JP2012127625A - Fault diagnosis apparatus to be used for air conditioning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To diagnose a fault of an air conditioning apparatus without increasing power consumption or deteriorating comfort during the fault diagnosis.SOLUTION: A fault diagnosis apparatus 200 diagnoses a fault of a refrigerant cycle circuit 100 based on one or a plurality of cycle parameters showing the state of the refrigerant cycle circuit 100. The fault diagnosis apparatus 200 includes a preliminary diagnosis part 21 and a fault diagnosis part 22. The preliminary diagnosis part 21 determines the possibility of fault in the refrigerant cycle circuit by comparing the cycle parameters with predetermined criteria during normal cooling and heating operations of the refrigerant cycle circuit 100. The fault diagnosis part 22 causes the refrigerant cycle circuit 100 to operate for fault diagnosis of the refrigerant cycle circuit 100 when the refrigerant cycle circuit 100 is determined to be likely to fail by the preliminary diagnosis part 21.

Description

  The present invention relates to a failure diagnosis device used for diagnosing a failure of an air conditioner.

  Conventionally, as a method of diagnosing a failure of an air conditioner, as shown in Patent Document 1, there is a method of diagnosing a failure by measuring an air conditioning cycle parameter during a cooling / heating operation.

  However, there is a problem that it is necessary to perform a great number of experiments corresponding to the installation conditions, the outside air temperature, the indoor load, and the actuator control to create a failure diagnosis standard. In addition, the number of experiments can be reduced by limiting the operating conditions for performing failure diagnosis, but the diagnosis frequency may be reduced and failure may not be detected for a long time.

  Moreover, as shown in Patent Document 2, there is an apparatus that performs an operation of fixing an actuator, measures an air-conditioning cycle parameter, and diagnoses a failure. If this is the case, the influence of actuator control is eliminated, and therefore the number of experiments for creating a failure diagnosis standard can be reduced.

  However, even if there is no abnormality in the air conditioner, it is necessary to periodically perform a failure diagnosis operation with the actuator fixed, resulting in an increase in power consumption and a decrease in comfort due to suppression of the cooling and heating capacity.

JP 2004-85088 A JP 2006-90614 A

  Accordingly, the present invention has been made to solve the above problems all at once, and is mainly intended to enable failure diagnosis of an air conditioner without causing an increase in power consumption and a decrease in comfort associated with failure diagnosis. This is an issue to be solved.

  That is, the failure diagnosis apparatus according to the present invention is a failure diagnosis apparatus that diagnoses a failure of the refrigeration cycle circuit based on one or a plurality of cycle parameters indicating the state of the refrigeration cycle circuit. During this time, the cycle parameter is compared with a predetermined determination criterion to determine the possibility of failure of the refrigeration cycle circuit, and the preliminary diagnosis unit determines that there is a possibility of failure of the refrigeration cycle circuit. And a failure diagnosis unit that performs failure diagnosis operation of the refrigeration cycle circuit and performs failure diagnosis of the refrigeration cycle circuit.

  In such a case, it is only necessary to perform failure diagnosis when the preliminary diagnosis unit determines that there is a possibility of failure, so there is no need to periodically perform failure diagnosis operation, which increases power consumption and comfort. Deterioration can be suppressed.

  Secondary regression analysis of experimental data at the time of abnormality based on the predetermined determination criteria based on the outside air temperature where the air conditioner forming the refrigeration cycle circuit is installed, the room temperature controlled by the air conditioner, and the number of indoor units operating It is desirable that Since the criterion is obtained by quadratic regression analysis, the number of experiments for creating the criterion can be reduced. Here, the reason why the quadratic regression analysis is used is that the characteristics of the cycle parameter with respect to the outside air temperature, room temperature, and the number of indoor units operating are monotonically increasing or monotonically decreasing, and do not have the maximum value and the minimum value. Therefore, the characteristics of the cycle parameter can be approximated without using a third-order or higher regression equation.

