JPH05172434A - Air conditioning apparatus - Google Patents

Abstract

PURPOSE:To prevent a heating capability from being reduced in the case that a cooling operation is mainly carried out and further to prevent a cooling capability from being damaged in the case a heating operation is mainly carried out by a method wherein a degree of opening of each of opening or closing valves placed at both ends of a plurality of heat exchangers at heat source machines, an opening or closing valve of the first bypassing circuit of the heat source machine and the fifth flow rate control device in the second bypassing circuit of the heat source machine is controlled. CONSTITUTION:In the case where a cooling operation is mainly carried out, a sensing signal of the first pressure sensing means 79 is inputted and in turn in the case where a heating operation is mainly carried out, a sensing signal of the second pressure sensing means 78 is inputted, means 50 for controlling a capacity of a heat exchanger on the side of the source machine controls a degree of opening of each of opening or closing valves 70 to 73 of a plurality of heat exchangers 3a and 3b of heat source machines, an opening or closing valve 74 of the first bypassing circuit 75 on the side of the heat source machine and the fifth flow rate control device 76 in the second bypassing circuit 77 at the heat source machine. In the case where a heating operation is mainly carried out, a discharging pressure of a compressor 1 is converged into a predetermined set pressure and in turn in the case where a cooling operation is mainly carried out, a suction pressure of the compressor 1 is converged between set pressures. Accordingly, in the case where the heating operation is mainly carried out, an evaporation pressure of the heat exchanger of the indoor cooling machine can be restricted from being excessively increased and then a cooling capability may not be damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-chamber heat pump air conditioner in which a plurality of indoor units are connected to one heat source unit. The present invention relates to heat exchange capacity control of a heat source side heat exchanger of an air conditioner capable of simultaneously performing cooling in an indoor unit and heating in the other indoor unit.

[0002]

2. Description of the Related Art The prior art of the present invention will be described below. FIG. 9 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner. 10 to 12 show operating states during cooling / heating operation in the air conditioner shown in FIG. 9, FIG. 10 is an operating state diagram of only cooling or heating, and FIGS. 11 and 12 show simultaneous cooling / heating operation. It shows the operation,
FIG. 11 is an operation state diagram showing heating-main operation (when the heating operation capacity is larger than the cooling operation capacity) and FIG. 12 is a cooling-main operation (when the cooling operation capacity is larger than the heating operation capacity).

In FIG. 9, A is a heat source unit, and B, C, and D are indoor units connected in parallel with each other, which will be described later, and have the same structure. As will be described later, E is a first branch portion 10, a second flow rate control device 13, a second branch portion 11,
First gas-liquid separation device 12, heat exchange parts 16a, 16b, 1
6c, 16d, 19, the third flow rate control device 15, and the fourth flow rate control device 17 are built-in repeaters. Further, 1 is a compressor, 2 is a four-way switching valve for switching the refrigerant flow direction of the heat source device, 3 is a heat source device side heat exchanger, 4 is an accumulator, and is connected to the compressor 1 via the four-way switching valve 2. There is. The heat source machine A is constituted by these. Further, 5 is an indoor heat exchanger provided in the three indoor units B, C, D, 6 is a four-way switching valve 2 of the heat source unit A and a relay unit E via a fourth check valve 33 described later. Thick connecting pipes 6b, 6
Reference numerals c and 6d respectively connect the indoor heat exchangers 5 and the relays E of the indoor units B, C, and D, and the first connection pipes on the indoor unit side corresponding to the first connection pipes 6, and 7 are heat source units. It is a second connection pipe that is thinner than the above-mentioned first connection pipe that connects the heat source unit side heat exchanger 3 of A and the relay unit E via a third check valve 32 described later.

Reference numerals 7b, 7c and 7d respectively connect the indoor heat exchangers 5 of the indoor units B, C and D to the relay E via the first flow control device 9 and the second connecting pipe 7 2 is a second connection pipe on the indoor unit side corresponding to. Reference numeral 21 denotes the first connection pipes 6b, 6c, 6d on the indoor unit side, and the first connection pipe 6
A second opening / closing valve for connecting the first connecting pipes 6b, 6c, 6d on the indoor unit side and a second connecting pipe 7 and a first opening / closing valve 21 Is a third on-off valve that bypasses the entrance and exit of the. Reference numeral 9 is a first flow rate control device which is connected close to the indoor heat exchanger 5 and is controlled by the superheat amount on the outlet side of the indoor heat exchanger 5 during cooling and by the subcool amount during heating. It is connected to the second connection pipes 7b, 7c, 7d on the machine side. Reference numeral 10 denotes a first connecting pipe 6b, 6c, 6d on the indoor unit side, which is switchably connected to the first connecting pipe 6 or the second connecting pipe 7.
Open / close valve 21 and second open / close valve 22, and further the first open / close valve 2
It is the 1st branch part provided with the 3rd on-off valve 23 which bypasses the entrance and exit of 1. 11 is the second connection pipe 7 on the indoor unit side
b, 7c, 7d, and a second branch portion including the second connection pipe 7. Reference numeral 12 is a first gas-liquid separation device provided in the middle of the second connection pipe 7, the gas phase portion of which is connected to the second on-off valve 22 of the first branch portion, and the liquid phase portion of which is the first. It is connected to the two branch parts 11. 13 is the first gas-liquid separation device 1
A second openable and closable connected between the second branch 11 and the second branch 11.
Flow control device (here, an electric expansion valve).

Reference numeral 14 is a bypass pipe connecting the second branch portion 11 and the first connection pipe 6, and 15 is a bypass pipe 14.
The third flow rate control device (here, an electric expansion valve) 16a provided in the middle of the bypass pipe 16a is provided downstream of the third flow rate control device 15 provided in the middle of the bypass pipe 14, and the second branch portion is provided. The second connection pipe 7b on the indoor unit side in 11
Second heat exchange with the joints of 7c and 7d, respectively
It is a heat exchange part. 16b, 16c, 16d are respectively provided downstream of the third flow rate control device 15 provided in the middle of the bypass pipe 14, and the second connection pipes 7b, 7c on the indoor unit side of the second branch section 11 are provided. 7d is a third heat exchanging unit for exchanging heat with each other. Reference numeral 19 is provided in the bypass pipe 14 downstream of the third flow rate control device 15 and downstream of the second heat exchange section 16a, and connects the first gas-liquid separation device 12 and the second flow rate control device 13. A first heat exchanging unit for exchanging heat with the pipe, and 17 is a fourth flow control device (here, a freely openable and closable flow controller connected between the second branching unit 11 and the first connecting pipe 6). Electric expansion valve)
Is.

On the other hand, reference numeral 32 is a third check valve provided between the heat source side heat exchanger 3 and the second connecting pipe 7, and from the heat source side heat exchanger 3 to the second check valve. Connection pipe 7
Allows refrigerant flow only to. Reference numeral 33 is a fourth check valve provided between the four-way switching valve 2 of the heat source unit A and the first connecting pipe 6, and only from the first connecting pipe 6 to the four-way switching valve 2. Allows refrigerant flow. Reference numeral 34 denotes a fifth check valve provided between the four-way switching valve 2 of the heat source unit A and the second connection pipe 7, and the refrigerant is provided only from the four-way switching valve 2 to the second connection pipe 7. Allow distribution. Reference numeral 35 denotes a sixth check valve provided between the heat source unit side heat exchanger 3 and the first connection pipe 6, from the first connection pipe 6 to the heat source unit side heat exchanger 3 Allows refrigerant flow only to.
The third, fourth, fifth and sixth check valves 32, 33, 3
The flow path switching valve device 40 is composed of 4, 35. Reference numeral 25 is a third pressure detecting means provided between the first branch portion 10 and the second flow rate control device 13, and 26 is the second flow rate control device 13 and the fourth flow rate control device 17. It is a fourth pressure detecting means provided between.

