JPH10238844A - Multitype air-conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a normal indoor machine as safety of the indoor machine under a stop is ensured by a method wherein the piping temperature of the indoor machine under an abnormal stop is detected by a piping temperature detecting means, the increase of drain due to a trouble of a solenoid valve is monitored by drain generation monitoring means, and during the generation of drain, a compressor is stopped. SOLUTION: When discharge abnormality of drain occurs to a chamber A and abnormality is detected by a water level sensor 11 or when a water level is not detected due to a trouble of the water level sensor 11, a piping temperature RH0 when the chamber A is stopped due to the occurrence of drain abnormality is detected. A piping temperature RH1 after a lapse of (t) time is detected and RH0 is compared with RH1. When the RH1 is not increased to a value higher than a specified value, it is decided that a solenoid valve 5 is failed in operation and there is a fear of drain leaking, and the compressor 2 is stopped. Even when one of indoor machines 7 and 12 is stopped due to the occurrence of drain abnormality, normal operation of an indoor machine in a room as safety of leakage of drain of an indoor machine under a stop is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-type air conditioner, and more particularly to the treatment of drain water in an indoor unit that is stopped due to a drain abnormality.

[0002]

2. Description of the Related Art As a conventional example of an air conditioner which performs control so that water does not always accumulate in a drain pan, there is one disclosed in Japanese Patent Application Laid-Open No. 8-193745. It consists of a thermistor for detecting the temperature of the inlet of a refrigeration cycle and a heat exchanger for evaporating a refrigerant, a drain pan for receiving dew generated by heat exchange, a pump for discharging water in the drain pan, and a water amount detection. An air conditioner equipped with a control device equipped with a microcomputer that controls the float switches to prevent the dew from being generated from the heat exchanger when the drain pan is full, and a predetermined value after the drain pan water level returns to normal The operation is such that the water in the drain pan is discharged for a time so that water does not always accumulate in the drain pan.

A multi-type air conditioner configured by connecting a plurality of indoor units to one outdoor unit is described, for example, in Japanese Patent Application Laid-Open No. 2-97848. This is to improve the workability of the confirmation work of checking the correspondence between the operating state of the outside and the inside of each room while performing the test operation for each room.

[0004]

The control device of the conventional multi-type air conditioner is configured as described above.
When there is an indoor unit that is stopped due to a drain pump failure, there is a risk that drain water may overflow in the indoor unit, and it is necessary to stop the compressor, and there is a problem that other indoor units cannot be operated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when a plurality of indoor units are performing a cooling operation, some indoor units are stopped due to a failure of a drain pump. Even if the stopped indoor unit does not accumulate drain water, the normal indoor unit can be operated, and if the solenoid valve that controls the refrigerant of the stopped indoor unit fails,
It is an object of the present invention to provide a multi-type air conditioner capable of detecting a condition in which a refrigerant flows into a stopped indoor unit and accumulates drain water, thereby preventing overflow of the drain water.

[0006]

According to a first aspect of the present invention, there is provided a multi-type air conditioner connected to an outdoor unit having a compressor or the like via refrigerant flow control means for controlling a refrigerant flow rate. A plurality of indoor units having an indoor heat exchanger and having a drain discharge device for discharging drain water generated from the indoor heat exchanger to the outside, and a pipe temperature of the indoor heat exchanger, which is provided in the indoor unit, is detected. If there is a pipe temperature detecting means to perform the cooling operation and stop the cooling operation due to a failure of the drain discharge device among the indoor units, the piping of the indoor heat exchanger of the indoor unit detected by the pipe temperature detecting means after the cooling operation is stopped. Based on temperature
Drain water generation monitoring means for monitoring generation of drain water by cooling the indoor heat exchanger due to leakage of refrigerant from the refrigerant flow rate control means, and drain water generation state monitoring means, wherein drain water is generated from the indoor heat exchanger. Means for stopping the operation of the compressor when it is determined that the state occurs.

According to a second aspect of the present invention, there is provided a multi-type air conditioner according to the first aspect, wherein the drain water generation monitoring means detects the pipe temperature at the time of cooling operation stoppage detected by the pipe temperature detecting means. RH0 is compared with the pipe temperature RH1 after the lapse of a predetermined time. If RH1−RH0 <ΔT (predetermined temperature), it is determined that drain water is generated from the indoor heat exchanger.

