JP2002213839A - Multichamber air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multichamber air conditioner in which bypass pipes are situated at the two ends of an on/off valve on the discharge side in a branch unit, high efficient operation is made available, without the flow of refrigerant to an indoor unit at stoppage, and the generation of refrigerant noise due to difference in pressure, when the indoor unit starts heating operation. SOLUTION: In a multichamber type air conditioner consisting of one outdoor unit 1, a branch unit 2, and a plurality of indoor units 3a, 3b, and 3c and enabling cooling heating simultaneous operation effected with an outdoor heat exchanger 5 being stopped, bypass pipes 19 having at least a throttle mechanism 18 are connected to the two ends of a third on/off valve 12 in the branch unit 2,. When an indoor unit in a stop starts heating operation, an electronic expansion valve 17 on the indoor side corresponding to an indoor unit, a third on/off valve 12, and a fourth on/off valve 13 are closed; then control is carried out, such that after the lapse of a given time or after the refrigerant pressure of an indoor heat exchanger 15 has reached a given pressure, the electronic expansion valve 17 on the indoor side and the third on/off valve 12 are opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit. More specifically, the present invention relates to generation of refrigerant noise generated at the start of heating operation. The present invention relates to a configuration of a refrigerant circuit that can be prevented.

[0002]

2. Description of the Related Art Conventional multi-room air conditioners of this type include:
For example, there is one as shown in FIG. In the figure, 1
Is an outdoor unit installed outside the room, 2 is a branching unit installed behind the ceiling in the room, etc., and 3a, 3b and 3c are three indoor units. The outdoor unit 1 mainly includes a compressor 4, an outdoor heat exchanger 5, and an outdoor electronic expansion valve 6. One of a first pipe (discharge gas pipe) 7 is provided on a discharge side of the compressor 4. One of second pipes (suction gas pipes) 8 is connected to the suction side, and the other is connected to the branch unit, respectively. The first on-off valve 9, the outdoor heat exchanger 5, and the electronics are connected from the discharge side of the compressor 4. The third pipe (liquid pipe) 10 is sequentially connected to one of the third pipes (liquid pipes) 10 via the expansion valve 6, and the other of the third pipe 10 is connected to the flow dividing unit. Also, the second open / close valve 11 is connected between the suction side of the compressor 4 and the space between the first open / close valve 9 and the outdoor heat exchanger 5.
Connected through.

The branch unit 2 mainly includes a branch pipe that branches from the first pipe 7, the second pipe 8, and the third pipe 10 from the outdoor unit 1 to the indoor units 3a, 3b, and 3c. The third on-off valve 12 is provided on the branch pipe of the first pipe 7 and the fourth on-off valve 13 is provided on the branch pipe of the second pipe 8, respectively. Fourth on-off valve
13 are connected in parallel to each other, connected to the respective indoor heat exchangers 15 of the indoor units 3a, 3b, and 3c at a fourth pipe 14, and from a branch pipe of the third pipe 10 to a fifth pipe 16 Each of the indoor units 3a, 3b, 3c is connected to an electronic expansion valve 17 on the indoor side.

The indoor units 3a, 3b, 3c mainly comprise an indoor heat exchanger 14 and an indoor electronic expansion valve 17, and a fourth pipe 14 from the branch unit 2 is connected to the indoor heat exchanger. 15
The other side of the indoor heat exchanger 15 is connected to one side of the indoor-side electronic expansion valve 17, and the indoor-side electronic expansion valve 17
A fifth pipe 16 from the flow dividing unit 2 is connected to the other side.

