JP2002022296A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure reliability and enhance serviceability of installation by shortening pumping-down time without inviting decrease in capacity of a compressor at the time of pumping-down operation. SOLUTION: In the case wherein an operation for starting a pumping-down operation is effected (step 11), a four-way valve is set to a state equivalent to a state for cooling operation mode (step 12), a motor-operated valve between an outdoor heat exchanger and a receiver is set to an open state (step 13), operation of the compressor and a timer are started (step 14), when the judgment that the timer has counted a specified time is made (step 15), the motor-operated valve between the outdoor heat exchanger and the receiver is closed (step 16), when the judgment that recovery of the refrigerant is completed is made (step 17), the pumping-down operation is finished (step 18).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having an air conditioner having a refrigerant circuit provided with a receiver for recovering surplus refrigerant, which is configured to improve the reliability and efficiency of pump-down operation control. About the machine.

[0002]

2. Description of the Related Art In a refrigerant circuit of an air conditioner, an accumulator, a compressor, a four-way switching valve, an outdoor heat exchanger disposed in an outdoor unit and an indoor heat exchanger disposed in an indoor unit are connected by refrigerant piping. Are connected and form a circulation path for the refrigerant.

In such a refrigerant circuit of an air conditioner, the refrigerant circulation direction is controlled by a four-way switching valve so that the outdoor heat exchanger functions as a condenser during cooling and the indoor heat exchanger functions as an evaporator. I do. In addition, at the time of heating, the refrigerant circulation direction is controlled by the four-way switching valve so that the outdoor heat exchanger functions as an evaporator and the indoor heat exchanger functions as a condenser.

[0004] In the case of a multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit, the amount of circulating refrigerant corresponding to the number of connected indoor heat exchangers and their capacity is required. It is becoming. Correspondingly, the capacity of the outdoor unit must be large. However, since not all indoor units are always in the operating state, when the number of indoor units in the operating state is small, excess refrigerant is generated due to the difference in capacity between the outdoor unit and the indoor unit, and this excess refrigerant is removed. A receiver for collection is required.

[0005] Usually, the receiver is connected in series to a liquid pipe side pipe connecting the outlet side of the outdoor heat exchanger and the liquid shutoff valve, and is configured to introduce excess refrigerant generated from the liquid pipe side pipe. . A gas vent pipe is provided at the upper part of the receiver to smoothly collect the surplus refrigerant, and is configured so that gas can be discharged to the accumulator suction side during the cooling operation via the capillary.

[0006]

In an air conditioner having a refrigerant circuit as described above, when performing maintenance processing or relocation work of the refrigerant circuit, the gas refrigerant remaining in each indoor unit and the refrigerant pipe is removed. A pump-down operation for recovering the refrigerant in the outdoor unit side refrigerant circuit between the liquid closing valve and the gas closing valve is performed.

In this pump-down operation, the liquid shut-off valve is closed, the four-way switching valve is set in a cooling operation path, and the compressor is operated to remove gaseous refrigerant remaining in each indoor heat exchanger. to recover. At this time, the recovered refrigerant becomes a liquid refrigerant and is stored in the receiver near the liquid shutoff valve, and the liquid refrigerant exceeding the capacity of the receiver is stored in the outdoor heat exchanger.

[0008] During the pump-down operation, the gas in the receiver is discharged by the gas release capillary provided in the gas release pipe, so that the liquid refrigerant can be smoothly introduced into the receiver.

However, in such a pump-down operation, when the collected liquid refrigerant exceeds the capacity of the receiver, the overflowed liquid refrigerant is discharged through the gas vent pipe and supplied to the suction side of the accumulator. There is a risk. Therefore, the liquid refrigerant is supplied to the suction side of the compressor via the accumulator, which may impair the performance of the compressor and may reduce the reliability of the compressor. In addition, it also involves a problem that the work time of the pump-down operation is lengthened and the serviceability of the construction is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to secure reliability without lowering the compressor performance during a pump down operation, and to improve construction serviceability by shortening a pump down time. I do.

[0011]

An air conditioner according to the present invention comprises an accumulator, a compressor, a four-way switching valve, an outdoor heat exchanger, and a liquid for connecting pipes to the indoor heat exchanger. A pipe side connection port and a gas pipe side connection port, a liquid shutoff valve provided between the outdoor heat exchanger and the liquid pipe side connection port, and a gas provided between the four-way switching valve and the gas pipe side connection port. A shutoff valve, a liquid refrigerant introduction pipe connected between the outdoor heat exchanger and the liquid shutoff valve for introducing surplus liquid refrigerant, and a vent for discharging the gaseous refrigerant inside to the accumulator suction side during the cooling operation. An outdoor unit-side refrigerant circuit including a receiver having a pipe, a refrigerant circuit connected to an indoor heat exchanger arranged in the indoor unit via a refrigerant pipe connected to the liquid pipe-side connection port and the gas pipe-side connection port An air conditioner having A refrigerant opening / closing means is provided between the external heat exchanger and the receiver, and when performing the pump-down operation, the four-way switching valve is set to a path for the cooling operation while the liquid closing valve is closed, and the refrigerant opening / closing means is provided. The compressor is opened to start a pump-down operation by the compressor, and the refrigerant opening / closing means is closed after a predetermined time has elapsed from the start of the pump-down operation.

Here, the refrigerant opening / closing means can be constituted by a liquid tube electric valve for refrigerant introduction provided in the refrigerant introduction pipe. The gas vent pipe may be provided with a gas vent capillary.

Further, the receiver has a bypass circuit for bypassing a liquid pipe side pipe between the outdoor heat exchanger and the liquid pipe close valve and a gas pipe side pipe between the four-way switching valve and the gas pipe close valve. It can be a configuration provided inside.

Further, the refrigerant opening / closing means may be an electric valve serving as a main pressure reducing circuit during a heating operation. Further, the predetermined time from the start of the pump-down operation to the closing of the refrigerant opening / closing means can be set to a time at which the inside of the receiver is estimated to be filled with the collected liquid refrigerant.

Further, a plurality of indoor heat exchangers can be connected via the liquid pipe side connection port and the gas pipe side connection port. The air conditioner according to the present invention includes an accumulator, a compressor, a four-way switching valve, an outdoor heat exchanger, a liquid pipe side connection port for connecting a pipe to the indoor heat exchanger side, and a gas pipe side connection. A port, a liquid shutoff valve provided between the outdoor heat exchanger and the liquid pipe side connection port, a gas shutoff valve provided between the four-way switching valve and the gas pipe side connection port, and an outdoor heat exchanger. An outdoor unit including a liquid refrigerant introduction pipe connected between liquid shutoff valves for introducing surplus liquid refrigerant, and a receiver having a gas vent pipe for discharging internal gaseous refrigerant to an accumulator suction side during cooling operation An air conditioner having a refrigerant circuit connected to an indoor heat exchanger disposed in an indoor unit via a refrigerant pipe connected to a liquid pipe side connection port and a gas pipe side connection port, Refrigerant opening / closing means in gas vent pipe When the pump-down operation is performed, the four-way switching valve is set to the path for the cooling operation while the liquid shut-off valve is in the closed state, and the refrigerant opening / closing means is opened to start the pump-down operation by the compressor. The refrigerant opening / closing means is configured to be closed after a predetermined time has elapsed from the start of the pump-down operation.

Here, the refrigerant opening / closing means can be constituted by an electric valve or a solenoid valve for venting provided in the venting pipe. Further, a gas venting capillary can be provided in the gas venting pipe.

Further, the receiver has a bypass circuit for bypassing a liquid pipe side pipe between the outdoor heat exchanger and the liquid pipe close valve, and a gas pipe side pipe between the four-way switching valve and the gas pipe close valve. It can be a configuration provided inside.

The predetermined time from the start of the pump-down operation to the closing of the refrigerant opening / closing means can be set to a time at which it is estimated that the receiver is filled with the recovered liquid refrigerant.

Further, a plurality of indoor heat exchangers can be connected via the liquid pipe side connection port and the gas pipe side connection port.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Refrigerant Circuit A] A refrigerant circuit A of an air conditioner to which one embodiment of the present invention is applied will be described with reference to FIG.

In FIG. 1, a plurality of indoor units 200A, 2A are connected to an outdoor unit 100 via branch units 300A, 300B.
00B... Are connected. Outdoor unit 1
Reference numeral 00 includes a compressor 101, a four-way switching valve 102, an outdoor heat exchanger 103, an accumulator 105, and the like. On the discharge side of the compressor 101, a discharge-side pressure protection switch 108 for detecting an abnormal rise in the discharge pressure is provided. Further, on the suction side of the compressor 101, a suction side pressure sensor 110 for detecting a suction pressure is provided.

On the discharge side of the compressor 101, an oil separator 107 for separating lubricating oil contained in the refrigerant and returning it to the compressor 101 is provided. The oil return pipe of the oil separator 107 is provided with a capillary 143 so that oil can be returned to the compressor 101 smoothly.

The outdoor unit 100 has an outdoor air thermistor 111 for detecting the outdoor air temperature and an outdoor heat exchange thermistor 11 for detecting the temperature of the outdoor heat exchanger 103.
2 are provided. Further, a fan 106 for sucking outside air and performing heat exchange between the sucked outside air and the refrigerant flowing inside the outdoor heat exchanger 103, and a fan motor 104 for rotating the fan 106 are provided. ing.

A refrigerant pipe extending from the outdoor unit 100 to the indoor unit has a liquid pipe connection port 114 extending from the outdoor heat exchanger 103 and a gas pipe connection port 115 extending through the four-way switching valve 102. And a liquid pipe closing valve 116 and a gas pipe closing valve 117 provided inside each connection port.

Further, in the outdoor unit 100, the refrigerant pipe located between the outdoor heat exchanger 103 and the liquid pipe closing valve 116 is a liquid pipe side pipe section 131, and the four-way switching valve 102, the gas pipe closing valve 117, Assuming that the refrigerant pipe located between them is a gas pipe side pipe section 132, the liquid pipe side pipe section 131 is provided with a motor-operated valve 161 acting as a main pressure reducing circuit during heating.

A receiver 121 for temporarily storing surplus refrigerant is provided between the electric valve 161 and the liquid shutoff valve 116. The receiver 121 includes a liquid refrigerant introduction / discharge pipe 151, a liquid refrigerant introduction / discharge pipe 152, and a gas vent circuit 168 connected to the suction side of the accumulator 105. The gas vent circuit 168 includes a pressure reducing orifice 164 provided on the gas vent pipe 169, a pressure equalizing valve 165 provided in a branch path of the accumulator 105 to the suction side, and a gas venting capillary 167.

Further, an injection circuit 166 is provided which branches off from between the motor-operated valve 161 and the receiver 121 and is connected to the compressor 101 side. The injection circuit 166 includes a pressure reducing capillary 163 and a solenoid valve 162 that opens and closes a refrigerant path.
01 when the temperature of the discharge pipe becomes high.
The configuration is such that the low-temperature refrigerant is returned to the compressor 101 from 31 to control the discharge pipe temperature.

The liquid pipe connection port 114 and the gas pipe connection port 115 of the outdoor unit 100 are provided with branch units 300A, 3B.
00B is connected. Branch unit 300A, 30
OB have the same configuration, and only one branch unit 300A will be described. The outdoor liquid pipe connection port 30 connected to the liquid pipe connection port 114 of the outdoor unit 100
1 and an outdoor gas pipe connection port 303 connected to the gas pipe connection port 115 of the outdoor unit 100. The branching unit 300A includes a liquid pipe side branch path that branches inside the outdoor liquid pipe connection port 301, and the distal end thereof is connected to the indoor liquid pipe connection port 302 of the number of indoor units to be connected.
Is composed. Also, the outdoor side gas pipe connection port 303
The gas pipe side branch path which branches in the inside of the inside, the tip is connected to the indoor side gas pipe connection port 3 of the number of indoor units to be connected
04. Here, the indoor units to be connected are 3
And a liquid pipe connection port 302A, 302B, 3
02C and indoor side gas pipe connection ports 304A, 304
B, 304C.

From the outdoor liquid pipe connection port 301 in the branching unit 300A to the indoor liquid pipe connection ports 302A to 302A-3.
In the branch path to 02C, there are electrically operated valves 305A to 305C for reducing the pressure of the refrigerant passing therethrough, and a liquid tube thermistor 306 for detecting the temperature of the refrigerant passing therethrough.
A to 306C are provided. In the branch path from the outdoor-side gas pipe connection port 303 in the branch unit 300A to each of the indoor-side gas pipe connection ports 304A to 304C, gas pipe thermistors 307A to 307C for detecting the temperature of the refrigerant passing therethrough are provided, respectively. Is provided.

Each branch unit 300A, 300B has
A plurality of indoor units 200 are connected. Here, the number of indoor units that can be connected to the branch unit 300 is three, indoor units 200A to 200C are connected to the branch unit 300A, and indoor units 200D to 200C are connected to the branch unit 300B.
F is connected. Each indoor unit 200A-200
Each of F can use both the indoor unit for the multi-unit and the indoor unit for the pair unit. Here, the case where the indoor unit for the pair unit is used will be described.

The indoor unit 200A includes an indoor heat exchanger 201. Refrigerant piping connected to the indoor heat exchanger 201 is connected to the outdoor unit via a liquid pipe connection port 204 and a gas pipe connection port 205. Derived. The indoor unit 200A includes a room temperature thermistor 202 for detecting the indoor temperature and an indoor heat exchange thermistor 203 for detecting the temperature of the indoor heat exchanger 201.

When a multi-unit indoor unit is used as the indoor unit connected to the branch unit 300, a liquid tube thermistor for detecting the temperature of the refrigerant flowing inside the liquid tube side pipe portion is provided. In this case, the liquid tube thermistor in the branch unit 300 can be omitted.

[Refrigerant Circuit B] A refrigerant circuit B to which one embodiment of the present invention is applied will be described with reference to FIG. This refrigerant circuit B has substantially the same configuration as the refrigerant circuit A,
The same parts are denoted by the same reference numerals and description thereof will be omitted.

In the refrigerant circuit B, a gas vent valve 170 for opening and closing the refrigerant flow is provided in the gas vent circuit 168 of the refrigerant circuit A. The vent valve 170 can be constituted by a motorized valve capable of adjusting the flow rate, or an electromagnetic valve whose flow rate cannot be adjusted.

[Refrigerant Circuit C] A refrigerant circuit C to which one embodiment of the present invention is applied will be described with reference to FIG. In the refrigerant circuit C, a bypass circuit is formed between the liquid pipe-side pipe section 131 and the gas pipe-side pipe section 132, and the receiver 121 is arranged on the bypass circuit. Portions that overlap with the refrigerant circuit A are denoted by the same reference numerals, and description thereof is omitted.

The outdoor unit 100 includes a compressor 101, a four-way switching valve 102, an outdoor heat exchanger 103, and an accumulator 105.
And so on. On the discharge side of the compressor 101, a discharge pipe thermistor 109 for detecting a discharge pipe temperature is provided.

The receiver 121 includes a liquid pipe side connection pipe 122 and a gas pipe side connection pipe 123. Liquid pipe side connection pipe 12
2 is connected to the liquid pipe side pipe 131 between the outdoor heat exchanger 103 and the liquid pipe closing valve 116, and is connected to the gas pipe side connection pipe 1.
Reference numeral 23 is connected to a gas pipe side pipe 132 between the four-way switching valve 102 and the gas pipe closing valve 117.

The liquid pipe side connection pipe 122 and the gas pipe side connection pipe 123 of the receiver 121 include a liquid pipe motorized valve (EVL) 128 and a gas pipe motorized valve (EVG) 129 as functional parts having a pressure reducing function and a refrigerant shutoff function. Is provided.

The receiver 121 and the gas pipe side piping section 1
A degassing circuit 171 is provided between 32. This degassing circuit 171 is configured by providing a degassing capillary 130 for depressurization in a degassing pipe attached to the upper part of the receiver 121. Here, a gas venting capillary 130 for recovering a gaseous refrigerant from the receiver 121 is provided toward the gas pipe side pipe portion 132 between the four-way switching valve 102 and the gas closing valve 117.

In the conventional refrigerant circuit, a gas venting capillary is provided in the pipe between the four-way switching valve and the accumulator, which is always a low-pressure pipe, in order to enhance the refrigerant recovery function during the pump-down operation. At the time of the operation / heating operation), the refrigerant flows from the high pressure side to the low pressure side, so that the efficiency is reduced during the normal operation. In addition, when the excess refrigerant during the heating operation is processed by the receiver, the flow characteristics of the capillary need to be reduced because the degassing capillary is always connected to the low-pressure pipe, and as a result, the refrigerant recovery during the pump-down operation is performed. It is difficult to improve the efficiency.

Here, during the pump down operation,
It is possible to return the gaseous refrigerant stored in the receiver 121 to the suction side of the accumulator via the degassing capillary 130, to smoothly recover the liquid refrigerant to the receiver 121, and during normal operation. By closing the liquid tube motorized valve 128 in the above, the refrigerant flow from the degassing capillary 130 can be cut off during the cooling operation,
By maintaining the inside of the receiver 121 at a high pressure during the heating operation, the backflow of the refrigerant from the liquid tube motorized valve 128 can be prevented, and excess refrigerant processing during the heating operation can be performed.

Further, an auxiliary heat exchanger 133 is provided between the gas pipe motorized valve 129 and the connection to the gas pipe side pipe 132. The auxiliary heat exchanger 133 can be provided in the outdoor heat exchanger 103, and
3 is preferably arranged at the bottom. In the drawing, a subcool heat exchanger 134 for supercooling the refrigerant from the outdoor heat exchanger outlet at the time of cooling is disposed below the outdoor heat exchanger 103, and further below the auxiliary heat exchanger 133. Has been arranged.

When the surplus refrigerant is discharged from the receiver when performing the cooling operation using such a refrigerant circuit, it is necessary to limit the refrigerant discharge speed in order to prevent rapid liquid back to the accumulator. But the auxiliary heat exchanger 133
As a result, the liquid refrigerant evaporates, so that the refrigerant discharge speed can be increased without performing a sudden liquid back to the accumulator. During the heating operation, the auxiliary heat exchanger 133 functions as a condenser,
It is possible to increase the speed at which the excess refrigerant is stored.

[Refrigerant Circuit D] A refrigerant circuit D to which one embodiment of the present invention is applied will be described with reference to FIG. This refrigerant circuit D has substantially the same configuration as the refrigerant circuit C,
Portions that overlap with the refrigerant circuit C are denoted by the same reference numerals, and description thereof is omitted.

In the refrigerant circuit D, a gas vent valve 172 for opening and closing the refrigerant flow in the gas vent circuit 171 of the refrigerant circuit C
Is provided. The gas vent valve 172 can be constituted by an electric valve capable of adjusting the flow rate, or an electromagnetic valve whose flow rate cannot be adjusted.

[Pump Down Operation Control] When performing maintenance or relocation work of the refrigerant circuit, the refrigerant remaining in each indoor heat exchanger 201 or the refrigerant pipe is transferred to the outdoor unit side refrigerant circuit in the outdoor unit 100. Perform pump down operation to recover.

The pump-down operation control in the refrigerant circuit C among the refrigerant circuits A to D will be described with reference to the flowchart shown in FIG. When performing the pump down operation, the operator closes the liquid shutoff valve 116,
The switch for starting the pump-down operation is operated.

In step S11, it is determined whether or not the pump down operation start switch has been operated. When the pump-down operation start switch is operated and a pump-down start signal is input, the process proceeds to step S12.

In step S12, the four-way switching valve 102 is switched to the pump down operation mode. Here, FIG.
The pump-down operation mode can be set by switching the four-way switching valve 102 to the cooling operation state indicated by the dotted line position.

In step S13, the liquid tube motorized valve 128 is set to the open state. Note that the gas pipe motorized valve 129 is closed, and the liquid refrigerant discharged from the outlet side of the outdoor heat exchanger 103 is set to be collected in the receiver 121.

In step S14, the operation of the compressor 101 is started. As a result, an operation equivalent to the cooling operation is started with the liquid closing valve 116 closed, and the refrigerant that has become liquid in the outdoor heat exchanger 103 that acts as a condenser is stored in the receiver 121. . At this time,
The gas refrigerant in the receiver 121 is supplied to the accumulator 10 via the degassing capillary 130 in the degassing circuit 171.
5, and the liquid refrigerant can be smoothly collected into the receiver 121.

In step S14, the count of the pump down timer is started simultaneously with the start of the operation of the compressor 101. The pump down timer counts the elapsed time from the start of the pump down operation, and is reset when the operation of the compressor 101 starts and starts counting the elapsed time.

In step S15, it is determined whether the elapsed time counted by the pump down timer has exceeded a predetermined time. Considering the capacity of the receiver 121, the condensing capacity of the outdoor heat exchanger 103, the operating frequency of the compressor 101 at the time of the pump-down operation, and the like, the time is slightly shorter than the time when it is estimated that the liquid refrigerant is filled in the receiver 121. The time is set in advance as a predetermined time. If it is determined that the time counted by the pump down timer has exceeded the predetermined time, the process proceeds to step S16.

In step S16, the liquid tube motorized valve 128 is closed. At this point, there is some room for collecting the liquid refrigerant in the receiver 121, and the collection of the liquid refrigerant in the receiver 121 stops by closing the liquid tube electric valve 128. Therefore, it is possible to prevent the liquid refrigerant collected in the receiver 121 from overflowing to the gas release circuit 171 side.

In step S17, it is determined whether or not the refrigerant collection has been completed. After closing the liquid tube motorized valve 128,
The refrigerant in the liquid state accumulates in the liquid pipe side pipe portion 131 and the outdoor heat exchanger 103. In step S17, for example, when the elapsed time from the start of the pump-down operation counted by the pump-down timer as described above exceeds a predetermined time, or when the compressor 101
When the value of the suction-side pressure sensor 110 for detecting the suction pressure of the indoor unit becomes equal to or less than a predetermined value, it is determined that almost all of the refrigerant on the indoor unit side has been recovered, and the process proceeds to step S18.

In step S18, the operation of the compressor 101 is stopped, and an indication that the pump-down operation has been completed is displayed. In response to this, the operator closes the gas shutoff valve 117 and starts maintenance work, removal work, and the like.

In such pump-down operation control, immediately after the start of the pump-down operation, the gas refrigerant in the receiver 121 is supplied to the accumulator 105 through the gas release circuit 171.
Therefore, the liquid refrigerant is smoothly collected into the receiver 121. Also, before the receiver 121 is filled with the recovered liquid refrigerant, the liquid tube motorized valve 128
Is closed, the liquid refrigerant overflowing from the receiver 121 is stored in the accumulator 105 and the compressor 10.
This prevents the compressor 101 from deteriorating in performance without flowing to the first side, thereby reducing the time required for the pump-down operation.

In the case of the refrigerant circuit A, the same operation and effect can be obtained by controlling the opening and closing of the electric valve 161 in place of the liquid tube electric valve 128 under the control. Further, in the case of the refrigerant circuit B, the same operation and effect can be obtained by performing opening / closing control of the gas vent opening / closing valve 170 instead of the liquid tube motorized valve 128 under the above-described control.

Further, in the case of the refrigerant circuit D, the gas vent opening / closing valve 17
The same operation and effect can be obtained by performing the opening / closing control of (2).

[Other Embodiments] Outdoor unit 100 and indoor unit 2
00 is not limited to the air conditioner of the type connected via the branch unit 300, but the outdoor unit 100
A similar configuration can be applied to a general multi-type air conditioner having a plurality of connection ports.

In a pair-type air conditioner in which the outdoor unit and the indoor unit correspond one-to-one, the same configuration is applied when the outdoor unit is provided with a receiver for recovering excess refrigerant. Is possible.

[0062]

According to the air conditioner of the present invention, the time for the pump-down operation can be shortened, and the serviceability can be improved. In addition, since the liquid refrigerant overflowing from the receiver during the pump-down operation is not returned to the compressor side, it is possible to prevent deterioration of the compressor and maintain high reliability.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a refrigerant circuit A.

FIG. 2 is a schematic configuration diagram of a refrigerant circuit B.

FIG. 3 is a schematic configuration diagram of a refrigerant circuit C.

FIG. 4 is a schematic configuration diagram of a refrigerant circuit D.

FIG. 5 is a flowchart of a pump-down operation control.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 outdoor unit 101 compressor 102 four-way switching valve 103 outdoor heat exchanger 105 accumulator 121 receiver 128 liquid pipe motorized valve 129 gas pipe motorized valve 130 gas release capillary 131 liquid pipe piping 132 gas pipe piping 133 auxiliary heat exchanger

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Sakamoto 2F, 1000 Oya, Okamoto-cho, Kusatsu-shi, Shiga F-term in the Shiga Works of Daikin Industries, Ltd. (Reference) 3L060 AA02 CC08 DD08 EE09 EE10 3L092 AA05 BA26 BA27 DA06 EA18 FA22 FA23

Claims (13)

[Claims] An accumulator (105) and a compressor (1).
01), the four-way switching valve (102), and the outdoor heat exchanger (1).
03), a liquid pipe side connection port (114) and a gas pipe side connection port (115) for pipe connection to the indoor heat exchanger (201) side, and the outdoor heat exchanger (103) and the liquid pipe side. A liquid shut-off valve (116) provided between the connection port (114) and a gas shut-off valve (1) provided between the four-way switching valve (102) and the gas pipe side connection port (115);
17), the outdoor heat exchanger (103) and the liquid shutoff valve (1).
16), a liquid refrigerant introduction pipe (151, 152, 122, 123) for introducing an excess liquid refrigerant, and an accumulator (1) for cooling the gaseous refrigerant in the cooling operation.
05) Degassing pipe for exhaust to the suction side (168,
The outdoor unit-side refrigerant circuit including the receiver (121) including the receiver unit (171) includes an indoor unit (200) via a refrigerant pipe connected to the liquid tube-side connection port (114) and the gas tube-side connection port (115). An air conditioner having a refrigerant circuit connected to an indoor heat exchanger (201) disposed inside the air conditioner, wherein refrigerant open / close means (161) is provided between the outdoor heat exchanger (103) and a receiver (121). , 128), when the pump-down operation is performed, the four-way switching valve (102) is set to the path for the cooling operation while the liquid shut-off valve (116) is closed, and the refrigerant switching means (161, 161) is set. 12
8) The compressor (101) is set in an open state to start a pump-down operation, and the refrigerant opening / closing means (161, 128) is closed after a lapse of a predetermined time from the start of the pump-down operation. . 2. A refrigerant pipe-operated valve (1) provided in the refrigerant introduction pipe (122) for introducing refrigerant.
The air conditioner according to claim 1, wherein 28). 3. The air conditioner according to claim 1, wherein the gas vent pipe (168, 171) is provided with a gas vent capillary (167, 130). 4. The receiver (121) includes a liquid pipe side pipe (131) between the outdoor heat exchanger (103) and a liquid pipe closing valve (116), and the four-way switching valve (102). The gas pipe side pipe (132) between the gas pipe closing valve (117) and a bypass circuit that bypasses the gas pipe side pipe (132).
3. The air conditioner according to any one of 3. 5. The air conditioner according to claim 1, wherein said refrigerant opening / closing means is a motor-operated valve (161) serving as a main pressure reducing circuit during a heating operation. 6. A predetermined time from the start of the pump-down operation to the closing of the refrigerant opening / closing means (161, 128) is set to a time at which the receiver (121) is estimated to be filled with the recovered liquid refrigerant. The air conditioner according to claim 1. 7. A plurality of indoor heat exchangers (201) are connectable via the liquid pipe side connection port (114) and the gas pipe side connection port (115). The air conditioner described in Crab. 8. An accumulator (105) and a compressor (1).
01), the four-way switching valve (102), and the outdoor heat exchanger (1).
03), a liquid pipe side connection port (114) and a gas pipe side connection port (115) for pipe connection to the indoor heat exchanger (201) side, and the outdoor heat exchanger (103) and the liquid pipe side. A liquid shut-off valve (116) provided between the connection port (114) and a gas shut-off valve (1) provided between the four-way switching valve (102) and the gas pipe side connection port (115);
17), the outdoor heat exchanger (103) and the liquid shutoff valve (1).
16), a liquid refrigerant introduction pipe (151, 152, 122, 123) for introducing an excess liquid refrigerant, and an accumulator (1) for cooling the gaseous refrigerant in the cooling operation.
05) Degassing pipe for exhaust to the suction side (168,
An outdoor unit-side refrigerant circuit including a receiver (121) having an indoor unit (200) via a refrigerant pipe connected to the liquid tube-side connection port (114) and the gas tube-side connection port (115). An air conditioner having a refrigerant circuit connected to an indoor heat exchanger (201) arranged in the air conditioner, wherein a refrigerant opening / closing means (170, 172) is provided in the gas vent pipe (168, 171), and a pump is provided. When performing the down operation, the four-way switching valve (102) is set to the path for the cooling operation while the liquid closing valve (116) is closed, and the refrigerant opening / closing means (170, 172) is opened. The air conditioner is characterized in that a pump down operation by the compressor (101) is started and the refrigerant opening / closing means (170, 172) is closed after a lapse of a predetermined time from the start of the pump down operation. . 9. The refrigerant opening / closing means (170, 172)
The air conditioner according to claim 8, wherein the air conditioner is an electric valve or a solenoid valve for degassing provided in the degassing pipe (168, 171). 10. The air conditioner according to claim 8, wherein the gas vent pipe (168, 171) is provided with a gas vent capillary (167, 130). 11. The receiver (121) includes a liquid pipe side pipe (131) between the outdoor heat exchanger (103) and a liquid pipe closing valve (116), and the four-way switching valve (102). The gas pipe side pipe (132) between the gas pipe closing valve (117) and a bypass circuit that bypasses the gas pipe side pipe (132).
An air conditioner according to any one of claims 10 to 10. 12. A predetermined time from the start of the pump-down operation to the closing of the refrigerant opening / closing means (170, 172) is set to a time at which the receiver (121) is estimated to be filled with the recovered liquid refrigerant. The air conditioner according to any one of claims 8 to 11, wherein 13. A plurality of indoor heat exchangers (201) are connectable via the liquid pipe side connection port (114) and the gas pipe side connection port (115).
3. The air conditioner according to any one of 2.