Next, the operation will be described. First, FIG.
The case of only the cooling operation will be described using. As shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, is heat-exchanged with the heat-source water in the heat-source-side heat exchanger 3, and is condensed into the third gas. Check valve 32,
The second connection pipe 7, the first gas-liquid separation device 12, and the second flow rate control device 13 are passed in this order, and further the second branch portion 11 and the second connection pipes 7b, 7c, 7d on the indoor unit side are connected. As a result, it flows into each indoor unit B, C, D. The refrigerant flowing into each indoor unit B, C, D is decompressed to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of each indoor heat exchanger 5, and the indoor heat exchanger 5 is cooled. It heats and exchanges heat with the room air, is gasified, and cools the room.

The refrigerant in the gas state is supplied to the first connection pipes 6b, 6c, 6d on the indoor unit side, the first opening / closing valve 21,
Third on-off valve 23, first connecting pipe 6, fourth check valve 3
3, the four-way switching valve 2 of the heat source unit A, and the accumulator 4 form a circulation cycle that is sucked into the compressor 1 to perform the cooling operation. At this time, the first opening / closing valve 21 and the third opening / closing valve 23
Is open and the second on-off valve 22 is closed. At this time, the refrigerant has a low pressure in the first connecting pipe 6 and the second connecting pipe 7
Due to the high pressure, it inevitably circulates to the third check valve 32 and the fourth check valve 33. In addition, during this cycle, a part of the refrigerant that has passed through the second flow rate control device 13 enters the bypass pipe 14 and is depressurized to a low pressure by the third flow rate control device 15 to generate the third pressure.
The second branch portion 11 in the heat exchange portions 16b, 16c, 16d of
Between the second connection pipes 7b, 7c, 7d on the indoor unit side, and the second connection pipes 7b, 7c on the indoor unit side of the second branch section 11 in the second heat exchange section 16a. , 7d and the refrigerant flowing into the second flow rate control device 13 in the first heat exchanging section 19 for heat exchange with the evaporated refrigerant. , Enters the fourth check valve 33, and is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4. On the other hand, the first, second, and third heat exchange units 1
The second branch portion 1 having sufficient subcooling by being heat-exchanged and cooled by 9, 16a, 16b, 16c, 16d.
Refrigerant No. 1 flows into the indoor units B, C, and D that are about to be cooled.

Next, the case of only the heating operation will be described with reference to FIG. That is, as shown by the dotted arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the fifth check valve 34, the second connecting pipe 7, and the first connecting pipe 7. The second on-off valve 2 passing through the gas-liquid separator 12
2. The first connection pipes 6b, 6c, 6d on the indoor unit side are sequentially passed into the indoor units B, C, D to exchange heat with indoor air to be condensed and liquefied to heat the room. The refrigerant in this liquid state is controlled by the subcool amount at the outlet of each indoor heat exchanger 5 and passes through the first flow rate control device 9 in a substantially fully opened state, and the second connection pipe 7b on the indoor unit side, From 7c and 7d, they flow into the second branch portion 11 and merge, and further pass through the fourth flow rate control device 17. Here, the pressure is reduced to a low pressure gas-liquid two-phase state by either the first flow rate control device 9 or the third and fourth flow rate control devices 15 and 17. The refrigerant decompressed to a low pressure flows into the sixth check valve 35 of the heat source device A and the heat source device side heat exchanger 3 through the first connection pipe 6, exchanges heat with the heat source water and evaporates to a gas state. And the four-way switching valve 2 of the heat source unit A,
A circulation cycle in which the compressor 1 is sucked through the accumulator 4 constitutes a heating operation. At this time, the second opening / closing valve 22 is open, and the first opening / closing valve 21 and the third opening / closing valve 23 are closed. At this time, the refrigerant inevitably circulates to the fifth check valve 34 and the sixth check valve 35 because the first connecting pipe 6 has a low pressure and the second connecting pipe 7 has a high pressure. At this time, the second flow rate control device 13 is normally in the predetermined minimum opening state.

Next, the case of the heating-main operation in the simultaneous cooling and heating operation will be described with reference to FIG. The high-temperature high-pressure refrigerant gas discharged from the compressor 1 is sent to the relay machine E through the four-way switching valve 2 and the fifth check valve 34 and the second connecting pipe 7 as shown by the dotted arrow in the figure. After passing through the first gas-liquid separation device 12, the second opening / closing valve 22 and the first connection pipes 6b and 6c on the indoor unit side in this order, and flowing into the indoor units B and C to be heated, and the indoor side The heat exchanger 5 exchanges heat with the indoor air to be condensed and liquefied to heat the room. The condensed and liquefied refrigerant passes through the first flow rate control device 9 which is controlled by the amount of subcool at the outlet of each indoor heat exchanger 5 and is in a substantially fully opened state, and is slightly depressurized and flows into the second branch portion 11. Part of this refrigerant passes through the second connection pipe 7d on the indoor unit side, enters the indoor unit D to be cooled, and has a first flow rate controlled by the superheat amount at the outlet of the indoor heat exchanger 5. After entering the control device 9 and being decompressed, it enters the indoor heat exchanger 5 to exchange heat and evaporate into a gas state to cool the room, and the first opening / closing valve 21 via the first connection pipe 6d. , And flows into the first connecting pipe 6 via the third opening / closing valve 23.
On the other hand, the other refrigerants are the pressure detected by the third pressure detecting means 25,
The pressure difference of the detected pressure of the fourth pressure detecting means 26 is controlled to be within a predetermined range, passes through the fourth flow rate control device 17, and merges with the refrigerant that has passed through the indoor unit D to be cooled and is thick. After passing through the first connecting pipe 6, the sixth check valve 35 of the heat source unit A and the heat source unit side heat exchanger 3 flow into the heat source unit A to exchange heat with the heat source unit and evaporate into a gas state.

This refrigerant constitutes a circulation cycle in which it is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4 to perform heating-main operation. At this time, the evaporation pressure of the indoor side heat exchanger 5 of the indoor unit D to be cooled and the pressure difference of the heat source unit side heat exchanger 3 are reduced due to switching to the thick first connection pipe 6. At this time, the second opening / closing valve 22 connected to the indoor units B and C is open, and the first opening / closing valve 21 and the third opening / closing valve 23 are closed. The first opening / closing valve 21 and the third opening / closing valve 23 connected to the indoor unit D are open, and the second opening / closing valve 22 is closed. At this time, the refrigerant inevitably circulates to the fifth check valve 34 and the sixth check valve 35 because the first connecting pipe 6 has a low pressure and the second connecting pipe 7 has a high pressure.

During this cycle, part of the liquid refrigerant is the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
It enters the bypass pipe 14 from the meeting portion of 7d, is depressurized to a low pressure by the third flow control device 15, and the third heat exchange portion 1
6b, 16c, 16d between the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch portion 11 and the second
The heat exchange section 16a performs heat exchange with the association section of the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch section 11, and the evaporated refrigerant is the first connection pipe. 6, after entering the heat source unit side heat exchanger 3 via the sixth check valve 35, exchanging heat with the heat source water to evaporate and vaporize, and then through the four-way switching valve 2 of the heat source unit A and the accumulator 4 to the compressor. Inhaled to 1. On the other hand, the second and third heat exchange parts 16a, 16b, 16c,
The refrigerant in the second branch portion 11 that has been heat-exchanged and cooled in 16d and is sufficiently subcooled flows into the indoor unit D that is about to be cooled. At this time, the second flow rate control device 13 is normally in the predetermined minimum opening state.

Next, the case of mainly cooling in the simultaneous heating and cooling operation will be described with reference to FIG. As shown by the solid line arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 flows into the heat source unit side heat exchanger 3 through the four-way switching valve 2 and exchanges heat with the heat source water to form a gas-liquid mixture. The phase becomes high temperature and high pressure. Then, the two-phase high-temperature high-pressure refrigerant is sent to the first gas-liquid separation device 12 of the relay machine E through the third check valve 32 and the second connection pipe 7. Here, the gaseous refrigerant is separated into a gaseous refrigerant and a liquid refrigerant, and the separated gaseous refrigerant flows through the second opening / closing valve 22 and the first connection pipe 6d on the indoor unit side in this order and flows into the indoor unit D to be heated. Then, the indoor heat exchanger 5 exchanges heat with the indoor air to condense and liquefy, and heat the room. Further, it is controlled by the amount of subcool at the outlet of the indoor heat exchanger 5, passes through the first flow rate control device 9 in a substantially fully opened state, is slightly decompressed, and flows into the second branch portion 11.

