JP6304194B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner.

  Conventionally, as an air conditioner, there is one in which a refrigerant circuit is configured by connecting a compressor, an outdoor heat exchanger, a pressure reducing mechanism, and an indoor heat exchanger in a ring shape with a refrigerant pipe. (See, for example, JP 2000-161749 A (Patent Document 1)). In this air conditioner, the refrigerant in the refrigerant circuit can be collected in the outdoor heat exchanger by pump-down operation, that is, forced cooling operation.

JP 2000-161749 A

  By the way, in the above conventional air conditioner, during the forced cooling operation, if the abnormality due to the inflow of air into the refrigerant circuit does not cause damage to the refrigerant circuit, the forced cooling operation continues without stopping abnormally. . Or if it is an abnormality of that extent, even if forced cooling operation stops abnormally, there is a possibility of restarting.

  As described above, when an abnormality that does not cause damage to the refrigerant circuit occurs, the compressor continues to compress air by continuing or restarting the forced cooling operation. As a result, since the internal temperature of the compressor increases, there is a concern that the refrigerant circuit may be damaged.

  Then, the subject of this invention is providing the air conditioner which can reduce the concern of damage to a refrigerant circuit.

In order to solve the above problems, the air conditioner of the present invention is
A refrigerant circuit having a compressor, an outdoor heat exchanger, a decompression mechanism, and an indoor heat exchanger;
A refrigerant sensor for detecting the temperature or pressure of the refrigerant compressed by the compressor;
A cooling operation control unit for controlling the refrigerant circuit to perform a cooling operation;
During the cooling operation, when the detected temperature or pressure by the refrigerant sensor is equal to or more than the first predetermined value, a compressor abnormality determination unit determines that the compressor is abnormal,
When it is determined that the compressor is abnormal, a compressor stop unit that stops the compressor;
After stopping of the compressor, temperature or pressure sensed by the coolant sensor, and whether the determined refrigerant circuit abnormality determining unit whether it is higher second predetermined value or more than the first predetermined value,
In order to notify the user that the refrigerant circuit may be damaged when it is determined that the temperature or pressure detected by the refrigerant sensor is equal to or higher than a second predetermined value higher than the first predetermined value. The refrigerant circuit abnormality notifying unit is provided.

  According to the above configuration, when the compressor abnormality determining unit determines that the compressor is abnormal during the cooling operation, the compressor stopping unit stops the compressor. Thereafter, if the temperature or pressure detected by the refrigerant sensor becomes equal to or higher than a second predetermined value (> first predetermined value), the refrigerant circuit abnormality notification unit may indicate that the refrigerant circuit may be damaged. The user can be notified. This prevents the compressor from being restarted and prevents the internal temperature of the compressor from rising. Therefore, the concern about damage to the refrigerant circuit can be reduced.

In the air conditioner of one embodiment,
The air conditioner is characterized in that the determination of the refrigerant circuit abnormality determination unit is performed until a predetermined time elapses after the temperature or pressure detected by the refrigerant sensor reaches the first predetermined value. .

  According to the embodiment, since the determination of the refrigerant circuit abnormality determination unit continues until the predetermined time elapses after the temperature or pressure detected by the refrigerant sensor reaches the first predetermined value, The reliability of determination can be increased.

In the air conditioner of one embodiment,
The compressor has a discharge pipe for discharging the refrigerant to the outside,
The refrigerant sensor is a discharge pipe temperature sensor that detects the temperature of the discharge pipe.

  According to the embodiment, the discharge pipe temperature sensor is normally attached to the discharge pipe of the compressor. Since such a discharge pipe temperature sensor is used as a refrigerant sensor, an increase in cost due to an increase in the number of sensors can be prevented.

The air conditioner of one embodiment is
An air inflow detection unit for detecting the inflow of air into the refrigerant circuit is provided.

  According to the embodiment, when the inflow of air into the refrigerant circuit is detected by the air inflow detection unit, the temperature or pressure detected by the refrigerant sensor after the stop of the compressor is not higher than a predetermined value. In addition, it is possible to notify the user that the refrigerant circuit may be damaged.

In the air conditioner of one embodiment,
The cooling operation is a forced cooling operation.

