JPH046369A - 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 at defrosting operation during simultaneous cooling and heating operation, a four-way valve is changed over and the indoor units in cooling operation continue cooling operation, and a first manifold and a first flow control valve, which are connected to the indoor units in heating operation, are closed. CONSTITUTION:At defrosting operation during simultaneous cooling and heating operation in which heating operation is main, the refrigerant in gas state passes through a first branch pipe 6d on the indoor unit side, a first manifold 10 and a changeover valve 8 at the first manifold, and induced into a compressor 1 via a first connecting pipe 6, a forth check valve 33, a four-way valve 2 at the heat source apparatus A and an accumulator 4 so that a circulating cycle is formed and defrosting operation is carried out while cooling operation is continued. First and second on-off valves of the changeover valves 8 of the first manifold connected to the other indoor units (in heating or air blowing operation or out of service are closed. Further, the first flow control valves 9 of the indoor units other than those to be brought in cooling operation are closed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] 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, and in particular, The present invention relates to an air conditioner that can perform heating and cooling selectively, and can simultaneously perform cooling with one indoor unit and heating with the other indoor unit.

[Traditional Atsunjutsu]

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.

[Invention or problem to be solved]

Conventional multi-room heat pump air conditioners are configured as described above, so all indoor units operate only for cooling or heating, so cooling or heating is performed only where needed, or vice versa. There were also problems with air conditioning being done where it was needed.

Particularly when installed in a large building, this poses a particular problem because the air conditioning load is significantly different between the interior and perimeter areas, or between general offices and rooms that are OAized, such as computer rooms.

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. The indoor unit can perform cooling and the other indoor unit can perform heating at the same time, and when installed in a large building, it can be used to open the interior and perimeter areas, or general offices and 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,
One heat source device consisting of an accumulator, etc., and a plurality of indoor units consisting of an indoor heat exchanger, a first flow rate control device, etc. are connected via the second connection pipe, and the above-mentioned a first branching section in which one of the indoor heat exchangers of the plurality of indoor units is switchably connected to the first connection pipe or the second connection pipe; a second branch connected to the other side of the indoor heat exchanger via the first flow rate control device and connected to the second connection pipe via the second flow rate control device; are connected via the second flow rate control device, and further, the second branch portion and the first connection pipe are connected via a fourth flow rate control device, and the first branch portion and the first connection pipe are connected via the fourth flow rate control device. A repeater incorporating a second flow rate control device, a fourth flow rate control device, and a second branch part is interposed between the heat source device and the plurality of indoor units, and the first connection pipe is configured to have a larger diameter than the second connecting pipe, a switching valve is provided between the first and second connecting pipes of the heat source device, the first connecting pipe is set to a low pressure, and the second connecting pipe is set to a low pressure. In an air conditioner that can be switched to high pressure and capable of simultaneous cooling and heating operation, when defrosting the simultaneous cooling and heating operation, the above-mentioned four-way selector valve is switched, and the indoor unit that is in cooling operation continues cooling operation, and the indoor unit that is in heating operation continues to operate. The indoor unit is characterized in that the connected first branch section and the first flow rate control device are closed.

[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 cooling indoor unit, and flows into the first connection pipe,
Return to the heat source machine.

In addition, in the case of cooling mainly, the high-pressure gas is exchanged with a heat source device in an arbitrary amount to form a two-phase state, and the separated gaseous refrigerant is transferred from the heat source device side switching valve and the second connection pipe through the first branch part. The air is introduced into the indoor unit to perform heating, and then flows into the second branch.

On the other hand, the separated liquid remaining refrigerant passes through the second flow rate adjustment device, joins with the refrigerant that has passed through the indoor unit that is intended to heat the air at the second branch, and flows into each indoor unit that is attempting to cool the room. After that, the air is guided from the first branch through the first connection pipe to the heat source equipment side switching valve and returned to the compressor.

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, heats, and then flows from the second branch to the first connection pipe. and returns to 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 pipe and the second branch, cooled, and transferred from the first branch to the first connection pipe. and returns to the heat source machine side switching valve.