On the other hand, the remaining liquid refrigerant passes through the second flow rate control device 13 controlled by the pressure detected by the third pressure detecting means 25 and the pressure detected by the fourth pressure detecting means 26,
It flows into the second branch portion 11 and merges with the refrigerant having passed through the indoor unit D that is going to be heated. The second branch portion 11 and the second connection pipes 7b and 7c on the indoor unit side are sequentially passed to flow into the indoor units B and C. The refrigerant flowing into each indoor unit B, C is
After the pressure is reduced to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of the indoor unit side heat exchanger 5, it flows into the indoor side heat exchanger 5 and heat-exchanges with indoor air to evaporate. Then it is gasified and the room is cooled. Further, the refrigerant in the gas state is used as the first connection pipe 6 on the indoor unit side.
b, 6c, first on-off valve 21, third on-off valve 23, first
A connecting cycle 6, a fourth check valve 33, a four-way switching valve 2 of the heat source unit A, and an accumulator 4 form a circulation cycle that is sucked into the compressor 1 to perform a cooling main operation. At this time, the first on-off valve 21 connected to the indoor units B and C, the third
The open / close valve 23 is open and the second open / close valve 22 is closed. The second opening / closing valve 22 connected to the indoor unit D is open, and the first opening / closing valve 21 and the third opening / closing valve 23 are closed.
At this time, the refrigerant circulates inevitably to the third check valve 32 and the fourth check valve 33 because the first connecting pipe 6 has a low pressure and the second connecting pipe 7 has a high pressure.

During this cycle, a part of the liquid refrigerant is supplied to the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
It enters the bypass pipe 14 from the meeting portion of 7d, is depressurized to a low pressure by the third flow control device 15, and the third heat exchange portion 1
6b, 16c, 16d between the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch portion 11 and the second
Of the second branch portion 11 between the second connection pipes 7b, 7c, 7d of the second branch portion 11 of the second heat exchanger portion 16a, and the first heat exchange portion 19 at the second flow rate. Heat is exchanged with the refrigerant flowing into the control device 13, and the evaporated refrigerant enters the first connection pipe 6 and the fourth check valve 33, and passes through the four-way switching valve 2 of the heat source device A and the accumulator 4. It is sucked into the compressor 1. On the other hand, the first, second and third heat exchange parts 19, 16a,
The refrigerant in the second branch portion 11 that is heat-exchanged and cooled in 16b, 16c, and 16d and is sufficiently subcooled flows into the indoor units B and C that are about to be cooled.

[0016]

Since the conventional multi-chamber heat pump type air conditioner is constructed as described above, in the case of the cooling-main operation in the cooling / heating simultaneous operation, the heat source side heat exchanger which becomes the condenser. When high-pressure gas refrigerant flows into the heat exchanger and the pressure loss becomes large, the condensation pressure in the indoor unit side heat exchanger of the heating indoor unit located downstream of the heat source unit side heat exchanger becomes low, and there is a problem that heating capacity does not come out. there were. or,
In the heating-main operation in the cooling / heating simultaneous operation, the low-pressure two-phase refrigerant flows in the heat source side heat exchanger, which serves as an evaporator, so that the pressure loss is large and the inside of the cooling indoor unit located upstream of the heat source side heat exchanger. There was a problem that the evaporation pressure in the machine side heat exchanger became high and the cooling capacity could not be obtained. Also, when the difference between the capacity of the cooling indoor unit and the capacity of the heating indoor unit is small in the heating-main operation as well, there is a problem that the evaporation capacity of the heat exchanger on the heat source unit side becomes excessive and the evaporation pressure becomes high, so that the cooling capacity cannot be obtained. In addition, when the difference between the capacity of the cooling indoor unit and the capacity of the heating indoor unit is small and the total capacity of the operating indoor unit is smaller than the capacity of the heat source unit in the heating-main operation as well, the condensing capacity of the heating indoor unit also decreases and the condensing pressure rises. However, there was a problem that it stopped due to abnormal high pressure. As an approximation technique, Japanese Patent Laid-Open No.
There is a publication of -118372.

The present invention has been made to solve the above problems, and a plurality of indoor units are connected to one heat source unit, and heating / cooling is selectively performed for each indoor unit. And in a multi-chamber heat pump type air conditioner that can perform cooling in one indoor unit and heating in the other indoor unit, suppress pressure loss of the heat source side heat exchanger in the case of cooling main operation in simultaneous cooling and heating operation However, by adjusting to an appropriate condensing capacity, the condensing pressure in the indoor unit side heat exchanger of the heating indoor unit is not increased and the heating capacity is not impaired.
In the case of heating-main operation in simultaneous heating and cooling operation, the pressure loss of the heat source side heat exchanger is suppressed, and the evaporation pressure in the indoor unit side heat exchanger of the cooling indoor unit is lowered by adjusting to an appropriate evaporation capacity. It is an object of the present invention to obtain an air conditioner that does not impair the cooling capacity and does not abnormally stop.

[0018]

An air conditioner according to the present invention includes a plurality of heat source side heat exchangers connected in parallel with each other and provided with open / close valves at both ends, and the plurality of heat source side heat exchangers. A first heat source unit side bypass circuit connected in parallel with the exchanger and having an opening / closing valve in the middle thereof, and a fifth flow rate control device connected in parallel with the plurality of heat source unit side heat exchangers and provided with a fifth flow rate control unit in the middle thereof. The heat source side bypass circuit of No. 2, the first pressure detecting means for detecting the suction side pressure of the compressor, and the second pressure detecting means for detecting the discharge side pressure of the compressor. And a detection signal of the first pressure detection means as an input, and opening / closing valves at both ends of the heat exchangers on the heat source side, a switching valve on the first heat source side bypass circuit, and a second heat source side bypass circuit. 5 controls the opening of the flow rate control device, and Inputting the detection signal of the second pressure detecting means, the opening / closing valves at both ends of the plurality of heat source unit side heat exchangers, the opening / closing valves of the first heat source unit side bypass circuit, and the second heat source unit side bypass circuit. The heat source device side heat exchange capacity control means for controlling the opening degree of the fifth flow rate control device is provided. Further, a gas side pipe communicating with a pipe connecting the four-way switching valve and one end side of the heat source device side heat exchanger through an on-off valve, and a liquid side pipe communicating with the other end side of the heat source device side heat exchanger. ,
And a connection pipe for allowing the inflow of the refrigerant from the first connection pipe or the outflow of the refrigerant to the second connection pipe via the flow path switching valve device. It is a thing.

[0019]

In the air conditioner according to the present invention, the heat source unit side heat exchanger capacity control unit receives the detection signal of the first pressure detecting unit during the cooling main operation and the detection signal of the second pressure detecting unit during the heating main operation. Respectively control the opening / closing valves at both ends of the plurality of heat source machine side heat exchangers, the opening / closing valves of the first heat source machine side bypass circuit and the fifth flow control device of the second heat source machine side bypass circuit, The suction side pressure and the discharge side pressure of the compressor are made to converge to predetermined target pressures. Also,
A gas side pipe that communicates with a pipe that connects the four-way switching valve and one end side of the heat source device side heat exchanger via a switching valve, a liquid side pipe that communicates with the other end side of the heat source device side heat exchanger, and a flow. Inflow of refrigerant from the first connecting pipe via the path switching valve device, or second
Since the gas-liquid separator provided with the connection pipe that allows the refrigerant to flow out to the connection pipe is provided, only the liquid refrigerant that contributes to the magnitude of the evaporation capacity can be supplied to the heat source side heat exchanger.

