JPH046367A - Air-conditioner - Google Patents

Abstract

PURPOSE:To allow indoor units to individually, selectively perform either cooling or heating operation at the same time by a method wherein control is carried out so that the interface between gas refrigerant and liquid refrigerant is kept lower than the preset position and the refrigerant at the outlet of a first heat exchanger is maintained at a set supercooling degree. CONSTITUTION:The valve lift of a third flow control valve 15 is increased so that the interface between the gas refrigerant and the liquid refrigerant in a gas-liquid separator 12 is maintained below the position of a liquid drain pipe 41. Thereby, lack of the heating capacity, which results from a shortage of the gas refrigerant with a decrease in the dryness of the refrigerant flowing into an relay apparatus E, is avoided. In addition, the valve lift of the third flow control valve 15 is decreased so that the refrigerant of the inlet side of a second flow control valve 13 is kept at the set suppercooling degree. As a result, the dryness of the refrigerant flowing into the relay apparatus increases, so that the flow rate of the gas refrigerant is prevented from becoming too high, and the uniform distribution of the refrigerant, which flows from the second manifold 11 into indoor units B, C and D to be brought in cooling operation, is prevented from being disturbed by lack of the supercooling of the refrigerant.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multi-room heat pump air conditioner in which a plurality of indoor units are connected to one heat source device.
In particular, the present invention relates to an air conditioner that can selectively perform heating and cooling for each indoor unit, and can simultaneously perform cooling with one indoor unit and heating with the other indoor unit.

[Traditional slope technique]

Conventionally, heat pump air conditioners have been common in which multiple indoor units are connected to one heat source unit using two pipes, a gas pipe and a liquid pipe, and each indoor unit performs heating and cooling operations. or all configured to provide cooling.

[Problem to be solved by the invention]

Conventional multi-room heat pump air conditioners are configured as described above, so they only operate the indoor units for cooling or heating, so they can be used for cooling or heating where it is needed, or vice versa. There was a problem with heating or cooling in places where it was needed.

Particularly when installed in a large building, this poses a particular problem because the air conditioning load differs markedly between the inch rear section and the verimeter section, or between the general office and a computer room or other OA room.

This invention was made to solve the above-mentioned problems. Multiple indoor units are connected to one heat source unit, and each indoor unit can selectively perform air conditioning and heating. If the indoor unit can be used for cooling and the other indoor unit for heating at the same time, and installed on a large hill, it can be used as an OA for the interior section and part of the verimeter, or for general offices, computer rooms, etc. To provide a multi-room heat pump type air conditioner that can handle each room even if the air conditioning loads differ significantly in each room.

[Means to solve the problem]

This invention includes a compressor, a four-way switching valve, a heat exchanger on the heat source side,
In a system in which one heat source device, such as an accumulator, and multiple indoor units, each consisting of an indoor heat exchanger, a first flow rate control device, etc., are connected via first and second connection pipes. , a first branch part that connects one of the indoor heat exchangers of the plurality of indoor units to the first connection pipe or the second connection pipe via the gas-liquid separation device; The other of the indoor heat exchangers of the plurality of indoor units,
A second branch section connected to the second connection pipe via the first flow rate control device is connected via the gas-liquid separation device and the second flow rate control device, and the second The branch part and the first connecting pipe are connected via a fourth flow rate control device, and one end is connected to the second branch part, and the other end is connected to the first connection pipe via a third flow rate control device. a bypass pipe connected to a connecting pipe, the bypass pipe connecting the third flow control device and the first connecting pipe, and the second connecting pipe connecting the second flow control device. a first heat exchange section that performs heat exchange with the piping that is connected to the gas-liquid separator; section, second branch section, second flow rate control device, third flow rate control device, fourth flow rate control device, fifth flow rate control device, first heat exchange section,
A repeater having a built-in boundary surface detection means and bypass piping is interposed between the heat source device and the plurality of indoor units, and the first connecting piping has a larger diameter than the second connecting piping. the first connection pipe to a low pressure, and the second connection pipe to a low pressure.
A switching valve is provided between the first and second connecting pipes of the heat source device, and the interface between the gaseous refrigerant and the liquid refrigerant in the gas-liquid separation device is set in advance. This is characterized by controlling the refrigerant state at the outlet of the first heat exchanger to a preset degree of supercooling, which is lower than the predetermined position.

[For production]

In this invention, in the case of heating mainly in simultaneous cooling and heating operation, high-pressure gas refrigerant is introduced into each indoor unit to be heated from the heat source equipment side switching valve, the second connection pipe, and the first branch part. Thereafter, a portion of the refrigerant flows from the second branch into the indoor unit to be cooled, and then flows from the first branch into the first connection pipe. On the other hand, the remaining refrigerant passes through the fourth flow rate control device, joins with the refrigerant that has passed through the indoor unit to be cooled, flows into the first connection pipe, and returns to the heat source unit.

In the case of cooling mainly, the high-pressure gas is exchanged with an arbitrary amount of heat in the heat exchanger on the heat source side of the heat source device, and then flows into the repeater through the heat source side switching valve and the second connection pipe to form a two-phase state. Here, the gas-liquid separator separates the gaseous refrigerant and the liquid refrigerant, and the separated gaseous refrigerant is introduced into the indoor unit to be heated via the first branch part to perform heating. Flows into the branch.