Then, when defrosting mainly by heating in simultaneous cooling and heating operation,
The high-temperature, high-pressure gas is defrosted by heat exchange with the heat source device, and is introduced from the heat source device side switching valve through the second connecting pipe and the second branch to the indoor unit that is being cooled, and is then cooled and cooled. It passes through the first connection pipe from the branch part and returns to the heat source equipment side switching valve. Note that at this time, the first branch and the first flow rate control device connected to the indoor unit to be heated are closed.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 is a diagram showing the overall configuration of an air conditioner according to an embodiment of the present invention, centering on the refrigerant. In addition, FIGS. 2 to 4 show operating states during cooling and heating operation in the embodiment shown in FIG. 1, and FIG.
Figures 3 and 4 show the operation of simultaneous cooling and heating operation. Figure 3 shows heating-dominant operation (when the heating operation capacity is larger than cooling operation capacity), and Figure 4 shows cooling-dominant operation (cooling operation capacity or heating operation capacity). FIG. FIG. 5 is an operational state diagram during defrost operation in the embodiment shown in FIG. 1.

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

In Figure 1, (A) is a heat source device, (B), (C),
(D) are indoor units connected in parallel to each other, each having the same configuration as described later. (E) includes a first branch, a second flow control device, a second branch, a gas-liquid separation device, a heat exchange section, a third flow control device, and a fourth branch, as described later.
A repeater with a built-in flow control device.

(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, which is connected to the above devices (1) to (3) to constitute a heat source device (A). (5) is the three indoor heat exchangers, (6) is the thick first connection pipe that connects the four-way switching valve (2) of the heat source device (A) and the repeater (E), (6b), (
6C), (6d) are indoor units (B), (C), respectively.
The indoor heat exchanger (5) of (D) and the repeater (E) are connected, and the first connection pipe on the indoor unit side corresponding to the first connection pipe (6), (7) is the heat source machine ( A) Heat source machine side heat exchanger (3
) and the repeater (E), the second connection pipes (7b), (7c), and (7d) are thinner than the first connection pipes (7b), (7c), and (7d) of the indoor units (B), (C), and (D), respectively. 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 connection on the indoor unit side. A switching valve branch of a first branch that connects the pipes (6a), (6b), and (6c) to the first connection pipe (6) or the second connection pipe (7) in a switchable manner. , an on-off valve (8a) is provided at the 10th point which is the connection part with the first connection pipe, and an on-off valve (8b) is provided at the 20th place which is the connection part with the second connection pipe.

(9) is the first control unit that is controlled by the superheat amount during cooling and the subcooling amount during heating on the outlet side of the indoor heat exchanger (5) connected adjacent to the indoor heat exchanger (5). In the flow control device, connect the second connection pipes (7b) and (7c) on the indoor unit side.
), (7d). α■ is the first connection pipe (6b), (6C), (6d) on the indoor unit side that is switchably connected to the first connection pipe (6) or the second connection pipe (7) side. The first branch part (01) consisting of the switching valve part (8) of the first branch part (01) is connected to the second connection pipe (7) on the indoor unit side.
b), (7c), (7d) and a second branch part consisting of a second connecting pipe, α2 is a gas-liquid separation device installed in the middle of the second connecting pipe (7), and the gas phase The part is connected to the tenth on-off valve (8a) of the switching valve part (8) of the first branch part, and the liquid phase part thereof is connected to the second branch part αυ.