[0020]

【Example】

Example 1. Examples of the present invention will be described below.
FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to an embodiment of the present invention. 3 to 5 show operation states during the heating and cooling operation in the embodiment of FIG. 1, FIG. 3 is an operation state diagram only for cooling or heating, and FIGS. 4 and 5 are operations for simultaneous cooling and heating operation. FIG. 4 is an operation state diagram showing heating-main operation (when the heating operation capacity is larger than the cooling operation capacity), and FIG. 5 is an operation operation state diagram showing cooling-main operation (when the cooling operation capacity is larger than the heating operation capacity). is there. In this embodiment, a case where three indoor units are connected to one heat source device will be described, but the same applies to a case where two or more indoor units are connected.

In FIG. 1, A is a heat source unit, and B, C, and D are indoor units connected in parallel with each other, as will be described later, and have the same structure. As will be described later, E is a first branch portion 10, a second flow rate control device 13, a second branch portion 11,
First gas-liquid separation device 12, heat exchange parts 16a, 16b, 1
6c, 16d, 19, the third flow rate control device 15, and the fourth flow rate control device 17 are built-in repeaters. Further, 1 is a compressor, 2 is a four-way switching valve that switches the refrigerant flow direction of the heat source device, 3 is parallel to each other, and a fourth opening / closing valve 70 is provided at both ends.
First heat source side heat exchanger 3a including fifth on-off valve 71
And a second heat source unit side heat exchanger 3b having a sixth opening / closing valve 72 and a seventh opening / closing valve 73 at both ends, and the first and second heat source unit side heat exchangers 3a and 3b in parallel. Connected to the 8th
First heat source machine side bypass circuit 75 including the open / close valve 74
And a second heat source unit side bypass circuit 77 which is connected in parallel to the first and second heat source unit side heat exchangers 3a and 3b and is provided with a fifth flow rate control device 76 on the way. The side heat exchangers 4 are accumulators, which are connected to the compressor 1 via the four-way switching valve 2. Reference numeral 79 is a first pressure detecting means provided between the four-way switching valve 2 and the accumulator 4. Reference numeral 78 is a second pressure detecting means provided between the four-way switching valve 2 and the compressor 1. The heat source machine A is constituted by these. Further, 5 is an indoor heat exchanger provided in the three indoor units B, C and D, 6 is a four-way switching valve 2 of the heat source unit A and a relay E is a fourth check valve 3 which will be described later.
Thick first connecting pipes 6b, 6c, which are connected via 3
Reference numeral 6d connects the indoor heat exchangers 5 of the indoor units B, C, and D to the repeater E, respectively, and the first connection pipe on the indoor unit side corresponding to the first connection pipe 6 and 7 of the heat source unit A. It is a second connection pipe that is thinner than the above-mentioned first connection pipe that connects the heat source unit side heat exchanger 3 and the relay unit E via a third check valve 32 described later.

Reference numerals 7b, 7c and 7d respectively connect the indoor heat exchangers 5 of the indoor units B, C and D to the relay E via the first flow rate control device 9 and to the second connection pipe 7. It is the corresponding second connection pipe on the indoor unit side. Reference numeral 21 denotes the first connection pipes 6b, 6c, 6d on the indoor unit side, and the first connection pipe 6
A second opening / closing valve for connecting the first connecting pipes 6b, 6c, 6d on the indoor unit side and a second connecting pipe 7 and a first opening / closing valve 21 Is a third on-off valve that bypasses the entrance and exit of the. Reference numeral 9 is a first flow rate control device which is connected close to the indoor heat exchanger 5 and is controlled by the superheat amount on the outlet side of the indoor heat exchanger 5 during cooling and by the subcool amount during heating. It is connected to the second connection pipes 7b, 7c, 7d on the indoor unit side. Reference numeral 10 denotes a first on-off valve 21 and a second on-off valve that connect the first connection pipes 6b, 6c, 6d on the indoor unit side to the first connection pipe 6 or the second connection pipe 7 in a switchable manner. 22 is a first branch portion including a third opening / closing valve 23 that bypasses the inlet / outlet of the first opening / closing valve 21. Reference numeral 11 denotes a second branch portion including the second connection pipes 7b, 7c, 7d on the indoor unit side and the second connection pipe 7. Reference numeral 12 is a second gas-liquid separation device provided in the middle of the second connecting pipe 7, the gas phase portion of which is connected to the second opening / closing valve 22 of the first branch portion, and the liquid phase portion of which is the first It is connected to the two branch parts 11. Reference numeral 13 is a second flow rate control device (here, an electric expansion valve) which is connected between the first gas-liquid separation device 12 and the second branch portion 11 and which can be opened and closed.

Reference numeral 14 is a bypass pipe connecting the second branch portion 11 and the first connection pipe 6, and 15 is a bypass pipe 14.
The third flow rate control device (here, an electric expansion valve) 16a provided in the middle of the bypass pipe 16a is provided downstream of the third flow rate control device 15 provided in the middle of the bypass pipe 14, and the second branch portion is provided. The second connection pipe 7b on the indoor air side in FIG.
Second heat exchange with the joints of 7c and 7d, respectively
It is a heat exchange part. 16b, 16c, 16d are respectively provided downstream of the third flow rate control device 15 provided in the middle of the bypass pipe 14, and the second connection pipes 7b, 7c on the indoor unit side of the second branch portion 11 are provided. 7d is a third heat exchanging unit for exchanging heat with each other. Reference numeral 19 is provided in the bypass pipe 14 downstream of the third flow rate control device 15 and downstream of the second heat exchange section 16a, and connects the first gas-liquid separation device 12 and the second flow rate control device 13. A first heat exchanging unit for exchanging heat with the pipe, and 17 is a fourth flow control device (here, a freely openable and closable flow controller connected between the second branching unit 11 and the first connecting pipe 6). Electric expansion valve)
Is.

On the other hand, reference numeral 32 is a third check valve provided between the heat source unit side heat exchanger 3 and the second connection pipe 7, and the heat source unit side heat exchanger 3 to the third check valve are provided. Refrigerant flow is allowed only to the second connecting pipe 7. Reference numeral 33 denotes a fourth check valve provided between the four-way switching valve 2 of the heat source unit A and the first connecting pipe 6, and from the first connecting pipe 6 to the four-way valve switching valve 2. Allows only refrigerant flow. Reference numeral 34 is a fifth check valve provided between the four-way switching valve 2 of the heat source unit A and the second connection pipe 7, and only from the four-way switching valve 2 to the second connection pipe 7. Allows refrigerant flow. 35
Is a sixth check valve provided between the heat source device side heat exchanger 3 and the first connection pipe 6, and from the first connection pipe 6 to the heat source device side heat exchanger 3. Allows only refrigerant flow. The third, fourth, fifth and sixth check valves 32, 3
The flow path switching valve device 40 is constituted by 3, 34, and 35. Example 2.90 is a second gas-liquid separation device provided between the flow path switching valve device 40 and the heat source unit side heat exchanger 3. Reference numeral 91 is a ninth on-off valve provided between the gas phase portion of the second gas-liquid separator and the four-way switching valve 2. 90a
Via the on-off valve 91, the upper part of the second gas-liquid separation device 90, the four-way switching valve 2 and the heat source unit side heat exchanger 3a,
A gas side pipe that communicates with a pipe that connects one end side of 3b, a liquid 90b that communicates the lower part of the second gas-liquid separation device and the other end side of the heat source unit side heat exchangers 3a, 3b. The side pipe 90c is a connection pipe that enables the inflow of the refrigerant from the first connection pipe 6 or the outflow of the refrigerant to the second connection pipe 7 via the flow path switching valve device 40. 25 is the above first
A third pressure detecting means 26 provided between the branch portion 10 and the second flow rate control device 13 is provided between the second flow rate control device 13 and the fourth flow rate control device 17. It is the fourth pressure detecting means.