On the other hand, the remaining separated liquid refrigerant passes through the second flow rate adjustment device, joins with the refrigerant that has passed through the indoor unit to be heated at the second branch, and flows into each indoor unit to be cooled. After cooling, the air is guided from the first branch through the first connection pipe to the heat source machine and returned to the compressor. Further, in the process of causing a part of the refrigerant to flow from the second branch section to the first connection pipe via the bypass pipe, the second heat exchanger is
The refrigerant flowing into the branch is cooled down to a sufficient degree of supercooling, and then flows into the indoor unit that is being cooled. On this occasion,
The interface between the gaseous refrigerant and the liquid refrigerant in the gas-liquid separator is controlled to be lower than a predetermined position, and the refrigerant state at the outlet of the first heat exchanger is controlled to a predetermined degree of supercooling.

Furthermore, in the case of only heating operation, the refrigerant is introduced into each indoor unit from the heat source equipment side switching valve through the second connection pipe and the first branch, performs heating, and is transferred from the second branch to the first connection. It passes through the piping and returns to the heat source machine via the heat source machine side switching valve.

In the case of only cooling operation, the refrigerant is introduced into each indoor unit from the heat source equipment side switching valve through the second connection piping and the second branch, performs cooling, and passes from the first branch to the first connection. It returns to the heat source equipment through the piping. Furthermore, in the process of causing a portion of the refrigerant to flow from the second branch section to the first connection pipe via the bypass pipe, the refrigerant flowing into the second branch section is cooled in the first heat exchange section. Then, it reaches a sufficient degree of supercooling and flows into the indoor unit that is being cooled.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 is an overall configuration diagram centered on the refrigerant system of an air conditioner according to a first embodiment of the present invention. In addition, Figures 2, 3, and 4 show the operating state during cooling/heating operation in the embodiment shown in Figure 1. Figures 4 and 4 show the operation of simultaneous heating and cooling operation, and Figure 3 shows the operation of simultaneous heating and cooling operations. FIG. 4 is an operational state diagram showing the main cooling operation (when the total capacity of the indoor units attempting to perform cooling operation is greater than the total capacity of the indoor units attempting to perform heating operation). FIG. 5 is an overall configuration diagram centered on the refrigerant system of an air conditioner according to another embodiment of the present invention.

In this embodiment, a case will be described in which three indoor units are connected to one heat source device, or the same applies to a case in which two or more indoor units are connected.

In Figure 1, (A) is a heat source device, (B), (C), (
In D), the indoor units are connected in parallel and have the same configuration, as will be described later. As will be described later, (E) is a repeater that incorporates a first branch part, a second flow ijk adjustment device, a second branch part, a gas-liquid separation device, and first and second heat exchange parts. . (1) is a compressor, (2) is a four-way switching valve that switches the refrigerant flow direction of the heat source machine, (3) is a heat exchanger on the heat source machine side, (4) is an accumulator, and the above equipment (1) to
(3) to constitute a heat source device (A).

(5) are the indoor heat exchangers of the indoor units (B), (C), and (D), respectively, and (6) are the four-way switching valve (2) and the repeater (E).
), (6b), (6c)
, (6d) are indoor units (B), (C), and (D), respectively.
Connect the indoor heat exchanger (5) and the repeater (E), and
(7) is the first connection pipe on the indoor unit side corresponding to the connection pipe (6), and (7) is the first connection pipe (6) connecting the heat source machine side heat exchanger (3) and the repeater (E). The thinner second connection pipes (7b), (7c), and (7d) are connected to the indoor unit (B), respectively.
), (C), (D), a second connection pipe on the indoor unit side that connects the indoor heat exchanger (5) and the repeater (E) and corresponds to the second connection pipe (7), ( 8) is the first (7) on the indoor unit side.
Connection pipes (6b), (6c), (6d) and a three-way switching valve that is switchably connected to the first connection pipe (6) or second connection pipe (7) side, (9) is on the indoor side Heat exchanger(
5) and is controlled by the degree of superheating during cooling on the outlet side of the indoor heat exchanger (5) and the degree of subcooling during heating; Connection piping (7
b), (7c), and (7d). α0) is the first connecting pipe (6b), (6c), (6d) on the indoor unit side and the first connecting pipe (6) or the second connecting pipe (7)
The first branch part, 01) consisting of a three-way switching valve (8) that is switchably connected to the second connection pipe (7b) on the indoor unit side
), (7c), and (7d), and the second branch part consisting of their confluence, O2 is a gas-liquid separator installed in the middle of the second connection pipe (A), and its gas phase part is It is connected to each tenth (8a) of the three-way switching valve (8), and its liquid phase part is connected to the second branch part (+1). a3 is a second flow rate adjustment device that can be opened and closed, and is connected between the gas-liquid separator az and the second branch 0υ; (141 is the connection between the second branch 0υ and the first connecting pipe (6)); Bypass piping connecting α9
(16b), (16c), and (16d) are provided downstream of the third flow rate regulator α9 of the bypass pipe o4, and the second The third heat exchange part (16a) is a bypass pipe 0 that exchanges heat with the second connection pipes (7b), (7c), and (7d) on each indoor unit side at the branch part αυ.
4, and downstream of the third heat exchanger (16b), (16c), (+6d), and the second The second heat exchange part 09) that exchanges heat with the confluence part of the connecting pipes (7b), (7C), and (7d) is the bypass pipe 04
) and a gas-liquid separation device O2 provided downstream of the third flow rate adjustment device 09 and downstream of the second heat exchange section (16a).
The first heat exchange section 07) which performs heat exchange with the piping connecting the flow rate control device 03 is connected to the second branch Oυ and the first heat exchange section 07).
A fourth flow rate control device (32), which can be opened and closed, is connected between the heat source side heat exchanger (3) and the second connection pipe (7). A third check valve is provided, which allows refrigerant to flow only from the heat source side heat exchanger (3) to the second connection pipe (7).