According to a third aspect of the present invention, there is provided a multi-type air conditioner according to the first aspect, wherein the drain water generation monitoring means has a predetermined time elapsed after the cooling operation stopped by the pipe temperature detection means. If the subsequent pipe temperature is equal to or lower than the predetermined temperature T, it is determined that drain water is generated from the indoor heat exchanger.

A multi-type air conditioner according to a fourth aspect of the present invention is the multi-type air conditioner according to the first aspect, further comprising: an indoor temperature detecting means for detecting an indoor temperature; The pipe temperature after a lapse of a predetermined time from the stop of the cooling operation detected by the detecting means is compared with the indoor temperature detected by the indoor temperature detecting means.
In the case of (predetermined temperature), it is determined that drain water is generated from the indoor heat exchanger.

[0010] In the multi-type air conditioner according to a fifth aspect of the present invention, in the multi-type air conditioner according to the second aspect, the pipe temperature detecting means may be configured so that the pipe temperature after the cooling operation is stopped is stabilized after the pipe temperature is stabilized. This is for detecting the pipe temperature RH1 after a lapse of time.

According to a sixth aspect of the present invention, there is provided the multi-type air conditioner according to the third aspect, wherein the pipe temperature detecting means is provided for a predetermined time after the pipe temperature after the cooling operation is stopped is stabilized. This is for detecting the pipe temperature after the passage.

According to a seventh aspect of the present invention, there is provided the multi-type air conditioner according to the fourth aspect, wherein the pipe temperature detecting means is provided for a predetermined time after the pipe temperature after the cooling operation is stopped is stabilized. It detects the piping temperature and the room temperature after the passage.

According to an eighth aspect of the present invention, there is provided a multi-type air conditioner according to the second aspect, further comprising means for detecting a room temperature and correcting a determination value ΔT according to the room temperature. The drain water generation monitoring means operates based on the corrected determination value ΔT.

A multi-type air conditioner according to a ninth aspect of the present invention is the multi-type air conditioner according to the third aspect, further comprising means for detecting an indoor temperature and correcting a determination value T according to the indoor temperature. The drain water generation monitoring means operates based on the corrected determination value T.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a refrigerant system diagram of the multi-type air conditioner of the present invention. In the figure, reference numeral 1 denotes an outdoor unit of an air conditioner, a compressor 2 for compressing a refrigerant, a switching valve 3 for changing a flow of the refrigerant to switch between a cooling operation and a heating operation, and a heat of the refrigerant in the outdoor unit 1. Heat exchanger 4 for performing the exchange,
The electromagnetic valve 5 is a refrigerant flow control means for stopping the flow of the refrigerant to the room A, and the electromagnetic valve 6 is a refrigerant flow control means for stopping the flow of the refrigerant to the room B.

Reference numeral 7 denotes an indoor unit in the room A, a heat exchanger 8 for exchanging heat of the refrigerant in the room A, an indoor temperature sensor 9 for detecting the room temperature in the room A, and a pipe temperature in the room A. A pipe temperature sensor 10 for detection and a water level sensor 11 for detecting a water level of a dish (hereinafter, a drain plate) for receiving water (hereinafter, drain water) in which the heat exchanger 8 is cooled and water in the atmosphere is solidified. ing.

The drain discharge device includes a water level sensor 11 for detecting a water level of a drain plate, a drain pump (not shown), and the like.

Reference numeral 12 denotes an indoor unit in the room B, and a heat exchanger 13 for exchanging heat of the refrigerant in the room B. An indoor temperature sensor 14 for detecting the indoor temperature of the room B, a pipe temperature sensor 15 for detecting a pipe temperature of the room B, and the heat exchanger 1
Reference numeral 3 denotes a water level sensor 16 for detecting the water level of a drain plate that receives drain water that has cooled and the water in the atmosphere has solidified.

Next, the operation will be described. FIG. 2 is a diagram showing a change in pipe temperature due to the amount of refrigerant leaking from the solenoid valve when the cooling operation is stopped, and FIG. 3 is a flowchart according to the first embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, when the drainage of the room A becomes abnormal due to the drain water discharge and the water level sensor 11 detects the abnormality,
If the drain water level cannot be detected due to the abnormality of No. 1 (hereinafter, the drain abnormality and the sensor abnormality will be the drain abnormality) (Step S)
31) The pipe temperature RH0 when the A-room is stopped due to the drain abnormality is detected (step S32).

As shown in FIG. 2, the pipe temperature of the indoor heat exchanger 8 after the cooling operation is stopped depends on the amount of refrigerant leaking from the solenoid valve 5, and when the amount of leaking refrigerant increases, the pipe temperature does not increase. Therefore, in step S33, the pipe temperature RH1 after the elapse of the time t is detected. Then, in step S34,
Compare RH0 and RH1. If RH1 has not risen by more than ΔT, the solenoid valve 5 has failed, and the amount of leaking refrigerant is judged to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water. In operation, the compressor 2 is stopped because drain water leaks and the room may be wet (step S35).

As described above, according to the first embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12
Even if the stand stops due to drain abnormality, the pipe temperature of the indoor unit during abnormal stop is detected, and the increase in drain water due to the failure of the solenoid valve is monitored to ensure the safety of drain water leakage of the indoor unit during stop. There is an effect that the indoor unit in a normal room can be operated while securing.

The functions required for the detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are essentially required for the air conditioner, and are not specially provided for this control. There is also an effect that the cost can be reduced.

Embodiment 2 FIG. In the first embodiment described above,
The pipe temperature RH0 of the indoor heat exchanger when the cooling operation is stopped, and t
Although the failure of the solenoid valve is determined by comparing with the pipe temperature RH1 after the lapse of time, it can also be determined by the pipe temperature RH1 itself after the lapse of t time. The pipe temperature of the indoor heat exchanger during the cooling operation is usually about 5 ° C., and the set room temperature is at least about 16 ° C. If the pipe temperature RH1 after elapse of t time does not exceed 10 ° C., for example, the electromagnetic It may be determined that the valve has failed.

FIG. 4 is a flowchart according to the second embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S <b> 41, when the A-room has a drain abnormality and the cooling operation is stopped, in step S <b> 42, t
After the lapse of time, the pipe temperature of the indoor heat exchanger 8 is detected. Then, in step S43, the pipe temperature is set to a predetermined T ° C.
(Eg, 10 ° C. as described above). When the pipe temperature is equal to or lower than T ° C., the solenoid valve 5 breaks down, and the amount of leaking refrigerant is determined to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water. The compressor 2 is stopped because the drain water leaks and there is a danger of wetting the room (step S44).

As described above, according to the second embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12
Even if the stand is stopped due to a drain error, the pipe temperature of the indoor unit that is abnormally stopped is detected, and the increase in the drain water due to the failure of the solenoid valve is monitored based on the pipe temperature itself. There is an effect that the indoor unit in a normal room can be operated while ensuring safety of leakage.

As in the first embodiment, the functions required for the detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are originally required for the air conditioner. There is also an effect that the cost can be reduced because it is not specially provided.

Embodiment 3 In the first embodiment described above,
The pipe temperature RH0 of the indoor heat exchanger when the cooling operation is stopped, and t
Although the failure of the solenoid valve is determined by comparing the piping temperature RH1 after the lapse of time, it can also be determined by comparing the room temperature with the piping temperature after the lapse of t time.

FIG. 5 is a flowchart according to the third embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S <b> 51, when the drainage of the room A becomes abnormal and the cooling operation is stopped, in step S <b> 52, the room temperature and the pipe temperature after elapse of t time are detected. Step S
At 53, it is determined whether the room temperature is higher than the pipe temperature by T ° C or more. If the pipe temperature is T ° C or higher, the solenoid valve 5 breaks down,
In addition, the amount of the leaking refrigerant is determined to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water, and the subsequent operation of the compressor 2 causes the drain water to leak out and wet the room. 2 is stopped (step S54).

As described above, according to the third embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12
Even if the table stops due to drain abnormality, the temperature of the indoor unit that is abnormally stopped is detected, and the indoor temperature is compared with the pipe temperature to monitor the increase in drain water due to a solenoid valve failure. Thus, there is an effect that the indoor unit in a normal room can be operated while ensuring the safety of drain water leakage of the indoor unit.

As in the first embodiment, the functions necessary for the detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are originally required for the air conditioner. There is also an effect that the cost can be reduced because it is not specially provided.

Embodiment 4 FIG. In the first embodiment described above,
The pipe temperature RH0 of the indoor heat exchanger when the cooling operation is stopped, and t
The failure of the solenoid valve is determined by comparing the pipe temperature RH1 after the lapse of time. However, if the pipe temperature RH1 is detected after the cooling operation is stopped and the pipe temperature is stabilized after the lapse of t time,
More reliable control becomes possible.

FIG. 6 is a flowchart according to the fourth embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S61, when the A-room has a drain abnormality and the cooling operation is stopped, in step S62, the piping temperature RH0 when the A-room is stopped due to the drain abnormality is reduced to To detect. Subsequently, in step S63, the pipe temperature after the cooling operation is stopped is detected and set as RHT (-1). Then, in step S64, the pipe temperature at time Δt after detecting RHT (−1) is detected and set as RHT (0).

In step S65, RHT (0) -RHT
It is determined whether (-1) is equal to or less than ΔT. If ΔT or less, it is determined that the pipe temperature is stable. If ΔT or more, it is determined that the pipe temperature is not stable, and the pipe temperature is detected and compared every Δt time (steps S63, S64, S6).
5).

When it is determined that RHT (0) -RHT (-1) becomes equal to or less than ΔT and the pipe temperature is stabilized, the pipe temperature RH
1 is detected (step S66), and in step S67, is compared with the pipe temperature RH0 at the time of stop. Piping temperature RH1 is △
If the temperature has not risen by more than T, the solenoid valve 5 is out of order, and the amount of leaking refrigerant is judged to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water. The compressor 2 is stopped because there is a danger that water leaks out and wets the room (step S68).

As described above, according to the fourth embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12 is used.
Even if the table stops due to drain error, the pipe temperature of the indoor unit during abnormal stop is detected after the pipe temperature has stabilized, and compared with the pipe temperature at the time of abnormal stop, the drain water increases due to a solenoid valve failure. By monitoring the condition, it is possible to operate the indoor unit in a normal room with higher accuracy while ensuring the safety of drain water leakage of the stopped indoor unit.

As in the first embodiment, the functions required for detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are originally required for the air conditioner. There is also an effect that the cost can be reduced because it is not specially provided.

Embodiment 5 In Embodiment 4 described above,
The pipe temperature RH0 of the indoor heat exchanger when the cooling operation is stopped, and t
Although the failure of the solenoid valve is determined by comparing with the pipe temperature RH1 after the passage of time, it can also be determined by the pipe temperature itself after the passage of t time.

FIG. 7 is a flowchart according to the fifth embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S71, when the drain of the room A becomes abnormal and the cooling operation is stopped, in step S72, the pipe temperature after the cooling operation is stopped is detected, and the RHT (−) is detected. 1). Then, the pipe temperature at time Δt after detecting RHT (−1) in step S73 is detected and set as RHT (0).

In step S74, RHT (0) -RHT
It is determined whether (-1) is equal to or less than ΔT. If ΔT or less, it is determined that the pipe temperature is stable. If ΔT or more, it is determined that the pipe temperature is not stable, and the pipe temperature is detected and compared every Δt time (steps S72, S73, and S7).
4).

When it is determined that RHT (0) -RHT (-1) has become equal to or less than ΔT and the pipe temperature has stabilized, the pipe temperature is detected (step S75). In step S76, it is determined whether the pipe temperature is equal to or lower than T ° C. When the pipe temperature is equal to or lower than T ° C., the solenoid valve 5 breaks down, and the amount of leaking refrigerant is determined to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water. The compressor 2 is stopped because the drain water leaks and there is a danger of wetting the room (step S77). The compressor 2 is stopped because there is a risk of getting the room wet (step S68).

As described above, according to the fifth embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12
Even if the table stops due to drain error, the pipe temperature of the indoor unit that has stopped abnormally is detected after the pipe temperature has stabilized, and the pipe temperature itself stops by monitoring the increase in drain water due to a solenoid valve failure. There is an effect that it is possible to operate the indoor unit in a normal room with higher accuracy while ensuring the safety of drain water leakage of the inside indoor unit.

As in the first embodiment, the functions necessary for the detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are originally required for the air conditioner. There is also an effect that the cost can be reduced because it is not specially provided.

Embodiment 6 FIG. In Embodiment 4 described above,
The pipe temperature RH0 of the indoor heat exchanger when the cooling operation is stopped, and t
Although the failure of the solenoid valve is determined by comparing the piping temperature RH1 after the lapse of time, it can also be determined by comparing the room temperature with the piping temperature after the lapse of t time.

FIG. 8 is a flowchart according to the sixth embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S81, when the A-room has a drain abnormality and the cooling operation is stopped, in step S82, the pipe temperature after the cooling operation is stopped is detected, and the RHT (−) is detected. 1). Then, the pipe temperature at time Δt after detecting RHT (−1) in step S83 is detected and set as RHT (0).

In step S84, RHT (0) -RHT
It is determined whether (-1) is equal to or less than ΔT. If ΔT or less, it is determined that the pipe temperature is stable. If ΔT or more, it is determined that the pipe temperature is not stable, and the pipe temperature is detected and compared every Δt time (steps S82, S83, S8).
4).

When it is determined that RHT (0) -RHT (-1) has become equal to or less than ΔT and the pipe temperature has stabilized, the pipe temperature is detected (step S85). In step S86, it is determined whether the room temperature is higher than the pipe temperature by T ° C or more. If the pipe temperature is equal to or higher than T ° C., the solenoid valve 5 breaks down, and the amount of leaking refrigerant is judged to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water. The compressor 2 is stopped because the drain water leaks and there is a danger of wetting the room (step S87).

As described above, according to the sixth embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12 is used.
Even if the table stops due to a drain error, the pipe temperature of the indoor unit during abnormal stop is detected after the pipe temperature has stabilized, and the indoor temperature is compared with the pipe temperature to reduce the increase in drain water due to a solenoid valve failure. By monitoring, it is possible to operate the indoor unit in a normal room with higher accuracy while ensuring the safety of drain water leakage of the stopped indoor unit.

As in the first embodiment, the functions necessary for the detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are originally required for the air conditioner. There is also an effect that the cost can be reduced because it is not specially provided.

Embodiment 7 FIG. In the first embodiment described above,
The pipe temperature RH0 of the indoor heat exchanger when the cooling operation is stopped, and t
Although the failure of the solenoid valve is determined by comparing with the pipe temperature RH1 after the lapse of time, a more accurate control is performed by detecting the room temperature at that time and correcting the determination value ΔT of the failure of the solenoid valve. Can be.

FIG. 9 is a flowchart according to the seventh embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S91, when the drain of the A room becomes abnormal and the cooling operation is stopped, the pipe temperature RH0 after the cooling operation is stopped is detected in step S92, and the step S93 is performed.
To detect the pipe temperature RH1 after elapse of the time t. In step S94, the indoor temperature is detected.
If it is higher, the judgment value ΔT is corrected to be higher. Then, in step S95, RH0 and RH1 are compared. If RH1 does not increase by ΔT or more, the solenoid valve 5 breaks down, and the amount of leaking refrigerant cools the indoor heat exchanger 8 to generate drain water. If the temperature is determined, the compressor 2 is stopped because the drain water leaks from the subsequent operation of the compressor 2 and there is a danger of wetting the room (step S96).

As described above, according to the seventh embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12 is used.
Even if the table stops due to drain abnormality, the pipe temperature during abnormal stop is detected, and the increase in drain water due to the malfunction of the solenoid valve is monitored to ensure the safety of drain water leakage during stop, and the normal room There is an effect that can be driven. Further, by correcting the determination value with the room temperature, highly accurate protection can be achieved. The function required for detection is a pipe temperature sensor 1
Only 0 and 15 and the pipe temperature sensors 10 and 15 are essentially required for the air conditioner, and are not specially provided for this control, so that there is also an effect that the cost can be reduced.

Embodiment 8 FIG. In the second embodiment described above,
Although the failure of the solenoid valve is determined based on the pipe temperature itself after the elapse of the time t, the control with higher accuracy can be performed by detecting the room temperature at that time and correcting the determination value T of the failure of the solenoid valve.

FIG. 10 is a flowchart according to the eighth embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S101, if the drainage of the room A becomes abnormal and the cooling operation is stopped, step S102 is performed.
Then, the pipe temperature of the indoor heat exchanger 8 after the elapse of the time t is detected. Then, in step S103, the room temperature is detected, and the lower the room temperature is, the higher the room temperature is, the higher the determination value T ° C is corrected. In step S104, it is determined whether the pipe temperature is equal to or lower than T ° C. If the pipe temperature is lower than T ° C., the solenoid valve 5 breaks down,
In addition, it is determined that the amount of the leaking refrigerant is a temperature at which the indoor heat exchanger 8 is cooled to generate drain water, and the subsequent operation of the compressor 2 may cause the drain water to leak out and wet the room. The machine 2 is stopped (step S105).

As described above, according to the eighth embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12 is used.
Even if the table stops due to drain abnormality, the pipe temperature during abnormal stop is detected, and the increase in drain water due to the malfunction of the solenoid valve is monitored to ensure the safety of drain water leakage during stop, and the normal room There is an effect that can be driven. Further, by correcting the determination value of the pipe temperature with the room temperature, highly accurate protection can be achieved. The functions required for the detection are only the pipe temperature sensors 10 and 15, and
Reference numeral 15 is essentially required for the air conditioner, and is not specially provided for this control, so that there is an effect that the cost can be reduced.

Embodiment 9 FIG. In Embodiment 4 described above,
The failure of the solenoid valve was determined by comparing the pipe temperature RH0 of the indoor heat exchanger when the cooling operation was stopped with the pipe temperature RH1 after the pipe temperature was stabilized. By correcting the determination value ΔT of the valve failure, more accurate control can be performed.

FIG. 11 is a flowchart of the ninth embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S <b> 111, when the drainage of the room A becomes abnormal and the cooling operation is stopped, step S <b> 112.
Pipe temperature RH when the A-room is stopped due to drain abnormality
0 is detected. Subsequently, in step S113, the pipe temperature after the cooling operation is stopped is detected, and is set as RHT (-1). Then, the pipe temperature at time Δt after detecting RHT (−1) in step S114 is detected and set as RHT (0).

In step S115, RHT (0) -RHT
It is determined whether (-1) is equal to or less than ΔT. If ΔT or less, it is determined that the pipe temperature is stable. If ΔT or more, it is determined that the pipe temperature is not stable, and the pipe temperature is detected and compared every Δt time (steps S113, S114, S1).
15).

When it is determined that RHT (0) -RHT (-1) is not more than ΔT and the pipe temperature is stable, the pipe temperature RH
1 is detected (step S116), the room temperature is detected in step S117, the lower the room temperature is, the higher the temperature is, the higher the determination value ΔT is corrected, the higher the room temperature is, and the comparison is made with the pipe temperature RH0 at the stop in step S118. If RH1 has not risen by more than ΔT, the solenoid valve 5 has failed, and the amount of leaking refrigerant is judged to be a temperature at which the indoor heat exchanger 8 is cooled to generate drain water. In operation, the compressor 2 is stopped because drain water leaks and there is a risk of wetting the room (step S119).

As described above, according to the ninth embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12 is used.
Even if the table stops due to drain abnormality, the pipe temperature during abnormal stop is detected, and the increase in drain water due to the malfunction of the solenoid valve is monitored to ensure the safety of drain water leakage during stop, and the normal room There is an effect that can be driven. Further, by correcting the determination value ΔT with the room temperature, highly accurate protection can be achieved. Further, since the detection is performed after the pipe temperature is stabilized, reliable detection can be performed. The functions required for detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensor 1
0 and 15 are originally required for the air conditioner and are not specially provided for this control, so that there is also an effect that the cost can be reduced.

Embodiment 10 FIG. In the above-described fifth embodiment, the failure of the solenoid valve is determined based on the pipe temperature itself after the pipe temperature is stabilized. However, by detecting the room temperature at that time and correcting the determination value of the failure of the solenoid valve, , More precise control is possible.

FIG. 12 is a flowchart according to the tenth embodiment of the present invention. In the multi-type air conditioner configured as shown in FIG. 1, in step S <b> 121, when the drainage of the room A becomes abnormal and the cooling operation is stopped, step S <b> 12 is performed.
In step 2, the pipe temperature after the cooling operation is stopped is detected, and the RHT (−
1). Then, in step S123, RHT (-
The pipe temperature at time Δt after detection of 1) is detected, and R
HT (0).

In step S124, RHT (0) -RHT
It is determined whether (-1) is equal to or less than ΔT. If ΔT or less, it is determined that the pipe temperature is stable. If ΔT or more, it is determined that the pipe temperature is not stable, and the pipe temperature is detected and compared every Δt time (steps S122, S123, and S1).
24).

When it is determined that RHT (0) -RHT (-1) becomes equal to or less than ΔT and the pipe temperature is stabilized, the pipe temperature is detected (step S125). In step S126, the room temperature is detected, and if the room temperature is low, the determination value T ° C. is corrected to be low, and to be high if the room temperature is high. In step S127, it is determined whether the pipe temperature is equal to or lower than T ° C. If the pipe temperature is lower than ° C., the solenoid valve 5 fails and the amount of leaking refrigerant is determined by the indoor heat exchanger 8.
Is determined to be a temperature at which drain water is generated by cooling the compressor, and the compressor 2 is stopped because the drain water leaks from the subsequent operation of the compressor 2 and there is a danger of wetting the room (step S
128).

As described above, according to the tenth embodiment, in the multi-type air conditioner, one of the indoor units 7 and 12
Even if the table stops due to drain abnormality, the pipe temperature during abnormal stop is detected, and the increase in drain water due to the malfunction of the solenoid valve is monitored to ensure the safety of drain water leakage during stop, and the normal room Driving can be effective. Also,
By correcting the determination value T ° C with the room temperature, highly accurate protection can be achieved. Further, since the detection is performed after the pipe temperature is stabilized, reliable detection can be performed. Further, the functions required for detection are only the pipe temperature sensors 10 and 15, and the pipe temperature sensors 10 and 15 are originally required for the air conditioner, and are not specially provided for this control, so that the cost can be reduced. There is also an effect.

[0065]

As described above, according to the present invention, in the multi-type air conditioner, even if there is an indoor unit which stops the cooling operation due to the failure of the drain discharge device, the pipe temperature detecting means is not stopped abnormally. The indoor unit pipe temperature is detected, and the drain water generation monitoring means monitors the increase in drain water due to the failure of the solenoid valve, and if it is determined that drain water is generated from the indoor heat exchanger, the Since the operation is stopped, there is an effect that the indoor unit in a normal room can be operated while ensuring the safety of the drain water leakage of the stopped indoor unit. Further, since the pipe temperature is detected after the pipe temperature is stabilized, reliable detection can be performed. Further, by correcting the determination value with the room temperature, highly accurate protection can be achieved. Further, the function required for detection is only the pipe temperature sensor, and the pipe temperature sensor is essentially required for the air conditioner, and is not specially provided for this control, so that there is an effect that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a system configuration and a refrigerant system diagram of a multi-type air conditioner according to Embodiments 1 to 10 of the present invention.

FIG. 2 is a diagram illustrating a change in a pipe temperature depending on a refrigerant amount when a cooling operation is stopped.

FIG. 3 is a flowchart illustrating the operation of the multi-type air conditioner according to Embodiment 1 of the present invention.

FIG. 4 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 2 of the present invention.

FIG. 5 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 3 of the present invention.

FIG. 6 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 4 of the present invention.

FIG. 7 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 5 of the present invention.

FIG. 8 is a flowchart illustrating an operation of a multi-type air conditioner according to Embodiment 6 of the present invention.

FIG. 9 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 7 of the present invention.

FIG. 10 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 8 of the present invention.

FIG. 11 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 9 of the present invention.

FIG. 12 is a flowchart illustrating an operation of the multi-type air conditioner according to Embodiment 10 of the present invention.

[Explanation of symbols]

Reference Signs List 1 outdoor unit, 2 compressor, 3 switching valve, 4 outdoor heat exchanger, 5 and 6 solenoid valve, 7 indoor unit A, 8, 13 indoor heat exchanger, 9, 14 indoor temperature sensor, 10, 15 pipe temperature sensor , 11, 16 Water level sensor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigenobu Mochizuki 2-6-1 Otemachi, Chiyoda-ku, Tokyo Within Mitsui Electric Engineering Co., Ltd. (72) Inventor Kazuhiro Kazama 2-6-Otemachi, Chiyoda-ku, Tokyo No. 2 Mitsubishi Electric Engineering Co., Ltd.

Claims (9)

[Claims] 1. An outdoor unit having a compressor and the like, and an indoor heat exchanger connected to the outdoor unit via refrigerant flow control means for controlling a refrigerant flow rate, and a drain generated from the indoor heat exchanger. A plurality of indoor units having a drain discharge device for discharging water to the outside of the room; a pipe temperature detecting means provided in the indoor unit, for detecting a pipe temperature of the indoor heat exchanger; In the case where the cooling operation is stopped due to a failure of the drain discharge device, the refrigerant flow rate control is performed based on the piping temperature of the indoor heat exchanger of the indoor unit detected by the piping temperature detecting unit after the cooling operation is stopped. Drain water generation monitoring means for monitoring generation of the drain water by cooling the indoor heat exchanger due to leakage of the refrigerant from the means; and If it is determined that the state in which the drain water is generated, the multi-type air conditioner which is characterized by comprising a means for stopping the operation of the compressor. 2. The drain water generation monitoring means includes a pipe temperature RH detected by the pipe temperature detection means when the cooling operation is stopped.
0 and the pipe temperature RH1 after a predetermined time has elapsed, and R
2. The multi-type air conditioner according to claim 1, wherein when H1-RH0 <[Delta] T (predetermined temperature), it is determined that the drain water is generated from the indoor heat exchanger. 3. The drain water generation monitoring means, when the pipe temperature after a lapse of a predetermined time from the cooling operation stop detected by the pipe temperature detection means is equal to or lower than a predetermined temperature T,
The multi-type air conditioner according to claim 1, wherein it is determined that the drain water is generated from the indoor heat exchanger. 4. An indoor temperature detecting means for detecting an indoor temperature, wherein the drain water generation monitoring means includes a pipe temperature after a predetermined time elapses from a cooling operation stop detected by the pipe temperature detecting means and the indoor temperature detecting means. Is compared with the detected indoor temperature, and if indoor temperature−pipe temperature ≧ T (predetermined temperature),
The multi-type air conditioner according to claim 1, wherein it is determined that the drain water is generated from the indoor heat exchanger. 5. The multi-type air according to claim 2, wherein the pipe temperature detecting means detects the pipe temperature RH1 after the predetermined time has passed after the pipe temperature after the cooling operation is stopped is stabilized. Harmony machine. 6. The multi-type air conditioner according to claim 3, wherein said pipe temperature detecting means detects the pipe temperature after a lapse of the predetermined time after the pipe temperature after the cooling operation is stopped is stabilized. Machine. 7. The pipe temperature detecting means according to claim 4, wherein the pipe temperature detecting means detects the pipe temperature and the indoor temperature after the predetermined time has elapsed after the pipe temperature after the cooling operation is stopped is stabilized. Multi type air conditioner. 8. A device for detecting a room temperature and correcting the determination value ΔT according to the room temperature, wherein the drain water generation monitoring unit operates based on the corrected determination value ΔT. The multi-type air conditioner according to claim 2, characterized in that: 9. A system for detecting a room temperature and for correcting the determination value T according to the room temperature, wherein the drain water generation monitoring unit operates based on the corrected determination value T. The multi-type air conditioner according to claim 3, wherein: