JPH04366373A - air conditioner - Google Patents

Abstract

PURPOSE:To obtain an air conditioning apparatus capable of selecting cooling or heating mode for a plurality of indoor equipment and carrying out cooling operation with the indoor equipment on one side and heating operation on the other side simultaneously and performing stabilized operation in conformity with even marked changes in air conditioning load. CONSTITUTION:In a multi-chamber type heat pump type air conditioning apparatus, when the discharge pressure of a compressor 1 exceeds a predetermined first setting pressure during the operation of the compressor 1, there is installed a controlling device 59 which is equipped with a microcomputer 60 which controls so that a solenoid on/off valve 48 may be opened in that case.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] This invention relates to a multi-room heat pump air conditioner that connects a plurality of indoor units to one heat source unit, and particularly relates to a multi-room heat pump air conditioner that connects a plurality of indoor units to one heat source unit. The present invention relates to an air conditioner that can simultaneously perform cooling with one indoor unit and heating with the other indoor unit.

0002

2. Description of the Related Art A conventional example will be explained below. FIG. 9 is an overall configuration diagram centered on the refrigerant system of a conventional air conditioner. 10, FIG. 11, and FIG. 12 show operating states during cooling/heating operation in the conventional example shown in FIG.
11 and 12 are operation status diagrams for cooling or heating only, and Figures 11 and 12 show operations for simultaneous cooling and heating operation. Figure 11 shows heating-dominant operation (the total capacity of the indoor units that are performing heating operation is the indoor unit that is performing cooling operation). FIG. 12 is an operation state diagram showing a case where the total capacity of the indoor units that are attempting to perform a cooling operation is larger than the total capacity of the indoor units that are attempting to perform a heating operation. Although this conventional example describes a case where three indoor units are connected to one heat source device, the same applies to a case where two or more indoor units are connected.

In FIG. 9, A is a heat source device, and B, C, and D are indoor units connected in parallel to each other, each having the same configuration as described later. E is a repeater that incorporates a first branch, a second flow control device, a second branch, a gas-liquid separation device, and first and second heat exchangers, as will be described later. 1 is a compressor, 2 is a heat source device that switches the refrigerant flow direction 4
3 is a heat exchanger on the heat source machine side, and 4 is an accumulator, which are connected to the above-mentioned devices 1 to 3 and constitute a heat source machine A. 5
are the indoor heat exchangers of the indoor units B, C, and D, respectively; 6 is the thick first connection pipe that connects the four-way switching valve 2 and the repeater E;
6b, 6c, and 6d connect the indoor heat exchangers 5 of the indoor units B, C, and D, respectively, and the repeater E, and 7 is the first connection pipe on the indoor unit side corresponding to the first connection pipe 6; Second connection pipes 7b, 7c, and 7d which are thinner than the first connection pipe 6 connecting the heat source machine side heat exchanger 3 and the repeater E are the indoor heat exchangers 5 of the indoor units B, C, and D, respectively. and repeater E, and connect the second
A second connection pipe on the indoor unit side corresponding to the connection pipe 7, 8
9 is a three-way switching valve that is switchably connected to the first connection pipes 6b, 6c, and 6d on the indoor unit side and the first connection pipe 6 or the second connection pipe 7 side, and 9 is a three-way switching valve that is connected to the indoor heat exchanger 5. A first flow rate control device that is connected closely and controlled by the degree of superheating during cooling and the degree of subcooling during heating on the outlet side of the indoor heat exchanger 5, and the second connecting pipe 7b on the indoor unit side. Connected to 7c and 7d.