  In order to reduce the number of experiments as much as possible, the predetermined criterion is that the outside air temperature is changed by at least three points, the room temperature is changed by at least two points, and the number of indoor units operated is at least It is desirable that the experimental data of the minimum 12 conditions changed by 2 points (2 points on the large capacity side) are subjected to a quadratic regression analysis.

  The reason why the room temperature is set to at least two points is that the change width of the room temperature is small, and a large error does not occur even if the linear approximation is performed from the data of two points for the change of only the room temperature. Regarding the temperature change during cooling, the outside air temperature is -10 ° C to 40 ° C, while the room temperature is about 20 ° C to 30 ° C.

  The number of indoor unit operations is at least two. For example, a multi air conditioner for buildings equipped with a plurality of indoor units is assumed to operate near the total number except for early morning, late at night and holidays. Because. For this reason, operation with a small number of operation is small in frequency, and it is not necessary to perform highly accurate detection.

  In order to perform preliminary diagnosis automatically by the preliminary diagnosis unit, it is desirable to have a determination reference data storage unit that stores determination reference data indicating the predetermined determination reference.

  At the time of failure diagnosis operation, the room temperature becomes a consequence, and therefore there is a possibility that failure diagnosis becomes inaccurate. Therefore, in order to perform failure diagnosis with high accuracy, the failure diagnosis unit adjusts the room temperature to a predetermined temperature when the preliminary diagnosis unit determines that there is a possibility of failure of the refrigeration cycle circuit. It is desirable that the refrigeration cycle circuit be operated for fault diagnosis.

  According to the present invention configured as described above, it is only necessary to perform a failure diagnosis when it is determined by the preliminary diagnosis unit that there is a possibility of a failure. An increase and a decrease in comfort can be suppressed.

The schematic diagram which shows the whole air conditioning system containing the failure diagnosis apparatus which concerns on one Embodiment of this invention. The functional block diagram of the failure diagnosis apparatus in the embodiment. The flowchart of the failure diagnosis in the same embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an air conditioner 100 that is a refrigeration cycle device according to the present embodiment, and a failure diagnosis apparatus 200 used in the air conditioner 100.

  As shown in FIG. 1, the air conditioner 100 basically includes a compressor 11, a heat exchanger (condenser) 12, an expansion valve 13, and a heat exchanger (evaporator) 14 in this order. It is configured to operate a refrigeration cycle by connecting and circulating a refrigerant inside. In addition, the code | symbol 15 in FIG. 1 selectively switches the heat exchangers 13 and 14 each arrange | positioned in the indoor unit 101 and the outdoor unit 102 to either a condenser or an evaporator by changing the flow of a refrigerant | coolant, This is a four-way valve that switches between indoor heating and cooling.

  Further, the air conditioning apparatus 100 is provided with various sensors (not shown) for measuring cycle parameters, and data from each sensor is transmitted to a failure diagnosis apparatus 200 described later and used for failure diagnosis. It is. The cycle parameter is a state quantity indicating the state of the refrigeration cycle, and is, for example, temperature, humidity, pressure, or the like at various locations of the refrigerant.

  The failure diagnosis apparatus 200 is a so-called computer having a CPU, a memory, an I / O channel, an output device such as a display, an input device such as a keyboard, an AD converter, etc., and a CPU according to a failure diagnosis program stored in the memory. As the peripheral device operates, the functions as the preliminary diagnosis unit 21, the determination reference data storage unit D1, the failure diagnosis unit 22, the failure reference data storage unit D2, and the like are exhibited as shown in FIG.

  In addition, the physical installation place of this failure diagnosis apparatus 200 is not ask | required. For example, it may be provided integrally with the air conditioner 100 or may be provided at another place through a communication line such as the Internet. In this embodiment, one failure diagnosis device 200 is provided for one air conditioner 100, but one failure diagnosis device is connected to a plurality of air conditioners. It doesn't matter. In that case, it is necessary to exchange identification data for identifying each air conditioner.

  Next, the operation of the failure diagnosis apparatus 200 will be described in detail with reference to FIG.

