JPH04278151A - Multi-chamber type air conditioner - Google Patents

Abstract

PURPOSE:To enable a normal operation to be carried out without having any leakage at a solenoid valve for selecting a cooling or a heating operation of an indoor device at any operational states without using any expensive solenoid valve or a complex refrigerant circuit in regard to a freezing cycle of a multi- chamber type air conditioner capable of selecting freely a cooling or a heating operation for every indoor device, to control an amount of circulation of refrigerant in response to the valve of horse power of each of the indoor devices and to stabilize a system without having any problem in reliability in the compressor such as a rapid increasing of each of discharging pressure and suction pressure. CONSTITUTION:The third connecting pipe 13' is connected to the second connecting pipe 12 through the second flow rate control device 15 and further it is provided with a flow passage changing-over mechanism 16 for changing- over a flow direction of refrigerant within the first connecting pipe 11 or the second connecting pipe 12 when either cooling or heating operation is carried out.

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. 2-106667.

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

In FIG. 4, 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 indoor expansion valve 7, a first solenoid valve 8, and a second solenoid valve 9.

One side of the indoor heat exchanger 6 is connected to the outdoor unit 1 and the indoor unit 5 via the first solenoid valve 8 and the gas-liquid separator 10.
The second connecting pipe 11 connects the outdoor unit 1 and the indoor unit 5 via the second solenoid valve 9.
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 solenoid valve 8.
It is switchably connected to the connecting pipe 11 or the second connecting pipe 12. Note that one side of the indoor heat exchanger 6 communicates with the upper part of the gas-liquid separator 10.

The other side of the indoor heat exchanger 6 is connected to a third connecting pipe 13 via an indoor expansion valve 7, and this third connecting pipe 13 is connected to a third connecting pipe 13 via a first flow rate control device 14. and is connected to the lower part of the gas-liquid separator 10 of the first connection pipe 11. In this conventional example, three indoor units 5 are connected, and to distinguish them, suffixes a, b, and c will be added.

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 first flow rate control device 14 is open, and each indoor 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 11.
, the gas-liquid separator 10, and the third flow rate controller 14.
is guided to the connecting pipe 13. Then, it flows into each indoor heat exchanger 6 through the indoor expansion valve 7, and after being evaporated and vaporized, it passes through the second electromagnetic valve 9, the second connection pipe 12, and the four-way valve 3 to the compressor 2. Return and perform 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 first flow rate control device 14 is open, and each indoor 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 led to each indoor heat exchanger 6 via the four-way valve 3, the second connection pipe 12, and the second solenoid valve 9, where it is condensed and liquefied, and then passed through the indoor expansion valve 7 to the third connection pipe 13. The first
The flow rate controller 14 reduces the pressure to a low-pressure two-phase state, passes through the gas-liquid separator 10 and the first connection pipe 11, enters the outdoor heat exchanger 4, evaporates and vaporizes, and returns to the compressor 2, where heating operation is performed. .

Next, the case of cooling-based operation will be explained using FIG. 5. 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 first flow rate control device 14 is open, and each indoor expansion valve 7 is opened 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 11.
A part of the refrigerant enters the gas-liquid separator 10 through the first electromagnetic valve 8c and is led to the indoor heat exchanger 6c, where it is condensed and liquefied, and passes through the indoor expansion valve 7c to the third refrigerant. Connection piping 1
3.

The remaining refrigerant passes through the first flow rate control device 14 and flows into the third connecting pipe 13, and then enters the indoor expansion valve 7c.
After joining with the refrigerant from the air, the refrigerant is evaporated in the indoor heat exchangers 6a, 6b via the indoor expansion valves 7a, 7b, and returns to the compressor 2 through the second connection pipe 12.

Next, the case of heating-based operation will be explained using FIG. 6. 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 first flow rate control device 14 is open, and each indoor expansion valve 7 is opened according to each indoor load.

The refrigerant discharged from the compressor 2 passes through the second connecting pipe 12 and is led to the indoor heat exchangers 6a, 6b via the second solenoid valves 9a, 9b, where it is condensed and liquefied to the indoor side. It flows into the third connection pipe 13 through the expansion valves 7a and 7b. Then, a part of the refrigerant is evaporated in the indoor heat exchanger 6c via the indoor expansion valve 7c, and flows into the gas-liquid separator 10 via the first electromagnetic valve 8c.

The remaining refrigerant is depressurized by the first flow control device 14, flows into the gas-liquid separator 10, joins with the refrigerant from the first solenoid valve 8c, passes through the first connection pipe 11, and is heated to the outdoor side. It is evaporated in the exchanger 4 and returned to the compressor 2.

[0017]

[Problems to be Solved by the Invention] However, in the above configuration, the flow directions of the refrigerant in the first solenoid valve 8 and the second solenoid valve 9 are reversed depending on whether the outdoor unit is in cooling operation or heating operation. As a result, a back pressure acts on the solenoid valve, causing leakage from the closed solenoid valve, resulting in a problem that normal operation cannot be performed.