03 is a second flow rate control device that can be opened and closed and is connected between the gas-liquid separator α■ and the second branch αυ, and 041 is a connection between the second branch αυ and the first connecting pipe (6). α9 is a third flow control device installed in the middle of bypass piping a4, (16b), (+6c), (1
6d) is provided downstream of the third flow rate control device α9 in the bypass pipe αD, and is connected to the second connection pipes (7b), (7c), and (7d) on each indoor unit side at the second branch αD. a third heat exchange section that exchanges heat with the merging section, (1
6a) is the third flow rate control device (I5) of the bypass pipe a4.
Connecting pipes (7b), (7c), (7d) of vg2 on each indoor unit side at the second branch o1)
a second heat exchange section that exchanges heat with the merging section of (19
+ is a pipe that connects the gas-liquid separation device (L5) and the second flow rate control device α3, which is provided downstream of the third flow rate control device α9 and downstream of the second heat exchange section (16a) in the bypass pipe α4. α'7)
is a fourth flow rate control device that is openable and closable and connected between the second branch portion (11) and the first connection pipe (6).

(32) is a third check valve provided between the heat source machine side heat exchanger (3) and the second connection pipe (A); ) to the second connection pipe (7). (33) is a fourth check valve provided between the four-way switching valve (2) of the heat source III (A) and the first connection pipe (6), and Refrigerant flow is allowed only from 6) to the four-way switching valve (2). (34) is a fifth check valve provided between the four-way switching valve (2) of the heat source device (A) and the second connection pipe (7); ) to the second connection pipe (7).

(35) is a sixth check valve provided between the heat source machine side heat exchanger (3) and the first connection pipe (6),
From the first connection pipe (6) to the heat source equipment side heat exchanger (
Refrigerant flow is allowed only to 3). The third check valve (3
2) The sixth check valve (35) constitutes a heat source machine side switching valve (40).

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 being condensed through heat exchange in the heat source equipment side heat exchanger (3), the third check valve (32), the second connection pipe (7),
It passes through the gas-liquid separator Q2, the second flow rate control device 03 in this order, and further passes through the second branch aD and the second connection pipe on the indoor unit side (
7b), (7C), and (7d), each indoor unit (B)
, (C) and (D). Then, each indoor unit (
The refrigerant flowing into B), (C), and (D) is controlled by the amount of superheat at the outlet of each indoor heat exchanger (5) through the first flow rate control bag! (9), the pressure is reduced to low pressure, and the indoor heat exchanger (5) exchanges heat with indoor air and evaporates.
It is gasified and cools the room. Then, this refrigerant in a gas state is transferred to the first connection pipe (6b) and (6) on the indoor unit side.
c), (6d), first branch part α0) passing through the switching valve part (8) of the first branch part, the first connecting pipe (6), the fourth
check valve (33), and four-way switching valve (2) of the heat source device (A).

A circulation cycle is configured in which the air is sucked into the compressor (1) through the accumulator (4) to perform cooling operation. At this time,
The tenth on-off valve (
8a) is closed, and the 20th on-off valve (8b) is opened. Moreover, at this time, since the first connection pipe (6) is at low pressure and the second connection pipe (7) is at high pressure, the refrigerant is inevitably passed through the third check valve (32) and the fourth check valve ( 33).

Furthermore, during this cycle, a part of the refrigerant that has passed through the second flow rate control device α3 enters the bypass pipe α4, is reduced to a low pressure through the third flow rate control bag flQ5, 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), (7) on each indoor unit side of section aυ
The refrigerant that has been evaporated through heat exchange with the refrigerant flowing into the second flow rate control device 03 in the first heat exchange section Q91 is transferred to the first connection pipe (6). ), enters the fourth check valve (34), passes through the four-way switching valve (2), and the accumulator (4), and is sucked into the compressor (1). On the other hand, the first, second and third heat exchange parts a91, (16a), (+
6b'), (16c), and (+6d'), the second branch part 0 is cooled by heat exchange and sufficiently subcooled.
The refrigerant in 1) is used in the indoor units (B) and (C) that are trying to cool the room.
), flows into (D).