  During normal cooling / heating operation, the preliminary diagnosis unit 21 constantly acquires cycle parameter measurement values from sensors provided in each unit of the air conditioner 100 (step S1). Then, the preliminary diagnosis unit 21 compares the cycle parameter measurement value with the determination criterion indicated by the determination criterion data stored in the determination criterion data storage unit D1 (step S2). When the preliminary diagnosis unit 21 determines that the cycle parameter measurement value is abnormal as a result of the comparison between the cycle parameter measurement value and the determination criterion, the preliminary diagnosis unit 21 outputs determination result data indicating the result to the failure diagnosis unit 22. To do.

  Note that the determination reference data stored in the determination reference data storage unit D1 is created based on previously performed experimental data. In the present embodiment, the criterion is that the outside air temperature at which the air conditioner 100 is installed is changed by at least three points, the room temperature adjusted by the air conditioner 100 is changed by at least two points, and the room of the air conditioner 100 is changed. The machine operation number is changed at least at two points on the large capacity side, and the experimental data of the minimum 12 conditions obtained is created by secondary regression analysis. For example, when it comes to the outside air temperature, there are 3 points of 10 ° C., 20 ° C. and 30 ° C., and when it comes to room temperature, it is 2 points of 20 ° C. and 30 ° C. It is two points of an operation state and an indoor unit operation state of 70%.

  The determination criteria are adjusted so that the preliminary diagnosis unit 21 can easily determine that there is a possibility of failure. The determination criterion of the present embodiment is created by correcting the experimental result so that it is determined that the refrigerant pressure is 0.3 MPa, the refrigerant temperature is 5K, and there is a possibility of failure. Here, in the preliminary diagnosis, since the number of data points is small, the preliminary failure determination accuracy is low. In addition, since the determination criteria are corrected, it is easy to determine that there is a possibility of failure even during normal operation. However, the preliminary diagnosis is a determination condition for entering the failure diagnosis operation, and even if it is erroneously determined that there is a possibility of failure during normal operation, it is unlikely to cause a problem for the user.

  When the preliminary diagnosis unit 21 determines that there is a possibility of failure, the failure diagnosis unit 22 first controls the air conditioner 100 to adjust the room temperature to a predetermined temperature (step S3). Here, the predetermined temperature is, for example, 25 ° C. in both the cooling operation and the heating operation. Different temperatures may be used.

  After adjusting the room temperature to a predetermined temperature, the failure diagnosis unit 22 controls each actuator of the air conditioner 100 to a predetermined fixed value (step S4). Examples of the actuator include a compressor, an outdoor fan, an outdoor expansion valve, an indoor fan, and an indoor expansion valve. And the failure diagnosis part 22 fixes each actuator to the following fixed values in the case of each of cooling operation and heating operation. Thus, the failure diagnosis part 22 of this embodiment has a function as a control part which controls the air conditioning apparatus 100. FIG.

<Cooling operation>
Compressor: 50% of maximum capacity
Outdoor fan ... Maximum rotation outdoor expansion valve ... Maximum opening indoor fan ... Maximum rotation indoor expansion valve ... 50% of maximum opening
<Heating operation>
Compressor: 50% of maximum capacity
Outdoor fan ... Maximum number of rotations Outdoor expansion valve ... 50% of maximum opening
Indoor fan ... Maximum number of rotations Indoor expansion valve ... Maximum opening

  Thereafter, the failure diagnosis unit 22 acquires cycle parameter measurement values from each sensor of the air conditioner 100 during failure diagnosis operation in which each actuator is controlled to the fixed value (step S5), and the failure reference data storage unit D2 Is compared with the failure criterion indicated by the failure criterion data stored in (step S6). When the failure diagnosis unit 22 determines that the cycle parameter measurement value is abnormal as a result of the comparison between the cycle parameter measurement value and the failure criterion, the failure diagnosis unit 22 generates failure data indicating the result, and the air conditioner Failure data indicating that 100 is a failure and the cause of the failure is output to the output device (step S7). On the other hand, when the failure diagnosis unit 22 determines that the cycle parameter measurement value is not abnormal, the failure diagnosis unit 22 returns the air conditioner 100 to the normal air conditioning operation (step S1).