  According to the embodiment, since the cooling operation is a forced cooling operation, it is possible to reduce the concern about damage to the refrigerant circuit when the pump is down.

In the air conditioner of one embodiment,
The sampling period of the refrigerant sensor is shorter in the forced cooling operation than in the forced cooling operation.

  According to the above embodiment, the refrigerant circuit abnormality determining unit can quickly determine the sampling period of the refrigerant sensor during the forced cooling operation shorter than during other operations.

  As is clear from the above, the present invention can provide an air conditioner that can reduce the concern of damage to the refrigerant circuit.

It is a refrigerant circuit diagram for demonstrating the air conditioner of 1st Embodiment of this invention. It is a control block diagram of the air conditioner. It is a flowchart for demonstrating the control at the time of the pump down driving | operation of the said air conditioner. It is a schematic graph of experiment. It is a refrigerant circuit diagram for demonstrating the modification of the said air conditioner. It is a control block diagram of the air conditioner of 2nd Embodiment of this invention.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

[First Embodiment]
FIG. 1 is a refrigerant circuit diagram for explaining an air conditioner according to a first embodiment of the present invention.

  The air conditioner includes a refrigerant circuit 1, a single indoor unit 2 installed indoors, and a single outdoor unit 3 installed outdoor. Thus, the air conditioner is a pair-type air conditioner in which the indoor unit 2 and the outdoor unit 3 are one-to-one.

  In the refrigerant circuit 1, for example, refrigerants such as R22 refrigerant, R410A refrigerant, and R32 refrigerant flow.

  The indoor unit 2 is connected to the outdoor unit 3 via first and second connection pipes 91 and 92 and has an indoor heat exchanger 4 and an indoor fan 5. The first and second connecting pipes 91 and 92 and the indoor heat exchanger 4 each constitute a part of the refrigerant circuit 1.

  The outdoor unit 3 includes a compressor 6, a four-way switching valve 7, an outdoor heat exchanger 8, an outdoor fan 9, an electric expansion valve (hereinafter referred to as "expansion valve") 10 and an accumulator 11 as an example of a pressure reducing mechanism. Have. In the outdoor unit 3, first and second shut-off valves 12 and 13 for controlling the flow of the refrigerant are arranged. The compressor 6, the four-way switching valve 7, the outdoor heat exchanger 8, the outdoor fan 9, the expansion valve 10, the accumulator 11, and the first and second closing valves 12 and 13 are each a part of the refrigerant circuit 1. It is composed.

  The compressor 6 has a discharge pipe 61 for discharging the refrigerant to the outside on the discharge side, and has a suction pipe 62 for sucking the refrigerant from the accumulator 11 on the suction side.

  The first closing valve 12 is interposed between the expansion valve 10 and the first communication pipe 91, and a liquid-phase refrigerant flows during the cooling operation. On the other hand, the second closing valve 13 is interposed between the four-way switching valve 7 and the second connection pipe 92, and a gas phase refrigerant flows during the cooling operation.

  FIG. 2 is a control block diagram of the air conditioner.

  The air conditioner includes a control device 50 including a microcomputer and an input / output circuit. The control device 50 performs arithmetic processing, determination processing, and the like to control the compressor 6, the four-way switching valve 7, the expansion valve 10, the indoor fan 5, the outdoor fan 9, and the like. Control device 50 also receives command signals (operation start command signal, indoor temperature setting command signal, etc.) from remote controller 60. The control device 50 also receives detection signals from a discharge pipe temperature sensor 71, an outdoor heat exchanger temperature sensor 72, an outdoor air temperature sensor 73, an indoor heat exchanger temperature sensor 74, an indoor temperature sensor 75, and the like as an example of a refrigerant sensor. Receive. These command signals and detection signals are used for controlling the compressor 6, the four-way switching valve 7, the expansion valve 10, the indoor fan 5, the outdoor fan 9, and the like. That is, the compressor 6, the four-way switching valve 7, the expansion valve 10, the indoor fan 5, the outdoor fan 9, and the like are controlled based on the command signal and the detection signal. The discharge pipe temperature sensor 71, the outdoor heat exchanger temperature sensor 72, the outdoor air temperature sensor 73, the indoor heat exchanger temperature sensor 74, and the indoor temperature sensor 75 are each composed of, for example, a thermistor.

  The remote controller 60 includes a display unit 60a that displays indoor set temperature, time, and the like. The display unit 60a is constituted by, for example, a monochrome liquid crystal display unit capable of displaying at least characters and numbers.

  The discharge pipe temperature sensor 71 is attached to the discharge pipe 61 of the compressor 6, and sends a detection signal indicating the temperature of the discharge pipe 61 to the control device 50. At this time, the control device 50 can detect the temperature of the refrigerant from the discharge pipe 61 to the four-way switching valve 7 based on the detection signal from the discharge pipe temperature sensor 71 using, for example, a table created in advance. It has become. Thus, the discharge pipe temperature sensor 71 is a temperature sensor for detecting the temperature of the refrigerant compressed by the compressor 6.

  The outdoor heat exchanger temperature sensor 72 is attached to the outdoor heat exchanger 8 and sends a detection signal indicating the temperature of the outdoor heat exchanger 8 to the control device 50. That is, the outdoor heat exchanger temperature sensor 72 is a temperature sensor for detecting the temperature of the refrigerant flowing in the outdoor heat exchanger 8.

  The outdoor temperature sensor 73 is installed at a location in the outdoor unit 3 that communicates with the outside, and sends a detection signal indicating the outdoor temperature to the control device 50.

  The indoor heat exchanger temperature sensor 74 is attached to the indoor heat exchanger 4 and sends a detection signal indicating the temperature of the indoor heat exchanger 4 to the control device 50. That is, the indoor heat exchanger temperature sensor 74 is a temperature sensor for detecting the temperature of the refrigerant flowing in the indoor heat exchanger 4.

  The indoor temperature sensor 75 is installed at a location in the indoor unit 2 that communicates with the room, and sends a detection signal indicating the room temperature to the control device 50.

  The control device 50 includes a pump-down operation control unit 50a, a compressor abnormality determination unit 50b, a compressor stop unit 50c, a refrigerant circuit abnormality determination unit 50d, and a refrigerant circuit abnormality notification unit 50e. The pump-down operation control unit 50a, the compressor abnormality determination unit 50b, the compressor stop unit 50c, the refrigerant circuit abnormality determination unit 50d, and the refrigerant circuit abnormality notification unit 50e are configured by software. The pump down operation control unit 50a is an example of a cooling operation control unit.

  The pump down operation control unit 50a controls the refrigerant circuit 1 to perform the pump down operation. More specifically, the pump-down operation is a forced cooling operation, and is started when the service person presses the operation / stop button 16 of the indoor unit 2 for a long time. Further, during the pump down operation, the pump down operation control unit 50a controls the compressor 6 so that the compressor 6 is driven at a constant frequency (for example, 50 Hz). Further, during the pump down operation, the discharge pipe temperature sensor 71 detects the temperature of the discharge pipe 61 of the compressor 6. At this time, the sampling period of the discharge pipe temperature sensor 71 is shorter in the pump down operation than in the operation other than the pump down operation (during normal cooling operation and heating operation). Specifically, for example, the sampling period of the discharge pipe temperature sensor 71 during normal cooling operation and heating operation is set to 500 msec, while the sampling period of the discharge pipe temperature sensor 71 during pump down operation is Set to 100 msec. During normal cooling operation and heating operation, the compressor 6 is not controlled so that the frequency is constant, and the frequency of the compressor 6 can be varied.

  The compressor abnormality determination unit 50b determines whether or not the compressor 6 is abnormal based on the temperature detected by the discharge pipe temperature sensor 71 (hereinafter referred to as “discharge pipe temperature”) during the pump down operation. judge. That is, during the pump down operation, if the discharge pipe temperature is lower than the first predetermined discharge pipe temperature, the compressor 6 is determined to be normal, while if the discharge pipe temperature is equal to or higher than the first predetermined discharge pipe temperature, It is determined that the machine 6 is abnormal. The first predetermined discharge pipe temperature is an example of a first predetermined value.

  The compressor stop unit 50c stops the compressor 6 when it is determined that the compressor 6 is abnormal. This prevents air compression by the compressor 6 from occurring.

  The refrigerant circuit abnormality determination unit 50d determines whether or not the discharge pipe temperature is equal to or higher than the second predetermined discharge pipe temperature after the compressor 6 is stopped. That is, the refrigerant circuit abnormality determination unit 50d determines that the possibility that the refrigerant circuit 1 is damaged is relatively low when the discharge pipe temperature is lower than the second predetermined discharge pipe temperature, while the discharge pipe temperature is lower than the second predetermined discharge temperature. If the temperature is higher than the tube temperature, it is determined that the possibility that the refrigerant circuit 1 is damaged is relatively high. The determination of the refrigerant circuit abnormality determination unit 50d is performed from when the discharge pipe temperature reaches the first predetermined discharge pipe temperature until a predetermined time elapses. Here, the second predetermined discharge pipe temperature used for determination by the refrigerant circuit abnormality determination unit 50d is set to be higher than the first predetermined discharge pipe temperature used for determination by the compressor abnormality determination unit 50b. The second predetermined discharge pipe temperature is an example of a second predetermined value.

  The refrigerant circuit abnormality notification unit 50e is for notifying the user that the refrigerant circuit 1 may be damaged when it is determined that the discharge pipe temperature is equal to or higher than the second predetermined discharge pipe temperature. More specifically, when it is determined that the discharge pipe temperature is equal to or higher than the second predetermined discharge pipe temperature, the refrigerant circuit abnormality notification unit 50e transmits a command signal for displaying an error on the display unit 60a of the remote control 60 to the remote control 60. Is done.

  The air conditioner having the above-described configuration can cause the indoor unit 2 and the outdoor unit 3 to perform a normal cooling operation or heating operation when the user operates the remote controller 60.

  During the cooling operation, the refrigerant discharged from the compressor 6 is transferred from the four-way switching valve 7 to the outdoor heat exchanger 8, the expansion valve 10, and the indoor heat exchanger 4 as indicated by solid arrows in FIG. Then, after flowing in this order, a cooling cycle returning to the compressor 6 through the four-way switching valve 7 and the accumulator 11 is executed. That is, the outdoor heat exchanger 8 functions as a condenser, while the indoor heat exchanger 4 functions as an evaporator.

  On the other hand, during the heating operation, the four-way switching valve 7 is switched, and the refrigerant discharged from the compressor 6 is transferred from the four-way switching valve 7 to the indoor heat exchanger 4 as indicated by the dashed arrows in FIG. Then, after flowing in this order to the expansion valve 10 and the outdoor heat exchanger 8, a heating cycle returning to the compressor 6 through the four-way switching valve 7 and the accumulator 11 is executed. That is, the indoor heat exchanger 4 functions as a condenser, while the outdoor heat exchanger 8 functions as an evaporator.

  When the air conditioner is relocated or repaired, the pump down operation is performed with the first closing valve 12 closed and the second closing valve 13 opened in order to collect the refrigerant in the outdoor heat exchanger 8. Done.

  Hereinafter, the control performed by the pump-down operation control unit 50a, the compressor abnormality determination unit 50b, the compressor stop unit 50c, the refrigerant circuit abnormality determination unit 50d, and the refrigerant circuit abnormality notification unit 50e during the pump-down operation will be described with reference to the flowchart of FIG. Will be described. The above control is started when the serviceman presses and holds the operation / stop button 16 of the indoor unit 2.

  When the control is started, first, in step S1, it is determined whether or not the outside air temperature is equal to or higher than a predetermined outside air temperature (for example, 45 ° C.). If it is determined in step S1 that the outside air temperature is equal to or higher than the predetermined outside air temperature, the process proceeds to the next step S2. Step S1 is repeated until it is determined that the outside air temperature is equal to or higher than the predetermined outside air temperature.

  Next, in step S2, it is determined whether or not the discharge pipe temperature is equal to or higher than a first predetermined discharge pipe temperature (eg, 118 ° C.). If it is determined in step S1 that the discharge pipe temperature is equal to or higher than the first predetermined discharge pipe temperature, the process proceeds to the next step S3. On the other hand, if it is determined in step S2 that the discharge pipe temperature is not equal to or higher than the first predetermined discharge pipe temperature, the process returns to step S1.

  Next, the compressor 6 is stopped at step S3. As a result, the compressor 6 cannot be restarted unless a person performs a restart operation of the compressor 6. That is, restart of the compressor 6 is prohibited.

  Next, in step S4, it is determined whether or not a predetermined time has elapsed since the discharge pipe temperature reached the first predetermined discharge pipe temperature. If it is determined in step S4 that a predetermined time (for example, a time within the range of 2 seconds to 10 seconds) has not elapsed since the discharge pipe temperature reached the first predetermined discharge pipe temperature, the next step Proceed to S5. On the other hand, if it is determined that a predetermined time has elapsed after the discharge pipe temperature reaches the first predetermined discharge pipe temperature, the process returns to step S1.

  Next, in step S5, it is determined whether or not the discharge pipe temperature is equal to or higher than a second predetermined discharge pipe temperature (for example, 127 ° C.). If it is determined in step S5 that the discharge pipe temperature is equal to or higher than the second predetermined discharge pipe temperature, the process proceeds to the next step S6. On the other hand, if it is determined in step S5 that the discharge pipe temperature is not equal to or higher than the second predetermined discharge pipe temperature, the process returns to step S4.

  Next, in step S6, an error code indicating that air compression by the compressor 6 has occurred is displayed on the display unit 60a of the remote controller 60.

  Here, step S2 is performed by the compressor abnormality determination unit 50b. Step S3 is performed by the compressor stop 50c. Steps S4 and S5 are performed by the refrigerant circuit abnormality determination unit 50d. Step S6 is performed by the refrigerant circuit abnormality notification unit 50e.

  Thus, after the compressor 6 is stopped, if the discharge pipe temperature becomes equal to or higher than the second predetermined discharge pipe temperature, an error code indicating that a problem has occurred in the pump down operation is displayed on the display unit 60a of the remote controller 60. Thus, the service person can quickly grasp that the air compression by the compressor 6 has occurred. Therefore, the operation of restarting the compressor 6 can be discouraged by the serviceman. As a result, the risk of damage to the refrigerant circuit 1 can be reduced.

  Further, since the compressor 6 does not automatically restart after the compressor 6 is stopped, the concern about the damage of the refrigerant circuit 1 can be further reduced.

  Further, since the determination of the refrigerant circuit abnormality determination unit 50d continues until the predetermined time elapses after the discharge pipe temperature reaches the first predetermined discharge pipe temperature, the refrigerant circuit 1 may be damaged. Can be detected with high probability. Therefore, the reliability of the determination can be improved.

  In addition, if the predetermined time has elapsed after the discharge pipe temperature reaches the first predetermined discharge pipe temperature, the determination of the refrigerant circuit abnormality determination unit 50d is not performed, and thus this determination is not performed more than necessary. Therefore, the control can be simplified.

  Further, since the discharge pipe temperature is used in the determination of the compressor abnormality determining unit 50b and the refrigerant circuit abnormality determining unit 50d, the number of sensors is not increased, and the manufacturing cost can be prevented from increasing.

  Further, the sampling period of the discharge pipe temperature sensor 71 is shorter during the pump down operation than during the operation other than during the pump down operation, so that the determination of the refrigerant circuit abnormality determination unit 50d is not delayed. it can.

  FIG. 4 schematically shows a graph obtained by an experiment conducted by the present inventors in order to investigate a change over time in the discharge pipe temperature. The experiment was performed in the refrigerant circuit 1, and the compressor 6 was continuously started during the experiment.

  When an abnormality that did not cause damage to the refrigerant circuit 1 occurred, the discharge pipe temperature did not rise to 127 ° C. or higher as shown by the dotted line in FIG. On the other hand, when an abnormality that causes damage to the refrigerant circuit 1 occurs, the discharge pipe temperature continues to rise after reaching 118 ° C. and reaches 127 ° C. or higher, as shown by the solid line in FIG. It was.

  Therefore, when the discharge pipe temperature becomes 127 ° C. or higher, the compressor 6 is preferably not started because there is a high possibility that an abnormality that causes damage to the refrigerant circuit 1 occurs.

  In the first embodiment, the air conditioner includes one indoor unit 2, but may include a plurality of indoor units. That is, the present invention may be applied to a multi-type air conditioner.

  In the first embodiment, the expansion valve 10 is used as an example of a pressure reducing mechanism. However, for example, a capillary tube may be used as an example of a pressure reducing mechanism.

  In the first embodiment, the pump-down operation control unit 50a, the compressor abnormality determination unit 50b, the compressor stop unit 50c, the refrigerant circuit abnormality determination unit 50d, and the refrigerant circuit abnormality notification unit 50e are configured by software. At least one may be configured by hardware.

  In the first embodiment, between the indoor unit 2 and the remote controller 60, a signal may be transmitted / received wirelessly, or a signal may be transmitted / received by wire.

  In the first embodiment, an internal temperature sensor that detects the internal temperature of the compressor 6 may be installed in the compressor 6. In this case, the compressor abnormality determining unit 50b and the refrigerant circuit abnormality determining unit 50d may use the internal temperature detected by the internal temperature sensor for the determination.

  In the first embodiment, whether or not the compressor 6 is abnormal is determined based on the discharge pipe temperature. However, the compressor 6 is abnormal based on the pressure of the refrigerant discharged from the compressor 6. It may be determined whether or not. In this case, for example, as shown in FIG. 5, a pressure sensor 81 as an example of a refrigerant sensor is attached to the discharge pipe 61 of the compressor 6, and the pressure of the refrigerant discharged from the compressor 6 is detected by the pressure sensor 81. To do.

  In this case, the compressor abnormality determination unit 50b determines that the compressor 6 is normal when the pressure detected by the pressure sensor 81 (hereinafter referred to as “discharge pressure”) is less than a first predetermined pressure. On the other hand, if the discharge pressure is equal to or higher than the first predetermined pressure, the compressor 6 may be determined to be abnormal.

  When it is determined that the compressor 6 is abnormal because the discharge pressure is equal to or higher than the first predetermined pressure, the refrigerant circuit abnormality determination unit 50d determines that the discharge pressure is the second predetermined pressure (the first predetermined pressure). If the pressure is lower than (pressure higher than the pressure), it is determined that the possibility that the refrigerant circuit 1 is damaged is relatively low. On the other hand, if the discharge pressure is equal to or higher than the second predetermined pressure, the refrigerant circuit 1 may be damaged. You may make it determine with comparatively high.

  Further, when it is determined that there is a relatively high possibility that the refrigerant circuit 1 is damaged because the discharge pressure is equal to or higher than the second predetermined pressure, an error code indicating that air compression has occurred by the compressor 6 is generated. You may display on the display part 60a of the remote control 60. FIG.

  Further, it may be notified to the service person by voice that the air compression by the compressor 6 has occurred. Alternatively, at least one of the indoor unit 2, the outdoor unit 3, and the remote controller 60 may be provided with an LED (light emitting diode), and the service person may be notified of the LED color or pattern.

[Second Embodiment]
FIG. 5 is a control block diagram of the air conditioner according to the second embodiment of the present invention. In FIG. 5, the same reference numerals as those in the first embodiment are assigned to the same components as those in the first embodiment. In the following description, the same reference numerals as those in the first embodiment are assigned to the same components as those in the first embodiment.

  The air conditioner is different from the first embodiment in that a control device 250 different from the control device 50 is provided. More specifically, the control device 250 includes a pump-down operation control unit 50a, a compressor abnormality determination unit 50b, a compressor stop unit 50c, a refrigerant circuit abnormality determination unit 50d, and a refrigerant circuit abnormality notification unit 50e, as well as software air. An inflow detection unit 250f is provided.

  The air inflow detection unit 250f is made of software in the same manner as the pump down operation control unit 50a and the like, and detects the inflow of air into the refrigerant circuit 1. More specifically, based on at least one of the temperature of the discharge pipe 61 of the compressor 6, the temperature of the indoor heat exchanger 4, and the temperature of the outdoor heat exchanger 8, the air flow into the refrigerant circuit 1. Inflow is detected.

  As described above, since the control device 250 includes the air inflow detection unit 250f, the refrigerant circuit 1 may be damaged even if the discharge pipe temperature is not equal to or higher than the second predetermined discharge pipe temperature. The displayed error code can be displayed on the display unit 60a of the remote controller 60.

  In the second embodiment, the air inflow detection unit 250f is based on at least one of the temperature of the discharge pipe 61 of the compressor 6, the temperature of the indoor heat exchanger 4, and the temperature of the outdoor heat exchanger 8. Although the inflow of air into the refrigerant circuit 1 is detected, the inflow of air into the refrigerant circuit 1 may be detected based on the input current of the compressor 6.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, what combined suitably the content described in the said 1st, 2nd embodiment is good also as one Embodiment of this invention. Further, for example, during the forced cooling operation for the operation inspection performed on the production line or during the normal cooling operation in which the frequency of the compressor 6 fluctuates, the abnormality determination similar to the first and second embodiments is performed. It is good also as one Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Refrigerant circuit 2 Indoor unit 3 Outdoor unit 4 Indoor heat exchanger 5 Indoor fan 6 Compressor 7 Four way switching valve 8 Outdoor heat exchanger 9 Outdoor fan 10 Expansion valve 11 Accumulator 12 1st closing valve 13 2nd closing valve 16 driving | operation / Stop button 50,250 Control device 50a Pump down operation control unit 50b Compressor abnormality determination unit 50c Compressor stop unit 50d Refrigerant circuit abnormality determination unit 50e Refrigerant circuit abnormality notification unit 60 Remote control 71 Discharge pipe temperature sensor 72 Outdoor heat exchanger temperature Sensor 73 Outside air temperature sensor 74 Indoor heat exchanger temperature sensor 75 Indoor temperature sensor 81 Pressure sensor 91 First connection pipe 92 Second connection pipe 250f Air inflow detection unit

Claims (6)

A refrigerant circuit (1) having a compressor (6), an outdoor heat exchanger (8), a pressure reducing mechanism (10), and an indoor heat exchanger;
A refrigerant sensor (71, 81) for detecting the temperature or pressure of the refrigerant compressed by the compressor (6);
A cooling operation control unit (50a) for controlling the refrigerant circuit (1) to perform a cooling operation;
During the cooling operation, when the detected temperature or pressure by the refrigerant sensor (71, 81) is equal to or more than the first predetermined value, the compressor (6) is equal compressor abnormality determining section is abnormal (50b )When,
A compressor stop unit (50c) for stopping the compressor (6) when it is determined that the compressor (6) is abnormal;
After stopping of the compressor (6), temperature or pressure detected by the refrigerant sensor (71, 81) is a refrigerant circuit determines whether a second predetermined value or more higher than the first predetermined value An abnormality determination unit (50d);
When it is determined that the temperature or pressure detected by the refrigerant sensor (71, 81) is equal to or higher than a second predetermined value higher than the first predetermined value, the refrigerant circuit (1) may be damaged. An air conditioner comprising: a refrigerant circuit abnormality notifying unit (50e) for notifying a user that there is. In the air conditioner according to claim 1,
The determination of the refrigerant circuit abnormality determination unit (50d) is performed from when the temperature or pressure detected by the refrigerant sensor (71, 81) reaches the first predetermined value until a predetermined time elapses. An air conditioner characterized by that. In the air conditioner according to claim 1 or 2,
The compressor (6) has a discharge pipe (61) for discharging the refrigerant to the outside,
The air conditioner characterized in that the refrigerant sensors (71, 81) are discharge pipe temperature sensors for detecting the temperature of the discharge pipe (61). In the air conditioner according to any one of claims 1 to 3,
An air conditioner comprising an air inflow detector (250f) for detecting the inflow of air into the refrigerant circuit (1). In the air conditioner according to any one of claims 1 to 4,
The air conditioner characterized in that the cooling operation is a forced cooling operation. The air conditioner according to claim 5,
The air conditioner characterized in that the sampling period of the refrigerant sensors (71, 81) is shorter in the forced cooling operation than in the forced cooling operation.

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