(33) is a fourth check valve provided between the four-way switching valve (2) of the heat source device (A) and the first connection pipe (6),
Refrigerant flow is allowed only from the first connection pipe (6) to the four-way switching valve (2). (34) is the fifth valve installed between the four-way switching valve (2) of the heat source device (A) and the second connection pipe (7).
This check valve allows refrigerant to flow only from the four-way switching valve (2) to the second connection pipe (7). (35) is a sixth check valve provided between the heat source side heat exchanger (3) and the first connection pipe (6), and is a sixth check valve provided between the heat source side heat exchanger (3) and the first connection pipe (6). Refrigerant flow is allowed only to the container (3). 3rd above
from the check valve (32) to the sixth check valve (35)
40).

(41) is a liquid draining pipe whose one end is connected to the gas-liquid separator 0 and the other end is connected to the first connecting pipe (6), and (42) is the liquid draining pipe (41) connected to the gas-liquid separator az and the first connecting pipe. Connection piping (6)
A fifth flow rate control device (43) provided between the gas-liquid separation device O2 and the first branch is provided downstream of the fifth flow rate control device (42) in the liquid draining pipe (41). This is a fourth heat exchange section that performs heat exchange with the piping connecting the section α0).

(23) is the second flow rate control device 03 and the first heat exchange section 0
The first temperature sensor attached to the pipe connecting 9, (2
5) is the first pressure sensor attached to the same pipe as the first temperature sensor (23), and (26) is the second branch 0υ
The second pressure sensor (52) attached to the first connecting pipe (6) and the first I7! The third pressure detector (51) is attached to the pipe connecting the branch 0υ, and the liquid drain pipe (4
The second temperature detector (53) is attached to the outlet side of the fourth heat exchange section (43) on the side 1), and the second temperature sensor (53) is attached to the outlet side of the first heat exchange section aω on the +4+ side. 3 temperature detector.

An embodiment of the invention configured in this manner will be described.

First, the case of only cooling operation will be explained using FIG.

That is, as shown by the solid line arrow in Fig. 2, the compressor (1)
The high temperature and high pressure refrigerant gas discharged from the four-way switching valve (2)
After passing through the heat source equipment side heat exchanger (3) for heat exchange and condensation, the third check valve (32), the second connection pipe (7),
It passes through the second flow rate adjustment device o3 of the gas-liquid separator #0, and then the second branch 0υ and the second connection pipe on the indoor unit side (
7b), (7c), and (7d), each indoor unit (B)
, (C), and (D) is reduced to a low pressure by the first flow rate regulator (9), which is controlled by the degree of superheating at the outlet of each indoor heat exchanger (5), and the indoor heat is released. Exchanger (
In step 5), it exchanges heat with the indoor air and evaporates into gas, cooling the room. Then, the refrigerant in the gas state passes through the three-way switching valve (8) of the first connection pipes (6b), (6C), and (6d) on the indoor unit side, and the first branch part aω. connection pipe (6), fourth check valve (33), four-way switching valve (2)
, an accumulator (4), and a circulation cycle in which the air is sucked into the compressor (1) to perform cooling operation. At this time, the 10th (8a) of the three-way switching valve (8) is closed, and the 10th (8b) and 30th (8C) are opened.

At this time, since the first connection pipe (6) has low pressure and the second connection pipe (7) has high pressure, the refrigerant inevitably flows to the third check valve (32) and the fourth check valve (33). is distributed.

Also, during this cycle, a part of the refrigerant that has passed through the second flow rate regulator α3 enters the bypass pipe α4, is reduced to a low pressure by the third flow rate regulator Oe, and is transferred to the third heat exchange section (16b ), (16c), (+6d) and the second connection pipes (7b), (7c), (7d) on each indoor unit side, and the second branch at the second heat exchange part (16a). Second connection pipes (7b), (7C), (7d) on each indoor unit side of section aυ
The evaporated refrigerant undergoes heat exchange with the refrigerant flowing into the second flow rate control device 03 in the first heat exchange section 09, and then flows into the first connection pipe (6). entry, fourth check valve (33), four-way switching valve (2), accumulator (4
) and is sucked into the compressor (1). On the other hand, the first, second and third heat exchange parts (191, (16a), (1
6b), (16c), and (16d) to exchange heat and cool the second branch part at+ to a sufficient degree of supercooling.
The refrigerant is used in the indoor units (B), (C), and
(D).