In order to solve this problem, it is 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 or has a large capacity. There was a problem that there was no. Another solution is to install four combinations of solenoid valves and check valves per indoor unit, but this has the drawbacks of being very expensive and requiring a complicated refrigerant circuit. Ta.

[0019] The present invention has been made in view of the above problems.
It has two connecting pipes compared to the conventional one, is easier to construct, and is inexpensive, eliminating leaks from the solenoid valve and allowing normal operation. In addition, the amount of refrigerant circulated through the heating indoor unit during cooling-based operation and the cooling indoor unit during heating-based operation is controlled to an appropriate amount, so that there are no problems with compressor reliability such as sudden increases in discharge or suction pressure, and the system is maintained. The present invention provides a multi-room air conditioner that can be stabilized and can freely perform heating and cooling for each indoor unit.

[0020]

[Means for Solving the Problems] In order to solve the above problems, the present invention connects the conventional third connection pipe to the second connection pipe via the second flow rate control device, and also connects the conventional third connection pipe to the second connection pipe, and A flow path switching mechanism is provided for switching the flow direction of the refrigerant in the first or second connection pipe during operation.

[0021]

[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, and leaks at the solenoid valve are eliminated. This system controls the amount of circulating refrigerant flowing through the compressor to an appropriate amount, allowing the compressor to operate normally without any problems with reliability.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An 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, 13' is a third connecting pipe, which is connected to the indoor heat exchanger 6 via the indoor expansion valve 7, and is connected to the first connecting pipe via the first flow rate control device 14. 11
It is connected to the lower part of the gas-liquid separator 10 provided in the , and is connected to the second connection pipe 12 via the second flow rate control device 15 .

Reference numeral 16 denotes a flow path switching mechanism, which includes a fourth connection pipe 18 that connects the second connection pipe 12 and the first connection pipe 11 via the first check valve 17; 12, the indoor unit 5 is connected from the confluence point 19 with the fourth connection pipe 18.
a position 20 on the side, and a position 22 on the side opposite to the indoor unit 5 from the confluence 21 with the fourth connection pipe 18 in the middle of the first connection pipe 11.
A fifth connection pipe 2 that connects with the second check valve 23
4, and the confluence point 19 in the middle of the second connection pipe 12 and position 2
0, and a fourth check valve 26 provided between the merging point 21 and the position 22 in the middle of the first connecting pipe 11.

The flow direction of each check valve is such that the first check valve 17 and the second check valve 23 flow from the second connecting pipe 12 to the first check valve 17 and the second check valve 23.
The third check valve 25 is the direction from the indoor unit 5 to the outdoor unit 1, and the fourth check valve 26 is the direction from the outdoor unit 1 to the indoor unit 5.

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 solenoid valve 9 is open, the first flow control device 14 is fully open, and the second
The flow rate control device 15 is closed, and each indoor 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 11.
, the fourth check valve 26, the gas-liquid separator 10, and the first flow rate control device 14, and are led to the third connection pipe 13'. Then, it flows into each indoor heat exchanger 6 through the indoor expansion valve 7,
After being evaporated, the air passes through the second electromagnetic valve 9, the third check valve 25, and then returns to the compressor 2 via the four-way valve 3 for 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 first flow rate control device 14 is closed, the second flow rate control device 15 is fully opened, and each indoor expansion valve 7 is opened according to each indoor load. degree.

The high temperature and high pressure gas discharged from the compressor 2 is
From the four-way valve 3, the flow passes through the second connection pipe 12, switches to the fourth connection pipe 18 due to the third check valve 25, flows into the first connection pipe 11, and flows into the gas-liquid separator 10. through the first solenoid valve 8 to each indoor heat exchanger 6,
Here, it is condensed and liquefied, the pressure is reduced to a low-pressure two-phase state by the indoor expansion valve 7, and it flows into the third connection pipe 13', and after passing through the second flow rate control device 15, the flow is transferred to the fifth connection pipe 24.
The air then passes through the first connection pipe 11, 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, the first flow rate control device 14 is opened to an opening degree that ensures a refrigerant circulation amount according to the horsepower of the heating indoor unit, the second flow rate control device 15 is closed, and each indoor expansion valve 7 is the 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 11.
A part of the refrigerant enters the gas-liquid separator 10 through the first electromagnetic valve 8c and is led to the indoor heat exchanger 6c, where it is condensed and liquefied, and passes through the indoor expansion valve 7c to the third refrigerant. Connection piping 1
3'.

Further, the remaining refrigerant is transferred to the first flow rate control device 14.
The refrigerant flows through the third connecting pipe 13' and joins with the refrigerant from the indoor expansion valve 7c, and then the indoor expansion valves 7a, 7b.
The pressure is reduced in the indoor heat exchangers 6a and 6b, and the gas is evaporated into the compressor 2 via the second solenoid valves 9a and 9b, the third check valve 25 in the second connection pipe 12, and the four-way valve 3. Return and perform 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 solenoid valve 9c is open, the first flow control device 14 is closed, and the second
The flow rate control device 15 is opened to an opening degree that can ensure a refrigerant circulation amount according to the horsepower number of the cooling indoor unit, and each expansion valve 7 is opened to an opening degree according to each indoor load.

The refrigerant discharged from the compressor 2 passes through the four-way valve 3
The flow passes through the second connecting pipe 12, switches to the fourth connecting pipe 18 due to the third check valve 25, passes through the first connecting pipe 11, enters the gas-liquid separator 10, and flows into the gas-liquid separator 10. 1 to the indoor heat exchangers 6a, 6b via the solenoid valves 8a, 8b, where it is condensed and liquefied, flows into the third connection pipe 13' through the indoor expansion valves 7a, 7b, and some of the The refrigerant is depressurized by the indoor expansion valve 7c, evaporated by the indoor heat exchanger 6c, and flows into the second connection pipe 12 through the second electromagnetic valve 9c.

Further, the remaining refrigerant is transferred to the second flow rate control device 15.
flows into the second connection pipe 12 through the second solenoid valve 9c.
After merging with the refrigerant from the flow, the flow is switched to the fifth connection pipe 24 due to the third check valve 25, and the flow is switched to the fifth connection pipe 24.
1, enters the outdoor heat exchanger 4, is evaporated, and returns to the compressor 2, where heating operation is performed.

As described above, in this embodiment, the third connection pipe 13' is also connected to the second connection pipe 12 via the second flow rate control device 15, and the first or Since the flow path switching mechanism 16 that switches the flow direction of the refrigerant in the connecting pipes 11 and 12 of No. 2 is provided, the direction of the refrigerant flowing through each of the solenoid valves 8 and 9 provided in the indoor unit 5 can be changed to cooling, mainly cooling, Since the direction can always be set in the same direction regardless of heating or heating-based operation, there is no back pressure acting on each solenoid valve 8, 9, eliminating leaks from closed solenoid valves that conventionally occur. You can.

Furthermore, the amount of refrigerant circulated through the heating indoor unit during cooling-based operation and the cooling indoor unit during heating-based operation is controlled to an appropriate amount, so that there are no problems with compressor reliability such as sudden increases in discharge or suction pressure. Moreover, it is possible to stabilize the system.

[0038]

As is clear from the above description, the present invention connects the conventional third connection pipe to the second connection pipe via the second flow rate control device, and also connects the conventional third connection pipe to the second connection pipe during cooling or heating operation. A multi-room air conditioner is constructed by providing a flow path switching mechanism for switching the flow direction of the refrigerant in the first or second connecting pipe.

[0039] As a result, the direction of the refrigerant flowing through each solenoid valve provided in the indoor unit can always be kept in the same direction regardless of whether the operation is cooling, mainly cooling, heating, or heating mainly, with inexpensive specifications. By eliminating back pressure from acting on the solenoid valve, leakage from the closed solenoid valve can be eliminated, allowing normal operation.

Furthermore, the amount of refrigerant circulated through the heating indoor unit during cooling-based operation and the cooling indoor unit during heating-based operation is controlled to an appropriate amount, so that there are no problems with the reliability of the compressor such as sudden increases in discharge or suction pressure. It is also possible to stabilize the system. In addition, only two pipes are required to connect the indoor unit and the outdoor unit, resulting in excellent construction efficiency.

[Brief explanation of the drawing]

[Fig. 1] Refrigeration cycle diagram of a multi-room air conditioner in an embodiment of the present invention

[Figure 2] Refrigeration cycle diagram showing the cooling-main operating state of the same embodiment

[Figure 3] Refrigeration cycle diagram showing the heating-main operating state of the same example

[Figure 4] Refrigeration cycle diagram of a conventional multi-room air conditioner

[Figure 5] Refrigeration cycle diagram showing the cooling-dominant operation state of a conventional multi-room air conditioner

[Fig. 6] 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 Second solenoid valve 10 Gas-liquid separator 11 First connection piping 12 Second connection pipe 13’ Third connection pipe 14 First flow control device 15 Second flow control device 16 Flow path switching mechanism

Claims (1)

[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 indoor expansion valve and an indoor heat exchanger are connected to each other through a first connecting pipe and a second connecting pipe. They are connected in parallel via piping, and one of the indoor heat exchangers is connected to the upper part of the gas-liquid separator provided in the middle of the first connection piping or to the second connection piping, and a first solenoid valve and a second solenoid valve, respectively. one side is connected to a third connection pipe via the indoor expansion valve, and one side of the third connection pipe is connected to the third connection pipe via the first flow rate control device. The first connecting pipe is connected to the lower part of the gas-liquid separator provided on the first connecting pipe, and the other side is connected to the second connecting pipe via a second flow rate control device. A multi-room air conditioner equipped with a flow path switching mechanism that switches the flow direction of refrigerant in a second connection pipe.