Next, the case of only heating operation will be described using FIG. 2. That is, as shown by the dotted 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 O2 and enters the first branch α0)
, the switching valve part (8) of the first branch part, the first valve part on the indoor unit side
Pass through the connecting pipes (6b), (6c), and (6d) in this order,
It flows into each indoor unit (B), (C), and (D), exchanges heat with indoor air, condenses and liquefies, and heats the room. and,
This liquid refrigerant passes through the first flow control device (9) that is controlled by the subcooling amount at the outlet of each indoor heat exchanger (5), and then passes through the second connection pipe (7b) on the indoor unit side. ,(
7c), (7d) flow into the second branch 01) and merge, further passing through the fourth flow control device α force, where the first
The low pressure two-phase state is reduced by the flow rate control device (9) or the fourth flow rate control device aη. Then, the refrigerant whose pressure has been reduced to a low pressure passes through the first connection pipe (6), flows into the heat source equipment side heat exchanger (3) from the sixth check valve (35), exchanges heat, and evaporates. It becomes a gas state and forms a circulation cycle in which it is sucked into the compressor (1) via the four-way switching valve (2) and the accumulator (4), thereby performing heating operation. At this time, the on-off valve (8a) of the switching valve section (8) of the first branch is open;
(8b) is closed. Also, at this time, the refrigerant is
Because the connecting pipe (6) is low pressure and the second connecting pipe (7) is high pressure, the fifth check valve (34) and the sixth check valve (
35).

A case in which heating is the main component in simultaneous cooling and heating operation will be explained using FIG. 3. This is the indoor unit (B), (C”l 2)
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),
Passing through the fifth check valve (34) and the second connection pipe (7),
It is sent to the repeater (E), passes through the gas-liquid separator α2, and then passes through the first branch part α0) and the switching valve part of the first branch part (α0).
8) Pass through the first connection pipes (6b) and (6c) on the indoor unit side in that order, and connect the indoor units (B) and (C) that are trying to heat the room.
The air flows into the room, exchanges heat with indoor air in the indoor heat exchanger (5), is condensed and liquefied, and heats the room. Then, this liquid refrigerant is controlled by the sub-cooling amount at the outlet of each indoor heat exchanger (5), passes through the first flow rate control device (9) which is in an almost fully open state, and is slightly depressurized before being transferred to the second branch. It flows into part 0υ. Then, a part of this refrigerant passes through the second connection pipe (7d) on the indoor unit side and passes through the indoor unit (7d) that is trying to cool the room.
D), enters the first flow rate control device (9) controlled by the amount of super heat at the outlet of the indoor heat exchanger (5), is depressurized, enters the indoor heat exchanger (5), and heats up. It is exchanged, evaporates, becomes a gas state, cools the room, and is connected to the first connection pipe (6) via the switching valve part (8) of the first branch part.
flows into.

On the other hand, other refrigerants are used for cooling through a fourth flow rate control device 07) which can be opened and closed and controlled by the high pressure of the second connection pipe (7) and the intermediate pressure value of the second branch αD. It joins with the refrigerant that has passed through the indoor unit (D), passes through the thick first connection pipe (6), and passes through the sixth check valve (35) of the heat source unit (A) and the heat exchanger on the heat source unit side (3). It flows into the water, exchanges heat and evaporates, becoming a gas. Then, the refrigerant is transferred to the four-way switching valve (
2) A circulation cycle is configured in which air is sucked into the compressor (1) via the accumulator (4), and heating-based operation is performed. At this time, due to the pressure difference between the evaporation pressure of the indoor heat exchanger (5) of the indoor unit (D) to be cooled and the evaporation pressure of the heat source equipment side heat exchanger (3), the thick first connection pipe (6) Become smaller to switch. Also, at this time, the 20th on-off valve (8b) of the switching valve section (8) of the first branch connected to the indoor units (B) and (C) is closed, and the 10th on-off valve (8a) is closed. is open, the first opening/closing valve (8a) of the switching valve section (8) of the first branch connected to the indoor unit (D) is closed, and the second opening/closing valve (8a) is closed.
The on-off valve (8b) of No. 0 is open. Furthermore, at this time, since the refrigerant is at low pressure in the first connection pipe (6) and high pressure in the second connection pipe (7), the refrigerant is inevitably passed through the fifth check valve (34) and the sixth check valve (34). 35).

Also, during this cycle, some liquid refrigerant flows to the second branch 0.
1) Second connection pipes (7b), (7c) on each indoor unit side
, enters the bypass pipe α from the confluence part of (7d), and enters the third
The flow rate control device 09 reduces the pressure to a low pressure, and the third heat exchange section (16b), (+6c), (+6d) connects the second connecting pipes (7b), (7c), (7d) on each indoor unit side. and the second connecting pipes (7b), (7c), (7d) on each indoor unit side of the second branch part av in the second heat exchange part (16a).
) between the confluence of the two.

Furthermore, heat exchange is performed between the first heat exchange part α9 and the refrigerant flowing from the second flow rate control device o3, and the evaporated refrigerant is
It enters the first connecting pipe (6), flows into the sixth check valve (35) of the heat source device (A), and the heat exchanger on the heat source device side (3), exchanges heat, evaporates, and becomes a gas state. . Then, this refrigerant is sucked into the compressor (1) through the four-way switching valve (2) of the heat source device (A) and the accumulator (4). On the other hand, the first, second, and third heat exchange parts 09, (16a), (16b), (16c
), (+66), the refrigerant in the second branch part αυ, which has been cooled by heat exchange and has been sufficiently subcooled, flows into the indoor unit (D) which is to be cooled.

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) and (C)
We will explain the case where two indoor units (D) are used for cooling, and one indoor unit (D) is used for heating.

That is, as shown by the solid line arrow in Fig. 4, the compressor (1)
The high-temperature, high-pressure refrigerant gas discharged from the heat exchanger (3) on the heat source side exchanges heat in an arbitrary amount to become a two-phase high-temperature, high-pressure gas.
Passing through the third check valve (32) and the second connection pipe (7),
It is sent to the gas-liquid separation device 02 of the repeater (E). and,
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 switching valve part (8) of the first branch part, and the first connection pipe on the indoor unit side. (6d), flows into the indoor unit (D) to be heated, exchanges heat with indoor air in the indoor heat exchanger (5), condenses and liquefies, and heats the room.

Further, it passes through the first flow rate control device (9) which is controlled by the subcooling amount at the outlet of the indoor heat exchanger (5) and is in a substantially fully open state, and is slightly depressurized before flowing into the second branch aD. On the other hand, the remaining liquid refrigerant separated by the gas-liquid separator α2 is transferred to the second
A second flow rate control device α3 that can be opened and closed is controlled by the high pressure of the connecting pipe (7) and the intermediate pressure value of the second branch aD.
The refrigerant flows through the second branch part a1) and joins with the refrigerant that has passed through the indoor unit (D) to be heated. and,
Second branch αD, second connection pipe on the indoor unit side (7b)
, (7C), and flows into each indoor unit (B) and (C). The refrigerant that has flowed into each of the indoor units (B) and (C) is then reduced to a low pressure by the first flow rate control device (9) that is controlled by the amount of superheat at the outlet of the indoor unit heat exchanger (5). It flows into the indoor heat exchanger (5), exchanges heat with indoor air, evaporates and becomes gas, and cools the room. Furthermore,
This gaseous refrigerant is transferred to the first connection pipes (6b), (6c) on the indoor unit side, the switching valve part (6c) of the first branch part (
8), passes through the first branch part α0), and connects to the first connecting pipe (6).
), the fourth check valve (33), the four-way switching valve (2) of the heat source device (A), and the accumulator (4) to form a circulation cycle in which the air is sucked into the compressor (1), and the cooling-main operation is performed. conduct.

At this time, the 20th on-off valve (8b) of the switching valve section (8) of the first branch connected to the indoor units (B) and (C) is open, and the 10th on-off valve (8a) is closed. and the switching valve part (8) of the first branch part connected to the indoor unit (D)
The 10th on-off valve (8a) is open, and the 20th on-off valve (8a) is open.
b) is closed. Also, at this time, since the refrigerant is at low pressure in the first connection pipe (6) and high pressure in the second connection pipe, it is necessary to use the third check valve (32) and the fourth check valve (33). distributed to.

Furthermore, during this cycle, some liquid refrigerant flows to the second branch 0.
1) Second connection piping (7b), (7C) on each indoor unit side
, (7d) enters the bypass pipe 04), is reduced to low pressure by the third flow rate control device O9, and is then transferred to each indoor unit side by the third heat exchange part (16b), (16c), (16d). between the second connection pipes (7b), (7c), and (7d) of the second heat exchange section (16a) and the second branch section Ql).
The second connection pipes (7b), (7c), (
The evaporated refrigerant undergoes heat exchange with the refrigerant flowing into the second flow rate control device a3 in the first heat exchange part α9, and then passes through the first connection pipe (6). ) to the compressor (
1) is inhaled.

On the other hand, the first, second, and third heat exchange parts αg), (16a'
), (16b), (16c), (+6d), the refrigerant in the second branch 0υ, 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.
).

Next, a defrosting operation in which heating is the main component in the simultaneous cooling and heating operation of the above-mentioned embodiment will be described with reference to FIG. Here, a case will be described in which two indoor units (B) and (C) are used for heating, and one indoor unit (D) is used for cooling.

That is, as shown by the solid line arrow in Fig. 5, the compressor (1)
The high-temperature, high-pressure refrigerant gas discharged from the heat source equipment side heat exchanger (3) exchanges heat and is condensed without melting the frost that has adhered to the heat source equipment side heat exchanger (3). 32), 2nd
It passes through the connecting pipe (7), the gas-liquid separator O2, and the second flow rate control device α3 in this order, and then passes through the second branch 0υ and the second connecting pipe (7d) on the indoor unit side, and then passes through the indoor unit ( D). The refrigerant that has flowed into the indoor unit (D) is then reduced to a low pressure by the first flow control device (9) that is controlled by the amount of superheat at the outlet of the indoor heat exchanger (5), and then transferred to the indoor heat exchanger (5). In (5), it exchanges heat with the indoor air and evaporates.
It is gasified and cools the room. Then, this refrigerant in a gas state is transferred to the first connection pipe (6d) on the indoor unit side,
branch part G (1), switching valve part (8) of the first branch part
passing through, the first connection pipe (6), and the fourth check valve (33)
, four-way switching valve (2) of heat source machine (A), accumulator (
A circulation cycle is constructed in which air is sucked into the compressor (1) via step 4), and defrost operation is performed after continuing cooling operation.

At this time, the tenth on-off valve (8) of the switching valve part (8) of the first branch part connected to the indoor unit that is trying to cool the room
a) is closed, and the 20th on-off valve (8b) is closed. In addition, the 10th switch valve section (8) of the first branch section connected to other indoor units (heating or stop/ventilation)
The on-off valve (8a) and the 20th on-off valve (8b) are both closed. Furthermore, the first flow rate control device other than the indoor unit that is attempting to cool the air is closed. Also, at this time, since the first connecting pipe (6) has a low pressure and the second connecting pipe (7) has a high pressure, the refrigerant is inevitably passed through the third check valve (32) and the fourth check valve ( 33).

Furthermore, during this cycle, part of the refrigerant that has passed through the second flow rate control device 03 enters the bypass pipe 04) and enters the third flow rate control device 03.
The pressure is reduced to low pressure by the flow rate control device α9, and the third heat exchange section (+6b), (16c), (16d) connects the second connecting pipes (7b), (7C), (7d) on each indoor unit side ) and the second branch part 01) at the second heat exchange part (16a).
The second connection pipes (7b), (7C), (
A first heat exchange section (19) is further connected to the confluence section of 7d).
The evaporated refrigerant undergoes heat exchange with the refrigerant flowing into the second flow rate control device G3, enters the first connection pipe (6) and the fourth check valve (33), and enters the four-way switching valve ( 2), is sucked into the compressor (1) via the accumulator (4). on the other hand,
First, second and third heat exchange parts Q9), (16a)
, (+6b), (16c), and (16d'), the refrigerant in the second branch part αυ, which has been cooled by heat exchange and has been sufficiently subcooled, flows into the indoor unit (D) to be cooled.

With these, each indoor heat exchanger (5) and the indoor unit side first connection pipe (6b), (6C
), the cooled refrigerant does not flow through the heating chamber, so there is no feeling of cold air inside the heated room. Furthermore, since the first connecting pipes (6b) and (6C) on the indoor unit side that are to be heated are not cooled by the refrigerant, the heating operation starts quickly after returning from the defrosting operation.

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

FIG. 6 is a configuration diagram of control during the defrosting operation during the heating-main operation in the simultaneous cooling and heating operation of the above-mentioned embodiment.

The start control of defrosting operation is performed using the compressor continuous operation time accumulation means (
Based on the continuous operation time signal of the compressor from 21) and the signal of the heat exchanger temperature on the heat source equipment side detected by the pipe temperature detector (a), the continuous time of operation below a predetermined temperature is determined by the pipe temperature continuous low temperature time integration means (22). Based on the signal, the defrosting operation start determination means (23) determines the start of the defrosting operation, and the control means (26)
) at the four-way switching valve (2), the first flow control device (9),
and the 10th on-off valve (8a) of the first branch, the 20th
This is realized by determining and controlling the opening degree or opening/closing of the on-off valve (8b).

Defrosting operation termination control is performed by defrosting operation start determination means (23)
After it is determined that the defrosting operation has started and the defrosting operation has started, the defrosting operation time signal accumulated by the defrosting operation time integration means (24) and the heat exchanger on the heat source equipment side detected by the piping temperature detector (21) Based on the temperature signal, the defrosting operation completion determination means (25
) determines the end of the defrosting operation, and the control means (26) controls the four-way switching valve (2), the first flow rate control device (9), and the tenth on-off valve (8a) of the first branch. , 2, which determines and controls the opening degree or opening/closing of the 20th on-off valve (8b).

FIG. 7 is a flowchart regarding the control during the defrosting operation during the heating-main operation in the simultaneous cooling and heating operation of the above-mentioned embodiment.

In step (27) and step (28), the compressor continuous operation time and the pipe temperature continuous low temperature time are determined, and if both are longer than a predetermined time, the defrosting operation control in step (29) and subsequent steps is entered. In step (29), the four-way switching valve (2) is switched so that the heat exchanger on the heat source equipment side becomes the condenser. In step (30), the first flow control device (9) of the indoor unit to be heated is fully opened. In step (31), both the 10th on-off valve (8a) and the 20th on-off valve (8b) of the first branch corresponding to the indoor unit to be heated are closed.

After starting the defrosting operation, the defrosting operation time and pipe temperature are determined at the step knob (41) and step (42).
If the defrosting operation time continues at a predetermined temperature or higher, the defrosting operation end control starts when the pipe temperature reaches a predetermined temperature or higher. In the step tube (43), the four-way switching valve (2) is returned to the state before the defrosting operation. In step (44), the first indoor unit that turns off when trying to heat the
Return the flow rate control device (9) to the state before defrosting operation. In step (36), the 10th on-off valve (8a) and the 20th on-off valve (8b) of the first branch corresponding to the indoor unit to be heated are returned to the state before the defrosting operation.

〔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 control device. A plurality of indoor units consisting of devices, etc. are connected via first and second connection pipes, and one of the indoor heat exchangers of the plurality of indoor units is connected to the first connection pipe or, Second
a first branch part switchably connected to the connecting pipe of the plurality of indoor units, and a first branch part connected to the other of the indoor heat exchangers of the plurality of indoor units via the first flow rate control device; 2
A second branch section connected to the second connection pipe via the flow rate control device is connected via the second flow rate control device, and further the second branch section and the first connection pipe are connected via the second flow rate control device. connection pipes are connected via a fourth flow rate control device, and the first branch, the second flow rate control device, the fourth flow rate control device and the second
A repeater having a built-in branch part is interposed between the heat source device and the plurality of indoor units, and the first connecting pipe is configured to have a larger diameter than the second connecting pipe, and the first connecting pipe is configured to have a larger diameter than the second connecting pipe. A switching valve is provided between the first and second connecting pipes of the heat source device, so that the first connecting pipe can be switched to low pressure and the second connecting pipe can be switched to high pressure.

At the time of defrosting in the simultaneous cooling and heating operation, the four-way switching valve is switched, the indoor unit in cooling operation continues cooling operation, and the indoor unit in heating operation is connected to the first branch and the first branch. By closing the flow rate control device No. 1, each indoor unit in heating operation is separated from the refrigerant circuit, eliminating the feeling of cold air in the heating room, and utilizing the amount of heat obtained from the cooling room.
Defrosting operation can be completed in a short time.

Furthermore, since the first connecting pipe on the indoor unit side during heating operation is not cooled by the refrigerant, heating operation starts quickly after returning from defrosting operation.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the overall configuration of an air conditioner according to an embodiment of the present invention, centering on the refrigerant. In addition, Figures 2, 3, and 4 show operating states during cooling/heating operation in the embodiment shown in Figure 1. Figure 2 is a diagram of operating states for cooling or heating only, and Figure 3 and Figure 4 are diagrams showing the operation of simultaneous heating and cooling operation. Figure 3 shows heating-dominant operation (when heating operation capacity is larger than cooling operation capacity), and Figure 4 shows cooling-dominant operation (when cooling operation capacity is greater than heating operation capacity). FIG. FIG. 5 is an operational state diagram during defrost operation in the embodiment shown in FIG. 1. Further, FIG. 6 is a block diagram of the control for the Dext operation in the embodiment shown in FIG. 1, and FIG. 7 is a flowchart of the control. In the figure, (A) is a heat source device, (B), (C), (D)
(E) is an indoor unit with the same configuration, (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, (5) is an indoor heat exchanger, (6) is the first connection pipe, (6b), (6C),
(6d) is the second connection pipe on the indoor unit side, (7b), (7
C), (7d) are the second connection pipes on the indoor unit side, (8) are the switching valves of the first branch, (8a) are the 10th on-off valves, and (8b) are the 20th on-off valves. , (9) is the first flow control device, α0) is the first branch, 01) is the second branch, α2 is the gas-liquid separation device, α3 is the second flow control device, α
4 is the bypass pipe, 0!19 is the third flow rate control device, (
16a), (+6b), (16c), (+6d) are the second
and the third heat exchange section, Og) is the first heat exchange section, 07)
(32) is the third check valve; (32) is the fourth flow control device; (32) is the third check valve;
3) is the fourth check valve, (34) is the fifth check valve, (35
) is the sixth check valve, and (40) is the heat source machine side switching valve. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oishi

Claims (1)

[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.
, connected via a second connection pipe, and one of the indoor heat exchangers of the plurality of indoor units is switchably connected to the first connection pipe or the second connection pipe. 1
and the other of the indoor heat exchangers of the plurality of indoor units via the first flow rate control device,
and a second branch section connected to the second connection pipe via the second flow rate control device, and further connected to the second branch section via the second flow rate control device. and the first above
connecting the connecting pipe through the fourth flow rate control device to the first branch section. A repeater incorporating a second flow rate control device, a fourth flow rate control device, and a second branching section is interposed between the heat source device and the plurality of indoor units, and the first connection The piping is configured to have a larger diameter than the second connecting piping, a switching valve is provided between the first and second connecting piping of the heat source device, the first connecting piping is set to low pressure, and the second connecting piping is connected to the second connecting piping. In an air conditioner that is capable of simultaneous cooling and heating operation, the four-way switching valve is switched during defrosting of simultaneous cooling and heating operation, and the indoor unit that is currently in cooling operation continues cooling operation, while the indoor unit is in heating operation. An air conditioner, wherein the indoor unit has the connected first branch part and the first flow rate control device closed.