In addition, during cooling operation, if the refrigerant sealed in the air conditioner is not sealed enough to fill the second connection pipe with high-pressure liquid refrigerant, the high-pressure two-phase condensed in the heat source side heat exchanger (3) After passing through the second connection pipe (A) and the gas-liquid separation bag #az, the refrigerant passes through the first, second, and third heat exchange parts (
19+, (16a), (16b), (16c), (+6
In step d), by exchanging heat with the refrigerant flowing through the bypass side, which has been reduced to a low pressure by the third flow rate control device 09,
It is liquefied, further cooled, sufficiently supercooled, and flows into the indoor units (B), (C), and (D) that are attempting to cool the air.

Next, the case of only heating operation will be described using FIG. 2. That is, as shown by the broken line arrow in FIG. 2, the high temperature and high pressure refrigerant gas discharged from the compressor (1) passes through the four-way switching valve (2), the fifth check valve (34), and the second connection. Piping (7) passes through the gas-liquid separator 0z, and the first branch 00)
, three-way switching valve (8), first connection pipe on the indoor unit side (6b
), (6c), (6d), and each indoor unit (B), (C
), (D) exchanges heat with indoor air, condenses and liquefies, heating the room. Then, this liquid refrigerant passes through the first flow rate adjustment device (9) that is controlled by the degree of subcooling at the outlet of each indoor heat exchanger (5), and then passes through the second connection on the indoor unit side. The pipes (7b), (7c), and (7d) flow into the second branch part 01), merge, and further pass through the fourth flow rate regulator α, where they flow into the first flow rate regulator (9).
) or the fourth flow rate regulator G force, the pressure is reduced to a low pressure two-phase state. Then, the refrigerant reduced to a low pressure passes through the first connection pipe (6) and passes through the sixth check valve (
35) The refrigerant that flows into the heat source machine side heat exchanger (3), undergoes heat exchange, evaporates, and becomes a gas is sucked into the compressor (1) via the four-way switching valve (2) and the accumulator (4). A circulation cycle is configured to perform heating operation. At this time, the three-way switching valve (8) has the 20th (8b) closed and the 10th
(8a) and the 30th (8C) are open circuits.

At this time, since the first connection pipe (6) has low pressure and the second connection pipe (7) has high pressure, the refrigerant inevitably flows to the fifth check valve (34) and the sixth check valve (35). is distributed.

A case in which heating is the main component in simultaneous cooling and heating operation will be described with reference to FIG. Here, two indoor units (B) and (C) are shown.
We will explain the case where one indoor unit (D) is used for heating and one indoor unit (D) is used for cooling.

That is, as shown by the solid line arrow in Fig. 3, the compressor (1)
The high temperature and high pressure refrigerant gas discharged from the four-way switching valve (2)
, the fifth check valve (34), the second connection pipe (7), the relay machine (E), the gas-liquid separator α2, the first branch α0), and the indoor unit. (B), the three-way switching valve (8) connected to (C), the first connection pipe on the indoor unit side (
The refrigerant that passes through steps 6b) and (6C) in this order and flows into the indoor units (B) and (C') that are being heated is condensed and liquefied by exchanging heat with the indoor air in the indoor heat exchanger (5). Heat the room. Then, this liquid refrigerant is controlled by the degree of subcooling at the outlet of the indoor heat exchanger (5), and is slightly depressurized through the first flow regulating device (I f9) which is almost fully open. The pressure becomes intermediate between high pressure and low pressure (intermediate pressure), and flows into the second branch part αυ from the second connection pipes (7b) and (7C) on the indoor unit side. Then, the indoor unit (D) that is about to be cooled through the second connection pipe (7d) on the indoor unit side.
After being depressurized by 9+, it enters the indoor heat exchanger (5) and undergoes heat exchange and evaporates. It becomes a gas, cools the room, and flows into the first connection pipe (6) via the three-way switching valve (8) connected to the indoor unit (D).

On the other hand, the other refrigerant passes through the second branch part aυ, and is controlled to keep the difference between the high pressure of the second connecting pipe (7) and the intermediate pressure of the second branch part aυ constant. The indoor unit (D) that is trying to cool down through the flow rate adjustment device Q7) of No. 5
It joins with the refrigerant that has passed through and flows into the thick first connection pipe (6), the sixth check valve (35), and the heat source equipment side heat exchanger (3).
It flows into the water, exchanges heat and evaporates, becoming a gas. The refrigerant forms a circulation cycle in which the refrigerant passes through the four-way switching valve (2) and the accumulator (4) and is sucked into the compressor (]) to perform heating-based operation. At this time, the indoor unit (D
), or the pressure difference between the evaporation pressure of the indoor heat exchanger (5) and the evaporation pressure of the heat source side heat exchanger (3), or the thick first connection pipe (6
) to switch to smaller size. At this time, the indoor unit (
In the three-way switching valves (8) connected to B) and (C), the 20th (8b) is closed, and the 10th (8a) and 30th (8a) are closed, respectively.
8c) is open circuited. In addition, the three-way switching valve (8) connected to the indoor unit (D) is the 20th (8b) and 30th (8c)
) is open, and the 10th (8a) is closed.

