JPH04309754A - Multiple chamber air conditioner - Google Patents

Abstract

PURPOSE:To carry out a normal operation without using an expensive solenoid valve or a complicated refrigerating circuit and while avoiding leakage from the solenoid valve adapted to select the cooling or heating operation of an air conditioner in a room in any operating condition. CONSTITUTION:One air conditioner 5 in a room is connected to a first connecting piping 10 and a second connecting piping 11 via a passage switching mechanism 14 adapted to switch a refrigerant passage between the cooling and heating operation and the other air conditioner 5 therein is connected to a third connecting piping 12 via an expansion valve 7 and to the first connecting piping 10 via a flow amount control device 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner, and more particularly to a refrigeration cycle for a multi-room air conditioner in which heating and cooling can be freely selected for each indoor unit.

0002

2. Description of the Related Art Conventionally, this type of multi-room air conditioner has been disclosed, for example, in Japanese Patent Application Laid-Open No. 2-97857.

[0003] The conventional multi-room air conditioner disclosed in the above-mentioned publication will be described below with reference to the drawings.

In FIG. 5, reference numeral 1 denotes an outdoor unit of a multi-room air conditioner, which is composed of a compressor 2, a four-way valve 3, and an outdoor heat exchanger 4. 5 is an indoor unit, an indoor heat exchanger 6,
It consists of an expansion valve 7, a first solenoid valve 8, and a second solenoid valve 9.

One side of the indoor heat exchanger 6 communicates with a first connecting pipe 10 that connects the outdoor unit 1 and the indoor unit 5 via a first solenoid valve 8, and communicates with a first connection pipe 10 that connects the outdoor unit 1 and the indoor unit 5 via a second solenoid valve 9. and communicates with a second connection pipe 11 that connects the outdoor unit 1 and the indoor unit 5, and by opening and closing the first solenoid valve 8 and the second solenoid valve 9, one of the indoor heat exchangers 6 is connected to the first It is switchably connected to the connecting pipe 10 or the second connecting pipe 11.

The other side of the indoor heat exchanger 6 is connected to an expansion valve 7.
It is connected to the third connecting pipe 12 through the
The connecting pipe 12 is connected to the first connecting pipe 10 via a flow rate control device 13. In addition, three indoor units 5 are connected in this conventional example, and the subscripts a, b, and c are used to distinguish them.
I will add .

Next, the operation of the multi-room air conditioner having the above configuration will be explained. First, the case of only cooling operation will be explained. The flow of refrigerant in this case is represented by solid arrows, and the open/close states of each valve are as follows. That is, the first electromagnetic valve 8 is closed, the second electromagnetic valve 9 is open, the flow rate control device 13 is open, and each expansion valve 7 is opened according to each indoor load.

The high temperature and high pressure gas discharged from the compressor 2 is
It is condensed and liquefied in the outdoor heat exchanger 4, and then transferred to the first connection pipe 10.
, and is led to the third connection pipe 12 through the flow rate control device 13. The air then flows into each indoor heat exchanger 6 through the expansion valve 7, where it is evaporated and vaporized, and then returns to the compressor 2 via the second electromagnetic valve 9 and the four-way valve 3, where it performs cooling operation.

Next, the case of only heating operation will be explained. The flow of refrigerant in this case is represented by a broken line arrow, and the open/close states of each valve are as follows. That is, the first electromagnetic valve 8 is closed, the second electromagnetic valve 9 is open, the flow rate control device 13 is open, and each expansion valve 7 is opened according to each indoor load.

[0010] The high temperature and high pressure gas discharged from the compressor 2 is
It is guided to each indoor heat exchanger 6 via the four-way valve 3 and the second electromagnetic valve 9, where it is condensed and liquefied, flows into the third connection pipe 12 via the expansion valve 7, and is controlled by the flow rate control device 13. It is depressurized to a low-pressure two-phase state, passes through the first connection pipe 10, enters the outdoor heat exchanger 4, is evaporated, and returns to the compressor 2, where heating operation is performed.

Next, the case of cooling-based operation will be explained with reference to FIG. Here, the operating state of each indoor unit 5 is indoor unit 5a, 5b...cooling, indoor unit 5c...heating, and the opening/closing state of each valve is as follows. That is, the first solenoid valves 8a and 8b are closed, the first solenoid valve 8c is open, and the second solenoid valves 9a and 9b are open.
The second electromagnetic valve 9c is closed, the flow rate control device 13 is open, and each expansion valve 7 has an opening degree according to each indoor load.

