JP2002147818A - Air conditioner and failure in operation deciding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner and its failures in operation deciding method, capable of rapidly and reliably detecting a failure in operation of the air conditioner, without being influenced by the environment conditions. SOLUTION: A failure in operation deciding method for an air conditioner, having a valve to regulate a flow rate of a refrigerant running from a condenser toward an evaporator comprises a process (S5), where a valve is caused to effect closing operation during operation of the air conditioner; a measuring process wherein the operation condition of the air conditioner changing due to closing operation is measured; and a decision process (S6) in which the occurrence of a failure in operation of the air conditioner is decided by using measurement of measured operating conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner and a method for determining a failure thereof, and more particularly, to an air conditioner having a valve for adjusting a flow rate of refrigerant flowing from a condenser to an evaporator, and an air conditioner having the same. The present invention relates to a failure determination method.

[0002]

2. Description of the Related Art Conventionally, as a method of judging a failure of an air conditioner, a change in the temperature of a refrigerant during normal operation is measured, and the measured temperature is within a predetermined temperature range (when the air conditioner is operating normally). (A temperature range assumed in some cases) is monitored. This is based on the fact that if a device such as an expansion valve of an air conditioner fails, conditions such as the refrigerant flow rate deviate from the condition range assumed during normal operation, resulting in a change in refrigerant temperature. Is what you do.

[0003]

However, the above-described conventional failure determination method has the following problems. That is, when a failure occurs in the air conditioner as described above, the temperature change of the refrigerant during the normal operation is relatively gentle, depending on the location of the failure. Also, due to environmental conditions of the air conditioner, etc., the temperature of the refrigerant varies during normal operation, and it may be difficult to distinguish the variation from the temperature change due to a failure. Therefore, in the conventional failure determination method, it is difficult to determine the failure, and it takes time to determine the failure.

An object of the present invention is to solve the above-described problems, and an object of the present invention is to detect a failure of an air conditioner quickly and accurately without being affected by environmental conditions. An object of the present invention is to provide an air conditioner and a failure determination method thereof.

[0005]

According to one aspect of the present invention, there is provided a method for determining a failure of an air conditioner, the method including determining a flow rate of a refrigerant flowing from a condenser to an evaporator. Wherein the step of closing the valve during operation of the air conditioner, the step of measuring the operating condition of the air conditioner changed by the closing operation, and the step of air conditioning using the measured value of the measured operating condition A determining step of determining whether there is a machine failure.

[0006] In this way, by forcibly closing the valve, it is possible to create operating conditions (cycle conditions) for failure determination in the air conditioner that are different from those during normal operation. The operating conditions for the failure determination include, for example,
By closing the valve during normal operation of the air conditioner,
This is a condition in which the flow rate of the refrigerant is rapidly reduced, and the temperature condition of the refrigerant and the like are changed to such an extent that normal operation is impossible. In a state where equipment such as a valve of an air conditioner is operating normally (no failure has occurred), the operating condition for failure determination can be quickly realized by closing the valve. On the other hand, if the closing operation of the valve is not performed normally due to the occurrence of a failure in the valve, the operating condition for failure determination cannot be realized. If the operating conditions for such failure determination are completely different from the operating conditions during normal operation, it can be easily determined whether or not a failure of a valve or the like has occurred and the operating conditions for failure determination have been realized. .

Accordingly, the presence or absence of a failure of a valve of an air conditioner is quickly and reliably determined by utilizing the operating condition for failure determination (by detecting whether the operating condition for failure determination can be realized). it can. In addition, by using operating conditions for failure determination different from normal operating conditions,
Even if the operating conditions during normal operation of the air conditioner fluctuate due to changes in the environmental conditions of the air conditioner, the air can be reliably removed without being affected by such changes in the operating conditions during normal operation. It is possible to perform a failure determination of the harmonic machine.

In the method for determining a failure of an air conditioner according to the first aspect, the measuring step may include measuring an amount of change in the temperature of the refrigerant at the valve outlet before and after the closing operation of the valve. The determining step may include determining whether there is a valve failure by comparing the amount of change in the temperature of the refrigerant with a reference value of the amount of change in the temperature of the refrigerant when the valve is closed. Good.