At this time, since the first connection pipe (6) has low pressure and the second connection pipe (7) has high pressure, the refrigerant inevitably flows to the fifth check valve (34) and the sixth check valve (35). is distributed.

Also, during this cycle, some liquid refrigerant enters the bypass pipe side from the confluence of the second connection pipes (7b), (7c), and (7d) on each indoor unit side, and enters the third flow rate adjustment device. 09, the pressure is reduced to low pressure, and the second connection pipe (7b) on each indoor unit side of the second branch part 0υ in the second heat exchange part (+6a), (
7c) and (7d) and the refrigerant flowing into the second flow rate control device 03 at the first heat exchange section a9, the evaporated refrigerant is transferred to the first heat exchange section a9. Connection piping (6)
It flows into the heat exchanger (3) on the heat source side through the sixth check valve (35), where it exchanges heat and evaporates into a gas state. Then, this refrigerant is transferred to the four-way switching valve (2), the accumulator (
4) and is sucked into the compressor (1).

On the other hand, the first, second and third heat exchanger α wings, (+6a
), (16b), (16c), and (16d), the second branch part 0 is cooled by heat exchange and has a sufficient degree of supercooling.
The refrigerant υ flows into the indoor unit (D) that is attempting to cool the room.

A case in which cooling is the main component in simultaneous heating and cooling operation will be described with reference to FIG. 4. Here, indoor units (B), (C)
The case where two indoor units (D) are trying to cool the room and one indoor unit (D) is trying to heat the room will be explained. That is, as shown by the solid line arrow in FIG. 4, the high temperature and high pressure refrigerant gas discharged from the compressor (1) passes through the four-way switching valve (2) and is transferred to the heat source equipment side heat exchanger (
3) The arbitrary amount of heat is exchanged to form a two-phase high-temperature, high-pressure gas, which is then passed through the third check valve (32) and second connection pipe (7) to the gas-liquid separation device α of the relay machine (E). Sent. Here, the gaseous refrigerant is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant is transferred to the first branch part α0), the direction switching valve (8), and the first connection pipe (6d) on the indoor unit side in this order. The air then flows into the indoor unit (D) that is attempting to heat the room, exchanges heat with indoor air in the indoor heat exchanger (5), condenses and liquefies, and heats the room. Furthermore,
It is controlled by the degree of subcooling at the outlet of the indoor heat exchanger (5) and is slightly reduced in pressure through the first flow rate regulator (9) which is in an almost fully open state, and becomes a pressure between high pressure and low pressure (intermediate pressure).
It flows into the second branch αD. On the other hand, the remaining liquid refrigerant flows into the second branch part OD through the second flow regulating device 03 that is controlled to keep the difference between the high pressure and the intermediate pressure constant,
It joins with the refrigerant that has passed through the indoor unit (D) that is being heated. Then, it passes through the second branch part 0υ and the second connection pipes (7b), (7c) on the indoor unit side, and passes through each indoor unit (B), (
C). This refrigerant is then used in the indoor unit (B),
The pressure is reduced to a low pressure by the first flow regulator (9), which is controlled by the degree of superheating at the outlet of the indoor heat exchanger (5) in (C), and the indoor heat exchanger (5) exchanges heat with indoor air. It evaporates and becomes gas, cooling the room. Then, this refrigerant in a gas state is transferred to the first connection pipe (6b) on the indoor unit side,
(6C), indoor unit (B), three-way switching valve (8) connected to (C), first branch part 00), first connection pipe (6)
, 14 check valves (33), a four-way switching valve (2), and an accumulator (4) to form a circulation cycle in which air is sucked into the compressor (1), and air-conditioning is mainly performed. At this time, the three-way switching valves (8) connected to the indoor units (B) and (C) are such that the 10th (8a) is closed, the 20th (8b) and the 30th
(8C) is open. In addition, the three-way switching valve (8) connected to the indoor unit (D) is the 10th (8a) and the 30th (8th)
c) is open, and the 20th (8b) is closed.

At this time, since the first connecting pipe (6) has a low pressure and the second connecting pipe (7) has a high pressure, the third check valve (32),
Refrigerant flows to the fourth check valve (3 buttons).

Also, during this cycle, some of the liquid refrigerant enters the bypass pipe 04) from the confluence of the second connection pipes (7b), (7C), and (7d) on each indoor unit side, and enters the bypass pipe 04). Equipment O
5, the pressure is reduced to low pressure, and the second connection pipe (7b) on each indoor unit side of the second branch part 0υ is connected to the second heat exchange part (+6a).
, (7C), and (7d), and the refrigerant that is evaporated through heat exchange with the refrigerant flowing into the second flow rate control device in the first heat exchange section 09). 1 connection piping (6
), the fourth check valve (33), the four-way switching valve (2),
It is sucked into the compressor (1) via the accumulator (4). On the other hand, the first, second and third heat exchange parts α mark, (16
a), (+6b), (16C), and (16d), the refrigerant in the second branch Gυ, which has been cooled by heat exchange and has been sufficiently subcooled, is sent to the indoor units (B) and (C) that are being cooled.
).

In addition, if the liquid level is the interface between the gaseous refrigerant and liquid refrigerant separated in the gas-liquid separator α2, or if it is below the liquid drain pipe (41) of the gas-liquid separator az, the gaseous refrigerant The liquid flows into the drain pipe (41) and is reduced to a low pressure by the fifth flow rate control device (42). Since the inlet of the fifth flow rate control device (42) is in a gas state, there is little refrigerant flowing through the fifth flow rate control device (42). Therefore, the refrigerant flowing through the liquid draining pipe (41) exchanges heat with the high-pressure gaseous refrigerant flowing from the gas-liquid separator α2 to the first branch αω in the fourth heat exchange part (43). The superheated gas becomes a low-pressure superheated gas and flows into the first connecting pipe (6).

Conversely, if the liquid level is the interface between the gaseous refrigerant and the liquid refrigerant separated in the gas-liquid separator G3, or is above the liquid drain pipe (41) of the gas-liquid separator az, the liquid refrigerant or liquid It flows into the extraction pipe (41) and is depressurized to a low pressure by the fifth flow rate control device (42). Since the inlet of the fifth flow rate control device (42) is in a liquid state, the amount of refrigerant flowing through the fifth flow rate control device (42) is greater than when the inlet is in a gaseous state. Therefore, the refrigerant flowing through the liquid drain pipe (41) exchanges heat with the high-pressure gaseous refrigerant flowing from the gas-liquid separator #03 into the first branch part aω in the fourth heat exchange part (43). Even if the first connection pipe (6
).

In addition, in the above embodiment, a three-way switching valve (8) is provided to connect the first connection pipes (6b), (6c), (6d) on the indoor unit side,
Either it is switchably connected to the first connection pipe (6) or the second connection pipe (7), or it is connected to the second connection pipe (7) as shown in FIG.
Similar effects can be obtained even if two electromagnetic on-off valves (30), (31) or other on-off valves are provided and connected in a switchable manner as described above.

Next, the control of the third flow rate control device α9 in the cooling-based operation of the first embodiment will be explained.

In Fig. 4, if the flow rate controlled by the flow rate of the refrigeration cycle is less than the processing capacity of the heat exchanger (3) on the heat source side, the dryness of the refrigerant flowing into the gas-liquid separator Oa will decrease, resulting in a shortage of gaseous refrigerant. , the liquid level at the interface between the gaseous refrigerant and the liquid refrigerant in the gas-liquid separator QZ rises, and the liquid refrigerant or the gaseous refrigerant mixes from the gas-liquid separator O2 to the first branch part α0),
By flowing into the indoor unit (D) to be heated through the first connection pipe (6d) on the indoor unit side, supercooling occurs at the outlet of the indoor heat exchanger (5d) of the indoor unit (D). temperature increases, resulting in insufficient heating capacity. In addition, as the liquid level of the gas-liquid separator α2 rises, liquid refrigerant flows into the liquid drain pipe (4I) and becomes liquid at the entrance of the fifth flow rate control device (42). Even if the flow rate flowing through the flow rate control device (42) increases and heat is exchanged in the fourth heat exchanger (43), the first connection pipe (6) does not become a superheated gas state and remains in a two-phase state. The degree of overripeness determined from the temperature detected by the second temperature sensor and the pressure detected by the third pressure sensor becomes small. Therefore, by increasing the opening degree of the third flow rate control device α9, the flow rate by the flow rate control of the refrigeration cycle is increased, and the dryness of the refrigerant flowing into the gas-liquid separation device α2 is increased, and an appropriate amount of gaseous refrigerant is The heating capacity of the room 111(d) to be heated can be secured.

On the other hand, if the flow rate due to the flow rate control of the refrigeration cycle is greater than the processing capacity of the heat exchanger (3) on the heat source side, the dryness of the refrigerant flowing into the gas-liquid separator increases, and the flow rate of the gaseous refrigerant becomes excessive. The state of
Since the gaseous refrigerant mixes with the liquid refrigerant and flows into the first heat exchanger side, the degree of supercooling at the outlet of the first heat exchanger α, that is, the inlet of the second flow rate control device 03 increases. The first, second and third heat exchange parts α(2), (16a)
, (16b), (+6c), and (16d), the heat exchange capacity is insufficient, and the degree of supercooling of the refrigerant flowing from the second branch part αυ to the indoor units (B) and (C) that are attempting to cool the air is insufficient. , refrigerant distribution deteriorates. In addition, gas-liquid separation device 02
As the liquid level decreases, gaseous refrigerant flows into the liquid drain pipe (41) and enters the fifth flow rate control device (42) into a gas state.
The flow rate decreases, heat is exchanged in the fourth heat exchange section (43), the state becomes a superheated gas, and the first connection pipe (6
), and the degree of superheat determined from the temperature detected by the second temperature detector and the pressure detected by the third pressure detector increases. Therefore, by reducing the opening degree of the third flow rate control device 09, the flow rate controlled by the flow rate control of the refrigeration cycle is reduced, the dryness of the refrigerant flowing into the gas-liquid separation device α2 is reduced, and an appropriate amount of gaseous refrigerant is By ensuring that the gaseous refrigerant is prevented from flowing into the first heat exchange section 09), a sufficient degree of supercooling is ensured for the refrigerant flowing into the indoor units (B) and (C) that are attempting to cool the room. This ensures good refrigerant distribution.

This will be explained below using FIGS. 6, 7, and 8.

FIG. 6 is a block diagram of the control of the third flow rate control device 09 of the first embodiment. First temperature detector (23)
The degree of supercooling (referred to as the first degree of supercooling (SCI)) is calculated by the first degree of supercooling calculating means (27) from the detected temperature and the detected pressure of the first pressure detector (25), The degree of superheat (first degree of superheat (SHI)) at the outlet of the fourth heat exchange section (43) is calculated from the temperature detected by the second temperature detector (51) and the pressure detected by the third pressure detector (52). ) is calculated by the first degree of superheat calculation means (28), and the degree of opening of the third flow rate control device is determined by the control means (29) from the first degree of supercooling and the first degree of superheat. Control.

FIG. 7 is a circuit diagram showing the electrical connections of the first embodiment. (60) is a microcomputer in the control device (59), and includes a CPU (61), a memory (62), an input circuit (63), and an output circuit (64). (65
), (66), (67), (68), (69), (70
) are the first, second and third temperature detectors (23
), (51), (53), resistors in series with the first, second and third pressure detectors (25), (26), (52), (
71) are first, second and third temperature detectors (23);
(51), (53) are A/D converters that convert the detection outputs of the first, second, and third pressure detectors (25), (26), and (52) into digital outputs; is given to the input circuit (63). Control transistors (72) and (73) that control the opening degree of the third flow rate control device α9 are connected to an output circuit (74) via resistors (74) and (75).

Figure 8 shows the memory (62) of the microcomputer (60).
) is a flowchart showing an opening degree control program for the third flow rate control device 09 stored in FIG. Step (80)
At step (82), it is determined whether the first superheat degree SHI is equal to or higher than the preset first set value.
), otherwise proceed to step (81). In step (81), the opening degree of the third flow rate control device is increased. In step (82), it is determined whether the first degree of supercooling SCI is greater than or equal to a predetermined second setting value, and if so, proceed to step (84); otherwise, proceed to step (83).

In step (83), the opening degree of the third flow rate control device 09 is decreased. In step (84), the opening degree of the third flow rate control device 09 is not changed.

〔Effect of the invention〕

As explained above, the air conditioner of the present invention includes one heat source device including a compressor, a four-way switching valve, a heat exchanger on the heat source side, an accumulator, etc., an indoor heat exchanger, and a first flow rate M. A plurality of indoor units consisting of button devices, etc. are connected to the first and second indoor units.
in which one of the indoor heat exchangers of the plurality of indoor units can be switched to the first connection pipe or the second connection pipe via the gas-liquid separation device. and the other of the indoor heat exchangers of the plurality of indoor units are connected to the second connection pipe via the first flow rate control device.
connecting the branch part through the gas-liquid separation device and a second flow rate control device, and connecting the second branch unit and the first connection pipe through a fourth flow rate control device, and further a bypass pipe connected at one end to the second branch section and at the other end connected to the first connection pipe via a third flow rate control device, the third flow rate control device and the first a first heat exchange section that performs heat exchange between a bypass piping between the connecting piping and a piping connecting the second connecting piping and the second flow rate control device; a liquid draining pipe connected to the gas-liquid separation device and connected to the first connecting pipe via the other end or the fifth flow rate control device, the fifth flow rate control device and the first connection line; and a fourth heat exchange section that performs heat exchange between a liquid drain pipe between the gas-liquid separator and the first branch section, and a fourth heat exchange section that performs heat exchange between the first branch section and the second branch section. branch, a second flow control device, a third
A repeater incorporating a flow rate control device, a fourth flow rate control device, a fifth flow rate control device, a first heat exchange section, a fourth heat exchange section, a liquid drain pipe, and a bypass pipe is connected to the heat source device. and the plurality of indoor units, and the first
The connecting pipe is configured to have a larger diameter than the second connecting pipe, and a switching valve that enables switching the first connecting pipe to low pressure and the second connecting pipe to high pressure is connected to the first connecting pipe of the heat source device. An air conditioner, characterized in that it is provided between the first and second connecting pipes.

Therefore, it is possible to perform heating and cooling selectively, with one indoor unit performing cooling and the other indoor unit heating at the same time.Moreover, it is possible to sufficiently subcool the liquid refrigerant before it is distributed to the indoor units. This improves the distribution of liquid refrigerant.