The refrigerant discharged from the compressor 2 is condensed and liquefied to some extent in the outdoor heat exchanger 4, and then transferred to the first connecting pipe 10.
A part of it is guided to the indoor heat exchanger 6c via the first electromagnetic valve 8c, where it is condensed and liquefied, and flows into the third connection pipe 12 through the expansion valve 7c. The remaining refrigerant flows into the third connection pipe 12 through the flow rate control device 13, joins with the refrigerant from the expansion valve 7c, and then evaporates in the indoor heat exchangers 6a, 6b via the expansion valves 7a, 7b. It is vaporized and returns to the compressor 2 through the second connection pipe 11.

Next, the case of heating-based operation will be explained with reference to FIG. Here, the operating state of each indoor unit 5 is indoor unit 5a, 5b...heating, indoor unit 5c...cooling, and the opening/closing state of each valve is as follows. That is, the first solenoid valves 8a and 8b are closed, the first solenoid valve 8c is open, and the second solenoid valves 9a and 9b are open.
The second electromagnetic valve 9c is closed, the flow rate control device 13 is open, and each expansion valve 7 has an opening degree according to each indoor load.

The refrigerant discharged from the compressor 2 passes through the second connecting pipe 11 and is guided to the indoor heat exchangers 6a and 6b via the second electromagnetic valves 9a and 9b, where it is condensed and liquefied to the expansion valve. It flows into the third connecting pipe 12 through 7a and 7b. A part of the refrigerant passes through the expansion valve 7c to the indoor heat exchanger 6.
It is evaporated at step c and flows into the first connection pipe 10 through the first electromagnetic valve 8c. In addition, the remaining refrigerant is transferred to the flow control device 13.
The pressure is reduced and flows into the first connection pipe 10, and the first solenoid valve 8
It joins with the refrigerant from c, evaporates in the outdoor heat exchanger 4, and returns to the compressor 2.

[0015]

However, in the above configuration, the flow direction of the refrigerant in the first solenoid valve and the second solenoid valve is reversed depending on whether the outdoor unit is in cooling operation or heating operation. This has had the problem that back pressure acts on the solenoid valve, causing leakage from the closed solenoid valve, making normal operation impossible. In order to solve this problem, it would be possible to use a solenoid valve that does not leak even when reverse pressure is applied, but this type of solenoid valve is very expensive, and there are problems such as there is no large capacity available. There was a point.

The present invention has been developed in view of the above-mentioned problems, and has superior workability compared to the conventional two connecting pipes, is inexpensive, eliminates leakage from the solenoid valve, and allows normal operation. To provide a multi-room air conditioner that can freely perform heating and cooling for each indoor unit.

[0017]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an outdoor unit consisting of a compressor, a four-way valve, and an outdoor heat exchanger, and a plurality of indoor units consisting of an expansion valve and an indoor heat exchanger. are connected in parallel through a first connection pipe and a second connection pipe, and one of the indoor heat exchangers has a flow path switching mechanism that switches a refrigerant flow path during cooling or heating operation; The first connection pipe and the second connection pipe are connected to each other via a second solenoid valve.
The other side of the indoor heat exchanger is connected to a third connecting pipe via an expansion valve, and the third connecting pipe is connected to the third connecting pipe via a flow rate control device. 1st
or the second connection pipe, whichever is connected to the outdoor heat exchanger.

[0018]

[Operation] With the above-described configuration, the present invention controls the flow direction of the refrigerant in the two solenoid valves provided per indoor unit.
Regardless of cooling or heating operation, the direction is always constant so that no back pressure acts on the solenoid valve, eliminating leaks in the solenoid valve and always allowing normal operation.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In addition, the same reference numerals are given to the same parts as in the conventional art, and detailed explanation thereof will be omitted.

In FIG. 1, reference numeral 14 denotes a flow path switching mechanism, which connects one of the indoor heat exchangers 6 and the second connecting pipe 11 to the first
It is connected to a fourth connecting pipe 16 that connects the solenoid valve 8 through the first check valve 15 and a fifth connecting pipe 18 that connects the second solenoid valve 9 through the second check valve 17. By reversing the directions of the first check valve 15 and the second check valve 17, the refrigerant flow path is connected to the fourth connection pipe 16 or the fifth connection pipe 1.
It is possible to switch to 8.

Furthermore, one of the first connecting pipes 10 and the fourth connecting pipe 16 are connected to the sixth connecting pipe 2 via the third check valve 19.
0, the other of the first connecting pipe 10 and the fifth connecting pipe 18 are connected to the seventh connecting pipe 22 via the fourth check valve 21, and the third check valve 19 and the fifth connecting pipe 18 are connected to the seventh connecting pipe 22 via the fourth check valve 21. By reversing the direction of the four check valves 21, the refrigerant flow path is connected to the sixth connection pipe 2.
It is possible to switch to the zero or fifth connection pipe 22.

