JP3126266B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, the number of refrigerant recovery operations within a predetermined time, the discharge temperature of a compressor after the refrigerant recovery operation,
Alternatively, the present invention relates to an air conditioner that detects a defect such as a shortage of refrigerant, a refrigerant leak, or damage to a refrigerant circuit component, based on a duration of the refrigerant at a condenser outlet that is lower than a predetermined degree of subcooling.

[0002]

2. Description of the Related Art FIG. 23 shows a circuit configuration of a refrigerant circuit used in a conventional air conditioner. In the figure,
1 is a compressor, 2 is a four-way switching valve, 3 is a heat source side heat exchanger,
4 is a flow control device, 5 is an indoor heat exchanger, 6 is an accumulator, 7 is an indoor blower, 8 is an indoor unit, 9 is a heat source unit,
Reference numeral 10 denotes a heat-source-side blower, 11a and 11b denote upper or lower liquid level detecting circuits provided from upper and lower positions of the accumulator 6 and communicate with a suction pipe of the compressor 1, respectively, and 12a and 12b denote upper or lower liquid level detecting circuits. Heaters 11a and 11b are overheated, respectively, and 13a and 13b are heaters 12a and 1b, respectively.
Upper or lower liquid level detection circuits 11a, 11a after being heated in 2b
Reference numeral 14 denotes a high pressure side pressure sensor, 15 denotes a low pressure saturation temperature generation circuit, 16 denotes a low pressure saturation temperature sensor, and 17 denotes a discharge temperature sensor of the compressor 1. In the figure, solid arrows indicate the flow direction of the refrigerant during the cooling operation, and broken arrows indicate the flow direction of the refrigerant during the heating operation. FIG. 24 is a control block diagram of the conventional refrigerant circuit. The operation control unit 18 controls the operation of the refrigeration cycle by the conventional refrigerant circuit.

Here, the operation during the cooling operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the heat-source-unit-side heat exchanger 3 through the four-way switching valve 2, and radiates heat to the air sent by the heat-source-unit blower 10 and condenses. It becomes a high-pressure liquid refrigerant. That is, the heat source unit side heat exchanger 3 is a condenser at this time. This liquid refrigerant is decompressed by the flow controller 4 and flows into the indoor heat exchanger 5 as a low-pressure gas-liquid two-phase refrigerant. In the indoor heat exchanger 5, the refrigerant absorbs heat from the air sent from the indoor blower 7, so that most of the liquid refrigerant evaporates, while the air is cooled and sent out indoors. That is, the indoor heat exchanger 5 is an evaporator at this time.
The refrigerant that has exited the indoor heat exchanger 5 flows into the accumulator 6 via the four-way switching valve 2, where the refrigerant is vapor-liquid separated into a non-evaporated liquid refrigerant and a gas refrigerant in the indoor heat exchanger 5. Returns from the outlet pipe of the accumulator 6 to the compressor 1 via the suction pipe of the compressor 1.

On the other hand, a part of the liquid refrigerant that has exited the heat source unit side heat exchanger 3 bypasses the indoor unit 8 and flows through the low pressure saturation temperature generation circuit 15 toward the inlet of the accumulator 6. Since the piping of the low-pressure saturation temperature generating circuit 15 is relatively thin, the flow rate of the refrigerant flowing therethrough is small and the pressure loss is large. Since the pressure loss is large as described above, the liquid refrigerant passing through the low-pressure saturation temperature generating circuit 15 is in a gas-liquid two-phase state. By providing the low-pressure saturation temperature generation circuit 15, the low-pressure saturation temperature sensor 1
6 can detect a temperature equal to the saturation temperature of the refrigerant at the low pressure side pressure. Thus, a refrigeration cycle for cooling is formed.

Next, the operation during the heating operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the indoor heat exchanger 5 via the four-way switching valve 2, and radiates and condenses the high-pressure liquid into the air sent from the indoor blower 7. While becoming a refrigerant, the air is heated and sent out from the indoor unit 8 to the room. That is, the indoor heat exchanger 5 is a condenser at this time. This liquid refrigerant is decompressed by the flow controller 4 and flows into the heat source device side heat exchanger 3 as a low-pressure gas-liquid two-phase refrigerant. In the heat source device side heat exchanger 3, the refrigerant absorbs heat from the air sent by the heat source device side blower 10, so that most of the liquid refrigerant portion evaporates. That is, the heat source unit side heat exchanger 3 is an evaporator at this time. The refrigerant flowing out of the heat source unit side heat exchanger 3 flows into the accumulator 6 via the four-way switching valve 2, and is separated into a gas refrigerant and a liquid refrigerant which has not been evaporated in the heat source unit side heat exchanger 3, Only the refrigerant returns to the compressor 1 from the outlet pipe of the accumulator 6 via the suction pipe of the compressor 1.

On the other hand, a part of the liquid refrigerant out of the refrigerant flowing out of the indoor heat exchanger 5 does not flow to the heat source unit side heat exchanger 3, bypasses the liquid refrigerant, and is low-pressure saturated toward the inlet of the accumulator 6. It flows in the temperature generating circuit 15. Since the piping of the low-pressure saturation temperature generating circuit 15 is relatively thin, the flow rate of the refrigerant flowing therethrough is small and the pressure loss is large. Since the pressure loss is large, the liquid refrigerant in the low-pressure saturation temperature generation circuit 15 is in a gas-liquid two-phase state. Due to the presence of the low-pressure saturation temperature generation circuit 15, the low-pressure saturation temperature sensor 16 detects a saturation temperature substantially equal to the saturation temperature of the refrigerant at the low pressure side pressure. Thus, a refrigeration cycle for heating is formed.

When the compressor 1 has a variable refrigerant discharge capacity (operating capacity), target high and low pressures are set in advance during a cooling operation and a heating operation, and the compressor is set so that the target high and low pressures are achieved. 1 is controlled. At this time, the high pressure is detected by the pressure sensor 14, and the low pressure is easily obtained by converting the temperature detected by the low-pressure saturation temperature sensor 16 into a pressure. If the amount of air blown by the heat source unit-side blower 10 can be made variable, the high and low pressures are adjusted by changing the amount of air blown.

Here, a method for detecting the liquid level of the liquid refrigerant in the accumulator 6 will be described. Now, it is assumed that sufficient liquid refrigerant is present in the accumulator 6 and the liquid level is higher than the upper liquid level detecting circuit 11a. At this time, a low-temperature liquid refrigerant flows through the upper liquid level detection circuit 11a.
Since this liquid refrigerant is heated by the heater 12a, a part thereof evaporates. Since the heat applied by the heater 12a is used to evaporate the liquid refrigerant, the temperature of the refrigerant in the upper liquid level detection circuit 11a is low and constant unless all of the liquid refrigerant evaporates. Since the heating amount of the heater 12a is relatively small, all of the refrigerant flows without evaporating. The temperature sensor 13a detects the gas-liquid two-phase refrigerant temperature at this low temperature. The lower liquid level detecting circuit 11b of the lower level functions in exactly the same way as the upper liquid level detecting circuit 11a, and the temperature sensor 13b detects a low refrigerant temperature. However, the liquid level detection circuit 11b
Is located at a lower position, the refrigerant pressure is higher by the liquid head. Therefore, the temperature detected by the temperature sensor 13b exhibits a slightly higher temperature than the temperature detected by the upper temperature sensor 13a.

When the liquid level in the accumulator 6 is lower than the upper liquid level detecting circuit 11a, the operation is as follows. A gas refrigerant flows in the upper liquid level detection circuit 11a. for that reason,
The heater 12a raises the temperature of the refrigerant. Therefore, for example, the temperature sensor 13a detects that the liquid refrigerant is in the upper liquid level detection circuit 11a.
Detects significantly higher temperatures than when flowing through. When the liquid level is lower than the lower liquid level detection circuit 11b,
The temperature detected by the temperature sensor 13b also increases. The liquid level was determined using such characteristics.

[0010] The reference contents of such a liquid level determination are shown in the table of FIG. When the liquid refrigerant flows through the upper or lower liquid level detection circuits 11a and 11b, the temperature detected by the temperature sensors 13a and 13b becomes close to the low pressure saturation temperature. Therefore, as shown in FIG. 25, the operation control unit 18 compares the detection temperature Tc detected by the low-pressure saturation temperature sensor 16 with the detection temperatures Ta and Tb detected by the temperature sensors 13a and 13b, thereby determining whether the refrigerant is liquid or gas. Then, the amount of refrigerant in the accumulator 6 (expressed here by the numerical value of AL) is determined from the temperature difference between the detected temperatures Ta and Tb.

When the liquid refrigerant remains in the accumulator 6, the gas refrigerant flowing to the compressor 1 is almost saturated. However, when the liquid refrigerant in the accumulator 6 runs out, the refrigerant flowing in the accumulator 6 becomes overheated, so that the discharge temperature of the compressor 1 increases. If the discharge temperature rises too much, the compressor 1 may be damaged.
Usually, a refrigerant recovery operation is performed. This refrigerant recovery operation is as follows. The places where the refrigerant is likely to accumulate in the refrigerant circuit are, in addition to the accumulator 6, the inside of the condenser and the piping from the condenser to the flow control device 4. This is because the refrigerant is a liquid refrigerant at these locations, and the density of the refrigerant is large and the amount of refrigerant in terms of weight is substantially large. Since such a liquid refrigerant is originally made difficult to flow by the flow control device 4, when the opening degree of the flow control device 4 is increased, the liquid refrigerant easily returns to the accumulator 6.

Therefore, the operation control unit 18 determines the liquid level or the amount of the refrigerant in the accumulator 6 as shown in the flowchart of FIG.
L = 0) is determined as (step S1), the and if the discharge temperature Td of the compressor 1 detected by the discharge temperature sensor 17 is determined to be higher than the predetermined temperature T ₁ of about the discharge temperature (step S2) is , The valve opening S of the flow control device 4
j from the current valve opening Sj ^* by a predetermined opening increase α (α>
0) By opening (step S3), a refrigerant recovery operation such as returning the refrigerant to the accumulator 6 (processing end: step S4) is performed. If the refrigerant in the refrigerant circuit runs short and the discharge temperature of the compressor 1 rises excessively to such an extent that the discharge temperature of the compressor 1 does not decrease even by the refrigerant recovery operation, the discharge temperature sensor 17 sets the high temperature. The operation control unit 18 abnormally stops the compressor 1 based on the detection. That is, the operation control unit 18 includes a configuration including the upper or lower liquid level detection circuits 11a and 11b, the heaters 12a and 12b, and the temperature sensors 13a and 13b provided in the accumulator 6.
With the function described above, an example of the accumulator refrigerant amount detecting means is configured. Further, the detected accumulator 6
Means for realizing the function of recovering the refrigerant in the refrigerant circuit to the accumulator 6 by the operation control unit 18 based on the amount of refrigerant in the refrigerant chamber is an example of the refrigerant recovery means.

[0013]

When the amount of liquid refrigerant in the accumulator 6 is small and the discharge temperature of the compressor 1 is high, the discharge temperature of the compressor 1 is reduced by performing the refrigerant recovery operation as described above. Can be reduced. In such an operation mode, the total refrigerant amount in the refrigerant circuit is an appropriate amount,
And it is limited to the case where the refrigerant can be returned to the accumulator 6 by the refrigerant recovery operation. However, the total amount of refrigerant in the refrigerant circuit may be less than an appropriate amount in some cases. For example, when the amount of refrigerant enclosed during installation is less than the appropriate amount, or when part of the refrigerant circuit is damaged due to external factors such as vibration or impact during operation and the refrigerant leaks out of the circuit, etc. It is.

In the prior art, in these cases, the refrigerant recovery operation was simply repeated, and it was difficult to find out that there was a shortage of refrigerant simply because the state in which the indoor functional power was hardly produced continued. In addition, even if the compressor leaks due to abnormal discharge temperature or the like when the refrigerant leaks during the operation and the refrigerant becomes considerably short, even a general user cannot know whether the refrigerant is insufficient. Once the refrigerant leaks to the outside, it is difficult to recover the refrigerant, and it is necessary to refill the refrigerant again. In addition, when the refrigerant leaks into the user's living area, problems such as toxicity of the refrigerant itself, insufficient oxygen concentration, and the like, and a fire may occur if the refrigerant is ignitable. Normally, disaster prevention can be considered by interlocking a refrigerant leak sensor and a ventilator, but from an economical point of view and an aesthetic view of a room, it is rare that a ventilator is provided only for a refrigerant leak.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and detects a shortage of refrigerant or leakage of refrigerant based on operating characteristics of a refrigerant circuit.
It is an object of the present invention to provide an air conditioner capable of minimizing the leakage of the refrigerant and the adverse effect on the human body even when the refrigerant leaks.

[0016]

An air conditioner according to the present invention detects a refrigerant circuit in which a compressor, a condenser, a flow controller, an evaporator, and an accumulator are sequentially connected, and a refrigerant amount in the accumulator. When the amount of refrigerant detected by the accumulator refrigerant amount detecting means is small in the air conditioner having the accumulator refrigerant amount detecting means, the refrigerant flow rate of the refrigerant circuit is increased by the flow control device to collect the refrigerant in the accumulator. a refrigerant recovery means for performing a refrigerant recovery run, counting means for counting the number of has been refrigerant recovery operation performed within a preset time, the number of the refrigerant recovery run in the counted predetermined time by counting means Operation control means for stopping the compressor when the pressure is equal to or more than a predetermined value.

The air conditioner according to the present invention also includes a refrigerant circuit in which a compressor, a condenser, a flow control device, an evaporator, and an accumulator are sequentially connected, and an accumulator refrigerant amount detecting unit for detecting the amount of refrigerant in the accumulator. Means, in an air conditioner having a discharge temperature detecting means for detecting a discharge temperature of the compressor, when the amount of refrigerant detected by the accumulator refrigerant amount detecting means is small, the flow rate of the refrigerant circuit in the refrigerant circuit by the flow rate control device. A refrigerant recovery means for performing a refrigerant recovery operation for increasing the amount of the refrigerant and recovering the refrigerant to the accumulator; and an operation control means for stopping the compressor when a discharge temperature detected after the refrigerant recovery operation is equal to or higher than a predetermined value. It is a feature.

[0018] The air conditioner according to the present invention also includes a first on-off valve provided in a refrigerant circuit between the condenser or the evaporator and the flow control device, and an evaporator or the condenser and the compressor. A second on-off valve provided in a refrigerant circuit between the first and second on-off valves, and when the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value, the first on-off valve and the second on-off valve Is closed.

The air conditioner according to the present invention is further provided with a third refrigerant circuit provided in a refrigerant circuit between the condenser and the flow control device.
And a fourth on-off valve disposed in a refrigerant circuit between the evaporator and the accumulator, and when the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value, the operation control means The compressor is stopped after the third on-off valve is closed, and then the fourth on-off valve is closed.

The air conditioner according to the present invention is further provided with a fifth on-off valve provided in a refrigerant circuit between the compressor and the condenser, and provided in a refrigerant circuit between the evaporator and the flow control device. When the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value, the operation control unit closes the fifth open / close valve and stops the compressor. The on-off valve of No. 6 is closed.

The air conditioner according to the present invention is further provided with outside air feeding means for feeding air outside the closed space into the closed space containing the evaporator or the condenser, and the discharge temperature of the compressor after the refrigerant recovery operation is reduced. When the value is equal to or more than a predetermined value, the operation control means drives and controls the outside air feeding means.

[0022]

In the air conditioner constructed as described above, for example, when the number of the refrigerant recovery operations performed within a certain predetermined time becomes larger than a certain number of times, that is, the refrigerant recovery operation within a certain predetermined time is performed. When the number of times of operation becomes equal to or more than a predetermined value, a malfunction of the refrigerant circuit such as a shortage of the refrigerant or a refrigerant leak can be notified. Then, by taking measures to solve the problem of the refrigerant circuit at an early stage, it is possible to prevent the refrigerant circuit from being unnecessarily operated to recover the refrigerant while the refrigerant circuit remains defective.

Further, when the discharge temperature of the compressor after the refrigerant recovery operation becomes higher than a predetermined temperature, that is, based on the discharge temperature of the compressor after the refrigerant recovery operation, the amount of refrigerant in the refrigerant circuit is insufficient, or Detecting a refrigerant leak from the refrigerant circuit allows early notification of a defect in the refrigerant circuit. Therefore, in the case where measures for solving such a problem are taken, it is possible to prevent the compressor from being damaged due to the high discharge temperature continuing by performing the refrigerant recovery operation with the refrigerant shortage or the refrigerant leakage. .

When a refrigerant leak is detected during a cooling operation or a heating operation, the refrigerant circuit is divided into a plurality of hermetically sealed areas by closing the first on-off valve and the second on-off valve. The entire amount of the refrigerant in the refrigerant circuit can be prevented from leaking. As a result, problems such as economic loss and environmental pollution can be suppressed as compared with the case where all the refrigerant leaks.

Further, upon detecting a refrigerant leak occurring in the evaporator, the compressor is stopped after closing the third on-off valve,
Then, by closing the fourth on-off valve, more refrigerant remaining in the refrigerant circuit can be collected in the accumulator. Therefore, it is possible to prevent the refrigerant from unnecessarily leaking from the evaporator.

Further, when the refrigerant leakage detected in the condenser is detected, the compressor is stopped after closing the fifth on-off valve,
Then, by closing the sixth on-off valve, more refrigerant remaining in the refrigerant circuit can be collected in the accumulator. Therefore, it is possible to prevent the refrigerant from unnecessarily leaking from the condenser.

When a refrigerant leak is detected from the refrigerant circuit in the closed space containing the evaporator or the condenser, fresh air from outside the closed space is forcibly fed into the closed space by the air feeding means. It is. Therefore, there is no need to separately provide a ventilation device for sending outside air into the closed space.

[0028]

[Embodiment 1] FIG. 1 is a refrigerant circuit diagram in an air conditioner according to an embodiment of the present invention, FIG. 2 is a control block diagram of the refrigerant circuit, and FIG. 3 is a control flowchart thereof. The liquid level detection method and the refrigerant recovery control method of the refrigerant circuit are shown in FIG.
26 to FIG. 26, and a detailed description thereof will be omitted here. As shown in FIGS. 1 and 2, the air conditioner of the present embodiment includes, in addition to the air conditioner of the conventional example, a display 19 for displaying that a refrigerant shortage or a refrigerant leak has been detected, and an air conditioner. A timer 20 for counting the operation time and a counter 21 for counting the number of refrigerant recovery operations are provided. Further, in place of the conventional operation control unit 18, an operation control unit 18a that realizes the main function of the present embodiment is also provided.

Here, the control flowchart shown in FIG. 3 will be described. First, in step S11, the operation of the air conditioner is started. At the same time, the timer 20 starts measuring time in step S12. Then, in step S13, the count value N (the number of refrigerant recovery operations) of the counter 21 is 0.
Is cleared. In step S14, the liquid level is AL
= 0 (refrigerant amount = small) is determined. If AL =
If it is 0, the process proceeds to step S15 to perform the refrigerant recovery operation. If AL is not 0, normal operation is performed in step S16. Thus, the operation is performed while repeating the liquid level determination. When the refrigerant recovery operation is performed in step S15, the counter 21 accumulates the current number of refrigerant recovery operation times N in step S17. Step measurement time of S18 the timer 20 t (operation time) to determine whether the reached a predetermined time t _1. If the measured time t is long beyond t _1, after resetting the measured time t of the timer 20 at step S19, repeats the process procedure from Step S12. If the operating time t at step S18 has not reached t _1, the refrigerant recovering operation times N went so far in step S20 it is determined whether not exceeded the predetermined number N _1. If not, the process returns to step S14, and the processing procedure is repeated again from the liquid level determination. At this time, the measurement time t of the timer 20 and the number N of refrigerant recovery operations of the counter 21 are not cleared. That is, means for realizing the processing functions in steps S14 to S19 by the operation control unit 18a is an example of the counting means.

On the other hand, when the refrigerant recovery operation count N exceeds the predetermined number N ₁ in step S20, step S2
In step 1, the operation control unit 18a determines that a refrigerant leak or a refrigerant shortage occurs. Then, in step S22, the compressor 1
Is stopped, the display 19 is caused to display a refrigerant leak or a refrigerant shortage state in step S23. That is, means for realizing the processing functions in step S20 and step S21 by the operation control unit 18a is an example of the first refrigerant circuit refrigerant amount detecting means. Thus, when performing the refrigerant recovery run times exceeding the predetermined number N ₁ in the predetermined time t _1, it is determined that the refrigerant leak or refrigerant shortage,
Further, by displaying the information externally and notifying it, it is possible to notify the malfunction of the refrigerant circuit without performing the refrigerant recovery operation many times while the state of the refrigerant shortage or the leakage of the refrigerant is unnecessary. Thereby, the malfunction of the refrigerant circuit can be corrected at an early stage, so that the performance of the air conditioner can be sufficiently exhibited.

Embodiment 2 FIG. FIG. 4 is a refrigerant circuit diagram in the air conditioner according to the embodiment of the present invention. The refrigerant circuit of FIG. 4 has substantially the same configuration of the refrigerant circuit as that of the conventional example, and the operation of the refrigerant at the time of cooling and at the time of heating is also the same.
In the figure, an on-off valve 22a which can be automatically opened and closed between a heat source device side heat exchanger 3 (a condenser during cooling and an evaporator during heating) and a flow control device 4 is provided on a refrigerant circuit in the second embodiment. (An example of a first on-off valve), and an on-off valve 22 that can be automatically opened and closed between the indoor heat exchanger 5 (evaporator for cooling and a condenser for heating) and the four-way switching valve 2
b (an example of a second on-off valve). The on-off valve 22a and the on-off valve 22b are provided in the heat source device 9. Further, in place of the conventional operation control unit 18, an operation control unit 18b for realizing the main function of this embodiment is provided. FIG. 5 is a control block diagram of the refrigerant circuit, and FIG.
Is a control flowchart of the same. As shown in FIG. 5, the operation control unit 18b includes an on-off valve 22a as described later.
In addition, opening and closing control of the opening and closing valve 22b is also performed.

Here, the control flowchart of FIG. 6 will be described. First, the operation of the air conditioner is started in step S31. Then, the on-off valve 22a and the on-off valve 22b are immediately opened to allow the refrigerant to flow (Step S).
32). Thereafter, in step S33, the liquid level of the refrigerant in the accumulator 6 is detected, and it is determined whether or not the liquid level is AL = 0 (refrigerant amount = small). If AL = 0,
Normal operation is performed in step S36, and thereafter, in step S33.
The normal operation is performed between and step S36 unless the liquid level becomes AL = 0. On the other hand, in step S33, AL
When = 0 is detected, the refrigerant recovery operation is performed so that the discharge temperature of the compressor 1 does not increase (Step S34). After the refrigerant recovery operation, in step S35, the discharge temperature sensor 17
The discharge temperature td is detected by (an example of a discharge temperature detecting means), and the detected discharge temperature td is a predetermined temperature td _1.
Determine if it is higher. The predetermined temperature td ₁ is lower than the temperature at which the compressor 1 may be damaged, and is determined in advance by experiments or the like. When td is td ₁ below performs the normal operation proceeds to step S36.

[0033] Conversely, when td is higher than td _1, since the refrigerant despite were refrigerant recovery operation of step S34 has not been recovered, or refrigerant shortage refrigerant is leaking in the refrigerant circuit (Step S3
7) In step S38, the compressor 1 is stopped. Then, the on-off valve 22a and the on-off valve 22b are closed (Step S39). That is, means for realizing the processing functions in step S35 and step S36 by the operation control unit 18b is an example of the second refrigerant circuit refrigerant amount detecting means. As described above, the shortage of the refrigerant in the refrigerant circuit or the leakage of the refrigerant from the refrigerant circuit is detected based on the discharge temperature td of the compressor 1 after the refrigerant recovery operation, and the defect of the refrigerant circuit is notified at an early stage. The compressor 1 can be prevented from being damaged due to the high discharge temperature when the refrigerant recovery operation is continued with the refrigerant shortage or the refrigerant leakage. Can,
The performance of this air conditioner can be fully exhibited. When a refrigerant leak is detected, the on-off valves 22a and 22b
Is closed, it is possible to prevent all the refrigerant remaining in the refrigerant circuit from leaking. As a result, problems such as economic loss and environmental pollution caused by leakage of the refrigerant can be suppressed. That is, here, the operation control unit 18
b functions as an example of a first control unit.

Embodiment 3 FIG. FIG. 7 shows the on-off valve 22a and the on-off valve 22 in the second embodiment.
FIG. 4 is a refrigerant circuit diagram showing an example in which “b” is provided in the indoor unit 8. In the case of this configuration, when refrigerant leaks on the indoor unit 8 side as compared with the second embodiment, the refrigerant in the pipe connecting the indoor unit 8 and the heat source unit 9 does not further leak to the indoor side. It shows more effective action and effect for ensuring safety.

Embodiment 4 FIG. FIG. 8 is a refrigerant circuit diagram in an air conditioner according to an embodiment of the present invention, FIG. 9 is a control block diagram of the refrigerant circuit, and FIG.
0 is the control flowchart. As shown in FIG. 8, the refrigerant circuit of this embodiment is substantially the same as the conventional example, but includes a temperature sensor 33 in a pipe extending from the heat source unit side heat exchanger 3 to the indoor unit 8, and The difference is that a temperature sensor 24 is provided between the heat exchanger 5 and the indoor side heat exchanger 5. The temperature sensor 33 is an example of a unit that detects the degree of subcooling of the refrigerant at the outlet of the heat source device side heat exchanger 3 that becomes a condenser during the cooling operation. And the detected temperature from the temperature sensor 33. Further, the temperature sensor 24 detects the degree of supercooling of the refrigerant at the outlet of the indoor heat exchanger 5 serving as a condenser during the heating operation. The degree of supercooling is determined by the saturation temperature corresponding to the pressure detected by the pressure sensor 14. Temperature sensor 2
4 and is simply obtained based on the difference from the detected temperature from step 4. As shown in the control block diagram of FIG.
8c is different from the conventional example in that a display 19 for displaying a trouble such as a refrigerant leak or a failure of the flow control device 4 is connected to the operation switch 23 of the air conditioner and the timer 20. different.

Here, the control flowchart of FIG. 10 will be described. First, when the operation switch 23 is turned on in step S41, the operation control unit 18c starts the compressor 1 and starts operation of the air conditioner. In step S42, the state of the flag F is determined. Flag F, the degree of supercooling of the outlet of the condenser is greater state than a predetermined value SC ₁ is 1 when lasted longer predetermined time t ₁ or more, otherwise defined 0. When this air conditioner is started for the first time, F = 0 because no operation has been performed in the past. Therefore, the processing procedure proceeds to step S43. If the operation has been performed so far and F = 1, the processing procedure directly proceeds to step S52. In step S43, the current supercooling degree SC
It is equal to or larger than the predetermined value SC _1. SC> S
For C ₁ proceeds to step S49, the timer 20 starts clocking. Then, in step S50, the timer 2
If 0 of the time t is accustomed to the predetermined time t ₁ or more, it is determined that the refrigerant quantity in the refrigerant circuit is appropriate, step S51
To set the flag F to 1. Conversely, in step S43, SC>
If this is not the SC _1, the timer 2 at step S44
0 is stopped. In steps S45 and S46, the determination in step S43 and the normal operation (step S46) are repeated until the operation switch 23 is turned off. When the operation switch 23 is turned off, the timer stop processing is performed again (step S47), and the air conditioner is stopped (step S48).

On the other hand, if the time t at which SC> SC ₁ is shorter than t ₁ in step S50, the operation switch 23 is set in step S45 while the timer 20 continues counting.
Unless is turned off, the normal operation of step S46 is continued, and the process returns to step S43 again. In step S51, F =
If it is set to 1 or if F = 1 has already been set in step S42, the timer 20 is stopped in step S52, and the operation switch 23 is turned off in step S53.
If not set to F, the normal operation is continued as it is (step S54). Next, in step S55, the current supercooling degree SC is determined whether a predetermined value SC ₂ smaller. Predetermined value SC ₂ is pre-defined as a predetermined value SC ₁ following degree of subcooling of the foregoing. Reason why the predetermined value SC ₂ was SC ₁ or less, is taken into consideration that it may in some operating conditions not necessarily obtain the same degree of supercooling SC and SC _1. If SC> a SC ₂ in step S55, starts again the counting of the timer 20 in step S57. Step S58 In SC <SC ₂ become time t is the predetermined time t ₂
It is determined whether or not the above continues. That is, means for realizing the processing functions in step S55 and step S57 by the operation control unit 18c is an example of the time measuring means.

If t ≧ t ₂ , step S59
In, it is determined that the amount of the refrigerant in the refrigerant circuit is smaller than when F = 1 was previously determined in step S51 for the first time, or that a problem has occurred in the flow control device 4. Normally, the relationship between the degree of supercooling SC and the degree of valve opening of the flow control device 4, as shown in FIG. 11, is when the flow control device 4 fails and the valve opening is too large or too small. Thus, it can be seen from the fact that the degree of supercooling SC decreases in each case. In step S60, step S5
In response to the determination result at step 9, the air conditioner is stopped, and the display 19 indicates that a problem such as a refrigerant leak or a failure of the flow control device 4 has occurred. That is, step S58 and step S59 are performed by the operation control unit 18c.
The means for realizing the processing function in is an example of the third refrigerant circuit refrigerant amount detecting means.

[0039] If not SC <SC ₂ in step S55, after the timer 20 is stopped in step S56, also in the case of t <t ₂ in step S58, the in any case returns to step S53 again. Then, unless the operation switch 23 is OFF, the normal operation (step S5)
4) is performed, and the determination processing in step S55 or step S58 is repeated. Thus, so far state supercooling degree SC is greater state than a predetermined value SC ₁ of the condenser outlet is continued for a predetermined time t ₁ or more, i.e., after it is determined that the amount of refrigerant is in a proper state, the condenser outlet by supercooling degree SC is determined that the or flow controller 4 is leaking refrigerant is faulty when the smaller state than the predetermined value SC ₂ has continued for a predetermined time t ₂ or more, the refrigerant leak more accurately It is possible to determine the state or the failure of the refrigerant circuit component and notify the user. Therefore, it is possible to quickly take these measures.

Embodiment 5 FIG. FIG. 12 is a refrigerant circuit diagram in an air conditioner according to an embodiment of the present invention, FIG. 13 is a control block diagram of the refrigerant circuit,
FIG. 14 is a control flowchart thereof. As shown in FIG. 12, on the refrigerant circuit in this embodiment, an on-off valve 22a that can be automatically opened and closed between the heat source unit side heat exchanger 3 and the flow control device 4, and the indoor side heat exchanger 5 An on-off valve 22b that can be automatically opened and closed is provided between the switching valve 2 and the on-off valve 22a and the on-off valve 22b.
It is provided within. Further, an on-off valve 25 is provided on a discharge pipe of the compressor 1 and a pipe bypassing the accumulator 6. Further, instead of the conventional operation control unit 18,
An operation control unit 18d for realizing the main function of this embodiment is also provided. Then, as shown in FIGS. 12 and 13,
The operation control unit 18d includes an on-off valve 22a and an on-off valve 22b,
The opening / closing control of the opening / closing valve 25 is also performed.

Here, the control flowchart of FIG. 14 will be described. First, in step S71, the operation of the air conditioner is started. Then, the on-off valve 22a and the on-off valve 22b are immediately opened to allow the refrigerant to flow (step S72). Then, in step S73, the accumulator 6
Is detected, and it is determined whether or not the liquid level is AL = 0 (refrigerant amount = small). If AL = 0, normal operation is performed in step S75, and thereafter, normal operation is performed between step S73 and step S75 unless the liquid level reaches AL = 0. If AL = 0 is detected in step S73, the discharge temperature td of the compressor 1 is determined in step S74.
Is higher than a predetermined temperature td ₂ . The predetermined temperature td ₂ is set in advance near the upper limit of a temperature range where there is no problem in practical use for the compressor 1. If the discharge temperature td is td ₂ temperature below continues normal operation as it proceeds to step S75, the repeats the determination process flow in step S73 or step S74.

[0042] If it is determined that td> td ₂ at step S74, the apparently perform the refrigerant recovery run as needing the refrigerant recovery operation (step S76). After the refrigerant recovery operation, the discharge temperature td is detected by the discharge temperature sensor 17 in step S77. Then, the detected discharge temperature td
It is determined whether or not a certain temperature is higher than a predetermined temperature td ₁ . The predetermined temperature td ₁ is lower than a temperature at which the compressor 1 may be damaged, and is determined in advance by experiments or the like. However, in some cases, td ₁ = td ₂ may be set. Then, in step S77, the discharge temperature t
when d is determined to td ₁ or less, the step S75
Proceed to normal operation. Conversely, td is higher than td ₁ has, it means that the refrigerant despite were refrigerant recovery operation has not been recovered in step S76, or refrigerant shortage is leaking refrigerant in the refrigerant circuit Is determined (step S78). Next, it is determined whether the current operation mode is a cooling cycle or a heating cycle (step S79). If the current operation mode is the cooling cycle, the on-off valve 22a (here, an example of the third on-off valve) on the high pressure side is first closed (step S80).
By closing one valve in this way, the discharge temperature td
It is expected that the pressure will rise, the low pressure will drop, or the high pressure will rise. While the compressor 1 is better to operate a long time it can be recovered a larger amount of refrigerant in the accumulator 6, in order to extend the life of the compressor 1, or the discharge temperature td exceeds the predetermined temperature td _3, the pressure detection alternatives the value of the low-pressure saturation temperature ET which is used as is or below a predetermined temperature ET _1, or a high pressure Pd is determined at above a predetermined target high Pd ₁ (step S81), the compressor in the case of any one Is stopped (step S82), and the low pressure side on-off valve 22b (here, an example of the fourth on-off valve) is immediately closed (step S83). That is, in this case, the operation control unit 18
d functions as an example of a second control unit.

On the other hand, if it is determined in step S79 that the current operation mode is not the cooling cycle but the heating cycle, the on-off valve 25 is opened first (step S8).
4) The on-off valve 22b (here, an example of a fifth on-off valve) on the high pressure side is closed (step S85). By closing one valve as in the cooling cycle, it is expected that the discharge temperature td will increase, the low pressure will decrease, or the high pressure will increase. However, when the on-off valve 25 is opened, the refrigerant discharged from the compressor 1 is bypassed to the low pressure side and reaches the accumulator 6, so that the discharge temperature of the high pressure does not rise rapidly. In this case as well, the refrigerant can be recovered more by operating the compressor 1 for a long time. However, in order to extend the life of the compressor 1, the discharge temperature td exceeds td ₃ or is used as an alternative means for pressure detection. If the value of the low-pressure saturation temperature ET there are below a predetermined temperature ET _1, or a high pressure Pd is determined at above a predetermined target high Pd ₁ (step S86), the compressor in the case of any one
Is stopped (step S87), and the low pressure side on-off valve 22a (here, an example of the sixth on-off valve) is immediately closed (step S88). That is, in this case, the operation control unit 18d functions as an example of a third control unit.

In this way, after the refrigerant recovery operation, the shortage of the refrigerant in the refrigerant circuit or the leakage of the refrigerant from the refrigerant circuit is detected based on the discharge temperature of the compressor 1 to notify the user of the trouble of the refrigerant circuit at an early stage. be able to. Therefore, by taking countermeasures against such defective parts,
When the refrigerant recovery operation is continued with the shortage of the refrigerant or the leakage of the refrigerant, the compressor 1 can be prevented from being damaged due to the high discharge temperature. Therefore, the performance of the air conditioner can be sufficiently exhibited. Further, when refrigerant leakage is detected, the compressor 1 is stopped after closing the high-pressure side on-off valve, and then the low-pressure side on-off valve is closed, so that the room provided in the room where the occupant is located is located. Even when there is a refrigerant leak in the inner heat exchanger 5 or the like, the refrigerant remaining in the refrigerant circuit can be returned to the accumulator. Therefore, the refrigerant does not leak to the indoor side unnecessarily,
Problems such as economic loss due to refrigerant leakage and health problems for residents can be minimized.

Embodiment 6 FIG. FIG. 15 is a refrigerant circuit diagram in an air conditioner according to an embodiment of the present invention, FIG. 16 is a control block diagram of the refrigerant circuit,
FIG. 17 is a control flowchart thereof. The refrigerant circuit of FIG. 15 is almost the same as the conventional example, but there is a difference on the indoor unit side, and an indoor-side blower 7a that sucks indoor air and returns it to the indoor side, and sucks fresh outdoor air to the indoor side. And a blower indoor side blower 7b (an example of outside air blowing means). Further, in place of the conventional operation control unit 18, an operation control unit 18e for realizing the main function of this embodiment is provided. As shown in the control block of FIG. 16, the indoor-side blowers 7a and 7b can be independently operated and stopped so as to be able to perform either interlocking or independent operation.

Here, the control flowchart of FIG. 17 will be described. First, the operation of the air conditioner is started in step S91. Then, in step S92, the accumulator 6
Is detected, and it is determined whether or not the liquid level is AL = 0 (refrigerant amount = small). If AL = 0, the normal operation is performed in step S95, and thereafter, the normal operation is continued between step S92 and step S95 unless the liquid level becomes AL = 0. If it is detected AL = 0 at step S92, the discharge temperature td of the compressor 1 determines whether higher than the predetermined temperature td ₂ at step S93. The predetermined temperature td ₂ is set in advance near the upper limit of a temperature range where there is no problem in practical use for the compressor 1. Discharge temperature t
If d is td ₂ at a temperature below continues normal operation as it proceeds to step S95, repeats the determination process flow in step S92 or step S93. If it is determined that td> td ₂ at step S93, apparently perform the refrigerant recovery run as needing the refrigerant recovery operation (step S94).

[0047] After the refrigerant recovery run, and detects the discharge temperature td by the discharge temperature sensor 17 in step S96, it is determined whether higher than the predetermined temperature td ₁ there is discharge temperature td detected. The predetermined temperature td ₁ is set in advance to a temperature at which the compressor 1 may be damaged. However, in some cases, td ₁ = td ₂ may be set. When td is td ₁ below in step S96, performs a normal operation proceeds to step S95. td is higher than td _1, since the refrigerant despite running refrigerant recovering operation is was not recovered in step S94, it is determined that the leakage of refrigerant in the refrigerant circuit (step S97). Then, in step S98, the compressor 1
Is stopped, and operation of the indoor-side blower 7b is started in step S99 to take in outside air into the room. That is, in this case, the operation control unit 18e functions as fourth control means.

According to the air conditioner of this embodiment,
By continuing the refrigerant recovery operation with the refrigerant leaking, it is possible to prevent the compressor 1 from being damaged due to the high discharge temperature, and to take measures for the defective part to take this air conditioning. The performance of the device can be fully exhibited. Then, when a refrigerant leak is detected, by forcing fresh air outside the closed space into a closed space such as a room, for example, the oxygen concentration in the closed space can be increased without separately providing a ventilation device. Therefore, the adverse effect of the leaked refrigerant on the occupants in the room can be economically suppressed with a simple configuration.

Embodiment 7 FIG. As shown in FIG. 18, the air conditioner according to the first embodiment includes flow rate control devices 4a and 4b, indoor heat exchangers 5a and 5a,
b, indoor unit 8 having indoor-side blowers 7a and 7b, respectively
The same operation and effect can be obtained when the present invention is applied to a refrigerant circuit in which two or more a and 8b are connected in parallel.

Embodiment 8 FIG. The air conditioner according to the second embodiment or the fifth embodiment has a configuration shown in FIG.
The same effect can be obtained when the invention is applied to a refrigerant circuit in which two or more indoor units 8a and 8b are connected in parallel as shown in FIG.

Embodiment 9 FIG. The air conditioner according to the fourth embodiment has the same operation and effect when applied to a refrigerant circuit in which two or more indoor units 8a and 8b are connected in parallel as shown in FIG.

Embodiment 10 FIG. In the air conditioner according to the third embodiment, two or more indoor units 8a and 8b as shown in FIG. 21 are connected in parallel to a plurality of indoor units 8a and 8b.
The same operation and effect are exhibited when applied to a refrigerant circuit provided with 2a ₁ and 22b ₁ .

Embodiment 11 FIG. In the air conditioner according to the sixth embodiment, two or more indoor units 8a and 8b as shown in FIG. 22 are connected in parallel to a plurality of indoor units 8a and 8b, and indoor air blowers 7a and 7a ₁ each suck indoor air.
Exhibit the, indoor blower 7b sucking outdoor air, the same effect even when 7b ₁ and is applied to a refrigerant circuit thus provided.

[0054]

Since the present invention is configured as described above, it has the following effects.
A failure of the refrigerant circuit such as a shortage of the refrigerant or a leakage of the refrigerant can be notified based on the number of times of the refrigerant recovery operation within the predetermined time. Then, when a solution to the malfunction of the refrigerant circuit is taken at an early stage, the refrigerant recovery operation is not performed unnecessarily with the malfunction of the refrigerant circuit, so that the performance of the apparatus can be sufficiently exhibited. Therefore, the maintainability of the air conditioner can be significantly improved.

Further, it is possible to detect the shortage of the refrigerant in the refrigerant circuit or the leakage of the refrigerant from the refrigerant circuit based on the discharge temperature of the compressor after the refrigerant recovery operation, and to notify the trouble of the refrigerant circuit at an early stage. Furthermore, in the case of taking measures to solve such a problem, it is possible to prevent the compressor from being damaged due to continuous high discharge temperature by performing the refrigerant recovery operation with the refrigerant shortage or the refrigerant leakage. Thereby, the performance of the device can be sufficiently exhibited, so that the reliability of the air conditioner can be significantly improved.

When a refrigerant leak is detected during a cooling operation or a heating operation, the first open / close valve and the second open / close valve are closed to divide the refrigerant circuit into a plurality of hermetically sealed regions. It is possible to prevent the entire amount of the refrigerant in the chamber from leaking. As a result, problems such as economic loss and environmental pollution can be suppressed as compared with the case where all the refrigerant leaks. As a result, the manageability of the air conditioner can be significantly improved.

Further, upon detecting a refrigerant leak occurring in the evaporator, the compressor is stopped after closing the third on-off valve,
Then, by closing the fourth on-off valve, more refrigerant remaining in the refrigerant circuit can be collected in the accumulator. Therefore, it is possible to prevent the refrigerant from unnecessarily leaking from the evaporator, and it is possible to minimize problems such as economic loss and environmental pollution caused by the leakage of the refrigerant from the evaporator. As a result, the manageability of the air conditioner can be significantly improved.

Further, when a refrigerant leak generated in the condenser is detected, the compressor is stopped after closing the fifth on-off valve,
Then, by closing the sixth on-off valve, more refrigerant remaining in the refrigerant circuit can be collected in the accumulator. Therefore, it is possible to prevent the refrigerant from unnecessarily leaking from the condenser, and it is possible to minimize problems such as economic loss and environmental pollution caused by the leakage of the refrigerant from the condenser. As a result, the manageability of the air conditioner can be significantly improved.

When a refrigerant leak is detected from a refrigerant circuit in a closed space containing an evaporator or a condenser, fresh air from outside the closed space is forcibly fed into the closed space by the air feeding means. be able to. Therefore, it is economical because there is no need to separately provide a ventilation device for sending outside air into the closed space, and since the closed space can be ventilated, the economics of the air conditioner and the safety of the occupants are significantly reduced. Can be enhanced.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram in an air conditioner according to Embodiment 1 of the present invention.

FIG. 2 is a control block diagram of a refrigerant circuit according to the first embodiment.

FIG. 3 is a control flowchart according to the first embodiment.

FIG. 4 is a refrigerant circuit diagram in an air conditioner according to Embodiment 2 of the present invention.

FIG. 5 is a control block diagram of a refrigerant circuit according to a second embodiment.

FIG. 6 is a control flowchart according to a second embodiment.

FIG. 7 is a refrigerant circuit diagram showing a third embodiment in which the on-off valve in the second embodiment is provided in an indoor unit.

FIG. 8 is a refrigerant circuit diagram in an air conditioner according to Embodiment 4 of the present invention.

FIG. 9 is a control block diagram of a refrigerant circuit according to a fourth embodiment.

FIG. 10 is a control flowchart according to a fourth embodiment.

FIG. 11 is a graph showing a relationship between a valve opening degree and a supercooling degree of the flow control device.

FIG. 12 is a refrigerant circuit diagram in an air conditioner according to Embodiment 5 of the present invention.

FIG. 13 is a control block diagram of a refrigerant circuit according to a fifth embodiment.

FIG. 14 is a control flowchart according to the fifth embodiment.

FIG. 15 is a refrigerant circuit diagram in an air conditioner according to Embodiment 6 of the present invention.

FIG. 16 is a control block diagram of a refrigerant circuit according to a sixth embodiment.

FIG. 17 is a control flowchart according to the sixth embodiment.

FIG. 18 is a refrigerant circuit diagram according to a seventh embodiment illustrating a modification of the air-conditioning apparatus according to the first embodiment.

FIG. 19 is a refrigerant circuit diagram according to an eighth embodiment illustrating a modification of the air-conditioning apparatus according to the second or fifth embodiment.

FIG. 20 is a refrigerant circuit diagram according to a ninth embodiment showing a modification of the air-conditioning apparatus according to the fourth embodiment.

FIG. 21 is a refrigerant circuit diagram according to a tenth embodiment illustrating a modification of the air-conditioning apparatus according to the third embodiment.

FIG. 22 is a refrigerant circuit diagram according to an eleventh embodiment illustrating a modification of the air-conditioning apparatus according to the sixth embodiment.

FIG. 23 is a refrigerant circuit diagram in a conventional air conditioner.

FIG. 24 is a control block diagram of a refrigerant circuit by a conventional air conditioner.

FIG. 25 is a table showing reference contents for liquid level determination of refrigerant in an accumulator by an operation control unit of a conventional air conditioner.

FIG. 26 is a control flowchart of a flow control device by an operation control unit of a conventional air conditioner.

[Explanation of symbols]

1 compressor, 2 four-way switching valve, 3 heat exchanger side heat exchanger,
4 flow control device, 4a flow control device, 4b flow control device, 5 indoor heat exchanger, 5a indoor heat exchanger,
5b indoor heat exchanger, 6 accumulator, 7 indoor blower, 7a indoor blower, 7a ₁ indoor blower,
7b indoor-side blower, 7b ₁ indoor-side blower, 8 indoor unit, 8a indoor unit, 8b indoor unit, 9 heat source unit, 10
Heat source unit side blower, 11a Upper liquid level detection circuit, 11b Lower liquid level detection circuit, 12a heater, 12b heater, 13
a temperature sensor, 13b temperature sensor, 14 pressure sensor, 15 low-pressure saturation temperature generation circuit, 16 low-pressure saturation temperature sensor, 17 discharge temperature sensor, 18a operation control unit,
18b operation control unit, 18c operation control unit, 18d operation control unit, 18e operation control unit, 19 display, 20
Timer, 21 counter, 22a on-off valve, 22a ₁
On-off valve, 22b On-off valve, 22b _{1 on-} off valve, 24 temperature sensor, 24a temperature sensor, 24b temperature sensor,
25 on-off valve, 33 temperature sensor.

Claims (6)

(57) [Claims] 1. An air conditioner comprising: a refrigerant circuit in which a compressor, a condenser, a flow control device, an evaporator, and an accumulator are sequentially connected; and an accumulator refrigerant amount detecting means for detecting a refrigerant amount in the accumulator. When the amount of refrigerant detected by the accumulator refrigerant amount detection unit is small, the refrigerant recovery unit performing a refrigerant recovery operation of increasing the refrigerant flow rate of the refrigerant circuit by the flow rate control device and recovering the refrigerant to the accumulator. Counting means for counting the number of the refrigerant recovery operations executed within a predetermined time set in advance, and when the number of the refrigerant recovery operations within the predetermined time counted by the counting means is equal to or more than a predetermined value. And an operation control means for stopping the compressor. 2. A refrigerant circuit in which a compressor, a condenser, a flow controller, an evaporator, and an accumulator are sequentially connected, an accumulator refrigerant amount detecting means for detecting an amount of refrigerant in the accumulator, and a discharge of the compressor. In an air conditioner having a discharge temperature detecting means for detecting a temperature, when the amount of refrigerant detected by the accumulator refrigerant amount detecting means is small, the flow rate control device increases the refrigerant flow rate of the refrigerant circuit to increase the refrigerant flow rate. A refrigerant recovery unit for performing a refrigerant recovery operation for recovering the refrigerant to the accumulator; and an operation control unit for stopping the compressor when the discharge temperature detected after the refrigerant recovery operation is equal to or higher than a predetermined value. An air conditioner characterized by the following. 3. A first on-off valve disposed in a refrigerant circuit between a condenser or an evaporator and a flow control device, and a first on-off valve disposed in a refrigerant circuit between an evaporator or a condenser and a compressor. 2 is provided, wherein when the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value, the first control valve and the second control valve are closed by operation control means. The air conditioner according to claim 2, characterized in that: 4. A third opening / closing valve provided in a refrigerant circuit between a condenser and a flow control device, and a fourth opening / closing valve provided in a refrigerant circuit between an evaporator and an accumulator. ,
When the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value, the operation control unit closes the third on-off valve and then stops the compressor, and then closes the fourth on-off valve. The air conditioner according to claim 2, wherein: 5. A fifth on-off valve provided in a refrigerant circuit between a compressor and a condenser, and a sixth on-off valve provided in a refrigerant circuit between an evaporator and a flow control device. When the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value,
The air conditioner according to claim 2, wherein the compressor is stopped after the operation control unit closes the fifth on-off valve, and thereafter, the sixth on-off valve is closed. 6. An outside air feeding means for feeding air outside the closed space into the closed space containing the evaporator or the condenser, and when the discharge temperature of the compressor after the refrigerant recovery operation is equal to or higher than a predetermined value, the operation control means. 3. The air conditioner according to claim 2, wherein the driving of the outside air feeding means is controlled by the external air supply means.