In the above configuration, the indoor unit 3a is in a heating operation, the indoor unit 3b is in a stopped state, and the indoor unit 3c
The state in which the heating operation is started from the stop will be described.
The second on-off valve 11 and the third on-off valve 12 of the indoor unit 3a
And the first on-off valve 9 and the fourth on-off valve 13 of the indoor unit 3a are closed, so that the high-temperature and high-pressure refrigerant vapor discharged from the compressor 4 is discharged from the first The refrigerant enters the indoor heat exchanger 15 of the indoor unit 3a through the pipe 7, and radiates heat into the room by the indoor heat exchanger 15 to warm the room. Liquid, and expands at the indoor side electronic expansion valve 17 to become a low-temperature and low-pressure refrigerant liquid, enters the outdoor heat exchanger 5 through the third pipe 10, and outputs the outdoor heat at the outdoor heat exchanger 5. And evaporates into low-temperature, low-pressure refrigerant vapor,
The refrigerant is sucked into the compressor 4 through the second on-off valve 11 and is compressed by the compressor 4 to become a high-temperature and high-pressure refrigerant vapor, thereby forming one refrigeration cycle, and the indoor unit 3a is operated for heating.

On the other hand, when the indoor unit 3c is stopped, the indoor electronic expansion valve 17 and the third on-off valve 12 corresponding to the indoor unit 3c are closed, and the fourth on-off valve 13 is open. The indoor heat exchanger 15 side has a low pressure after the third on-off valve 12 in the state. Further, the first pipe (discharge gas pipe) 7 side of the third on-off valve 12 has a high pressure. When the indoor unit 3c starts the heating operation from this stopped state, the indoor-side electronic expansion valve 17 and the third on-off valve 12 are opened, the fourth on-off valve 13 is closed, and the high-pressure refrigerant on the discharge side of the compressor 4 is displaced by a dashed arrow. As shown by, the third on-off valve 12, the indoor heat exchanger 15, the indoor side electronic expansion valve
17, returning to the compressor 4 through the same route as the indoor unit 3a through the third pipe 10, the indoor unit 3c is operated for heating.

However, in the above configuration, when the heating operation is started, the third on-off valve 12 is opened, and the high-pressure portion and the low-pressure portion are connected at once, so that a loud refrigerant noise due to the pressure difference is generated. Therefore, when all the operation indoor units in the same refrigerant system are performing the heating operation, a small amount of refrigerant is also supplied to the stopped indoor units. However, in the case of an indoor unit installed in a small room or the like, the room is warmed by the heat radiation from the indoor heat exchanger 15 even when the indoor unit is stopped. In addition, there is a problem that a large amount of refrigerant is circulated and the efficiency is reduced.

[0008]

In view of the above problems, in the present invention, bypass pipes are provided at both ends of a discharge-side on-off valve in a flow dividing unit, and the efficiency is improved without flowing refrigerant to a stopped indoor unit. It is an object of the present invention to provide a multi-room air conditioner capable of performing a good operation and preventing generation of refrigerant noise caused by a pressure difference when an indoor unit starts a heating operation.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is characterized in that a branch is made from a discharge side of a compressor, and a first open / close valve, an outdoor heat exchanger, an electronic expansion valve, While connecting the connection part, while connecting the second connection part to the other pipe line, branching from the suction side of the compressor, connecting the third connection part to one of the pipe lines, the other pipe line An outdoor unit having a second on-off valve connected between the first on-off valve and the outdoor heat exchanger, and a first pipe connected to the second connection portion, branched from the first pipe, and a plurality of third pipes. While the on-off valves are connected in parallel, a second pipe is connected to the third connection portion, branched from the second pipe, a plurality of fourth on-off valves are connected in parallel, and the plurality of third on-off valves are connected. And the fourth on-off valve are connected in parallel, each is connected to a plurality of fourth pipes, and a third pipe is connected to the first connection part. And a branch unit branched from the third pipe, and a flow dividing unit in which a plurality of fifth pipes are connected in parallel, and the fourth pipe is connected to the fifth pipe via an indoor heat exchanger and a room-side electronic expansion valve. And a plurality of indoor units. Operation and heating operation selectively, or, can be performed simultaneously, further in the multi-room air conditioner configured to enable simultaneous cooling and heating operation to stop the outdoor heat exchanger,
A bypass pipe having at least a throttle mechanism is connected to both ends of the third on-off valve in the flow dividing unit, and when the indoor unit in a stopped state starts heating operation, the indoor side corresponding to the indoor unit is started. The electronic expansion valve, the third on-off valve, and the fourth on-off valve are closed, and after a predetermined time has elapsed, or after the refrigerant pressure of the indoor heat exchanger has reached a predetermined pressure, the indoor-side electronic expansion valve and the third on-off valve Is configured to be opened.