In addition, control during cooling-main operation is performed by setting the interface between the gaseous refrigerant and the liquid refrigerant in the gas-liquid separation device to be lower than the position of the liquid drain pipe, and setting the refrigerant state at the outlet of the first heat exchange section. By controlling the temperature to a supercooling degree, we ensure that the indoor unit that is trying to heat the room has an appropriate heating capacity.
It is possible to ensure a sufficient degree of subcooling of the refrigerant flowing into the indoor unit to be cooled. That is, by increasing the opening degree of the third flow rate control device so that the interface between the gaseous refrigerant and the liquid refrigerant in the gas-liquid separator is lower than the position of the liquid drain pipe, the flow rate by controlling the flow rate of the refrigeration cycle can be increased. This prevents the dryness of the refrigerant flowing into the repeater from decreasing due to the processing capacity of the heat exchanger on the heat source equipment side, thereby preventing the heating capacity from being insufficient due to the lack of gaseous refrigerant. By reducing the degree of opening of the third flow rate control device so that the degree of supercooling on the inlet side of the flow rate control device becomes the set degree of supercooling, the flow rate due to the flow rate control of the refrigeration cycle or that of the heat exchanger on the heat source machine side is reduced. Because the amount exceeds the heat exchange capacity, the dryness of the refrigerant flowing into the repeater increases, preventing the flow rate of gaseous refrigerant from becoming excessive, and prevents gas that cannot flow into the indoor unit that is trying to heat. The refrigerant flows into the second heat exchange section, and then flows into the first heat exchange section, where the heat exchange capacity is insufficient in the first and second heat exchange sections, and flows from the second branch section to the indoor unit that is trying to cool the air. It is possible to prevent a situation in which the degree of subcooling of the inflowing refrigerant is insufficient and the distribution of the refrigerant is reduced.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram centered on the refrigerant system of an air conditioner according to a first embodiment of the present invention. Figure 2 is a diagram of the operating state of only cooling or heating of the embodiment shown in Figure 1;
The figure is a diagram of the operating state of the heating main body (when the total capacity of the indoor units trying to heat the room is larger than the total capacity of the indoor units trying to cool the room) of the embodiment shown in Figure 1.
The figure is a diagram of the operating state of the cooling-main unit (when the total capacity of the indoor units attempting to cool the system is larger than the total capacity of the indoor units attempting to heat the vehicle) of the embodiment shown in Figure 1.
The figure is an overall configuration diagram centered on the refrigerant system of an air conditioning button device according to another embodiment of the present invention, FIG. 6 is a configuration diagram of the control of the third flow rate control device of the first embodiment, and FIG. 7 is a circuit diagram showing its electrical connections, and FIG. 8 is a flow chart showing its operation. In the figure, (A) is a heat source device, (B), (C), (D)
is an indoor unit, (E) is a repeater, (1) is a compressor, (2) is a four-way switching valve, (3) is a heat exchanger on the heat source side, (4) is an accumulator, (5b), (5c) , (5d) is the indoor heat exchanger, (6) is the first connection pipe, (6b), (6C)
, (6d) is the first connection pipe on the indoor unit side, and (7) is the second connection pipe.
(7b), (7C), (7d) are the second connection pipes on the indoor unit side, (8b), (8C), (8d) are three-way switching valves, (9b), (9C), (9d) is the first flow rate adjustment device, O is the first branch, αD is the second branch, O
2 is a gas-liquid separation device, 03 is a second flow rate adjustment device, 04)
09 is a bypass pipe, 09 is a third flow rate adjustment device, (16a
), <16b), (16c), (+6d) are the second and third heat exchange parts, (19) is the first heat exchange part, 07) is the fourth flow rate control device, and (23) is the second heat exchange part. 1 temperature sensor, (2
5) is the first pressure detector, (51) is the second temperature detector, (52) is the third pressure detector, (27) is the first supercooling degree calculation means, and (28) is the first 1 superheat degree calculation means, (2
9) is a control means, (32) is a third check valve, (33) is a fourth check valve, (34) is a fifth check valve, (35) is a sixth check valve, (4o) is a switching valve, (41) is a drain pipe, (42) is a fifth flow rate control device, and (43) is a fourth heat exchange section. In addition, the same symbols in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 8

Claims (1)

[Scope of Claims] One heat source device consisting of a compressor, a four-way switching valve, a heat exchanger on the heat source side, an accumulator, etc., and a plurality of indoor units consisting of an indoor heat exchanger, a first flow rate control device, etc. machine and the first
, connected via a second connection pipe, one of the indoor heat exchangers of the plurality of indoor units is connected to the first connection pipe.
or a first branch part that is switchably connected to a second connection pipe via a gas-liquid separator, and the other of the indoor heat exchangers of the plurality of indoor units. a second branch section connected to the second connection pipe via the flow rate control device, and a second branch section connected to the second connection pipe via the gas-liquid separation device and the second flow rate control device; and a first connecting pipe via a fourth flow control device, one end of which is connected to the second branch, and the other end of which is connected to the first connecting pipe via a third flow rate control device. a bypass pipe connected to the third flow rate control device and the first flow rate control device;
a first heat exchange section that performs heat exchange between a bypass piping between the connecting piping and a piping connecting the second connecting piping and the second flow rate control device; Boundary surface detection means for detecting the boundary surface between the gaseous refrigerant and the liquid refrigerant in the apparatus is provided, and the first branch section, the second branch section, the second flow control device, the third flow control device, and the third flow control device are provided. A repeater having a built-in flow rate control device, a first heat exchanger, a boundary surface detection means, and bypass piping of No. 4 is interposed between the heat source device and the plurality of indoor units, and the first The connecting pipe is configured to have a larger diameter than the second connecting pipe, and a switching valve that enables switching the first connecting pipe to low pressure and the second connecting pipe to high pressure is installed in the first connecting pipe of the heat source device. and a supercooling device provided between the second connecting pipe, in which the interface between the gaseous refrigerant and the liquid refrigerant in the gas-liquid separation device is lower than a predetermined position, and the refrigerant state at the outlet of the first heat exchange section is set. An air conditioner characterized by controlling the temperature to