  Note that the failure reference data stored in the failure reference data storage unit D2 is created based on previously performed experimental data. In this embodiment, it is created from the experimental data at the time of abnormality when the actuator is fixed at room temperature. Since the only parameter that changes is the outside air temperature, it can be created with a small number of data points.

<Effect of this embodiment>
According to the failure diagnosis apparatus 100 according to the present embodiment configured as described above, failure diagnosis is performed only when it is determined by the preliminary diagnosis unit 21 that there is a possibility of failure, so it is necessary to periodically perform failure diagnosis operation. Therefore, an increase in power consumption and a decrease in comfort can be suppressed. In addition, the number of experiments can be reduced by creating a criterion for preliminary diagnosis using quadratic regression analysis. Furthermore, since the preliminary diagnosis is always performed during the normal cooling / heating operation, there is no need to limit the operating conditions for performing the diagnosis, and the diagnosis frequency does not decrease. In addition, since the failure diagnosis is performed after the temperature is adjusted to room temperature, a highly accurate failure diagnosis is possible.

<Other modified embodiments>
The present invention is not limited to the above embodiment. For example, you may comprise so that the failure data obtained by the failure diagnosis part of the said embodiment may be transmitted to a monitoring apparatus by radio | wireless or a wire communication. In this case, the failure can be predicted by remotely monitoring the air conditioner. As a result, it is possible to eliminate the trouble diagnosis work that has conventionally been performed locally by service personnel. In addition, it is possible to cope with a lack of cooling / heating capacity due to a failure, and it is possible to prevent the user's comfort from being impaired.

  In addition, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

100 ... Air conditioner (refrigeration cycle circuit)
200 ... Failure diagnosis device 21 ... Preliminary diagnosis unit 22 ... Failure diagnosis unit D1 ... Determination criterion data storage unit

Claims (6)

A failure diagnosis device for diagnosing a failure in a refrigeration cycle circuit based on one or more cycle parameters indicating the state of the refrigeration cycle circuit,
During normal cooling / heating operation of the refrigeration cycle circuit, the cycle parameter and a predetermined criterion are compared, and a preliminary diagnosis unit that determines the possibility of failure of the refrigeration cycle circuit;
A failure diagnosis unit that performs a failure diagnosis operation of the refrigeration cycle circuit and performs a failure diagnosis of the refrigeration cycle circuit when the preliminary diagnosis unit determines that there is a possibility of failure of the refrigeration cycle circuit Diagnostic device.   Secondary regression analysis of experimental data at the time of abnormality based on the predetermined determination criteria based on the outside air temperature where the air conditioner forming the refrigeration cycle circuit is installed, the room temperature controlled by the air conditioner, and the number of indoor units operating The fault diagnosis apparatus according to claim 1, wherein   The predetermined criterion is that the experimental data under a minimum of 12 conditions, wherein the outside air temperature is changed at least at three points, the room temperature is changed at at least two points, and the number of indoor units operated is changed at at least two points, is secondary. The failure diagnosis apparatus according to claim 2, which is a regression analysis.   The failure diagnosis apparatus according to claim 1, further comprising a determination reference data storage unit that stores determination reference data indicating the predetermined determination reference.   The failure diagnosis unit is configured to perform a failure diagnosis operation of the refrigeration cycle circuit after adjusting a room temperature to a predetermined temperature when the preliminary diagnosis unit determines that there is a possibility of failure of the refrigeration cycle circuit. Item 5. The fault diagnosis apparatus according to 1, 2, 3, or 4.   6. The failure diagnosis according to claim 1, wherein the failure diagnosis unit diagnoses a failure of the refrigeration cycle circuit based on the cycle parameter in a state where each actuator of the refrigeration cycle circuit is fixed. apparatus.