JPH04217759A - Multiroom type air-conditioner - Google Patents

Abstract

PURPOSE:To prevent the occurrence of leak in way that a reverse pressure is not exerted on a solenoid valve and to enable execution of constantly normal operation by a method wherein the direction of the flow of a refrigerant in two solenoid valves per one indoor machine is kept in a normally constant state despite of cooling and heating operation. CONSTITUTION:During cooling operation, high temperature high pressure gas delivered from a compressor 2 is condensed and liquefied by means of a heat exchanger on the outdoor side and guided through a piping 10 and a two-way valve 14 to a piping 12. After the gas flows through an expansion valve 7 to a heat exchanger 6 on the indoor side and is vaporized for gasification, it flows through a solenoid valve 9 and a four-way valve 3 to the compressor 2. During cooling operation, high temperature high pressure gas from the compressor 2 flows through the four-way valve 3 to a piping 11 and a flow is switched in the middle to a piping 18 by means of a check valve 25. The gas flows in a piping 10 and is guided through a solenoid valve 8 to a heat exchanger on the indoor side, where it is condensed for liquefaction. The pressure of liquefied gas is reduced by means of the expansion valve 7 and flows to the piping 12. After it flows through a two-way valve 15, a flow is switched to a piping 24 and the liquefied gas flows through a piping 10 to a heat exchanger 4 on the outdoor side and is gasified and returned to the compressor. The above circulating 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. 2-97857.

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

In FIGS. 4 to 6, 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. Reference numeral 5 denotes an indoor unit, which includes an indoor heat exchanger 6, an expansion valve 7, a first solenoid valve 8, and a second solenoid valve 9.

One end 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 connecting 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 end of the indoor heat exchanger 6 is connected to the first The connecting pipe 10 and the second connecting pipe 11 are switchably connected to each other.

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 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 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 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 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 directions of the refrigerant in the first solenoid valve 8 and the second solenoid valve 9 are reversed depending on whether the outdoor unit 1 is in a cooling operation or a heating operation. Therefore, back pressure acts on the solenoid valve,
There was a problem in that leakage occurred from the solenoid valve in the closed state, making normal operation impossible.

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 problems of being extremely expensive and complicating the refrigerant circuit. was.

[0017] The present invention was made in view of the above problems, and
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.
To provide a multi-room air conditioner that can freely perform heating and cooling for each indoor unit.

[0018]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention connects one end of the indoor heat exchanger to the first connecting pipe and the second connecting pipe, respectively with a first solenoid valve and a second solenoid valve. the other end is connected to a third connecting pipe via an expansion valve, and one end of the third connecting pipe is connected to the first connecting pipe via a first two-way valve. the other end is connected to the second connection pipe via a second two-way valve, and the flow direction of the refrigerant in the first and second connection pipes is switched during cooling or heating operation. The configuration includes a flow path switching mechanism.

[0019]

[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.

[0020]

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 FIGS. 1 to 3, reference numeral 14 denotes a first two-way valve, and one end of the third connecting pipe 12 is connected to the first connecting pipe 10 via the first two-way valve 14. 15 is a second two-way valve, and the other end of the third connection pipe 12 is connected to the second two-way valve 15.
It is connected to the second connection pipe 11 via.

Reference numeral 16 denotes a flow path switching mechanism, which includes a fourth connection pipe 18 that connects the second connection pipe 11 and the first connection pipe 10 via the first check valve 17; 11, the indoor unit 5 is connected from the confluence 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 10.
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 11 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 10.

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 11 to the first check valve 17 and the second check valve 23.
The third check valve 25 is from the indoor unit 5 to the outdoor unit 1, and the fourth check valve 26 is 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 two-way valve 14 is open, and the second two-way valve 1
5 is closed, 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.
, the fourth check valve 26 , and the first two-way valve 14 to be led to the third connecting pipe 12 . Then, it flows into each indoor heat exchanger 6 through the expansion valve 7, and after being evaporated and vaporized, the second
It returns to the compressor 2 via the solenoid valve 9, the third check valve 25, 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 first two-way valve 14 is closed, and the second two-way valve 15 is closed.
is open, and each expansion valve 7 has an opening degree according to each indoor load.

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 11, switches to the fourth connection pipe 18 due to the third check valve 25, flows into the first connection pipe 10, and flows into 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, and the pressure is reduced to a low-pressure two-phase state by the expansion valve 7 , flows into the third connecting pipe 12 , and passes through the second two-way valve 15 . The flow is the fifth
The air is switched to the connecting pipe 24, passes through the first connecting 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 solenoid valve 9c is closed, the first two-way valve 14 is closed, the second two-way valve 15 is closed, and each 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 10.
through the indoor heat exchanger 6c via the first solenoid valve 8c.
Here, it is condensed and liquefied, and flows into the third connecting pipe 12 through the expansion valve 7c. The pressure is then reduced by the expansion valves 7a and 7b, and evaporated by the indoor heat exchangers 6a and 6b.
5 and returns to the compressor 2 via the four-way valve 3, where cooling operation is performed.

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 two-way valve 14 is closed, the second two-way valve 15 is closed, and 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
The flow passes through the second connecting pipe 11, switches to the fourth connecting pipe 18 due to the third check valve 25, flows into the first connecting pipe 10, and then flows into the second electromagnetic valves 9a, 9b. It is guided to the indoor heat exchangers 6a, 6b, where it is condensed and liquefied, and flows into the third connecting pipe 12 through the expansion valves 7a, 7b. Then, the pressure is reduced by the expansion valve 7c and the indoor heat exchanger 6c
It is evaporated to some extent and flows into the second connection pipe 11 through the second electromagnetic valve 9c, and the flow is switched to the fifth connection pipe 24 due to the third check valve 25, and then the flow is transferred to the first connection pipe. 10
It passes through the outdoor heat exchanger 4 and is evaporated into compressor 2.
Return to and perform heating operation.

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]

As is clear from the above description, the multi-room air conditioner of the present invention connects one end of the indoor heat exchanger to the first connecting pipe and the second connecting pipe, and the first solenoid valve, respectively. The third connection pipe has one end connected to the third connection pipe via the first two-way valve, and the other end thereof is connected to the third connection pipe via the first two-way valve. The other end is connected to the first connecting pipe, and the other end is connected to the second connecting pipe via a second two-way valve, and the flow of refrigerant in the first and second connecting pipes during cooling or heating operation. It is equipped with a flow path switching mechanism that switches the direction.

Since the present invention has a multi-room air conditioner configured as described above, each solenoid valve provided in the indoor unit can be used regardless of whether it is used for cooling, cooling-only, heating, or heating-only operation with inexpensive specifications. The direction of the refrigerant flowing through the refrigerant can be kept constant at all times, eliminating back pressure from acting on each electromagnetic valve, eliminating leaks from closed electromagnetic valves, and allowing 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 the drawing]

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

[Fig. 2] Refrigeration cycle diagram showing the cooling-mainly operating state of the multi-room air conditioner of the same example.

[Fig. 3] Refrigeration cycle diagram showing the heating-main operating state of the multi-room air conditioner 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 Expansion valve 8 First solenoid valve 9 Second solenoid valve 10 First connection piping 11 Second connection pipe 12 Third connection pipe 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 expansion valve and an indoor heat exchanger are connected via a first connection pipe and a second connection pipe. one end of the indoor heat exchanger is switchably connected to the first connection pipe and the second connection pipe via a first solenoid valve and a second solenoid valve, respectively, and the other end of the indoor heat exchanger is connected in parallel with each other. is connected to a third connecting pipe via an expansion valve, and the third connecting pipe has one end connected to the first connecting pipe via a first two-way valve, and the other end connected to a second two-way valve. A multi-room air conditioner that is connected to the second connecting pipe via a valve and includes a flow path switching mechanism that switches the flow direction of the refrigerant in the first and second connecting pipes during cooling or heating operation. Machine.