In this case, the normal closing operation of the valve causes the refrigerant to evaporate near the valve outlet side. Then
The temperature near the valve outlet will drop sharply. Such a change in the temperature of the refrigerant near the valve outlet side does not occur during the normal operation of the air conditioner, and therefore can be easily and reliably detected. Then, when the amount of change (the amount of decrease) in the temperature of the refrigerant becomes equal to or greater than a preset reference value, it is understood that the valve is operating normally (performing the closing operation). If the amount of change in the temperature is equal to or less than the reference value, it is determined that the closing operation of the valve is not sufficient (the opening degree of the valve is not sufficiently small) despite the instruction of the closing operation being issued. This indicates that a failure has occurred in the valve.

In the air conditioner failure determination method according to the first aspect, the air conditioner may include a compressor for compressing a refrigerant. The measuring step may include measuring an amount of change in the operating current of the compressor before and after the closing operation of the valve, and the determining step includes the measurement of the amount of change in the operating current and a case where the valve is closed. May be determined by comparing the reference value of the change amount of the operating current with the reference value.

In this case, when the flow rate of the refrigerant is rapidly reduced by closing the valve, the operating current of the compressor is also reduced. If the amount of decrease in the flow rate of the refrigerant is set to a level that is impossible during normal operation, the measured value of the amount of change (decrease) in the operating current of the compressor increases accordingly. Therefore, when the amount of decrease in the operating current of the compressor is equal to or greater than the preset reference value, it can be understood that the valve is operating normally (performing the closing operation). If the amount of decrease in the operating current is equal to or less than the reference value, the valve closing operation is not sufficient even though the valve closing operation command is issued (the valve opening is not sufficiently small). ), Indicating that a failure has occurred in the valve.

In the air conditioner failure determination method according to the first aspect, the air conditioner includes a compressor for compressing a refrigerant;
It may have a current detector for measuring the operating current of the compressor, and an outlet thermometer installed on the valve outlet side. The measuring step is a step of measuring the amount of change in the temperature of the refrigerant at the outlet side of the valve before and after the closing operation of the valve using an outlet side thermometer, and at the inlet side of the valve before and after the closing operation of the valve. Measuring the temperature difference change amount, which is the change amount of the difference between the temperature of the refrigerant and the temperature of the refrigerant at the outlet side of the valve, and the operating current of the compressor before and after the valve closing operation using a current detector. Measuring a current change amount. The determining step includes determining whether there is a failure in the valve, the outlet-side thermometer, and the current detector using the measured values of the temperature change amount, the temperature difference change amount, and the current change amount. You may.

[0013] In this case, by using three data of the temperature change amount, the temperature difference change amount, and the current change amount at the valve outlet side, not only the presence / absence of the occurrence of the failure in the valve but also the operation condition is detected. It is possible to quickly and easily determine whether or not a failure has occurred in the outlet-side thermometer and the current detector. For example, when the amount of change in temperature at the valve outlet side is not sufficient after closing the valve and the amount of change in current satisfies the reference value, it is understood that the outlet-side thermometer has failed. If the current change does not satisfy the reference value after the valve is closed and the temperature change and the temperature difference change at the valve outlet satisfy the reference values, respectively, the current detector fails. You can see that there is. In addition, after the valve is closed, if the current change, the temperature change at the valve outlet side, and the temperature difference change do not satisfy the reference values, the probability that a plurality of detectors will fail at the same timing is extremely high. The small size indicates that the valve has failed.

It is preferable that the method for determining a failure of an air conditioner according to the first aspect further includes a return step of opening the valve after a lapse of a predetermined time after performing the determination step.

Here, if the valve is kept closed after the valve is closed to determine a failure, not only does the normal operation of the air conditioner be hindered, but also a sufficient amount of refrigerant can be obtained. If the flow rate is not ensured, it may cause damage to equipment such as a compressor. Therefore, by opening the valve automatically after a certain period of time as described above, such damage to the device can be prevented.

It is preferable that the method for determining a failure of an air conditioner according to the first aspect further includes a return step of opening a valve when the determination step determines that no failure has occurred in the air conditioner.

In this case, the valve is automatically opened after it is determined that no failure has occurred, and the air conditioner is returned to normal operation. It can be reliably prevented.

In the method for determining a failure of an air conditioner according to the first aspect, in the return step, the opening degree may be determined based on the opening degree of the valve before performing the valve closing operation.
Preferably, the valve is opened.

In this case, the opening degree of the valve in the return step is determined on the basis of the opening degree of the valve in the normal operation state before performing the failure determination operation. Can be reproduced. Therefore, it is possible to prevent the operating state of the air conditioner from largely changing before and after the failure determination operation.

An air conditioner according to another aspect of the present invention is an air conditioner having a valve for adjusting a flow rate of a refrigerant flowing from a condenser to an evaporator, wherein the valve is closed during operation of the air conditioner. The air conditioner includes an operating unit, a measuring unit that measures an operating condition of the air conditioner that changes due to the closing operation, and a determining unit that determines whether there is a failure in the air conditioner using the measured value of the measured operating condition.

In this manner, by forcibly closing the valve, it is possible to create operating conditions (cycle conditions) for failure determination in the air conditioner that are different from those during normal operation. In a state in which devices such as a valve of an air conditioner are operating normally (no failure has occurred), the operating condition for the failure determination can be quickly realized by closing the valve, while a failure occurs in the valve. When the closing operation is not performed normally due to the occurrence of the failure, the operating condition for failure determination cannot be realized.

Therefore, using the operating conditions for failure determination (by detecting whether the operating conditions for failure determination can be realized), the presence / absence of a failure in an air conditioner valve or the like is quickly and reliably determined. it can. In addition, by using operating conditions for failure determination different from normal operating conditions,
Even if the operating condition during normal operation of the air conditioner changes due to a change in the environmental condition of the air conditioner, it is possible to reliably determine the failure of the air conditioner.

In the air conditioner according to the above other aspect, it is preferable that the measuring means has an outlet thermometer provided on the outlet side of the valve, and the judging means is provided for the outlet thermometer before and after the closing operation of the valve. It is preferable to include means for determining the presence or absence of a valve failure based on the measured value.

In this case, when the valve normally closes, the refrigerant evaporates near the valve outlet, so that the temperature near the valve outlet drops rapidly. Such a change in the temperature of the refrigerant near the valve outlet side does not occur during the normal operation of the air conditioner, and therefore can be easily and reliably detected. Then, when the amount of change (the amount of decrease) in the temperature of the refrigerant becomes equal to or greater than a preset reference value, it is understood that the valve is operating normally (performing the closing operation). If the amount of change in the temperature is equal to or less than the reference value, it is determined that the closing operation of the valve is not sufficient (the opening degree of the valve is not sufficiently small) despite the instruction of the closing operation being issued. This indicates that a failure has occurred in the valve.

In the air conditioner according to another aspect, the air conditioner may further include a compressor for compressing the refrigerant. The measuring unit may include a current detector that measures an operating current of the compressor, and the determining unit determines whether there is a valve failure based on a measured value of the current detector before and after the valve closing operation. Means may be included.

In this case, when the flow rate of the refrigerant is rapidly reduced by closing the valve, the operating current of the compressor is also reduced. Therefore, when the amount of decrease in the operating current of the compressor is equal to or greater than the preset reference value, it is understood that the valve is operating normally (performing the closing operation). If the amount of decrease in the operating current is equal to or less than the reference value, the valve closing operation is not sufficient even though the valve closing operation command is issued (the valve opening is not sufficiently small). ), Indicating that a failure has occurred in the valve.

In the air conditioner according to the above another aspect, the air conditioner may further include a compressor for compressing a refrigerant. The measuring means may include an outlet thermometer provided on the outlet side of the valve, and a current detector for measuring an operating current of the compressor. The judging means has means for judging the presence / absence of a failure in the valve, the current detector, and the outlet thermometer based on the measured value of the outlet thermometer and the measured value of the current detector before and after the closing operation of the valve. It may be.

In this case, by using two kinds of data, ie, the measured value of the outlet thermometer and the measured value of the current detector, not only the presence / absence of a failure in the valve but also the operating condition of the detector is detected. It is possible to quickly and easily determine whether or not a failure has occurred in the outlet-side thermometer and the current detector. For example, when the measured value at the outlet thermometer does not show a predetermined change amount after the valve is closed, but the measured value at the current detector satisfies a reference value expected with the valve closing operation. It can be seen that the outlet thermometer has failed. Also,
After closing the valve, if the measured value at the outlet thermometer shows a predetermined change while the measured value at the current detector does not satisfy the above reference value, the current detector has failed. I understand. In addition, after the valve is closed, if the measured values at the outlet thermometer and the current detector do not satisfy the expected reference values due to the valve closing operation, the plurality of detectors fail at the same timing. The very small probability indicates that the valve has failed.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings below, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

(Embodiment 1) FIG. 1 is a schematic diagram showing Embodiment 1 of an air conditioner according to the present invention. First Embodiment An air conditioner according to a first embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 1, in the air conditioner, a condenser 1, an expansion valve 2, an evaporator 3, and a compressor 4 are respectively connected by circulation pipes through which a refrigerant circulates. Expansion valve 2
Is an electronic expansion valve whose opening can be adjusted by a microcomputer using a stepping motor or the like. The blower fan 6 is used to blow air to the condenser 1, and the blower fan 5 is used to blow air to the evaporator 3. In FIG.
By circulating the refrigerant in the direction indicated by the arrow, a heat pump cycle is realized.

The expansion valve 2, which is installed in a pipe from the condenser 1 to the evaporator 3 and adjusts the flow rate of the refrigerant, has an inlet as one of the measuring means provided in a circulation pipe located on the inlet side thereof. A side temperature detector (thermometer) 8 is provided. Further, an outlet-side temperature detector (thermometer) 9 as one of the measuring means is installed in the circulation line located on the outlet side of the expansion valve 2. The compressor 4 for compressing the refrigerant is provided with an operating current detector 10 as one of measuring means for measuring the operating current of the compressor 4. Inlet side temperature detector 8,
The outlet-side temperature detector 9 and the operating current detector 10 are each connected to a control device 7 as determination means for performing a failure determination described later.

FIG. 2 is a flow chart showing a control flow of a method for determining a failure in the air conditioner shown in FIG. Embodiment 1 of the air conditioner failure determination method according to the present invention will be described with reference to FIG.

Referring to FIG. 2, in the failure determination method for an air conditioner according to the present invention, when the failure determination control is started, a failure determination (failure diagnosis) command is received by controller 7 (see FIG. 1). A step (S1) of confirming whether or not there is is performed. Here, if the failure determination command has not been received, step S1 is performed until the failure determination command is received.
repeat.

When it is confirmed in step S1 that the control device 7 has received the failure determination command, a step of confirming whether the operation cycle (operating conditions) of the air conditioner shown in FIG. 1 is stable. (S2) is performed. If the operation cycle is not stable, the process S is continued until a predetermined condition is satisfied and the operation cycle is confirmed to be stable.
Repeat 2. When it is confirmed that the operation cycle is stable, a step (S3) of setting a determination time used for failure determination control described later is performed. Next, a step (S4) of storing the opening (N) of the expansion valve 2 in a state where the operation cycle before performing the failure determination is stable is performed.
Thereafter, a step (S5) of rapidly closing the expansion valve 2 is performed.

Thereafter, as a measurement step, the outlet-side temperature of the expansion valve 2 is detected by the outlet-side temperature detector 9. Then, the measured value is transmitted from the outlet-side temperature detector 9 to the control device 7, and the control device 7 determines whether the temperature at the outlet side of the expansion valve has decreased by a certain value as a determination step (S
Perform 6).

Here, by rapidly closing the expansion valve 2,
The refrigerant flow rate at the outlet side of the expansion valve 2 decreases. Then, the refrigerant near the outlet of the expansion valve 2 undergoes an evaporation phenomenon, so that the temperature near the outlet of the expansion valve 2 rapidly decreases.
For this reason, if the expansion valve 2 is operating normally, the expansion valve 2
Since the temperature at the outlet side of the valve rapidly decreases, it is possible to determine whether the expansion valve 2 is operating normally by detecting the temperature drop.

When the amount of decrease (change) of the outlet-side temperature of the expansion valve 2 is equal to or more than a fixed value (reference value), it is understood that the expansion valve 2 is operating normally as described above. As a result, it is determined that there is no failure (S8). On the other hand, when the temperature on the outlet side of the expansion valve 2 has not decreased to the predetermined temperature (when the amount of decrease in the outlet side temperature is equal to or less than the reference value), it is determined whether the determination time set in step S3 has elapsed. (S7) is performed. Step S6 and step S7 are repeated to monitor the outlet-side temperature of the expansion valve 2 until the determination time has elapsed. If the outlet-side temperature of the expansion valve 2 has not decreased by a certain value or more even after the determination time has elapsed, it is considered that the expansion valve 2 has not performed the closing operation as instructed. As a result, it is considered that an operation failure has occurred in the expansion valve 2, and it is determined that there is a failure (S
9). When such a failure determination is made, it is preferable to notify the user of the air conditioner of the occurrence of the failure, such as displaying a warning light.

In this manner, by forcibly closing the expansion valve 2, the air conditioner suddenly increases the flow rate of the refrigerant as an operating condition (cycle condition) for failure determination different from that during normal operation. A condition can be created that lowers the temperature of the refrigerant to a degree that is not possible during normal operation. In a state where the expansion valve 2 is operating normally, such a condition that the temperature of the refrigerant rapidly decreases can be quickly realized. On the other hand, when the closing operation of the expansion valve 2 is not performed normally due to the failure of the expansion valve 2, the temperature of the refrigerant does not sufficiently decrease as described above.

Therefore, by detecting whether or not the conditions for suddenly closing the expansion valve 2 such as a sudden decrease in refrigerant flow rate and a decrease in refrigerant temperature as the operating conditions for failure determination can be realized, the presence or absence of a failure in the expansion valve 2 is detected. Can be determined quickly and reliably. Further, the degree of the temperature decrease of the refrigerant due to the rapid closing of the expansion valve 2 is sufficiently larger than the degree of the variation in the temperature of the refrigerant under the normal operating conditions. Even if the operating conditions during normal operation of the air conditioner fluctuate, the failure determination of the expansion valve 2 of the air conditioner can be reliably performed.

After a certain period of time has elapsed since the failure determination (S8) or the failure determination (S9) is made, the expansion valve 2 is opened based on the opening (N) before the determination to perform normal operation. (S10) is performed.

Here, if the operation of closing the expansion valve 2 is performed as it is, it is conceivable that equipment such as the compressor 4 may be damaged due to insufficient flow of the refrigerant in the air conditioner. Therefore, by opening the valve automatically after a certain period of time as described above, such damage to the device can be prevented.

It is preferable that the opening when the expansion valve 2 is opened in the step of returning to the normal operation (S10) is determined based on the opening (N) before the judgment as described above. By doing so, the normal operation state before the determination can be reproduced with high accuracy. Therefore, it is possible to prevent the operating state of the air conditioner from largely changing before and after the failure determination operation.

When it is determined that there is a failure, it is preferable to immediately stop the operation of the air conditioner depending on the degree of the failure and to take necessary measures such as inspection and repair of the failed part.

(Embodiment 2) FIG. 3 is a flowchart showing Embodiment 2 of the air conditioner failure judgment method according to the present invention. Embodiment 2 of the air conditioner failure determination method according to the present invention will be described with reference to FIG.

Referring to FIG. 3, the air conditioner failure determination method basically includes the same steps as those of the air conditioner failure determination method according to the first embodiment of the present invention shown in FIG.
However, a step (S6) of judging whether or not the expansion valve outlet temperature has decreased by a certain value in the flowchart shown in FIG.
Instead, in the failure determination method shown in FIG. 3, it is determined whether or not the operating current of the compressor 4 has decreased by a certain value (S1).
Perform 1). This means that when the step (S5) of rapidly closing the expansion valve 2 is performed, the amount of refrigerant circulating in the cycle of the air conditioner shown in FIG. 1 is reduced, and the operating current of the compressor 4 is also reduced. It was used. Specifically, an operating current of the compressor 4 is detected by an operating current detector 10 installed in the compressor 4. After the step of rapidly closing the expansion valve 2 (S5), the operating current of the compressor 4 sharply decreases as described above. Then, the measured value of the detected operating current is transmitted to the control device 7. The control device 7 calculates the amount of change in the operating current before and after the rapid closing operation of the expansion valve 2 from the measured value of the operating current of the compressor 4. In the control device 7,
A step (S11) of determining whether or not the operating current has decreased by a certain value is performed by comparing the amount of change in the operating current before and after the sudden closing operation of the expansion valve 2 with a preset reference value. .

Also in this case, the same effects as those of the air conditioner failure determination method according to Embodiment 1 of the present invention can be obtained. That is, when the amount of decrease in the operating current of the compressor 4 is equal to or more than the preset reference value, it is understood that the expansion valve 2 is operating normally (performing the closing operation). Further, when the amount of decrease in the operating current is equal to or less than the reference value, even though the closing operation command is issued to the expansion valve 2,
This indicates that the closing operation of the expansion valve 2 is not sufficient (the opening degree of the expansion valve 2 is not sufficiently small). In this way, it is possible to easily and reliably determine whether a failure has occurred in the expansion valve 2. Further, by using an operating condition different from the normal operation of rapidly closing the expansion valve 2, it is possible to stably determine the failure without being affected by the environmental condition of the air conditioner.

(Embodiment 3) FIG. 4 is a flowchart showing Embodiment 3 of a method for determining a failure of an air conditioner according to the present invention. Embodiment 3 of the air conditioner failure determination method according to the present invention will be described with reference to FIG.

Referring to FIG. 4, the failure determination method basically includes the same steps as those of the air conditioner failure determination method according to the first embodiment of the present invention shown in FIG. For checking whether the side temperature has decreased by a certain value (S
Instead of 6), a step (S12) of confirming whether or not the operating condition of the air conditioner has undergone a predetermined change with the rapid closing of the expansion valve 2 is performed. The data for evaluating the operating conditions used in step S12 include, for example, (a) a decrease in the outlet-side temperature of the expansion valve 2 based on the data measured by the outlet-side temperature detector 9 before and after the expansion valve 2 is rapidly closed. (B) The expansion valve 2 is rapidly closed with respect to the temperature difference between the expansion valve inlet side temperature detected by the inlet side temperature detector 8 and the outlet side temperature of the expansion valve 2 detected by the outlet side temperature detector 9. The three types of evaluation data are used: the amount of change in the temperature difference before and after the operation, and (c) the amount of decrease in the operating current of the compressor 4 detected by the operating current detector 10 before and after the expansion valve 2 is rapidly closed. . When the expansion valve 2 operates normally and each of the inlet-side temperature detector 8, the outlet-side temperature detector 9, and the operating current detector 10 operates normally, the above-mentioned three evaluation data are set in advance. A change that satisfies the set reference value is shown.

On the other hand, for example, the inlet-side temperature detector 8, the outlet-side temperature detector 9, and the operating current detector 10 are operating normally, respectively. If the expansion valve 2 is not sufficiently closed, the outlet side temperature of the expansion valve 2 does not sufficiently decrease, the amount of change in the temperature difference does not become a sufficiently large value, and the operating current of the compressor 4 decreases. Each of the above-mentioned three evaluation data does not show a predetermined change such that the amount is not as large as a predetermined value, and it can be seen that a failure has occurred in the expansion valve 2.

If any of the operating current detector 10, the inlet-side temperature detector 8 and the outlet-side temperature detector 9 is malfunctioning, the expansion valve 2 is rapidly closed and the compressor 4 Evaluation data relating to the operating current (decrease in operating current) and evaluation data based on the measured values of the temperature detectors 8 and 9 installed before and after the expansion valve 2 (decrease in outlet side temperature and change in temperature difference) ) Shows a predetermined change and the other does not show an expected change. In this case, it can be seen that a malfunction has occurred in the detector used to derive the evaluation data that does not show a predetermined change. For example, if the amount of decrease in the operating current satisfies a predetermined reference value, but the amount of decrease in the outlet thermometer and the amount of change in the temperature difference do not satisfy the predetermined reference values, the outlet-side temperature detector 9 or the outlet-side temperature detector It can be seen that a failure has occurred in both the detector 9 and the inlet-side temperature detector 8. On the other hand, while the amount of decrease in the outlet-side thermometer and the amount of change in the temperature difference satisfy a predetermined reference value, if the amount of decrease in the operating current does not satisfy the predetermined reference value, a failure occurs in the operating current detector 10. You can see that there is.

It should be understood that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0053]

According to the present invention, the use of operating conditions for failure determination realized by closing a valve allows quick and reliable determination of the presence or absence of a failure of a valve or the like regardless of environmental conditions. An air conditioner that can be determined and a failure determination method for the air conditioner can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing Embodiment 1 of an air conditioner according to the present invention.

FIG. 2 is a flowchart showing a control flow of a failure determination method in the air conditioner shown in FIG.

FIG. 3 is a flowchart showing Embodiment 2 of a method for determining a failure of an air conditioner according to the present invention.

FIG. 4 is a flowchart illustrating a third embodiment of a method for determining a failure of an air conditioner according to the present invention.

[Explanation of symbols]

1 condenser, 2 expansion valve, 3 evaporator, 4 compressor,
5, 6 blower fan, 7 controller, 8 inlet temperature detector (thermometer), 9 outlet temperature detector (thermometer), 10
Operating current detector.

Claims (11)

[Claims] 1. A method for judging a failure of an air conditioner having a valve for adjusting a flow rate of a refrigerant flowing from a condenser to an evaporator, comprising the steps of: closing the valve during operation of the air conditioner; A measurement step of measuring an operating condition of the air conditioner that changes by the closing operation; anda determining step of determining whether or not the air conditioner has a failure by using a measured value of the measured operating condition. Machine failure determination method. 2. The method according to claim 1, wherein the measuring step includes measuring an amount of change in the temperature of the refrigerant at the outlet of the valve before and after the closing operation of the valve. The failure of the air conditioner according to claim 1, further comprising determining whether or not the valve has failed by comparing the reference value of the amount of change in the temperature of the refrigerant when the valve is closed. Judgment method. 3. The air conditioner has a compressor that compresses the refrigerant, and the measuring step includes measuring a change amount of an operating current of the compressor before and after closing the valve. The determining step is to determine whether there is a failure of the valve by comparing the measured value of the amount of change in the operating current with a reference value of the amount of change in the operating current when the valve is closed. The method for determining a failure of an air conditioner according to claim 1, comprising: 4. An air conditioner, comprising: a compressor for compressing the refrigerant; a current detector for measuring an operating current of the compressor; and an outlet thermometer installed on the valve outlet side. The measuring step is a step of measuring the amount of change in the temperature of the refrigerant at the outlet side of the valve before and after the closing operation of the valve using the outlet side thermometer, and before and after the closing operation of the valve, Measuring a temperature difference change amount that is a change amount of a difference between a temperature of the refrigerant at an inlet side of the valve and a temperature of the refrigerant at an outlet side of the valve; and closing the valve using the current detector. Measuring a current change amount of the operating current of the compressor before and after, wherein the determination step uses respective measured values of the temperature change amount, the temperature difference change amount, and the current change amount. Determining whether there is a failure in the valve, the outlet-side thermometer, and the current detector. The method for determining a failure of an air conditioner according to claim 1. 5. The air conditioner failure determination according to claim 1, further comprising a return step of opening the valve after a predetermined time has elapsed after performing the determination step. Method. 6. The air conditioner according to claim 1, further comprising a return step of opening the valve when it is determined in the determination step that no failure has occurred in the air conditioner. Failure determination method for air conditioners. 7. The valve according to claim 5, wherein, in the return step, the valve is opened so as to have an opening determined based on the opening of the valve before the valve is closed. The method for determining a failure of the air conditioner according to the above. 8. An air conditioner having a valve for adjusting a flow rate of refrigerant flowing from a condenser to an evaporator, means for closing the valve during operation of the air conditioner, and An air conditioner, comprising: a measuring unit that measures a changing operating condition of the air conditioner; and a determining unit that determines whether the air conditioner has a failure by using a measured value of the measured operating condition. 9. The measuring means has an outlet thermometer installed on the outlet side of the valve, and the determining means is based on a measured value of the outlet thermometer before and after closing the valve. The air conditioner according to claim 8, further comprising: means for determining whether the valve has a failure. 10. The air conditioner further includes a compressor that compresses the refrigerant, the measuring unit includes a current detector that measures an operating current of the compressor, and the determining unit closes the valve. The air conditioner according to claim 8, further comprising a unit configured to determine whether the valve has a failure based on a measurement value of the current detector before and after operation. 11. The air conditioner further includes a compressor that compresses the refrigerant, the measuring unit includes an outlet thermometer installed at an outlet of the valve, and a current that measures an operating current of the compressor. Having a detector, the determination means, based on the measured value of the outlet thermometer and the measured value of the current detector before and after the closing operation of the valve, the valve, the current detector and the The air conditioner according to claim 8, further comprising a unit that determines whether the outlet-side thermometer has a failure.