Each of the bypass pipes is provided with a series circuit of an on-off valve and a throttle mechanism.

[0011] Further, a solenoid valve is used as the on-off valve.

In addition, a configuration is employed in which a capillary tube is used for the aperture mechanism.

Further, the throttle mechanism is configured to use an electronic expansion valve.

[0014] Further, the flow dividing unit comprises a plurality of flow dividing units respectively corresponding to the plurality of indoor units and each including the third on-off valve, the fourth on-off valve, and at least a bypass pipe having a throttle mechanism. It has become.

Further, a pressure sensor or a pressure switch is provided on a pipe of each of the indoor heat exchangers to control opening and closing of an on-off valve of the bypass pipe.

Further, an oil separator is provided on the discharge side of the compressor for separating oil and returning the oil to the suction side of the compressor.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below as examples based on the attached drawings. FIG. 1 is a configuration diagram of a refrigerant circuit in a first embodiment of a multi-room air conditioner according to the present invention. In the figure, 1 is an outdoor unit installed outside the room, 2 is a shunt unit installed behind the ceiling in the room, and 3a, 3b, 3c are three indoor units connected in parallel, respectively.

The outdoor unit 1 branches off from the discharge side of the compressor 4 and has a first opening / closing valve 9, an outdoor heat exchanger 5, an outdoor electronic expansion valve 6, and a first connection part A1 in one of its pipelines. On the other hand, the second connecting part A2 is connected to the other pipe line, the branch is branched from the suction side of the compressor 4, the third connecting part A3 is connected to one of the pipe lines, and the other pipe line is connected. A second on-off valve 11 is connected between the first on-off valve 9 and the outdoor heat exchanger 5.

The branch unit 2 is connected to the second connecting portion A2.
A first pipe (discharge gas pipe) 7 is connected to the first pipe 7 and branched from the first pipe 7 to connect a plurality of third on-off valves 12 in parallel.
A second pipe (intake gas pipe) 8 is connected to the third connection portion A3, branched from the second pipe 8, and a plurality of fourth on-off valves 13 are connected in parallel. 12 and the fourth on-off valve 13 are connected in parallel, respectively, and each is connected to a plurality of fourth pipes.
14, a third pipe (liquid pipe) 10 is connected to the first connection part A1, and a branch is made from the third pipe 10, and a plurality of fifth pipes 16 are connected in parallel.

The indoor units 3a, 3b, 3c are mainly composed of an indoor heat exchanger 15 and an electronic expansion valve 17 on the indoor side, and a fourth pipe 14 from the branch unit 2 is connected to the indoor heat exchanger 15 The other side of the indoor heat exchanger 15 is connected to one side of the indoor-side electronic expansion valve 17, and the other side of the indoor-side electronic expansion valve 17 is connected to the fifth pipe 16 from the flow dividing unit 2. It is connected. A bypass pipe 19 provided with at least a throttle mechanism 18 at both ends of the third on-off valve 12 in the flow dividing unit 2
Are connected.

