in the refrigeration cycle.

According to the second embodiment described above, when using a compressor with a small capacity variable range in which an appropriate restriction can be obtained with a capillary tube, in addition to the effects of the first embodiment, the expansion valve The advantage is that the amount of refrigerant in the refrigeration cycle can be properly controlled using an inexpensive pressure reducer (capillary tube) without using a refrigeration cycle.

FIG. 3 is a cycle configuration diagram of an air conditioner according to a third embodiment of the present invention.

In FIG. 3, the same parts as in FIG. 1 are denoted by the same numbers. 29 is a second pressure reducer provided at the indoor unit side outlet of the outdoor heat exchanger 6, and the resistance of this second pressure reducer 29 is such that during cooling operation, the resistance of the pipe a'
17a, the temperature of the refrigerant in the pipe b'l'1 is selected to be lower than the temperature of the air-conditioned room. 27 is outdoor unit IA
Capillary tube 28 related to resistance, installed between the inlet and outlet of B3B (the indoor unit located farthest from the
The resistance of the capillary tube 28 is such that during heating operation, when the indoor unit B3B is stopped, the amount of refrigerant flowing into the bypass circuit 27 is slightly larger than the amount of refrigerant condensed due to heat radiation from the pipe b15b. Choose flowingly.

The operation of the air conditioner constructed in this way according to FIG. 3 will be explained. During cooling operation, the liquid refrigerant condensed in the outdoor heat exchanger 6 is depressurized by the second pressure reducer 29 and becomes a gas-liquid two-phase liquid refrigerant.

b'17b (in case of dual cooling) to expansion valve A10.
The pressure is reduced again by the expansion valve B14 and the indoor heat exchanger A7. A9
．． Bll and B13 absorb heat from the air conditioned room. in this case,
Although the refrigerant also flows through the flow path 27, the resistance of the capillary tube 28 causes the expansion valve A10. The resistance is much greater than that of the expansion valve B14, and there is almost no thermal loss.

However, if cooling of one of the air-conditioned rooms is no longer necessary, for example, indoor unit (B3B) is no longer necessary, and even if the expansion valve B14 in this indoor unit BaB is fully closed, the inside of piping b'17b is Since the refrigerant flows through the bypass passage 27, the amount of refrigerant in the piping is almost the same as when all rooms are cooled.

On the other hand, during heating operation, the indoor heat exchanger A7°A9. Bl
The liquid refrigerant condensed in B13 is depressurized by expansion valve AIO and expansion valve B14, and becomes gas-liquid two-phase.
, b'17b and returns to the second compressor 4.

In addition, if heating of one of the air-conditioned rooms is no longer necessary, for example, indoor unit) B3B is no longer needed, and even if solenoid valve B12 in this indoor unit) BaB is closed, piping b
Inside the lsb, more refrigerant flows through the bypass circuit 27 than the amount of refrigerant condensed by heat radiation, so the inside of the pipe b15b is always a gas refrigerant chamber, and there is no difference in the amount of refrigerant compared to during full cooling/heating operation.

In fact, since the liquid refrigerant remains in the first indoor heat exchanger B11, the amount of refrigerant in the refrigeration cycle becomes appropriate, and the refrigeration cycle can always be operated with high efficiency.

According to the third embodiment described above, in addition to the effects of the first embodiment, the pipe a15a and the pipe b1.5b use gas refrigerant for both cooling and heating, and the pipe a'17a and the pipe b
In '17b, both cooling and heating are gas-liquid two-phase, and the amount of refrigerant in the piping is reduced, so the amount of refrigerant sealed in the refrigeration cycle can be reduced.

In addition, even if the amount of refrigerant in the pipes varies greatly between cooling and heating, and even if the pipes are long, the system can always be operated with an appropriate amount of refrigerant.

FIG. 4 is a cycle configuration diagram of an air conditioner according to a fourth embodiment of the present invention.

In FIG. 4, the same parts as in FIG. 3 are denoted by the same numbers. And 30 is the compressor side branch point 16a
The branch point 1 on the compressor side of the pipe b15b leading from the indoor unit (indoor unit) B3 on the side away from one person in the outdoor unit
A solenoid valve C provided near 6a.

The operation when the indoor unit) B3 is stopped during heating operation of the air conditioner according to FIG. Therefore, the explanation will be omitted).

When stopping the indoor unit B3 during heating operation, close the solenoid valve B i-2 in advance, and after a predetermined period of time has elapsed after the start of operation, the inside of the first indoor heat exchanger B], ] and the piping are closed. blsb
After the liquid refrigerant is condensed inside, the solenoid valve C30 is closed. As a result, the excess refrigerant is transferred to the first indoor heat exchanger Bll.
and piping 1) 15 b, and the amount of refrigerant in the refrigeration cycle becomes appropriate.

In addition, the length of piping b 1.5 b is long, and the length of piping b l
If there is a risk that the amount of refrigerant remaining in 5b becomes large and the amount of refrigerant in the refrigeration cycle becomes small and the degree of superheating of the outdoor heat exchanger 6 increases, during operation,
Solenoid valve B12 until the degree of superheating of the outdoor heat exchanger 6 is exhausted.
may be opened, and a portion of the liquid refrigerant remaining in the first outdoor heat exchanger B i I and the pipes b ] and 5 b may be returned to the refrigeration cycle.

According to the fourth embodiment described above, the bypass circuit 27
Therefore, all the amount of circulating refrigerant can be used, and the third
The efficiency is even better than that of the embodiment, and there is an effect that efficiency does not decrease even if the piping is lengthened.

FIG. 5 is a schematic diagram showing the main parts of an indoor unit of an air conditioner according to a fifth embodiment of the present invention.

In FIG. 5, the same parts as in FIG. 1 are denoted by the same numbers. And 32 is a small electromagnetic valve provided in parallel with the check valve 31. Normally, the solenoid valve 8, which has little resistance to flow in both directions of cooling and heating, is expensive. Therefore, instead of using the solenoid valve 8, a small solenoid valve 32 installed in parallel with the check valve 31 is used.The solenoid valve 32 is used to flow the refrigerant during heating operation, and the check valve 31 is closed during cooling operation. This has the advantage of reducing power consumption and cost.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide an air conditioner that has a simple structure and in which the amount of refrigerant in the refrigerating cycle is always appropriate regardless of whether the air conditioner is operated in a single room or in multiple rooms.

[Brief explanation of drawings]

1 to 4 are cycle configuration diagrams of air conditioners according to the first to fourth embodiments of the present invention, and FIG. 5 is a diagram of the indoor unit of the air conditioner according to the fifth embodiment of the present invention. FIG. 3 is a schematic diagram showing main parts. 1, IA...Outdoor unit, 2.2A, 2B Mountain indoor unit A, 3.3A, 3B...Indoor unit B14
Compressor, 5... Four-way switching valve, 6... Outdoor heat exchanger, 7... First indoor heat exchanger A, 8... Solenoid valve, 9... No. 2 indoor heat exchanger A110...
Expansion valve A11]...first indoor heat exchanger B1]2.
...Solenoid valve B113...Second indoor heat exchanger B11
4... Expansion valve B, 15-... Piping, 15b-... Piping,
16a. 16b... Compressor side branch point, 17... Piping, 18a
. 18b...Outdoor heat exchange side branch point, 19...Cooling capillary tube A121...Heating capillary tube A123...Cooling capillary tube B125.
...Capillary tube for heating B127...No.41
42 circuits, 28... capillary tubes, 29...
Second Ya No. 20! Kaya9 figure

Claims (5)

[Claims] 1. At least a branch point on the compressor side of the piping exiting from the four-way switching valve of an outdoor unit having a compressor, a four-way switching valve, and an outdoor heat exchanger, and an outdoor heat exchanger side of the piping exiting from the outdoor heat exchanger. In an air conditioner in which a plurality of indoor units each having at least an indoor heat exchanger and a pressure reducer are sequentially connected in parallel between the branch point and the indoor heat exchanger, a solenoid valve is installed in the middle of the indoor heat exchanger. An air conditioner characterized by: 2. An indoor heat exchanger capable of retaining an amount of refrigerant approximately equal to the amount of refrigerant during heating operation between the solenoid valve and a branch point on the compressor side when the solenoid valve is closed. 2. The air conditioner according to claim 1, wherein the air conditioner is installed at a midway position of the air conditioner. 3. The air conditioner according to claim 2, wherein a second pressure reducer is provided at the indoor unit side outlet of the outdoor heat exchanger. 4. 4. The air conditioner according to claim 3, wherein a bypass circuit having resistance is provided between the inlet and outlet of the indoor unit located farthest from the outdoor unit. 5. Claim 3: A solenoid valve is provided near the compressor side branch point on the piping leading from the compressor side branch point to the indoor unit on the side away from the outdoor unit.
Air conditioner as described in section.