The first solenoid valve 8 is located indoors from the confluence 23 of the fourth connection pipe 16 and the sixth connection pipe 20, and the second solenoid valve 9 is located between the fifth connection pipe 18 and the seventh connection pipe 20. Connection piping 2
The first check valve 15 is located on the indoor side from the confluence point 24 of the second connection pipe 11, and the first check valve 15 is located on the second connection pipe 11 side from the confluence point 23.
The check valve 17 is located on the second connection pipe 11 side from the confluence point 24 , the third check valve 19 is located on the first connection pipe 10 side from the confluence point 23 , and the fourth check valve 19 is located on the first connection pipe 10 side from the confluence point 23 are located on the side of the first connection pipe 10 from the confluence point 24, and the flow direction of each check valve is such that the first check valve 15 is located from the second connection pipe 11 to the indoor unit 5.
The second check valve 17 is from the indoor unit 5 to the second connecting pipe 11, and the third check valve 19 is from the first connecting pipe 10.
The fourth check valve 21 is the direction from the indoor unit 5 to the first connection pipe 10.

Next, the operation in such a configuration will be explained. First, the case of only cooling operation will be explained. The flow of refrigerant in this case is represented by solid arrows, and the open/close states of each valve are as follows. That is, the first solenoid valve 8 is closed,
The second electromagnetic valve 9 is open, the flow rate control device 13 is fully open, and each expansion valve 7 has an opening degree that corresponds to each indoor load.

The high temperature and high pressure gas discharged from the compressor 2 is
It is condensed and liquefied in the outdoor heat exchanger 4, and then transferred to the first connection pipe 10.
, and is led to the third connecting pipe 12 through the flow control device 14. Then, it flows into each indoor heat exchanger 6 through the expansion valve 7, and after being evaporated and vaporized, the second solenoid valve 9 and the second
It returns to the compressor 2 via the check valve 17 and the four-way valve 3, and performs cooling operation.

Next, the case of only heating operation will be explained. The flow of refrigerant in this case is represented by a broken line arrow, and the open/close states of each valve are as follows. That is, the first solenoid valve 8 is open, the second solenoid valve 9 is closed, the flow rate control device 13 is fully open, and each expansion valve 7 is closed.
is the opening degree according to each indoor load.

The high temperature and high pressure gas discharged from the compressor 2 is
Passing from the four-way valve 3 through the second connection pipe 11 to the first solenoid valve 8
It is guided to each indoor heat exchanger 6 via the heat exchanger 6, where it is condensed and liquefied, the pressure is reduced to a low-pressure two-phase state by the expansion valve 7, and it flows into the third connection pipe 12, and flows into the flow rate control device 13 and the first It passes through the connection pipe 10, enters the outdoor heat exchanger 4, is evaporated, and returns to the compressor 2, where heating operation is performed.

Next, the case of cooling-based operation will be explained using FIG. 2. Here, the operating state of each indoor unit 5 is indoor unit 5a, 5b...cooling, indoor unit 5c...heating, and the opening/closing state of each valve is as follows. That is, the first solenoid valves 8a and 8b are closed, the first solenoid valve 8c is open, and the second solenoid valves 9a and 9b are open.
The second electromagnetic valve 9c is closed, and the flow rate control device 13 is opened to an opening that can ensure a refrigerant circulation amount according to the horsepower number of the heating indoor unit.
Each expansion valve 7 has an opening degree according to each indoor load.

The refrigerant discharged from the compressor 2 is condensed and liquefied to some extent in the outdoor heat exchanger 4, and then transferred to the first connecting pipe 10.
A part of the refrigerant passes through the third check valve 19 and is led to the indoor heat exchanger 6c via the first electromagnetic valve 8c, where it is condensed and liquefied, and passes through the expansion valve 7c to the third refrigerant. It flows into the connecting pipe 12. In addition, the remaining refrigerant flows into the third connection pipe 12 through the flow rate control device 13, and after joining with the refrigerant from the expansion valve 7c, the pressure is reduced by the expansion valves 7a and 7b, and the pressure is reduced by the indoor heat exchangers 6a and 6b. It is evaporated and returned to the compressor 2 via the four-way valve 3 via the second electromagnetic valves 9a and 9b, the second check valves 17a and 17b, and the second connection pipe 11, and performs cooling operation.

Next, the case of heating-based operation will be explained using FIG. 3. Here, the operating state of each indoor unit 5 is indoor unit 5a, 5b...heating, indoor unit 5c...cooling, and the opening/closing state of each valve is as follows. That is, the first solenoid valves 8a and 8b are open, the first solenoid valve 8c is closed, and the second solenoid valves 9a and 9b are closed.
The second electromagnetic valve 9c is opened, the flow rate control device 13 is opened to an opening degree that can ensure a refrigerant circulation amount according to the horsepower number of the cooling indoor unit,
Each expansion valve 7 has an opening degree according to each indoor load.