Next, the operation of the present invention in the above configuration will be described. In FIG. 1, a description will be given of a state in which the indoor unit 3a performs the heating operation, the indoor unit 3b is in the stopped state, and the indoor unit 3c starts the heating operation. Open the second on-off valve 11 and the third on-off valve 12 of the indoor unit 3a,
The first on-off valve 9 and the fourth on-off valve 13 of the indoor unit 3a
As a result, the high-temperature and high-pressure refrigerant vapor discharged from the compressor 4 passes through the first pipe 7 and enters the indoor heat exchanger 15 of the indoor unit 3a, as indicated by a solid line arrow. By radiating heat into the room and warming the room in the exchanger 15, the high-temperature and high-pressure refrigerant vapor condenses into a high-temperature and high-pressure refrigerant liquid, and expands at the indoor-side electronic expansion valve 17 to become a low-temperature and low-pressure refrigerant liquid. And enters the outdoor heat exchanger 5 through the third pipe 10, and absorbs and evaporates outdoor heat in the outdoor heat exchanger 5 to become low-temperature and low-pressure refrigerant vapor. And is sucked into the compressor 4 through the compressor 4
, And becomes a high-temperature and high-pressure refrigerant vapor to form one refrigeration cycle, and the indoor unit 3a is operated for heating.

On the other hand, when the heating operation is started from the stopped state of the indoor unit 3c, the electronic expansion valve 16, the third on-off valve 12, and the fourth on-off valve 13 on the indoor side corresponding to the indoor unit 3c are closed and the compression is started. The high-pressure refrigerant on the discharge side of the unit 4 passes through the bypass pipe 19 and passes through the indoor heat exchanger 15 as indicated by the dashed arrow.
After a predetermined time elapses (for example, a time when the pressure difference between the indoor heat exchanger 15 and the high pressure on the discharge side of the compressor 4 decreases to 0.5 MPa or the like), the indoor-side electronic expansion valve 17 and the second By controlling the three on-off valves 12 to be opened, the indoor unit 3c can perform the heating operation without generating the refrigerant noise, and the refrigerant flows back to the compressor 4 similarly to the indoor unit 3a.

FIG. 2 is a refrigerant circuit showing a second embodiment according to the present invention. In the drawing, each of the bypass pipes 19 is provided with a series circuit of an on-off valve 20 formed of an electromagnetic valve and a throttle mechanism 18 formed of a capillary tube. 2, a description will be given of a state in which the indoor unit 3a performs the heating operation, the indoor unit 3b stops, and a state in which the indoor unit 3c starts the heating operation, as described above. Indoor unit
The operation of 3a is the same as that of the first embodiment, and will not be described here.

When the heating operation is started from the stopped state of the indoor unit 3c, the electronic expansion valve 16, the third on-off valve 12, and the fourth on-off valve 13 on the indoor side corresponding to the indoor unit 3c are started.
Is closed, and the on-off valve 20 is opened. As indicated by a dashed arrow, the high-pressure refrigerant on the discharge side of the compressor 4 passes through the bypass pipe 19, and is applied to the indoor heat exchanger 15 via the on-off valve 20 and the throttle mechanism 18. Later (for example, the pressure difference between the indoor heat exchanger 15 and the high pressure on the discharge side of the compressor 4 is 0.5 MPa
After the refrigerant pressure in the indoor heat exchanger 15 reaches a predetermined pressure (for example, 1.96 MPa), the on-off valve 20 is closed, and the electronic expansion valve 17 and the third on-off valve 12 on the indoor side are closed. By controlling the opening of the indoor unit
3c can perform a heating operation without generating a refrigerant noise, and the refrigerant flows through the compressor 4 as in the indoor unit 3a.
Is returned to.

As shown in FIG. 2, a pressure sensor (or pressure switch) 23 for detecting a refrigerant pressure is provided in a pipe of each indoor heat exchanger 15 to control the opening and closing of the on-off valve 20.
While the pressure sensor 23 is connected to a control unit (microcomputer) 22 provided on the indoor unit side, the opening and closing of the on-off valve 20 is controlled by a command from the control unit 22, and the on-off valve 20 opens when the heating operation starts. The on-off valve 20 is closed after the predetermined time, which has been set in advance by the control unit 22, or after the refrigerant pressure detected by the pressure sensor 23 reaches the predetermined pressure.