10 is the first connection pipe 6b, 6 on the indoor unit side.
c, 6d, and a three-way switching valve 8 that is switchably connected to the first connecting pipe 6 or the second connecting pipe 7.
11 is the second connection pipe 7b, 7c on the indoor unit side.
, 7d and a second branching section consisting of a confluence section thereof; 12 is a gas-liquid separation device provided in the middle of the second connecting pipe 7; It is connected to the port 8a, and its liquid phase part is connected to the second branch part 11. 13 is a second flow rate regulating device that can be opened and closed and is connected between the gas-liquid separation device 12 and the second branch 11; 14 is a second flow rate regulating device;
A bypass pipe 15 connects the branch part 11 and the first connection pipe 6, and 15 is a third pipe provided in the middle of the bypass pipe 14.
The flow rate adjustment devices 16b, 16c, and 16d are provided downstream of the third flow rate adjustment device 15 in the bypass pipe 14, and are connected to the second connection pipes 7b, 7c, and 7d on each indoor unit side in the second branch portion 11. The third heat exchange section 16a is downstream of the third flow rate adjustment device 15 of the bypass piping 14 and the third heat exchange section 16b, 1 performs heat exchange with the bypass pipe 14, respectively.
6c, 16d, and the second branch part 11
Second connection pipes 7b, 7c, 7d on each indoor unit side in
A second heat exchange section 19 is provided downstream of the third flow rate adjustment device 15 of the bypass pipe 14 and downstream of the second heat exchange section 16a and is a gas-liquid separation device. 12 is a first heat exchange section that performs heat exchange with a pipe connecting the second flow rate control device 13; 17 is a second branch section 1;
1 and the first connection pipe 6 which can be opened and closed.
32 is a third check valve provided between the heat source side heat exchanger 3 and the second connection pipe 7, and 32 is a third check valve provided between the heat source side heat exchanger 3 and the second connection pipe 7. Allow refrigerant flow only to

33 is the four-way switching valve 2 and the first
A fourth check valve provided between the connecting pipe 6 and the connecting pipe 6,
Refrigerant flow is allowed only from the first connection pipe 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 connecting pipe 7, and allows refrigerant to flow only from the four-way switching valve 2 to the second connecting pipe 7. do. 35 is a sixth check valve provided between the heat source side heat exchanger 3 and the first connection pipe 6, and allows refrigerant flow only from the first connection pipe 6 to the heat source side heat exchanger 3. do. The third check valve 32 to the sixth check valve 35 constitute a switching valve 40. Reference numeral 41 denotes a liquid draining pipe whose one end is connected to the gas-liquid separator 12 and the other end to the first connecting pipe 6, and 42 is a liquid draining pipe connected to the gas-liquid separator 12 of the liquid draining pipe 41 and the first connecting pipe 6. Piping, 42 is the gas-liquid separator 12 of the liquid draining pipe 41 and the first
A fifth flow rate control device 43 is provided between the connection pipe 6 of the liquid draining pipe 41 and downstream of the fifth flow rate control device 42, and connects the gas-liquid separation device 12 and the first branch section 10. This is the fourth heat exchange section that performs heat exchange with the piping that is connected to the pipe. 23
25 is a first temperature detector attached to the piping connecting the second flow rate control device 13 and the first heat exchanger 19, and 25 is a first pressure detector attached to the same piping as the first temperature detector 23. Detector 26 is a second pressure detector attached to the second branch 11 , 52 is the first connecting pipe 6 and the first branch 10
51 is a second temperature sensor attached to the outlet side of the fourth heat exchanger 43 on the side of the liquid draining pipe 41; 53 is a second temperature sensor attached to the outlet side of the fourth heat exchanger 43 on the side of the bypass pipe 14; This is a third temperature detector attached to the outlet side of the heat exchange section 19 of the first heat exchange section 19.

The operation of the conventional example configured as described above will be explained. First, the case of only cooling operation will be described using FIG. 10. That is, as shown by the solid arrow in FIG. 10, the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, exchanges heat with the heat exchanger 3 on the heat source side, and is condensed. through the check valve 32, the second connection pipe 7, the gas-liquid separation device 12, and the second flow rate adjustment device 13 in this order,
Furthermore, the second branch part 11 and the second connection pipe 7b on the indoor unit side
, 7c, 7d and flowing into each of the indoor units B, C, and D, the refrigerant is reduced to a low pressure by a first flow rate regulating device 9 that is controlled by the degree of heating at the outlet of each indoor heat exchanger 5. The indoor heat exchanger 5 exchanges heat with indoor air, evaporates and gasifies the air, thereby cooling the room. Then, the refrigerant in the gas state passes through the first connection pipes 6b, 6c, 6d on the indoor unit side, the three-way switching valve 8, and the first branch part 10, and then passes through the first connection pipe 6b, 6c, and 6d on the indoor unit side, the three-way switching valve 8, and the first branch part 10.
, fourth check valve 33, four-way switching valve 2, accumulator 4
This constitutes a circulation cycle in which the air is sucked into the compressor 1 through the air, and air conditioning operation is performed. At this time, the first port 8a of the three-way switching valve 8 is closed, and the second port 8b and third port 8c are opened.