The refrigerant discharged from the compressor 2 passes through the four-way valve 3
from the second connecting pipe 11 to the first check valves 15a, 1
5b, the indoor heat exchanger 6 via the second solenoid valves 9a, 9b
a, 6b, where it is condensed and liquefied to the expansion valves 7a, 7b.
It flows into the third connection pipe 12 through the. Then, a part of the refrigerant is depressurized by the expansion valve 7c, evaporated to some extent by the indoor heat exchanger 6c, and flows into the first connection pipe 10 through the first electromagnetic valve 9c and the fourth check valve 21. In addition, the remaining refrigerant flows into the third connection pipe 12 through the flow rate control device 13, joins with the refrigerant from the fourth check valve 21, and then passes through the first connection pipe 10 for outdoor heat exchange. The air enters the compressor 4, evaporates, and returns to the compressor 2 for heating operation.

Furthermore, there is no problem in a configuration in which one check valve is connected to each of the fourth connection pipe and the fifth connection pipe, as in the second embodiment shown in FIG.

As described above, the direction of the refrigerant flowing through each of the solenoid valves 8 and 9 provided in the indoor unit 5 can always be kept in the same direction regardless of whether the operation is cooling, mainly cooling, heating, or mainly heating. Therefore, no back pressure acts on each electromagnetic valve 8, 9, and leakage from the electromagnetic valve in the closed state, which conventionally occurs, can be eliminated.

[0033]

[Effects of the Invention] As is clear from the above description, the present invention provides an outdoor unit consisting of a compressor, a four-way valve, an outdoor heat exchanger,
a plurality of indoor units consisting of an expansion valve and an indoor heat exchanger;
connected in parallel via a connecting pipe and a second connecting pipe,
One of the indoor heat exchangers is switched to the first connecting pipe and the second connecting pipe via a flow path switching mechanism and first and second electromagnetic valves that switch the refrigerant flow path during cooling or heating operation. the other side of the indoor heat exchanger is connected to a third connection pipe via an expansion valve, and the third
The connecting pipe is connected to either the first connecting pipe or the second connecting pipe, whichever is connected to the outdoor heat exchanger, via a flow rate control device.

Therefore, the multi-room air conditioner of the present invention has inexpensive specifications and can control the direction of refrigerant flowing through each solenoid valve provided in the indoor unit, regardless of whether the operation is cooling, mainly cooling, heating, or heating mainly. It is always possible to maintain a constant direction, eliminate back pressure from acting on each electromagnetic valve, eliminate leaks from closed electromagnetic valves, and perform normal operation. In addition, only two pipes are required to connect the indoor unit and the outdoor unit, resulting in excellent construction efficiency.

[Brief explanation of drawings]

FIG. 1: Refrigeration cycle diagram of a multi-room air conditioner according to the first embodiment of the present invention.

[Fig. 2] A refrigeration cycle diagram showing the cooling-mainly operating state of the multi-room air conditioner of the first embodiment.

[Fig. 3] Refrigeration cycle diagram showing the heating-main operating state of the multi-room air conditioner of the first embodiment.

[Fig. 4] Refrigeration cycle diagram of a multi-room air conditioner according to a second embodiment of the present invention.

[Figure 5] Refrigeration cycle diagram of a conventional multi-room air conditioner

[Figure 6] Refrigeration cycle diagram showing the cooling-dominant operation state of a conventional multi-room air conditioner

[Figure 7] Refrigeration cycle diagram showing the heating-main operating state of a conventional multi-room air conditioner

[Explanation of symbols]

1 Outdoor unit 2 Compressor 3 Four-way valve 4 Outdoor heat exchanger 5 Indoor unit 6 Indoor heat exchanger 7 Indoor expansion valve 8 First solenoid valve 9 First solenoid valve 10 First connection piping 11 Second connection pipe 12 Third connection pipe 13 Flow rate control device 14 Flow path switching mechanism

Claims (2)

[Claims] Claim 1: An outdoor unit consisting of a compressor, a four-way valve, and an outdoor heat exchanger, and a plurality of indoor units consisting of an expansion valve and an indoor heat exchanger are connected to each other through a first connecting pipe and a second connecting pipe. one of the indoor heat exchangers connects the first connection pipe and The other side of the indoor heat exchanger is connected to a third connecting pipe via an expansion valve, and the third connecting pipe is connected to the third connecting pipe via a flow rate control device. The multi-room air conditioner is connected to either the first connecting pipe or the second connecting pipe, whichever is connected to the outdoor heat exchanger. Claim 2: The second connection pipe is switchably connected to the fourth connection pipe or the fifth connection pipe, and the first connection pipe is switchably connected to the sixth connection pipe or the seventh connection pipe. The multi-chamber according to claim 1, further comprising the flow path switching mechanism configured such that the sixth connection pipe is connected to the fourth connection pipe and the seventh connection pipe is joined to the fifth connection pipe. type air conditioner.