In the above-mentioned operation state, the stopped indoor unit has the electronic expansion valve 17 and the third on-off valve 12 on the indoor side thereof closed, the fourth on-off valve 13 opened, and the first indoor unit is stopped. In the case of the embodiment, the stop indoor unit is the fourth on-off valve 13
Is open, the fourth on-off valve 13
From the third on-off valve 12 and the efficiency drops slightly. When the fourth on-off valve 13 of the stop indoor unit is closed, the refrigerant condenses in the indoor heat exchanger 15 of the stop indoor unit, and the amount of refrigerant in the circuit becomes insufficient. Thus, as in the second embodiment, when the heating operation is started, the on-off valve 20 is opened, and the electronic expansion valve 17 on the indoor side, the third on-off valve
When the 12 and the fourth on-off valve 13 are closed, the bypass from the fourth on-off valve 13 to the third on-off valve 12 in the flow dividing unit 2 is eliminated.

Next, a case where all the indoor units 3a, 3b, 3c are simultaneously operated for cooling will be described with reference to FIG. The first on-off valve 9 and the fourth on-off valve 13 are opened, the second on-off valve 11 and the third on-off valve 12 are closed, and the throttle mechanism 18 is fully closed. The high-temperature and high-pressure refrigerant vapor enters the outdoor heat exchanger 5 through the first opening / closing valve 9 and is condensed by radiating heat to the outdoor heat exchanger 5 to become a high-temperature and high-pressure refrigerant liquid. The refrigerant expands at the indoor side electronic expansion valve 17 through the third pipe 10 to become a low-temperature low-pressure refrigerant liquid, enters the indoor heat exchanger 15, and enters the indoor heat exchanger.
By absorbing indoor heat at 15 and cooling the room,
The low-temperature low-pressure refrigerant liquid evaporates into low-temperature low-pressure refrigerant vapor, which is sucked into the compressor 4 through the second pipe 8,
The refrigerant is compressed by the compressor 4 to become a high-temperature and high-pressure refrigerant vapor, thereby forming one refrigeration cycle. When all the indoor units 3a, 3b, and 3c perform the heating operation at the same time, the operation of the indoor unit 3a in FIG. 2 may be applied to all the indoor units.

Also, as shown in FIG.
A plurality of branch units 2a, 2b, 3c corresponding to the plurality of indoor units 3a, 3b, 3c, respectively, and including a bypass pipe 19 having the third on-off valve 12, the fourth on-off valve 13, a throttle mechanism, and the like. With this configuration, it can be installed at an arbitrary location according to each indoor unit, and the convenience of installation can be improved. Further, an oil separator 21 is provided on the discharge side of the compressor 4 for separating oil and returning the oil to the suction side of the compressor 4, so that the refrigerating machine oil can be circulated effectively.

As described above, the bypass pipe provided with the throttle mechanism 18 or the series circuit of the throttle valve 20 and the throttle mechanism 18 at both ends of the third on-off valve 12 in the flow dividing unit 2, respectively.
19, connect the indoor electronic expansion valve 1 corresponding to the indoor unit to start heating operation of the stopped indoor unit.
7, the third on-off valve 12 and the fourth on-off valve 13 are closed, and after a lapse of a predetermined time or after the refrigerant pressure of the indoor heat exchanger 5 reaches a predetermined pressure, the indoor-side electronic expansion valve 17 and the third By controlling the opening and closing valve to open, efficient operation is enabled without flowing refrigerant to the stopped indoor unit, and generation of refrigerant noise caused by a pressure difference when the indoor unit starts heating operation A multi-room air conditioner that can prevent

[0030]

As described above, according to the present invention,
By providing a bypass mechanism provided with a throttle mechanism or a series circuit of an on-off valve and a throttle mechanism at both ends of the third on-off valve in the flow dividing unit, efficient operation is performed without flowing refrigerant to the stopped indoor unit. A multi-room air conditioner capable of preventing generation of refrigerant noise caused by a pressure difference when the indoor unit starts the heating operation.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing a first embodiment of a multi-room air conditioner according to the present invention.