At this time, since the first connecting pipe 6 is under low pressure and the second connecting pipe 7 is under high pressure, the refrigerant inevitably flows to the third check valve 32 and the fourth check valve 33. Also, during this cycle, a part of the refrigerant that has passed through the second flow rate adjustment device 13 enters the bypass pipe 14, is reduced in pressure to a low pressure by the third flow rate adjustment device 15, and is transferred to the third heat exchange section 16b, 16c,
16d, the second connection pipes 7b, 7c, 7 on each indoor unit side
d, the second heat exchange section 16a and the second branch section 1
Heat is transferred between the confluence part of the second connection pipes 7b, 7c, and 7d on each indoor unit side of 1, and further between the refrigerant flowing into the second flow rate control device 13 in the first heat exchange section 19. The evaporated refrigerant after the exchange enters the first connection pipe 6 and passes through the fourth check valve 33.
, the four-way switching valve 2, and the accumulator 4 before being sucked into the compressor 1. On the other hand, the first, second and third heat exchange parts 19
, 16a, 16b, 16c, 16d, and the refrigerant in the second branch section 11, which has been cooled and has a sufficient degree of supercooling, is used to cool the indoor units B, C, and D.
flows into. In addition, when the refrigerant sealed in the air conditioner during cooling operation is not sealed enough to fill the second connection pipe with high-pressure liquid refrigerant, the high-pressure two-phase refrigerant condensed in the heat source side heat exchanger 3 , after passing through the second connection pipe 7 and the gas-liquid separation device 12, at the first, second and third heat exchange parts 19, 16a, 16b, 16c, 16d,
By exchanging heat with the refrigerant flowing through the bypass side, which has been reduced in pressure to a low pressure by the third flow rate control device 15, the indoor units B, C, which are liquefied and further cooled, have a sufficient degree of supercooling, and are about to be cooled. Flows into D.

Next, the case of only heating operation will be explained using FIG. That is, as shown by the broken line arrow in FIG. 10, 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, the second connection pipe 7, and the gas-liquid separation device. 12, the first branch part 10, the three-way switching valve 8, and the first connection pipes 6b, 6c, 6d on the indoor unit side.
The refrigerant flowing into each of the indoor units 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 rate adjustment device 9 controlled by the degree of subcooling at the outlet of each indoor heat exchanger 5, and then passes through the second connection pipes 7b, 7c, 7d on the indoor unit side. It flows into the second branch part 11 and joins, further passing through the fourth flow rate adjustment device 17, where it flows into the first flow rate adjustment device 9 or the fourth flow rate adjustment device 17.
The pressure is reduced to a low pressure two-phase state by either one of the flow rate adjusting devices 17. The refrigerant, which has been reduced in pressure to a low pressure, passes through the first connection pipe 6, flows into the sixth check valve 35, and the heat exchanger 3 on the heat source equipment side, where it exchanges heat, evaporates, and becomes a gas. , the four-way switching valve 2, the compressor 1 via the accumulator 4
A circulation cycle is configured in which air is sucked into the air, and heating operation is performed. At this time, the three-way switching valve 8 has its second port 8b closed, and its first port 8a and third port 8c opened. At this time, since the first connecting pipe 6 is under low pressure and the second connecting pipe 7 is under high pressure, the refrigerant inevitably flows to the fifth check valve 34 and the sixth check valve 35.

[0009] A case in which heating is the main component in simultaneous cooling and heating operation will be explained using FIG. 11. Here, indoor units B and C
A case will be explained in which two indoor units D are trying to heat the room and one indoor unit D is trying to cool the room. In other words, as shown by the solid line arrow in FIG. It passes through the gas-liquid separator 12, and then passes through the first branch 10, the three-way switching valve 8 connected to the indoor units B and C, and the first connection pipes 6b and 6c on the indoor unit side, and is heated. The refrigerant that has flowed into the indoor units B and C exchanges heat with indoor air in the indoor heat exchanger 5, condenses and liquefies, and heats the room. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlet of the indoor heat exchanger 5, passes through the first flow rate regulator 9 which is in an almost fully open state, and is slightly depressurized to reach an intermediate level between high pressure and low pressure. The pressure becomes (intermediate pressure), and the second connecting pipe 7b, 7c on the indoor unit side flows to the second branch part 1.
1. And the second connection pipe 7d on the indoor unit side
The air enters the indoor unit D that is being cooled, is depressurized by the first flow rate regulator 9 controlled by the degree of superheating at the outlet of the indoor heat exchanger 5, and then enters the indoor heat exchanger 5 for heat exchange. It evaporates into a gas state, cools the room, and flows into the first connection pipe 6 via the three-way switching valve 8 connected to the indoor unit D.