Next, the operation will be described. First, the case of only the cooling operation will be described with reference to FIG. As shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, is heat-exchanged with the heat-source water in the heat-source-side heat exchanger 3, and is condensed into the third gas. Of the check valve 32, the second connection pipe 7, the first gas-liquid separation device 12, and the second flow rate control device 13 in this order, the second branch portion 11, and the second connection pipe on the indoor unit side. It passes through 7b, 7c, 7d and flows into each indoor unit B, C, D. The refrigerant flowing into each indoor unit B, C, D is decompressed to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of each indoor heat exchanger 5, and the indoor heat exchanger 5 is cooled. It heats and exchanges heat with the room air, is gasified, and cools the room.

The refrigerant in the gas state is supplied to the first connecting pipes 6b, 6c, 6d on the indoor unit side, the first opening / closing valve 21,
Third on-off valve 23, first connecting pipe 6, fourth check valve 3
3, the four-way switching valve 2 of the heat source unit A, and the accumulator 4 form a circulation cycle that is sucked into the compressor 1 to perform the cooling operation. At this time, the first opening / closing valve 21 and the third opening / closing valve 23
Open, the second on-off valve 22 is closed. At this time, the refrigerant has a low pressure in the first connecting pipe 6 and a high pressure in the second connecting pipe 7, so that the third check valve 32 and the fourth check valve 3 are inevitable.
Distribution to 3. In addition, during this cycle, a part of the refrigerant that has passed through the second flow rate control device 13 enters the bypass pipe 14 and is depressurized to a low pressure by the third flow rate control device 15, so that the third heat exchange parts 16b, 16c, 16d between the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch portion 11 and also on the indoor unit side of the second branch portion 11 on the second heat exchange part 16a. Of the second connection pipes 7b, 7c, and 7d, and further with the refrigerant flowing into the second flow rate control device 13 in the first heat exchange unit 19, heat is exchanged and evaporated. The refrigerant enters the first connecting pipe 6 and the fourth check valve 33, and is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4. On the other hand, the first, second, and third heat exchange units 1
The second branch portion 1 having sufficient subcooling by being heat-exchanged and cooled by 9, 16a, 16b, 16c, 16d.
Refrigerant No. 1 flows into the indoor units B, C, and D that are about to be cooled.

Next, the case of only the heating operation will be described with reference to FIG. That is, as shown by the dotted arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the fifth check valve 34, the second connecting pipe 7, and the first connecting pipe 7. The second on-off valve 2 passing through the gas-liquid separator 12
2. The first connection pipes 6b, 6c, 6d on the indoor unit side are sequentially passed into the indoor units B, C, D to exchange heat with indoor air to be condensed and liquefied to heat the room. The refrigerant in this liquid state is controlled by the subcool amount at the outlet of each indoor heat exchanger 5 and passes through the first flow rate control device 9 in a substantially fully opened state, and the second connection pipe 7b on the indoor unit side, From 7c and 7d, they flow into the second branch portion 11 and merge, and further pass through the fourth flow rate control device 17. Here, the pressure is reduced to a low pressure gas-liquid two-phase state by either the first flow rate control device 9 or the third and fourth flow rate control devices 15 and 17. The refrigerant decompressed to a low pressure flows into the sixth check valve 35 of the heat source device A and the heat source device side heat exchanger 3 through the first connection pipe 6, exchanges heat with the heat source water and evaporates to a gas state. And the four-way switching valve 2 of the heat source unit A,
A circulation cycle in which the compressor 1 is sucked through the accumulator 4 constitutes a heating operation. At this time, the second opening / closing valve 22 is open, and the first opening / closing valve 21 and the third opening / closing valve 23 are closed. At this time, the refrigerant inevitably circulates to the fifth check valve 34 and the sixth check valve 35 because the first connecting pipe 6 has a low pressure and the second connecting pipe 7 has a high pressure. At this time, the second flow rate control device 13 is normally in the predetermined minimum opening state.

Next, the case of the heating-main operation in the cooling / heating simultaneous operation will be described with reference to FIG. The high-temperature high-pressure refrigerant gas discharged from the compressor 1 is sent to the relay machine E through the four-way switching valve 2 and the fifth check valve 34 and the second connecting pipe 7 as shown by the dotted arrow in the figure. After passing through the first gas-liquid separation device 12, the second opening / closing valve 22 and the first connection pipes 6b and 6c on the indoor unit side in this order, and flowing into the indoor units B and C to be heated, and the indoor side The heat exchanger 5 exchanges heat with indoor air to condense and liquefy, and heats the room. The condensed and liquefied refrigerant passes through the first flow rate control device 9 which is controlled by the amount of subcool at the outlet of each indoor heat exchanger 5 and is in a substantially fully opened state, and is slightly depressurized and flows into the second branch portion 11.

Part of this refrigerant passes through the second inspection pipe 7d on the indoor unit side, enters the indoor unit D to be cooled, and is controlled by the superheat amount at the outlet of the indoor heat exchanger 5. After entering the flow rate control device 9 of No. 1 and being decompressed, it enters the indoor heat exchanger 5 to exchange heat and evaporate into a gas state to cool the room, and to connect the first connection pipe 6d on the indoor unit side. After that, it flows into the first connecting pipe 6 via the first opening / closing valve 21 and the third opening / closing valve 23. On the other hand, the other refrigerant passes through the fourth flow rate control device 17 which is controlled so that the pressure difference between the pressure detected by the third pressure detecting means 25 and the pressure detected by the fourth pressure detecting means 26 falls within a predetermined range. , Indoor unit D trying to cool
Through the thick first connecting pipe 6 which merges with the refrigerant passing through
The sixth check valve 35 and the second gas-liquid separation device 90 of the heat source unit A
, The liquid refrigerant is split into the heat source unit side heat exchanger 3 and exchanges heat with the heat source water to evaporate and become a gas state. On the other hand, the gaseous refrigerant divided in the second gas-liquid separator 90 is sucked into the compressor 1 via the four-way switching valve 2 and the accumulator 4. Here, the liquid refrigerant that has flowed into the second gas-liquid separation device 90 and has been split into the heat source device side heat exchanger 3 has a fourth opening / closing valve 70 at both ends of the first heat source device side heat exchanger 3a. Fifth on-off valve 71
And a sixth opening / closing valve 72, a seventh opening / closing valve 73 at both ends of the second heat source unit side heat exchanger 3b, and the first and second heat source unit side heat exchangers 3a, 3b are connected in parallel. The opening and closing of the eighth opening / closing valve 74 of the first heat source unit side bypass circuit 75, and
Further, the fifth heat source unit side bypass circuit 77 is connected in parallel with the first and second heat source unit side heat exchangers 3a and 3b.
The heat exchange amount of the heat source side heat exchanger 3 is adjusted so that the flow rate is adjusted by adjusting the opening degree of the flow rate control device 76 and the pressure detected by the second pressure detection means 78 becomes a predetermined target pressure. To be adjusted arbitrarily.

This refrigerant constitutes a circulation cycle in which it is sucked into the compressor 1 via the four-way switching valve 2 of the heat source unit A and the accumulator 4, and performs heating-main operation. At this time, the evaporation pressure of the indoor side heat exchanger 5 of the indoor unit D to be cooled and the pressure difference of the heat source unit side heat exchanger 3 are reduced due to switching to the thick first connection pipe 6. At this time, the second opening / closing valve 22 connected to the indoor units B and C is open, and the first opening / closing valve 21 and the third opening / closing valve 23 are closed. The first opening / closing valve 21 and the third opening / closing valve 23 connected to the indoor unit D are open, and the second opening / closing valve 22 is closed. At this time, the refrigerant inevitably circulates to the fifth check valve 34 and the sixth check valve 35 because the first connecting pipe 6 has a low pressure and the second connecting pipe 7 has a high pressure.

During this cycle, part of the liquid refrigerant is the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
It enters the bypass pipe 14 from the meeting portion of 7d, is depressurized to a low pressure by the third flow control device 15, and the third heat exchange portion 1
6b, 16c, 16d between the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch portion 11 and the second
The heat exchange section 16a performs heat exchange with the association section of the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch section 11, and the evaporated refrigerant is the first connection pipe. 6, after entering the heat source unit side heat exchanger 3 via the sixth check valve 35, exchanging heat with the heat source water to evaporate and vaporize, and then through the four-way switching valve 2 of the heat source unit A and the accumulator 4 to the compressor. Inhaled to 1. On the other hand, the second and third heat exchange parts 16a, 16b, 16c,
The refrigerant in the second branch portion 11 that has been heat-exchanged and cooled in 16d and is sufficiently subcooled flows into the indoor unit D that is about to be cooled. At this time, the second flow rate control device 13 is normally in the predetermined minimum opening state.

Next, the case of mainly cooling in the simultaneous heating and cooling operation will be described with reference to FIG. As shown by the solid arrow in the figure, the high-temperature high-pressure refrigerant gas discharged from the compressor 1 flows into the heat source unit side heat exchanger 3 via the four-way switching valve 2,
It exchanges heat with the heat source water to form a gas-liquid two-phase high-temperature high-pressure state. Here, the first heat source unit side heat exchanger 3a is set so that the pressure detected by the first pressure detecting means 79 becomes a predetermined target pressure.
Of the fourth on-off valve 70 and the fifth on-off valve 71 at both ends of the second heat-generating unit side heat exchanger 3b
2, the seventh on-off valve 73, and the eighth on-off valve 74 of the first heat generator side bypass circuit 75 connected in parallel with the first and second heat source side heat exchangers 3a and 3b, The ninth on-off valve 91 provided between the gas phase portion of the second gas-liquid separation device and the four-way switching valve 2 is opened and closed, and the first and second heat source unit side heat exchangers 3a, 3b, the opening degree of the 5th flow control device 76 of the 2nd heat source machine side bypass circuit 77 is adjusted, and the heat exchange amount of the heat source machine side heat exchanger 3 is arbitrarily adjusted. After that, this gas-liquid two-phase high-temperature and high-pressure refrigerant has a third
It is sent to the first gas-liquid separation device 12 of the relay machine E via the check valve 32 and the second connection pipe 7. Here, the separated and separated gaseous refrigerant and liquid refrigerant pass through the second opening / closing valve 22 and the indoor unit side first connection pipe 6d in this order,
It flows into the indoor unit D that is going to be heated, and the indoor heat exchanger 5
Heats the room by exchanging heat with the room air to condense and liquefy.
Further, it is controlled by the amount of subcool at the outlet of the indoor heat exchanger 5, passes through the first flow rate control device 9 in a substantially fully opened state,
It is slightly decompressed and flows into the second branch portion 11.

On the other hand, the remaining liquid refrigerant passes through the second flow rate control device 13 controlled by the pressure detected by the third pressure detecting means 25 and the pressure detected by the fourth pressure detecting means 26,
The indoor unit D which flows into the second branch portion 11 and tries to heat
It merges with the refrigerant that has passed through. The second branch portion 11 and the second connection pipes 7b and 7c on the indoor unit side are passed in this order, and each indoor unit B,
Flow into C. The refrigerant flowing into each indoor unit B, C is depressurized to a low pressure by the first flow rate control device 9 controlled by the superheat amount at the outlet of the indoor unit heat exchanger 5, and then the indoor heat exchanger 5 Flows into the room, heat exchanges with the room air, evaporates and is gasified, and cools the room. Further, the refrigerant in the gas state is used as the first connection pipes 6b, 6 on the indoor unit side.
c, the first opening / closing valve 21, the third opening / closing valve 23, the first connecting pipe 6, the fourth check valve 33, the four-way switching valve 2 of the heat source unit A,
A circulation cycle in which the air is sucked into the compressor 1 via the accumulator 4 is configured to perform a cooling main operation. At this time, the first opening / closing valve 21 and the third opening / closing valve 23 connected to the indoor units B and C are open, and the second opening / closing valve 22 is closed. The second opening / closing valve 22 connected to the indoor unit D is open, and the first opening / closing valve 21 and the third opening / closing valve 23 are closed. At this time, the refrigerant has a low pressure in the first connecting pipe 6 and a high pressure in the second connecting pipe 7, so that the third check valve 32 and the fourth check valve 3 are inevitably formed.
Distribution to 3.

During this cycle, a part of the liquid refrigerant is supplied to the second connecting pipes 7b, 7c on the indoor unit side of the second branch portion 11,
It enters the bypass pipe 14 from the meeting portion of 7d, is depressurized to a low pressure by the third flow path control device 15, and the third heat exchange unit 1
6b, 16c, 16d between the second connection pipes 7b, 7c, 7d on the indoor unit side of the second branch portion 11 and the second
Of the second branch portion 11 between the second connection pipes 7b, 7c, 7d of the second branch portion 11 of the second heat exchanger portion 16a, and the first heat exchange portion 19 at the second flow rate. Heat is exchanged with the refrigerant flowing into the control device 13, and the evaporated refrigerant enters the first connection pipe 6 and the fourth check valve 33, and passes through the four-way switching valve 2 of the heat source unit A and the accumulator 4. It is sucked into the compressor 1. On the other hand, the first, second and third heat exchange parts 19, 16a,
The refrigerant in the second branch portion 11 that is heat-exchanged and cooled in 16b, 16c, and 16d and is sufficiently subcooled flows into the indoor units B and C that are about to be cooled.

Next, the fourth opening / closing valve 70 and the fifth opening / closing valve 7 in the heating-main operation and the cooling-main operation of the cooling / heating simultaneous operation.
The control of the first, sixth opening / closing valve 72, the seventh opening / closing valve 73, the eighth opening / closing valve 74, and the fifth flow rate control device 76 will be described. FIG. 6 shows a fourth on-off valve 70, a fifth on-off valve 71, a sixth
Open / close valve 72, seventh open / close valve 73, eighth open / close valve 74,
The control mechanism of the 5th flow control device 76 is shown, 50 is the 1st
The fourth opening / closing valve 70, the fifth opening / closing valve 71, according to the pressures detected by the pressure detecting means 79 and the second pressure detecting means 78.
Sixth on-off valve 72, seventh on-off valve 73, eighth on-off valve 7
It is a heat source unit side heat exchange capacity adjusting means for controlling the opening / closing of No. 4 and the opening degree of the fifth flow rate control device 76. FIG. 7 is a flowchart showing the control contents of the heat source unit side heat exchange capacity control means 50 in the heating-main operation in the cooling / heating simultaneous operation. First, a method of controlling the heat exchange capacity of the heat source unit by the heat exchange unit of the heat source unit 50 will be described. In this embodiment, the heat exchange capacity on the heat source unit side is adjusted in the following three stages. The first stage corresponds to the case where the heat exchange capacity on the heat source unit side is the largest, and corresponds to the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72, and the seventh opening / closing valve. By opening the valve 73 and controlling the opening of the fifth flow control device 76, the refrigerant is circulated through both the first and second heat source unit side heat exchangers 3a and 3b and the fifth flow control device 76 is controlled. At the opening of the flow rate control device 76, the amount of bypass refrigerant is adjusted from the full opening to the first set opening. In this case, when the fifth flow rate control device 76 of the second heat source unit side bypass circuit 77 is fully closed, the air conditioner is circulated to the first and second heat source unit side heat exchangers 3a and 3b. Since all the refrigerant that is operating flows in, the pressure loss increases, the evaporating pressure in the cooling indoor unit becomes high, and the cooling capacity does not come out. Set a degree.

The second stage corresponds to the case where the next larger heat exchange capacity on the heat source unit side is required, and the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72, the above-mentioned 7th
The first opening / closing valve 73 and the eighth opening / closing valve 74 are opened, and the opening degree of the fifth flow rate control device 76 is controlled.
And the second heat source unit side heat exchangers 3a, 3b, and the first bypass circuit 75, the refrigerant is circulated, and the opening degree of the fifth flow rate control device 76 allows the bypass refrigerant amount to be fully opened to fully closed. Adjust up to. In this case, the refrigerant flow rate of the second heat source unit side bypass circuit 77 when the fifth flow rate control device 76 is fully opened and the eighth open / close valve 7 in the middle of the flow rate.
The pressure loss of the first heat source device side bypass circuit 75 is set so that the refrigerant flow rates of the first heat source device side bypass circuit 75 are equal. Thereby, the bypass flow rate in the second stage can be continuously adjusted from the bypass flow rate in the first stage.

The third stage corresponds to the case where the heat exchange amount on the heat source unit side is the smallest, and corresponds to the fourth on-off valve 70, the fifth on-off valve 71, the sixth on-off valve 72, and the sixth on-off valve. No. 7 open / close valve 73 is closed, the eighth open / close valve 74 is opened, and the opening degree of the fifth flow rate control device 76 is fully opened. The heat exchange amounts of the vessels 3a and 3b are eliminated. In this way, by adjusting the heat exchange capacity on the heat source unit side in three stages, a continuous heat exchange capacity on the heat source unit side can be obtained, the high pressure does not rise excessively, the low pressure does not pull in, and the simultaneous cooling and heating operation is performed. In this case, the cooling capacity and the heating capacity can be sufficiently obtained in the heating-main operation.

Next, the control contents of the heat-source-unit-side heat exchange capacity control means 50 in the heating-main operation in the simultaneous cooling and heating operation will be described with reference to the flowchart of FIG. Step 51
Then, the detected pressure of the second pressure detecting means 78 is compared with the predetermined first set pressure, and if the detected pressure is lower than the first set pressure, the routine proceeds to step 52. In step 52, it is judged whether the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72, and the seventh opening / closing valve 73 are opened or closed. Valve, step 5
Return to 1. When the valve is opened, the process proceeds to step 54 and the above eighth
It is determined whether the opening / closing valve 74 is open or closed. If the valve is open, the process proceeds to step 55, the valve is closed, and the process returns to step 51. When the valve is closed, the routine proceeds to step 56, where the opening degree of the fifth flow rate control device 76 is judged, and when it is opened from the first predetermined opening slightly opened from the fully closed state, the opening degree is set at step 57. Return to aperture step 51. Also, in the case of the first predetermined opening degree, step 5
Return to 1.

On the other hand, when it is judged at step 51 that the detected pressure is equal to or higher than the first set pressure, the routine proceeds to step 58. In step 58, the detected pressure of the second pressure detecting means 78 is compared with the second set pressure which is set higher than the first target pressure in advance, and when the detected pressure is higher than the second set pressure, step 59. If the detected pressure is less than or equal to the second set pressure, the process returns to step 51. In step 59, the opening degree of the fifth flow rate control device 76 is determined, and if it is not fully opened, the operation proceeds to step 60, the opening degree is increased, and the operation returns to step 51. In the case of full opening, it is determined in step 61 whether the eighth opening / closing valve 74 is open or closed. If it is closed, the valve is opened in step 62, the process proceeds to step 62, the valve is opened, and the process returns to step 51. In the case of opening the valve, the routine proceeds to step 63, where the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72, the seventh opening
Open / close valve 73 is judged to be open / closed, and if it is open, step 6
4, the valve is closed and the process returns to step 51. If the valve is closed, the process returns to step 51. In this way, the pressure detected by the fourth pressure detecting means 79 can be set to a value between the first set pressure and the second set pressure.

FIG. 8 is a flow chart showing the control contents of the heat source unit side heat exchange capacity control means 50 in the case of the cooling main operation in the cooling / heating simultaneous operation. First, a method of controlling the heat exchange capacity of the heat source unit by the heat exchange unit of the heat source unit 50 will be described. In this embodiment, the heat exchange capacity on the heat source unit side is adjusted in the following three stages. The first stage corresponds to the case where the largest heat exchange capacity on the heat source unit side is required.
0, the fifth opening / closing valve 71, the sixth opening / closing valve 72, and the seventh opening / closing valve 73 are opened, and the opening of the fifth flow control device 76 is controlled to control the first and The refrigerant is circulated through both of the second heat source unit side heat exchangers 3a and 3b, and the bypass refrigerant amount is adjusted from the full opening to the first set opening at the opening degree of the fifth flow rate control device 76. .. In this case, the fifth heat source unit side bypass circuit 77 has the fifth component.
When the flow rate control device 76 is completely closed, all the refrigerant circulating in the air conditioner flows into the first and second heat source unit side heat exchangers 3a and 3b to increase the pressure loss. Since the condensing pressure becomes low and the heating capacity does not come out, the fifth flow rate control device 76 is provided with a first predetermined opening degree which is slightly open rather than fully closed.

The second stage corresponds to the case where the next larger heat exchange capacity on the heat source side is required, and the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72, the above-mentioned 7th
The first opening / closing valve 73 and the eighth opening / closing valve 74 are opened, and the opening degree of the fifth flow rate control device 76 is controlled.
And the second heat source unit side heat exchangers 3a, 3b, and the first bypass circuit 75, the refrigerant is circulated, and the opening degree of the fifth flow rate control device 76 allows the bypass refrigerant amount to be fully opened to fully closed. Adjust up to. In this case, the refrigerant flow rate of the second heat source unit side bypass circuit 77 when the fifth flow rate control device 76 is fully opened and the eighth open / close valve 7 in the middle of the flow rate.
The pressure loss of the first heat source device side bypass circuit 75 is set so that the refrigerant flow rates of the first heat source device side bypass circuit 75 are equal. Thereby, the bypass flow rate in the second stage can be continuously adjusted from the bypass flow rate in the first stage. The third stage corresponds to the case where the minimum heat exchange amount on the heat source unit side is required, and the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72,
By closing the seventh opening / closing valve 73, opening the eighth opening / closing valve 74, and fully opening the opening degree of the fifth flow rate control device 76, the first and second heat source unit sides Heat exchanger 3
The heat exchange amounts of a and 3b are eliminated. In this way, by controlling the heat exchange capacity on the heat source unit side in three stages, the cooling capacity and the heating capacity in the cooling-main operation in the cooling / heating simultaneous operation can be achieved without the high pressure rising excessively and the low pressure not pulling down. You get enough.

Next, the control contents of the heat-source-unit-side heat exchange capacity control means 50 in the case of the cooling-main operation in the simultaneous cooling and heating operation will be described with reference to the flowchart of FIG. Step 10
When the detected pressure is higher than the third set pressure by comparing the detected pressure of the first pressure detecting means 79 with the preset third set pressure in step 1, the routine proceeds to step 102. Step 1
02, the fourth on-off valve 70, the fifth on-off valve 71,
Whether the sixth on-off valve 72 and the seventh on-off valve 73 are opened or closed is determined. If they are closed, the valve is opened in step 103 and the process returns to step 101. If the valve is open, proceed to step 104,
Whether the eighth opening / closing valve 74 is opened or closed is determined.
The routine proceeds to step 105, the valve is closed, and the routine returns to step 101.
When the valve is closed, the routine proceeds to step 106, where the opening degree of the fifth flow rate control device 76 is judged, and when it is opened from the first predetermined opening slightly opened from the fully closed state, the opening degree is opened at step 107. Return to aperture step 101. Further, when the opening degree is the first predetermined opening degree, the process also returns to step 101.

On the other hand, if it is determined in step 101 that the detected pressure is less than or equal to the third set pressure, the process proceeds to step 108.
In step 108, the detected pressure of the third pressure detecting means 78 is compared with the fourth set pressure which is set lower than the third set pressure in advance. If the detected pressure is lower than the fourth detected pressure, step If the detected pressure is equal to or higher than the fourth set pressure, the process returns to step 101. Step 109
Then, the opening degree of the fifth flow rate control device 76 is determined. In step 109, the opening degree of the fifth flow rate control device 76 is determined, and if not fully opened, the operation proceeds to step 110, the opening degree is increased, and the operation returns to step 101. If it is fully open, the routine proceeds to step 111, where it is judged whether the eighth on-off valve 74 is open or closed. If it is closed, the valve is opened at step 112 and the routine returns to step 101. In the case of opening the valve, the routine proceeds to step 113, where the fourth opening / closing valve 70, the fifth opening / closing valve 71, the sixth opening / closing valve 72, and the seventh opening / closing valve 73.
Whether the valve is open or closed is determined, and if the valve is open, the process proceeds to step 114 and is closed, and the process returns to step 101. If the valve is closed, the process returns to step 101. In this way, the third pressure detecting means 7
The detected pressure of 8 may be a value between the third set pressure and the 42nd set pressure.