FIG. 2 is a refrigerant circuit diagram showing a second embodiment according to the present invention.

FIG. 3 is a refrigerant circuit diagram showing a simultaneous cooling operation state of the indoor unit according to the present invention.

FIG. 4 is a refrigerant circuit diagram of a conventional multi-room air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Branching unit 3a, 3b, 3c Indoor unit 4 Compressor 5 Outdoor heat exchanger 6 Electronic expansion valve outside a room 7 First piping 8 Second piping 9 First opening / closing valve 10 Third piping 11 Second opening / closing valve 12 Third on-off valve 13 Fourth on-off valve 14 Fourth pipe 15 Indoor heat exchanger 16 Fifth pipe 17 Indoor electronic expansion valve 18 Throttle mechanism 19 Bypass pipe 20 On-off valve A1 First connection part A2 Second connection part A3 Third connection

Claims (8)

[Claims] 1. A branch from the discharge side of a compressor, one of which connects a first on-off valve, an outdoor heat exchanger, an electronic expansion valve, and a first connection portion, and the other of which connects to a second pipe. Along with connecting the connection portion, the compressor branches off from the suction side thereof, and a third connection portion is connected to one of the pipelines, and the other pipeline is connected between the first on-off valve and the outdoor heat exchanger. An outdoor unit to which a second on-off valve is connected, and a first pipe connected to the second connection portion,
While branching from the first pipe, while connecting a plurality of third on-off valves in parallel, connecting a second pipe to the third connection portion, branching from the second pipe, a plurality of fourth on-off valves in parallel. And connecting the plurality of third on-off valves and the fourth on-off valve in parallel to each other to connect to a plurality of fourth pipes, connecting a third pipe to the first connection part, A branch unit branched from the third pipe and a plurality of fifth pipes connected in parallel, and a plurality of fifth pipes connected to the fifth pipe via an indoor heat exchanger and an indoor-side electronic expansion valve from the fourth pipe. An indoor unit, and controls the opening and closing of the first on-off valve, the second on-off valve, the third on-off valve and the fourth on-off valve in accordance with an operation state, thereby performing cooling operation and heating for each of the plurality of indoor units. Operation can be performed selectively or simultaneously, and the outdoor heat exchanger In the multi-chamber air conditioner configured to enable simultaneous cooling and heating operations to be performed while being stopped, a bypass pipe having at least a throttle mechanism is connected to both ends of the third on-off valve in the flow dividing unit. When the heating operation of the stopped indoor unit is started, the electronic expansion valve, the third on-off valve, and the fourth on-off valve on the indoor side corresponding to the indoor unit are closed, and after a lapse of a predetermined time, or After the refrigerant pressure of the exchanger reaches a predetermined pressure, the multi-room air conditioner is controlled to open the electronic expansion valve and the third on-off valve on the indoor side. 2. The multi-room air conditioner according to claim 1, wherein each of the bypass pipes is provided with a series circuit of an on-off valve and a throttle mechanism. 3. The multi-room air conditioner according to claim 1, wherein an electromagnetic valve is used as the on-off valve. 4. The multi-room air conditioner according to claim 1, wherein a capillary tube is used for the throttle mechanism. 5. The multi-room air conditioner according to claim 1, wherein an electronic expansion valve is used for the throttle mechanism. 6. The flow dividing unit comprises a plurality of flow dividing units respectively corresponding to the plurality of indoor units and each including the third on-off valve, the fourth on-off valve, and a bypass pipe having at least a throttle mechanism. The multi-room air conditioner according to claim 1, wherein: 7. A pressure sensor or a pressure switch is provided in a pipe of each of the indoor heat exchangers to control opening and closing of an on-off valve of the bypass pipe.
The multi-room air conditioner as described. 8. The multi-chamber air conditioner according to claim 1, wherein an oil separator for separating oil and returning the oil to a suction side of the compressor is provided on a discharge side of the compressor.