On the other hand, other refrigerants pass through the second branch section 11, which is controlled to keep the difference between the high pressure of the second connecting pipe 7 and the intermediate pressure of the second branch section 11 constant. It passes through the fifth flow rate adjustment device 17, merges with the refrigerant that has passed through the indoor unit D that is being cooled, flows into the thick first connection pipe 6, and then passes through the sixth check valve 35 and heat exchanger on the heat source unit side. It flows into the vessel 3, exchanges heat and evaporates into a gas state. The refrigerant forms a circulation cycle in which the refrigerant is sucked into the compressor 1 via the four-way switching valve 2 and the accumulator 4, and performs heating-dominant operation. At this time,
The pressure difference between the evaporation pressure of the indoor heat exchanger 5 and the evaporation pressure of the heat source side heat exchanger 3 of the indoor unit D to be cooled becomes smaller because the first connection pipe 6 is switched to the thicker one. At this time, the second ports 8b of the three-way switching valves 8 connected to the indoor units B and C are closed, and the first ports 8a and third ports 8c are opened. Further, in the three-way switching valve 8 connected to the indoor unit D, the second port 8b and the third port 8c are open, and the first port 8a is closed.

At this time, since the first connecting pipe 6 is under low pressure and the second connecting pipe 7 is under high pressure, the refrigerant inevitably flows to the fifth check valve 34 and the sixth check valve 35. Also, during this cycle, some of the liquid refrigerant is transferred to the second connection pipe 7b on the side of each indoor unit.
, 7c and 7d enter the bypass pipe 14 from the confluence part of the pipes, and the pressure is reduced to a low pressure by the third flow rate regulating device 15. Furthermore, the first
The evaporated refrigerant undergoes heat exchange with the refrigerant flowing into the second flow rate control device 13 in the heat exchange section 19, enters the first connection pipe 6, passes through the sixth check valve 35, and is transferred to the heat source. It flows into the machine-side heat exchanger 3, exchanges heat, and evaporates into a gas state. This refrigerant is then sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4. On the other hand, the first, second and third heat exchange parts 19, 16a, 16b, 16c, 16d
The refrigerant in the second branch section 11, which has been cooled by heat exchange and has been sufficiently subcooled, flows into the indoor unit D which is to be cooled.

[0012] A case in which cooling is the main component in simultaneous heating and cooling operation will be explained using FIG. 12. Here, indoor units B and C
A case will be explained in which two indoor units D are trying to cool the room and one indoor unit D is trying to heat the room. That is, as shown by the solid line arrow in FIG. 12, the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, exchanges an arbitrary amount of heat with the heat exchanger 3 on the heat source equipment side, and becomes a two-phase high-temperature, high-pressure refrigerant gas. becomes a gas, and the third check valve 32,
It is sent to the gas-liquid separator 12 of the relay machine E through the second connection pipe 7. Here, it is separated into gaseous refrigerant and liquid refrigerant,
The separated gaseous refrigerant passes through the first branch part 10, the three-way switching valve 8, and the first connection pipe 6d on the indoor unit side in this order, flows into the indoor unit D to be heated, and then enters the indoor heat exchanger 5. It exchanges heat with indoor air, condenses and liquefies, heating the room. Furthermore, it is controlled by the degree of subcooling at the outlet of the indoor heat exchanger 5, and is slightly reduced in pressure through the first flow rate regulator 9, which is in an almost fully open state, and becomes a pressure between high pressure and low pressure (intermediate pressure).
It flows into the branch part 11 of. On the other hand, the remaining liquid refrigerant flows into the second branch part 11 through the second flow rate adjustment device 13 that is controlled to keep the difference between the high pressure and the intermediate pressure constant, and flows into the second branch part 11 to heat the indoor unit D. It merges with the refrigerant that passed through it.

[0013]Then, the water passes through the second branch 11 and the second connection pipes 7b, 7c on the indoor unit side, and flows into each of the indoor units B, C. Then, this refrigerant is transferred to the indoor heat exchanger 5 of the indoor units B and C.
A first flow regulating device 9 controlled by the degree of superheating at the outlet of
The pressure is reduced to a low pressure by the indoor heat exchanger 5, and the air is evaporated and gasified by exchanging heat with indoor air to cool the room. Then, the refrigerant in a gas state is transferred to the first connection pipes 6b, 6c on the indoor unit side and the three-way switching valve 8 connected to the indoor units B, C.
, the first branch part 10, the first connection pipe 6, the fourth check valve 33, the four-way switching valve 2, and the accumulator 4 to the compressor 1.
A circulation cycle is configured in which air is sucked into the air, and air-conditioning is mainly used. At this time, the three-way switching valve 8 connected to indoor units B and C
The first port 8a is closed, and the second port 8b and third port 8c are open. In addition, the three-way switching valve 8 connected to the indoor unit D has the first port 8a and the third port 8c open, and the second port 8
b is closed.

At this time, the first connection pipe 6 is at low pressure, and the second
Because the connecting pipe 7 is under high pressure, the third check valve 32,
The refrigerant flows to the fourth check valve 33. Also, during this cycle, some of the liquid refrigerant is transferred to the second connection pipe 7 on each indoor unit side.
It enters the bypass pipe 14 from the junction of b, 7c, and 7d,
The pressure is reduced to low pressure by the third flow rate adjustment device 15, and the second heat exchanger 16a is transferred to the second
The refrigerant that has been evaporated through heat exchange with the refrigerant flowing into the second flow rate control device in the first heat exchange section 19 is The air enters the connecting pipe 6, passes through the fourth check valve 33, 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 19, 16a, 16b, 1
The refrigerant in the second branch part 11, which has been cooled by heat exchange in 6c and 16d and has been sufficiently subcooled, flows into the indoor units B and C which are to be cooled.

Furthermore, if the liquid level, which is the interface between the gaseous refrigerant and the liquid refrigerant separated in the gas-liquid separator 12, is below the liquid drain pipe 41 of the gas-liquid separator 12, the gaseous refrigerant The liquid flows into the liquid drain pipe 41 and is reduced in pressure to a low pressure by the fifth flow rate control device 42. Since the inlet of the fifth flow rate control device 42 is in a gas state, the amount of refrigerant flowing through the fifth flow rate control device 42 is small. Therefore, the refrigerant flowing through the drain pipe 41 is
In the fourth heat exchange section 43, heat is exchanged with the high pressure gaseous refrigerant flowing into the first branch section 10 from the gas-liquid separator 12 to become a low pressure superheated gas, which flows into the first connection pipe 6. do. Conversely, if the liquid level, which is the interface between the gaseous refrigerant and the liquid refrigerant separated in the gas-liquid separator 12, is above the liquid drain pipe 41 of the gas-liquid separator 12, the liquid refrigerant is drained. Piping 4
1 and is depressurized to a low pressure by the fifth flow rate control device 42. Since the inlet of the fifth flow rate control device 42 is in a liquid state,
The amount of refrigerant flowing through the fifth flow rate control device 42 is larger than that in the case where the inlet is in a gaseous state. Therefore, even if the refrigerant flowing through the liquid drain pipe 41 exchanges heat with the high-pressure gaseous refrigerant flowing from the gas-liquid separator 12 into the first branch part 10 in the fourth heat exchange section 43, the refrigerant flows at a low pressure. It does not become superheated gas, but flows into the first connection pipe 6 in a two-phase state.

[0016]

[Problems to be Solved by the Invention] In the conventional air conditioner as described above, for example, when the number of indoor units in cooling operation increases, the suction pressure of the compressor 1 increases, and the compressor There was a problem in that the discharge pressure of the compressor 1 increased, and the reliability of the compressor 1 decreased due to the increase in the discharge pressure. Also,
For example, when the number of indoor units that perform heating operation during heating operation decreases, the discharge pressure of the compressor 1 increases transiently, and there is a problem that the reliability of the compressor 1 decreases due to the increase in discharge pressure.

[0017] This invention was made in order to solve the above-mentioned problems. For example, even when the number of indoor units used for cooling or heating changes, the discharge pressure of the compressor is prevented from increasing and stabilized. The purpose of the present invention is to obtain an air conditioner that can be operated in a controlled manner.

[0018]

[Means for Solving the Problems] The present invention provides one heat source device including a compressor, a four-way switching valve, a heat source device side heat exchanger, an accumulator, etc., an indoor heat exchanger, and a first flow rate control device. In a device in which a plurality of indoor units consisting of devices, etc. are connected via first and second connection pipes, one of the indoor heat exchangers of the plurality of indoor units is connected to the first connection pipe. Alternatively, the first branch part switchably connected to the second connection pipe and the other of the indoor heat exchangers of the plurality of indoor units may be connected to the second connection pipe via the first flow rate control device. A second branch section formed by connecting to the connection pipe of is connected via a second flow rate control device, and the second branch section and the first branch section are
connection pipe is connected via a fourth flow rate control device, further, one end is connected to the second branch part, and the other end is connected to the first connection line via a third flow rate control device. a bypass pipe between the third flow control device and the first connection pipe, and a pipe connecting the second connection pipe and the second flow control device. A first heat exchange section that performs heat exchange, the first branch section, the second branch section, the second flow control device, the third flow control device, the fourth flow control device, the first A repeater having a built-in heat exchange section and bypass piping is interposed between the heat source device and the plurality of indoor units, and the first connecting piping has a larger diameter than the second connecting piping. A switching valve is provided between the heat source device and the first and second connection pipes, and the switching valve is configured to switch the first connection pipe to the low pressure of the heat source device and the second connection pipe to the high pressure of the heat source device. A bypass path on the heat source machine side connecting the second connection pipe on the high-pressure refrigerant outflow side of the switching valve and the first connection pipe on the low-pressure refrigerant inflow side of the switching valve, and the above-mentioned one in the middle of the piping of the bypass path. A sixth electromagnetic on-off valve is provided to control opening and closing of the bypass passage, and when the discharge pressure of the compressor exceeds a preset first set pressure, the sixth electromagnetic on-off valve is opened. It is something to do.

[0019]

[Operation] In this invention, in any of the cooling operation, cooling-based operation, heating operation, and heating-based operation,
When the discharge pressure of the compressor exceeds a preset first set pressure while the compressor is in operation, the sixth electromagnetic on-off valve is opened.

[0020]

【Example】

Example 1. Examples of the present invention will be described below. FIG. 1 is an overall configuration diagram centered on the refrigerant system of an air conditioner according to a first embodiment of the present invention. Also, Figure 2, Figure 3, Figure 4
1 shows the operating state during cooling/heating operation in one embodiment of FIG. 1, FIG. 2 shows the operating state of cooling or heating only, and FIGS. 3 and 4 show the operation of simultaneous cooling/heating operation.
Figure 3 shows heating-dominant (when the total capacity of indoor units attempting heating operation is greater than the total capacity of indoor units attempting cooling operation), and Figure 4 shows cooling-dominant operation (the case where the total capacity of indoor units attempting cooling operation). FIG. 3 is an operation state diagram showing a case where the capacity is larger than the total capacity of the indoor units that are about to be operated for heating. FIG. 5 is an overall configuration diagram centered on the refrigerant system of an air conditioner according to another embodiment of the present invention. Although this embodiment describes a case where three indoor units are connected to one heat source device, the same applies to a case where two or more indoor units are connected. In FIGS. 1 to 4, A to D,
Nos. 1 to 43 and 51 to 53 are completely the same as the conventional device described above, and the same effects can be obtained. 49 is a heat source machine side bypass passage connecting between the heat source machine side switching valve 40 and the second connection pipe 7 and between the heat source machine side switching valve 40 and the first connection pipe 6; A sixth electromagnetic on-off valve 54 is provided in the middle of the piping of the machine side bypass passage 49 and controls opening and closing of the heat source machine side bypass passage 49; temperature sensor,
55 is a fourth pressure sensor attached to the same pipe as the temperature sensor 54 in step 4 above.

Next, in the cooling operation of the first embodiment,
Control of the sixth electromagnetic on-off valve 48 will be explained. In FIG. 2, when the discharge pressure of the compressor 1 increases transiently and exceeds a preset first setting pressure, opening the sixth electromagnetic on-off valve 48 causes the second connection pipe 7 to open.
The high-pressure liquid refrigerant flowing through flows into the first connecting pipe 6 on the low-pressure side via the bypass path 49 and the sixth electromagnetic on-off valve 48, and then flows through the fourth check valve 33, the four-way switching valve 2, and the accumulator 4. It passes through the air and is sucked into the compressor 1. As a result, the refrigerant is bypassed from the high pressure to the low pressure, thereby reducing the high pressure and the discharge pressure of the compressor 1 accordingly. Although the control of the sixth electromagnetic on-off valve 48 has been described in the case of cooling operation, similar effects can be obtained even in the case of mainly cooling operation as shown in FIG.

Next, in the heating operation of the first embodiment,
Control of the sixth electromagnetic on-off valve 48 will be explained. In FIG. 2, when the discharge pressure of the compressor 1 increases transiently and exceeds a preset first setting pressure, opening the sixth electromagnetic on-off valve 48 causes the second connection pipe 7 to open.
The high-pressure refrigerant flowing through flows into the first connecting pipe 6 on the low-pressure side via the bypass path 49 and the sixth electromagnetic on-off valve 48, and then passes through the sixth check valve 35, the heat source equipment side heat exchanger 3, It passes through the four-way switching valve 2 and the accumulator 4 and is sucked into the compressor 1. As a result, the refrigerant is bypassed from the high pressure to the low pressure, thereby reducing the high pressure and the discharge pressure of the compressor 1 accordingly. Although the control of the sixth electromagnetic on-off valve 48 has been described in the case of heating operation, similar effects can be obtained even in the case of heating mainly shown in FIG.

[0023] This will be explained below using FIGS. 6, 7, and 8. FIG. 6 is a configuration diagram regarding control of the sixth electromagnetic on-off valve 48 of the above embodiment. The fourth pressure detector 55 detects the discharge pressure of the compressor 1, and the comparison means 56 compares the pressure detected by the fourth pressure detector 55 with the preset first pressure.
Compare with the set pressure. The control means 57 determines and controls whether to open or close the sixth electromagnetic on-off valve 48 .

FIG. 7 is a circuit diagram showing the electrical connections of the first embodiment. 60 is a microcomputer in the control device 59, which includes a CPU 61, a memory 62, an input circuit 63,
It has an output circuit 64. 65 and 66 are the fourth
This is a resistor connected in series with the temperature sensor 54 and the fourth pressure sensor 55, and its output is given to the input circuit 63. A transistor 72 that controls opening and closing of the sixth electromagnetic on-off valve 48 is connected to the output circuit 64 via a resistor 77.

FIG. 8 is a flow chart showing the opening/closing control program for the sixth electromagnetic on/off valve stored in the memory 62 of the microcomputer 60. In step 90, it is determined whether the pressure detected by the fourth pressure detector exceeds the first set pressure set in advance, and if it does, the process proceeds to step 91; otherwise, the process proceeds to step 94. In step 91, the sixth electromagnetic on-off valve 48 is opened. In step 92, it is determined whether the pressure detected by the fourth pressure detector is lower than a second set pressure set in advance. If it is, the process proceeds to 93; otherwise, the process proceeds to step 91. In step 93, the sixth
The electromagnetic on-off valve 48 is closed. In step 94, the sixth
The electromagnetic on-off valve 48 is closed.

Example 2. In the above embodiment, a three-way switching valve 8 is provided to connect the first connection pipes 6b, 6c, 6 on the indoor unit side.
d and the first connection pipe 6 or the second connection pipe 7, and as shown in FIG. Even if they are connected in a switchable manner, the same effects as in the above embodiment can be obtained.

[0027]

[Effects of the Invention] As explained above, the air conditioner of the present invention includes a single heat source machine including a compressor, a four-way switching valve, a heat exchanger on the heat source machine side, an accumulator, etc., an indoor heat exchanger, In a device in which a plurality of indoor units including a first flow rate control device, etc. are connected via first and second connection pipes, one of the indoor heat exchangers of the plurality of indoor units is connected to the indoor heat exchanger of the plurality of indoor units. The first branch part switchably connected to the first connecting pipe or the second connecting pipe and the other of the indoor heat exchangers of the plurality of indoor units are connected to the first flow rate control device. A second branch part connected to the second connection pipe via the second connection pipe is connected via a second flow rate control device, and the second branch part and the first connection pipe are connected to a fourth flow rate. a bypass pipe connected via a control device, one end connected to the second branch, and the other end connected to the first connection pipe via a third flow rate control device; A first heat exchanger that performs heat exchange between a bypass pipe between the flow control device of No. 3 and the first connection pipe, and a pipe connecting the second connection pipe and the second flow control device. Equipped with a replacement part,
A repeater incorporating the first branch section, the second branch section, the second flow rate control device, the third flow rate control device, the fourth flow rate control device, the first heat exchange section, and bypass piping. is interposed between the heat source equipment 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 connected to the heat source equipment. A switching valve is provided between the heat source device and the first and second connection pipes, which enables switching the second connection pipe to the low pressure and the high pressure of the heat source device,
A heat source machine side bypass path connecting the high pressure refrigerant outflow side second connection pipe of the switching valve and the low pressure refrigerant inflow side first connection pipe of the above switching valve, and opening/closing of the bypass path in the middle of the piping of this bypass path. By having a configuration equipped with a sixth electromagnetic on-off valve that controls The refrigerant can be bypassed to lower the high pressure and reduce the compressor discharge pressure. Therefore, it is possible to prevent the discharge pressure of the compressor from increasing, and it is possible to prevent the reliability of the compressor from decreasing due to the increase in the discharge pressure of the compressor.

[Brief explanation of the drawing]

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

FIG. 2 is a diagram showing the operating state of the air conditioner shown in FIG. 1 in only cooling or heating mode.

FIG. 3 is a diagram illustrating the operating state of the air conditioner shown in FIG. 1 mainly for heating.

FIG. 4 is an operational state diagram showing the cooling main body of the air conditioner shown in FIG. 1;

FIG. 5 is an overall configuration diagram centered on the refrigerant system of an air conditioner showing another embodiment of the present invention.

FIG. 6 is a block diagram for explaining control of a sixth electromagnetic on-off valve in the present invention.

FIG. 7 is a control circuit diagram of the air conditioner shown in FIG. 1.

FIG. 8 is a flowchart showing a control operation of the air conditioner shown in FIG. 1;

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

10 is a diagram illustrating the operating state of the air conditioner shown in FIG. 9 in only cooling or heating mode; FIG.

FIG. 11 is a diagram illustrating the operating state of the air conditioner shown in FIG. 9, mainly for heating.

12 is a diagram illustrating a cooling-based operation state of the air conditioner shown in FIG. 9; FIG.

[Explanation of symbols]

A Heat source equipment B, C, D Indoor unit E Relay machine 1 Compressor 2 4-way switching valve 3 Heat source equipment side heat exchanger 4 Accumulator 5 Indoor heat exchanger 6 First connecting pipe 7 Second connecting pipe 9 1 flow control device 10 first branch section 11 second branch section 13 second flow control device 14 bypass piping 15 third flow control device 16a second heat exchange section 16b, 16c, 16d third heat Exchange part 17
Fourth flow rate control device 19 First heat exchange section 40 Switching valve 48 Sixth electromagnetic on-off valve 49 Heat source device side bypass path 55 Fourth pressure detector 56 Control means

Claims (1)

[Claims] Claim 1: 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. in which one of the indoor heat exchangers of the plurality of indoor units is connected to the first connection pipe or the second connection pipe. A switchably connected first branch part and the other of the indoor heat exchangers of the plurality of indoor units are connected to the second connection pipe via the first flow rate control device. Second
The second branch and the first connection pipe are connected via a fourth flow control device, and one end of the second branch is connected to the second connection pipe via a second flow control device. connected to the branch part, and the other end is connected to the first flow rate controller via the third flow rate control device.
and a bypass pipe connected to the connection pipe of the above-mentioned third
A first heat exchanger that performs heat exchange between a bypass pipe between the flow rate control device and the first connection pipe, and a pipe connecting the second connection pipe and the second flow rate control device. The first branch part, the second branch part, the second flow rate control device, the third flow rate control device, the fourth flow rate control device, the first heat exchange part, and the bypass piping are built in. A repeater 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 heat source device and the first and second connection pipes, which enables the switching valve to switch the pressure to the low pressure of the heat source device and the second connection pipe to the high pressure of the heat source device. The second connection pipe on the high-pressure refrigerant outflow side of the valve and the first connection pipe on the low-pressure refrigerant inflow side of the switching valve
A bypass passage on the heat source machine side that connects the connection piping of the bypass passage, and a sixth electromagnetic on-off valve that controls the opening and closing of the bypass passage are provided in the middle of the piping of the bypass passage, and the discharge pressure of the compressor is set in advance to the first An air conditioner comprising: control means for opening the sixth electromagnetic on-off valve when the set pressure is exceeded.