[0044]

As described above, in the air conditioner according to the present invention, the detection signal of the first pressure detecting means is input during the cooling main operation, and the detection signal of the second pressure detecting means is input during the heating main operation. The heat-source-unit-side heat exchanger capacity control means respectively has an on-off valve at both ends of the heat-source-unit-side heat exchanger,
The opening / closing valve of the first heat source unit side bypass circuit and the opening degree of the fifth flow rate control device of the second heat source unit side bypass circuit are controlled, and the discharge side pressure of the compressor is set to the first set pressure during heating main operation. And the second set pressure, and the suction side pressure of the compressor is made to converge between the third set pressure and the fourth set pressure during the cooling main operation, so that the heating main operation is performed. In this case, it is possible to suppress an excessive rise in the evaporation pressure in the indoor unit side heat exchanger of the cooling indoor unit, and the cooling capacity blade is not impaired. Further, in the case of the cooling main operation, the decrease of the condensing pressure in the indoor unit side heat exchanger of the heating indoor unit is suppressed, and the heating capacity is not impaired. Also, when the difference between the capacity of the cooling indoor unit and the capacity of the heating indoor unit is small in the heating-main operation as well, the evaporation capacity of the heat exchanger on the heat source unit side is appropriately controlled, so that an excessive rise in the evaporation pressure can be suppressed and the cooling capacity can be reduced. It is possible to achieve stable operation without stopping due to abnormal high-pressure pressure without damaging the engine. Further, a gas side pipe communicating with a pipe connecting the four-way switching valve and one end side of the heat source device side heat exchanger via an on-off valve, and a liquid side pipe communicating with the other end side of the heat source device side heat exchanger, and A gas-liquid separator provided with a connection pipe for allowing the inflow of the refrigerant from the first connection pipe or the outflow of the refrigerant to the second connection pipe through the flow path switching valve device. As a result, only the liquid refrigerant that contributes to the magnitude of the evaporation capacity can be supplied to the heat source machine side heat exchanger, and in particular, the accurate flow rate control by the fifth flow rate control device of the second heat source machine side bypass circuit can be performed. It has the effect of increasing the control positive.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram for explaining an operating state of only cooling or heating of the air conditioner shown in FIG.

FIG. 4 is a refrigerant circuit diagram for explaining an operating state of a heating-main operation of the air conditioning apparatus shown in FIG.

5 is a refrigerant circuit diagram for explaining an operating state of a cooling-main operation of the air conditioning apparatus shown in FIG.

FIG. 6 is a block diagram showing a configuration of a heat source unit side heat exchange capacity control means system of the air conditioner shown in FIG. 2.

FIG. 7 is a flowchart of a heat-source-unit-side heat exchange capacity adjusting means system for heating-main operation of the air-conditioning apparatus according to the embodiment of the present invention.

FIG. 8 is a flowchart of a heat-source-unit-side heat exchange capacity control means system in a cooling-main operation of the air conditioner according to the embodiment of the present invention.

FIG. 9 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner.

10 is a refrigerant circuit diagram for explaining an operating state of only cooling or heating of the air conditioner shown in FIG. 9.

FIG. 11 is a refrigerant circuit diagram for explaining an operating state of a heating-main operation of the air conditioning apparatus shown in FIG. 9.

FIG. 12 is a refrigerant circuit diagram for explaining an operating state of a cooling-main operation of the air conditioning apparatus shown in FIG. 9.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way switching valve 3 Heat source machine side heat exchanger 3a 1st heat source machine side heat exchanger 3b 2nd heat source machine side heat exchanger 4 Accumulator 5 Indoor side heat exchanger 9 1st flow control device 10 1st branch part 11 2nd branch part 13 2nd flow rate control device 14 Bypass piping 15 3rd flow rate control device 16a, 16b, 16c, 16d, 19 Heat exchange part 17 4th flow rate control device 21 1st Open / close valve 22 second open / close valve 23 third open / close valve 40 flow path switching valve device 70 fourth open / close valve 71 fifth open / close valve 72 sixth open / close valve 73 seventh open / close valve 74 eighth open / close Valve 75 First heat source device side bypass circuit 76 Fifth flow rate control device 77 Second heat source device side bypass circuit 78 Second pressure detecting means 79 First pressure detecting means 90 Gas-liquid separation device 91 Ninth opening and closing Valve A Heat source machine B, C, D Internal mechanism E relay machine

Claims (2)

[Claims] 1. A heat source unit comprising a compressor, a four-way switching valve, a plurality of heat source unit side heat exchangers connected in parallel with each other, an accumulator, etc., an indoor side heat exchanger, and a first flow rate control. A plurality of indoor units including devices, etc. are connected via first and second connecting pipes, and one of the indoor unit side heat exchangers of the plurality of indoor units is connected to the first indoor unit. A first branch portion having first and second opening / closing valves that are switchably connected to the connection pipe or the second connection pipe; and the other of the indoor heat exchangers of the plurality of indoor units, A second flow rate control device is interposed between the second flow path control device and a second branch part connected to the second connection pipe via the first flow rate control device, and the second branch part and the first The connection pipe is connected through a fourth flow rate control device, one end is further connected to the second branch portion, and the other end is the first The first through the flow rate control device of No. 3
The bypass pipe connected to the connection pipe of
A bypass pipe between the flow control device and the first connection pipe, and a heat exchange section for performing heat exchange between the second connection pipe and the pipe connecting the first flow control device. ,
During the operation in which the heat source unit side heat exchanger serves as a condenser, the refrigerant is allowed to flow only from the refrigerant outlet side of the condenser to the second connection pipe side, and from the first connection pipe to the four-way switching valve side. During the operation in which only the refrigerant is circulated and the heat source side heat exchanger is the evaporator, the refrigerant is circulated only from the first connecting pipe to the refrigerant inflow side of the evaporator, and the four-way switching valve is connected to the second side. A flow path switching valve device that allows circulation of the refrigerant only on the connection pipe side of the heat source device side heat exchanger is provided with an opening / closing valve at both ends, and the heat source device side heat exchanger is further connected in parallel with the heat source device side heat exchanger. A first heat source unit side bypass circuit having an opening / closing valve in the middle thereof, and a second heat source unit side bypass circuit connected in parallel with the plurality of heat source unit side heat exchangers and provided with a fifth flow rate control device on the way. And a first detecting the pressure on the suction side of the compressor. Force detection means and second pressure detection means for detecting the discharge side pressure of the compressor are provided, and when the cooling main operation is performed, the detection signal of the first pressure detection means is input, and the plurality of heat source side heat Open / close valves at both ends of the exchanger, open / close valves for the first heat source unit side bypass circuit, and the second
The opening degree of the fifth flow rate control device of the heat source side bypass circuit is controlled, and at the time of the heating main operation, the detection signal of the second pressure detecting means is input to open and close both ends of the plurality of heat source side heat exchangers. A heat source device side heat exchange capacity control means for controlling the opening degree of the valve, the opening / closing valve of the first heat source device side bypass circuit, and the fifth flow rate control device of the second heat source device side bypass circuit. An air conditioner characterized by. 2. A gas side pipe communicating with a pipe connecting the four-way switching valve and one end side of the heat source side heat exchanger through an on-off valve, and a liquid communicating with the other end side of the heat source side heat exchanger. A gas-liquid separation device provided with a side pipe and a connection pipe that allows the refrigerant to flow in from the first connection pipe or to flow out to the second connection pipe via the flow path switching valve device. The air conditioner according to claim 1, further comprising: