JPH10197031A - Air conditioner failure detection device - Google Patents

Abstract

(57) [Problem] To provide a failure detection device of an air conditioner capable of detecting a failure without complicating the configuration of a compressor itself. The evaporator includes a temperature sensor for measuring a surface temperature, a memory for storing a reference temperature of the evaporator in a state where the compressor is stopped, and a reference temperature difference between the reference temperature and the temperature of the evaporator. ,
If the difference between the temperature measured by the temperature sensor 10 and the reference temperature is less than the reference temperature difference, it is determined that the compressor 20 is abnormal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure detection device for detecting a failure of an air conditioner, and more particularly to a failure detection device of an air conditioner for performing indoor air conditioning.

[0002]

2. Description of the Related Art At present, most indoor air conditioners are provided with an indoor heat exchanger provided indoors, an outdoor heat exchanger provided outdoor, and a heat exchanger between an indoor heat exchanger and an outdoor heat exchanger. And a compressor that circulates a refrigerant. In the air conditioner having such a configuration, a change in the current supplied to the compressor is generally monitored using a current sensor in order to detect a failure of the compressor provided outside together with the outdoor heat exchanger.

FIG. 4 is a diagram for explaining a method for detecting such a compressor failure. The illustrated compressor failure detection device includes a compressor motor 1, an AC power supply 3 for supplying power to the motor 1, and a current sensor 5 for detecting a change in current supplied to the motor 1. The current sensor 5 in this case is a coil that detects a change in the current supplied to the motor 1.

[0004] When some abnormality occurs in the motor 1, the motor 1 is supplied even though power is supplied.
Stops rotating, the supply current to the motor 1 passing through the coil 5 changes, and an overcurrent flows through the coil. The illustrated example is configured to directly measure the overcurrent and output the overcurrent to a microcomputer controlling the compressor through an input circuit to detect an abnormality of the compressor.

[0005]

However, inserting a coil for detecting a change in current into the compressor not only complicates the structure of the compressor, but also requires the coil 5 used in such a structure. In addition, since it is necessary to use expensive components such as a current transformer, the cost of the failure detection device is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a failure detection device for an air conditioner that simplifies the structure of a compressor and does not use a coil for detecting a current change. It is intended to provide.

[0007]

According to a first aspect of the present invention, there is provided an air conditioner failure detecting apparatus for detecting a failure of an air conditioner driven by a compressor. Reference temperature storage means for storing a reference temperature of the indoor heat exchanger at the time, reference temperature difference storage means for storing a reference temperature and a reference difference temperature which is a temperature difference of the indoor heat exchanger when the compressor is operating, A heat exchanger temperature measuring means for measuring the temperature of the heat exchanger, and a measured differential temperature which is a temperature difference between the measured temperature measured by the heat exchanger temperature measuring means and the reference temperature is obtained. Temperature difference judging means for judging whether or not the temperature has reached, and a compressor stop for stopping the compressor when the measured temperature difference is judged to be less than the reference temperature difference. It is characterized in that it has a means.

With this configuration, the compressor can be stopped when the temperature change of the heat exchanger is smaller than the normal range. Therefore, it is possible to detect the abnormality of the compressor using the temperature change of the heat exchanger and to cope with the abnormality.

According to a second aspect of the present invention, the failure detection device for an air conditioner further includes an operation timing means for timing the operation time of the compressor, and the measured differential temperature to be compared with the reference differential temperature is determined by the operation timing means. The measured differential temperature is obtained by using the measured temperature measured after the end of the time measurement.

With this configuration, the measured differential temperature can be correctly determined by determining the measured differential temperature after the compressor has been operating for a predetermined time or more and the temperature has stabilized.

According to a third aspect of the present invention, there is provided the air conditioner failure detecting device, further comprising an operation stop timer for measuring an operation stop time of the compressor, wherein the reference temperature stored beforehand is determined by the operation stop timer. Is updated to the temperature measured after the end of the time measurement.

With this configuration, the reference temperature is updated according to the environment such as the air temperature, and the temperature of the heat exchanger immediately after the operation of the compressor is stopped is adopted as the reference temperature. Can be prevented. Therefore, an appropriate temperature of the heat exchanger can be adopted as the reference temperature without being affected by the temperature during operation.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram illustrating the configuration of an air conditioner and a failure detection device of the present invention provided in the air conditioner. The illustrated air conditioner includes an evaporator 7 placed in a room A, a compressor 20 and a condenser 8 placed in an outdoor B, and a compressor 20 for circulating a refrigerant between the two. The direction of the arrow shown in the figure indicates the direction in which the refrigerant flows when cooling is performed by the air conditioner.

The condenser 8 is provided with a fan 9 for blowing air to the condenser 8 to increase the efficiency of heat exchange in the condenser 8. Further, in the present embodiment, the evaporator 7 is particularly provided with a temperature sensor 10 for measuring the temperature of the surface of the evaporator 7 and a microcomputer 12 for inputting the measured temperature value output by the temperature sensor 10.

In the present embodiment, hereinafter, only the case where the failure detection device for an air conditioner of the present embodiment is applied to an air conditioner performing a cooling operation will be described.

In the present embodiment, when the compressor 20 starts operating, the compressor 20 sucks and compresses the refrigerant, converts the refrigerant into a high-temperature and high-pressure gas, and discharges the gas to the condenser 8. The discharged refrigerant exchanges heat with the outside air in the condenser 8 to lower the temperature. The refrigerant that has passed through the condenser 8 passes through the filter 2 to remove foreign substances, and is decompressed by the expansion valve 4 provided at the inlet of the evaporator 7 (when the refrigerant is flowing in the direction of the arrow), so that the evaporator 7 It flows into. The surface of the evaporator 7 into which the refrigerant has flowed is gradually cooled until the temperature of the evaporator 7 becomes equilibrium with the temperature of the refrigerant, so that the indoor air passing therethrough can be cooled.

The temperature of the surface of the evaporator 7 cooled by the refrigerant is measured by a temperature sensor 10, and the measured temperature of the surface of the evaporator 7 is input to the microcomputer 12 for processing. As the temperature sensor 10, for example, a thermistor-type temperature sensor that detects the temperature by electric resistance may be used.

Next, the processing in the microcomputer 12 of the temperature measured by the temperature sensor 10 will be described with reference to FIG.

The microcomputer 12 has a CPU 14 for processing and outputting input information, a memory 15 for storing data necessary for the processing of the CPU 14, and a timer 13 for counting time according to the processing. First, the temperature of the surface of the evaporator 7 measured by the temperature sensor 10 is input to the CPU 14. The memory 15 that supplies data to the CPU 14 stores in advance a reference temperature that can be generally regarded as the temperature of the surface of the evaporator 7 before the compressor operates. C
The PU 14 compares the input measured temperature on the surface of the evaporator 7 (hereinafter, simply referred to as a measured temperature) with a reference temperature and calculates the difference. When the air conditioner is performing the cooling operation, the surface of the evaporator 7 should be colder than at the start of the cooling. Therefore, the value obtained by subtracting the measured temperature from the reference temperature is a positive number.

It is to be noted that the stored reference temperature is a temperature which should be appropriately changed depending on factors such as the season and the time zone. Therefore, in the present embodiment, while the operation of the compressor 20 is stopped, the reference temperature is updated to the measured temperature after the operation is stopped.

The memory 15 stores in advance the difference between the reference temperature and the measured temperature (reference cooling temperature) at which the air conditioner can be determined to be operating normally, together with the reference temperature. The CPU 14 compares the difference between the calculated reference temperature and the measured temperature with the reference cooling temperature. As a result of this comparison, when the difference between the calculated reference temperature and the measured temperature has reached the reference cooling temperature, it is determined that the compressor 20 is operating normally. , It is determined that an abnormality has occurred in any of the air conditioners including the compressor 20, and the compressor 2
0, the fan 9 is stopped.

However, after the compressor 20 is operated, a predetermined time is required until the temperature of the surface of the evaporator 7 is stabilized and the reference cooling temperature is lowered. Therefore, the timer 12 measures the predetermined time after the compressor is started and sends it to the CPU 14. The CPU 14 compares the difference between the measured temperature after the lapse of the predetermined time and the reference temperature with the reference cooling temperature, and , Judge abnormal.

Also, when the reference temperature of the memory 15 is updated, a predetermined time from the stop of the compressor 20 is required in order to correctly obtain the temperature of the surface of the evaporator 7 when the compressor 20 is stopped, without affecting the operation of the compressor 20. The measurement temperature after elapse is updated as the reference temperature. The timer 13 also counts a predetermined time after the compressor 20 stops.

FIG. 3 is a flowchart showing the processing performed in this embodiment described above.

In this embodiment, when the process is started, it is first determined whether the compressor has been turned on from off (S1). If the compressor is turned on from off,
An on-timer for measuring the operation time of the compressor is set (S2), and an off-timer for measuring the operation stop time is reset (S3). At this time, it is assumed that the off timer does not advance until it is reset and then set again.

If it is determined in step 1 that the compressor has not been turned on from off, it is determined whether the compressor has been turned on from off (S12), an off timer is set (S13), and an on timer is set. It is reset (S14). At this time, it is also assumed that the on-timer does not advance until it is reset and then set again.

Next, a temperature measured by a temperature sensor (TH sensor) for measuring the temperature (TH) of the surface of the evaporator is input (S4), and the input temperature TH is measured when the compressor is kept off for t1. It is determined whether or not it has been performed (S5). If the temperature TH was measured after a time t1 since the compressor was turned off,
The temperature TH is replaced with the reference temperature THM stored in the memory (S7). The time t1 is determined in the process of step 7 by:
This is the time set to adopt this as THM after the temperature of the evaporator surface cooled when the compressor is turned on sufficiently returns to the original temperature. In the present embodiment, the time t1 is set to 6 minutes.

On the other hand, when the temperature TH is measured during a time less than the time t1 after the compressor is turned off, the temperature TH is stored in the memory as a reference temperature (TH).
M) (S6). As a result, when TH is higher than THM, the temperature of the evaporator surface is considered to have sufficiently returned to the original temperature from the time of operation of the compressor. Therefore, TH is set to the same value as when time t1 has elapsed. T
Replace with HM (S7).

On the other hand, if TH is lower than THM, T
After H has been cooled by the refrigerant circulation during the operation of the compressor, the temperature may not have returned sufficiently. Also, TH must be lower than THM when the compressor is on, and in any case, T
The process proceeds to the next process without updating the HM.

In the next process, it is determined whether or not the input temperature TH was measured while the compressor was on for t2 (S8). If the temperature TH was measured after t2 was continued. Takes the difference (dT) between the reference temperature input to the memory and THM, and if the difference between TH and THM has reached dT, returns assuming that the compressor is operating normally.

The time t2 is determined by the processing in step 9
This is the time set to compare TH with THM after the temperature of the evaporator surface has started to cool and stabilized after the compressor was turned on. In the present embodiment, this t2
For 6 minutes.

If the difference between TH and THM is less than dT, the cooling rate of the temperature of the evaporator surface will be lower than the normal range, and an abnormality will occur in any of the air conditioners including the compressor. Could be. Therefore, for example, this is displayed on the control panel of the air conditioner (S10), and the compressor is stopped (S1).
1).

In this embodiment described above, the temperature of the evaporator surface after the compressor is turned on is measured, and the normal or abnormal condition of the compressor is determined based on the difference between this temperature and the normal temperature of the evaporator surface. ing. Therefore, it is possible to determine whether the compressor is abnormal or normal without measuring an overcurrent or the like of the compressor body. In addition, by judging whether the abnormality is normal or not based on the temperature of the evaporator surface, it is possible to comprehensively judge an abnormality that cannot be detected by detecting overcurrent of the compressor.

In addition, both the updating of the reference temperature and the measurement of the evaporator temperature take sufficient time of 6 minutes for the temperature of the evaporator surface to stabilize, so that it is appropriate to control the air conditioner. Temperature can be adopted.

In this embodiment, only the failure detection processing during the cooling operation of the air conditioner has been described.
It goes without saying that the failure detection device for an air conditioner of the present embodiment can also be used during a heating operation of the air conditioner.

[0036]

According to a first aspect of the present invention, there is provided a failure detecting device for an air conditioner, wherein a temperature difference between a temperature measured by a heat exchanger temperature measuring means and a reference temperature is obtained, and the measured temperature difference satisfies the reference temperature difference. If not, the compressor is turned off. Therefore, the failure of the air conditioner can be detected and the abnormality can be dealt with without complicating the structure of the compressor, such as adding a coil for detecting a current change to the compressor.

The fault detecting device for an air conditioner according to the present invention further includes an operation time measuring means for measuring the operation time of the compressor, and the difference in temperature measured after the temperature of the heat exchange means is stabilized is set to a reference temperature difference. Can be compared to Therefore, it is possible to calculate an appropriate measured differential temperature, and it is possible to further enhance the reliability of the air conditioner.

According to a third aspect of the present invention, there is provided the air conditioner failure detection apparatus further comprising an operation stop time measuring means for measuring the operation stop time of the compressor, wherein the temperature measured after the temperature of the heat exchange means is stabilized is used as a reference. It can be updated as temperature. Therefore, an appropriate temperature can be adopted as the reference temperature, and an appropriate measured differential temperature can be calculated, so that the reliability of the air conditioner can be further improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a failure detection device for an air conditioner according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a failure detection device of the air conditioner according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating a process performed by the failure detection device for the air-conditioning apparatus according to the embodiment of the present invention.

FIG. 4 is a diagram illustrating a conventional failure detection device for an air conditioner.

[Explanation of symbols]

 7 evaporator, 9 fan, 10 temperature sensor, 12 microcomputer, 13 timer, 14 CPU, 15 memory, 20 compressor.

Claims (3)

[Claims] An air conditioner failure detection device, which is driven by a compressor (20) and detects a failure of an air conditioner, wherein a reference of an indoor heat exchanger (7) when the operation of the compressor (20) is stopped. Reference temperature storage means (1) for storing temperature
5); a reference temperature difference storage means (15) for storing a reference temperature and a reference temperature difference which is a temperature difference of the indoor heat exchanger (7) when the compressor (20) is operated; and an indoor heat exchanger (7). A) a heat exchanger temperature measuring means (10) for measuring the temperature of the heat exchanger, and a measured temperature difference between the measured temperature measured by the heat exchanger temperature measuring means (10) and the reference temperature.
A differential temperature determining means (14) for determining whether the measured differential temperature has reached a reference differential temperature, and a case where the measured differential temperature is determined to be less than the reference differential temperature by the differential temperature determining means (14). Has a compressor (2
And a compressor stopping means (14) for stopping 0). 2. An operation timing means (13) for timing the operation time of the compressor (20), wherein the measured differential temperature compared with the reference differential temperature is determined by the operation timing means (13) for a predetermined time. 2. The failure detection device for an air conditioner according to claim 1, wherein the temperature difference is a measurement temperature difference obtained by using a measurement temperature measured after completion of the time measurement. 3. 3. An operation stop timer means (13) for measuring the operation stop time of the compressor (20), wherein the previously stored reference temperature is determined by the operation stop timer means (13) for a predetermined time. 3. The failure detection device for an air conditioner according to claim 1, wherein the temperature is updated to the measured temperature after the time measurement is completed. 4.