Refrigeration cycle device and method for determining the cause of malfunction

Abstract

To make it possible to determine the cause of an abnormality in a refrigeration cycle device.SOLUTION: A method for determining the cause of an abnormality includes: a step of stopping driving of a compressor when a discharge temperature of the compressor becomes an abnormal temperature; a step of measuring a time from start of the driving of the compressor until the discharge temperature becomes the abnormal temperature; a step of counting the number of times when the discharge temperature becomes the abnormal temperature; and a step of determining the cause of the abnormality in a refrigeration cycle device on the basis of the time and the number of times.SELECTED DRAWING: Figure 3

Description

Technical Field

[0005] ,

[0001] The present invention relates to a refrigeration cycle device and a method for determining the cause of an abnormality.

Background Art

[0002] In an air conditioner using a refrigeration cycle (heat pump cycle), during its operation, the operation of the compressor and the opening degree of the expansion valve are controlled. By controlling the opening degree of the expansion valve (normal control) during normal operation in the air conditioner, the circulation amount of the refrigerant in the cycle is adjusted. For this reason, the heating degree of the refrigerant gas at the outlet of the compressor can be adjusted. Thereby, heat exchange is efficiently performed in the compressor, and liquid return to the compressor is suppressed.

[0003] An air conditioner that stops operation when the discharge temperature of the compressor exceeds the maximum discharge temperature and then changes the opening degree of the expansion valve when restarting the operation has been studied (for example, Patent Document 1). In the air conditioner of Patent Document 1, when the discharge temperature of the compressor exceeds the maximum discharge temperature, the opening degree of the expansion valve at that time stores a predetermined value, and when restarting the operation after a predetermined time has elapsed, the opening degree of the expansion valve is set to a value obtained by adding a correction value to the stored predetermined value, thereby suppressing the operation from stopping due to the discharge temperature exceeding the maximum discharge temperature in the next operation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Even in the air conditioner of Patent Document 1, the discharge temperature of the compressor may exceed the maximum discharge temperature even when the opening degree of the expansion valve is changed. In the air conditioner of Patent Document 1, the cause of the discharge temperature of the compressor exceeding the maximum discharge temperature cannot be specified.

[0006] The present invention has been made in view of the above problems, and its purpose is to provide a refrigeration cycle device capable of determining the cause of an abnormality and a method for determining the cause of an abnormality. [Means for solving the problem]

[0007] The refrigeration cycle device according to the present invention comprises an expansion valve for expanding a refrigerant, a compressor for compressing the refrigerant, an adjustment unit for adjusting the opening degree of the expansion valve, a drive control unit for controlling the operation of the compressor, and a detection unit for detecting the discharge temperature of the compressor. When the discharge temperature reaches an abnormal temperature, the drive control unit stops the operation of the compressor. The refrigeration cycle device further comprises a timing unit for measuring the time from the start of operation of the compressor until the discharge temperature reaches the abnormal temperature, a counting unit for counting the number of times the discharge temperature reaches the abnormal temperature, and a determination unit for determining the cause of the abnormality in the refrigeration cycle device when specific conditions based on the time and the number of times are met. If the specific conditions are not met, the adjustment unit changes the opening degree of the expansion valve, and then the drive control unit restarts the operation of the compressor.

[0008] The abnormality cause determination method according to the present invention is used in a refrigeration cycle device equipped with a compressor for compressing the refrigerant. The abnormality cause determination method includes the steps of: stopping the operation of the compressor when the discharge temperature of the compressor reaches an abnormal temperature; measuring the time from the start of operation of the compressor until the discharge temperature reaches the abnormal temperature; counting the number of times the discharge temperature reaches the abnormal temperature; and determining the cause of the abnormality in the refrigeration cycle device based on the time and the number of times. [Effects of the Invention]

[0009] According to the present invention, the cause of an abnormality in a refrigeration cycle device can be determined. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram of an air conditioner equipped with a refrigeration cycle device according to this embodiment. [Figure 2] This is a diagram showing the refrigeration cycle device of this embodiment. [Figure 3] This is a flowchart of an air conditioner according to the first embodiment. [Figure 4] This is a flowchart of an air conditioner according to the second embodiment. [Figure 5] This is a flowchart of an air conditioner according to the third embodiment. [Figure 6] This is a flowchart of an air conditioner according to the fourth embodiment. [Figure 7] This is a flowchart of an air conditioner in a modified form. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the refrigeration cycle device and air conditioner according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and will not be repeated in the description.

[0012] First, the refrigeration cycle device 10 of this embodiment will be described with reference to Figure 1. Figure 1 is a block diagram of an air conditioner 10A equipped with the refrigeration cycle device 10.

[0013] As shown in Figure 1, the air conditioner 10A comprises an indoor unit 100, a remote control 105, and an outdoor unit 200. Typically, the indoor unit 100 is located indoors, and the outdoor unit 100 is located outdoors.

[0014] Refrigerant circulates between the indoor unit 100 and the outdoor unit 200. For example, when the indoor unit 100 cools a room, the heat from the room where the indoor unit 100 is located is discharged to the outside where the outdoor unit 200 is located via the refrigerant. Conversely, when the indoor unit 100 heats a room, the heat from the outside where the outdoor unit 200 is located is transferred to the room where the indoor unit 100 is located via the refrigerant.

[0015] The indoor unit 100 comprises an indoor control unit 110, a remote control transmitting / receiving unit 120, and an indoor fan motor 130.

[0016] The indoor control unit 110 controls the indoor unit 100. The indoor control unit 110 includes an indoor operation control unit 111 and an indoor command transmission unit 112. The indoor operation control unit 111 controls the operation of the indoor unit 100. The indoor command transmission unit 112 transmits a drive signal to the indoor fan motor 130. The indoor fan motor 130 rotates the fan disposed in the indoor unit 100. The fan rotated by the indoor fan motor 130 sucks indoor air and supplies it to the indoor heat exchanger 160 (see FIG. 2), and also sends out the air heat-exchanged in the indoor heat exchanger 160 into the room.

[0017] The remote control transceiver unit 120 transmits and receives signals between the remote control 105 and the indoor operation control unit 111 described later. Typically, when the operator operates the remote control 105, the remote control 105 transmits an operation signal to the remote control transceiver unit 120. The remote control transceiver unit 120 receives the operation signal and transmits it to the indoor operation control unit 111. The indoor operation control unit 111 controls each part in the indoor unit 100 according to the operation signal.

[0018] Note that the remote control 105 may receive a signal from the remote control transceiver unit 120. For example, when the remote control 105 has a display unit, the remote control 105 receives a signal from the remote control transceiver unit 120 and displays an image on the display unit. Also, when the remote control 105 has an audio output unit, the remote control 105 receives a signal from the remote control transceiver unit 120 and outputs audio.

[0019] For example, the remote control 105 displays the operation mode of the air conditioner 10A and accepts an operation instruction.

[0020] The outdoor unit 200 includes an outdoor control unit 210, an outdoor fan motor 220, a compressor 230, an expansion valve 240, a four-way valve 250, a suction solenoid valve 260, and a discharge temperature sensor 273.

[0021] The indoor fan motor 130 of the indoor unit 100, and the outdoor fan motor 220, compressor 230, expansion valve 240, four-way valve 250, and suction solenoid valve 260 of the outdoor unit 200 constitute part of the refrigeration cycle device 10 that circulates refrigerant between the indoor unit 100 and the outdoor unit 200.

[0022] The outdoor fan motor 220 rotates the fan located on the outdoor unit 200. The fan rotated by the outdoor fan motor 220 supplies outside air to the outdoor heat exchanger 280 (see Figure 2).

[0023] The compressor 230 compresses the refrigerant. As the refrigerant is compressed, its temperature rises.

[0024] The expansion valve 240 expands the refrigerant. As the refrigerant expands, its temperature decreases.

[0025] The discharge temperature sensor 273 is, for example, a thermocouple and detects the temperature of the refrigerant discharged from the compressor 230 (hereinafter referred to as "discharge temperature"). The discharge temperature sensor 273 is an example of the "detection unit" of the present invention.

[0026] The outdoor control unit 210 controls the outdoor unit 200. The outdoor control unit 210 includes an outdoor operation control unit 211, an outdoor command transmission unit 212, an adjustment unit 213, a drive control unit 214, a temperature determination unit 216, a discrimination unit 218, a counting unit 219, a timing unit 219a, and a warning unit 219b.

[0027] The outdoor operation control unit 211 controls the operation of the outdoor unit 200. The outdoor command transmission unit 212 transmits drive signals to the outdoor fan motor 220, the four-way valve 250, and the suction solenoid valve 260.

[0028] The adjustment unit 213 adjusts the opening degree of the expansion valve 240. More specifically, the adjustment unit 213 adjusts the opening degree of the expansion valve 240 by outputting an adjustment instruction, which is one of the drive signals, to the expansion valve 240.

[0029] The drive control unit 214 controls the drive of the compressor 230. More specifically, the drive control unit 214 controls the drive of the compressor 230 by outputting a compressor drive signal, which is one of the drive signals, to the compressor 230.

[0030] The temperature determination unit 216 determines that a high discharge temperature error has occurred if the discharge temperature of the compressor 230 is at a predetermined abnormal temperature. When a high discharge temperature error occurs, the drive control unit 214 outputs a drive signal (hereinafter referred to as "compressor stop instruction") to stop the operation of the compressor 230. As a result, the compressor 230 stops operating.

[0031] The counting unit 219 counts the number of times N the discharge temperature reaches the abnormal temperature.

[0032] The timing unit 219a measures the time T from the start of operation of the compressor 230 until the discharge temperature reaches an abnormal temperature.

[0033] The warning unit 219b warns of the cause of the abnormal temperature. For example, the warning unit 219b causes the cause of the abnormal temperature to be displayed on the display unit of the remote control 105. In one example, the warning unit 219b displays the cause of the abnormal temperature as text information or image information on the display unit of the remote control 105. Alternatively, the warning unit 219b outputs the cause of the abnormal temperature as audio information. For example, the warning unit 219b outputs the cause of the abnormal temperature as audio information from the audio output device in the indoor unit 100.

[0034] The discrimination unit 218 determines the cause of the malfunction in the refrigeration cycle device 10 based on specific conditions. The specific conditions are predetermined based on the number of times counted by the counting unit 219 and the time measured by the timing unit 219a.

[0035] Each of the indoor control unit 110 and the outdoor control unit 210 includes a processor and a memory unit. The processor includes, for example, a Central Processing Unit (CPU). The memory unit includes a storage device such as semiconductor memory and stores data and computer programs. The processor controls each component of the air conditioner 10A, including the refrigeration cycle device 10, by executing the computer programs stored in the memory unit. In Figure 1, the memory unit of the outdoor control unit 21 is denoted by the reference numeral "217".

[0036] Next, the overall configuration of the refrigeration cycle device 10 will be described with reference to Figures 1 and 2. Figure 2 is a diagram showing the refrigeration cycle device 10.

[0037] As shown in Figure 2, the refrigeration cycle device 10 further comprises an indoor heat exchanger 160, an outdoor heat exchanger 280, a two-way valve 291, and a three-way valve 292. Arrow D1 indicates the direction in which the refrigerant flows during the cooling cycle. The refrigerant flow path, along arrow D1, sequentially passes from the compressor 230 through the four-way valve 250, the outdoor heat exchanger 280, the expansion valve 240, the two-way valve 291, the indoor heat exchanger 160, the three-way valve 292, the suction solenoid valve 260, and the four-way valve 250, before returning to the compressor 230. In the heating cycle, the direction in which the refrigerant flows is opposite to that of arrow D1.

[0038] The four-way valve 250 is connected via refrigerant piping to the discharge and suction pipes of the compressor 230, the outdoor heat exchanger 280, and the indoor heat exchanger 160. During operation, the four-way valve 250 switches between a cooling operation state, in which the discharge pipe of the compressor 230 is connected to the outdoor heat exchanger 280 and the suction pipe of the compressor 230 is connected to the indoor heat exchanger 160, and a heating operation state, in which the discharge pipe of the compressor 230 is connected to the indoor heat exchanger 160 and the suction pipe of the compressor 230 is connected to the outdoor heat exchanger 280, according to a control signal transmitted from the outdoor control unit 29.

[0039] The two-way valve 291 and the three-way valve 292 are positioned at the refrigerant inlet and outlet of the outdoor unit 200. Both the two-way valve 291 and the three-way valve 292 are manually opened when the air conditioner 10A is installed.

[0040] The two-way valve 291 is installed in the refrigerant piping. The two-way valve 291 closes when the refrigerant piping is removed from the outdoor unit 200, preventing refrigerant from leaking out of the outdoor unit 200.

[0041] The three-way valve 292 is installed in the refrigerant piping. The three-way valve 292 is closed when the refrigerant piping is removed from the outdoor unit 200 to prevent refrigerant from leaking to the outside from the outdoor unit 200. Furthermore, when it is necessary to recover refrigerant from the outdoor unit 200 or from the entire refrigeration cycle system 10 including the indoor unit 100, the refrigerant is recovered through the three-way valve 292.

[0042] The discharge temperature sensor 273 is located in the discharge pipe of the compressor 230. The suction temperature sensor 274 is located in the suction pipe of the compressor 230.

[0043] [First Embodiment] Next, the operation of the air conditioner 10A equipped with the refrigeration cycle device 10 of the first embodiment will be described with reference to Figures 1 to 3. Figure 3 is a flowchart illustrating the operation of the air conditioner 10A of this embodiment.

[0044] As shown in Figure 3, in step S101, the indoor control unit 110 receives an operation command for the air conditioner 10A via the remote control 105.

[0045] Next, in step S102, the operation of the refrigeration cycle device 10 in the air conditioner 10A is started. Specifically, in the indoor control unit 110, the indoor control unit 110 drives the indoor fan motor 130 via the indoor command transmission unit 112 and instructs the outdoor control unit 210 to start the operation of the outdoor unit 200. The outdoor control unit 210 drives the outdoor fan motor 220, the four-way valve 250, and the suction solenoid valve 260, respectively, via the outdoor command transmission unit 212. The outdoor control unit 210 further outputs an adjustment instruction to the expansion valve 240 via the adjustment unit 213 to adjust the opening degree of the expansion valve 240 to an initial value. The outdoor control unit 210 further outputs a compressor drive signal to the compressor 230 via the drive control unit 214 to start driving the compressor 230.

[0046] In step S103, the counting unit 219 sets the count N to an initial value (i.e., "zero"). The timing unit 219a starts measuring time T.

[0047] In step S104, the temperature determination unit 216 periodically acquires the discharge temperature of the compressor 230 from the discharge temperature sensor 273. The temperature determination unit 216 determines whether or not the discharge temperature has reached an abnormal temperature. If the temperature determination unit 216 determines that the discharge temperature has not reached an abnormal temperature (No in step S104), it executes step S104 again. On the other hand, if the temperature determination unit 216 determines that the discharge temperature has reached an abnormal temperature (Yes in step S104), it determines that a high discharge temperature error has occurred and executes step S105.

[0048] In step S105, the operation of the refrigeration cycle device 10 in the air conditioner 10A is stopped. In particular, the drive control unit 214 stops the drive of the compressor 230 in response to the compressor stop instruction.

[0049] Next, in step S106, the timing unit 219a stops measuring time T. Therefore, the measured time T represents the time from the start of operation of the compressor 230 until the discharge temperature reaches an abnormal temperature. The discrimination unit 218 determines whether the measured time T satisfies the first specific condition. The first specific condition is part of the specific conditions, and is that time T is within the time threshold T1. The time threshold T1 is, for example, 60 minutes. If the first specific condition is not met (No in step S106), the process proceeds to step S107. On the other hand, if the first specific condition is met (Yes in step S106), the process proceeds to step S109.

[0050] In step S107, the outdoor control unit 210 resets the count N to its initial value using the counting unit 219.

[0051] Next, in step S108, the outdoor control unit 210 outputs an adjustment instruction to the expansion valve 240 via the adjustment unit 213 to increase the opening degree of the expansion valve 240 beyond its current state. Also, the operation of the refrigeration cycle device 10 in the air conditioner 10A is restarted by the same control as in step S102. The timing unit 219a also starts measuring time T after initialization. After the execution of step S108, the process returns to step S103.

[0052] In step S109, the outdoor control unit 210 increments the count N by 1 using the counting unit 219.

[0053] Next, in step S110, the discrimination unit 218 determines whether the count N satisfies the second specific condition. The second specific condition is part of the specific conditions, and is that the count N has reached the threshold count N1. The threshold count N1 is, for example, 5, and is an example of the "first threshold count" in the present invention. If the second specific condition is not satisfied (No in step S110), the process proceeds to step S108. On the other hand, if the second specific condition is satisfied (Yes in step S110), the process proceeds to step S111.

[0054] In step S111, the discrimination unit 218 determines that the cause of the malfunction in the refrigeration cycle device 10 is at least one of refrigerant leakage and sticking of the expansion valve. The discrimination unit 218 stops the operation of the refrigeration cycle device 10 in the air conditioner 10A. The outdoor control unit 210 also functions as a warning unit 219b and notifies the indoor control unit 110 that the cause of the malfunction in the refrigeration cycle device 10 is at least one of refrigerant leakage and sticking of the expansion valve 240, and that the operation of the air conditioner 10A is prohibited. The indoor control unit 110, via the remote control transmitting / receiving unit 120, displays on the display unit of the remote control 105 that the cause of the malfunction is at least one of refrigerant leakage and sticking of the expansion valve 240, and that the operation of the air conditioner 10A is prohibited.

[0055] In this embodiment, if the discharge temperature reaches an abnormal temperature, the expansion valve 240 is opened wider than its current position, provided that the first specific condition is not met. On the other hand, if both the first and second specific conditions (i.e., the specific conditions) are met, the discharge temperature will reach an abnormal temperature despite the increased opening of the expansion valve 240. In this case, it is determined that the cause of the malfunction in the refrigeration cycle device 10 is at least one of refrigerant leakage and sticking of the expansion valve.

[0056] [Second Embodiment] Next, the operation of the air conditioner 10A equipped with the refrigeration cycle device 10 of the second embodiment will be described with reference to Figures 1, 2, and 4. Figure 4 is a flowchart illustrating the operation of the air conditioner 10A of the second embodiment.

[0057] As shown in Figure 4, steps S201 to S215 are executed in the air conditioner 10A. Steps S201 to S210 are the same as steps S101 to S110 shown in Figure 3, so their respective explanations are omitted. In the second embodiment, the threshold count N1 is, for example, 4.

[0058] In step S211, the outdoor control unit 210 outputs an adjustment instruction (hereinafter referred to as "full open instruction") to the expansion valve 240 via the adjustment unit 213 to fully open the expansion valve 240. In addition, the operation of the refrigeration cycle device 10 in the air conditioner 10A is restarted by the same control as in step S102. The timing unit 219a also starts measuring time T after initialization.

[0059] Next, in step S212, the temperature determination unit 216 determines whether the discharge temperature has reached an abnormal temperature, in the same manner as in step S104 shown in Figure 3. If the temperature determination unit 216 determines that the discharge temperature has not reached an abnormal temperature (No in step S212), it executes step S212 again. On the other hand, if the temperature determination unit 216 determines that the discharge temperature has reached an abnormal temperature (Yes in step S212), it executes step S213.

[0060] In step S213, the timing unit 219a stops measuring time T. Therefore, the measured time T represents the time from the restart of the compressor 230 in step S211 until the discharge temperature reaches an abnormal temperature. The discrimination unit 218 determines whether the measured time T satisfies the third specific condition. The third specific condition is part of the specific conditions, and is that time T is within the time threshold T2. The time threshold T2 is, for example, 10 minutes. If the third specific condition is not met (No in step S213), the process proceeds to step S214. On the other hand, if the third specific condition is met (Yes in step S213), the process proceeds to step S215.

[0061] In step S214, the discrimination unit 218 determines that the cause of the malfunction in the refrigeration cycle device 10 is a refrigerant leak. The discrimination unit 218 stops the operation of the refrigeration cycle device 10 in the air conditioner 10A. The outdoor control unit 210 also functions as a warning unit 219b and notifies the indoor control unit 110 that the cause of the malfunction in the refrigeration cycle device 10 is a refrigerant leak and that the operation of the air conditioner 10A is prohibited. The indoor control unit 110, via the remote control transmitting / receiving unit 120, displays on the display unit of the remote control 105 that the cause of the malfunction is a refrigerant leak and that the operation of the air conditioner 10A is prohibited.

[0062] In step S215, the discrimination unit 218 determines that the cause of the malfunction in the refrigeration cycle device 10 is the sticking of the expansion valve 240. The discrimination unit 218 stops the operation of the refrigeration cycle device 10 in the air conditioner 10A. The outdoor control unit 210 also functions as a warning unit 219b and notifies the indoor control unit 110 that the cause of the malfunction in the refrigeration cycle device 10 is the sticking of the expansion valve 240 and that the operation of the air conditioner 10A is prohibited. The indoor control unit 110, via the remote control transmitting / receiving unit 120, displays on the display unit of the remote control 105 that the cause of the malfunction in the refrigeration cycle device 10 is the sticking of the expansion valve 240 and that the operation of the air conditioner 10A is prohibited.

[0063] In this embodiment, when the second specific condition is met (step S210), the operation of the refrigeration cycle device 10 is restarted with the expansion valve 240 fully open. In this case, when the third specific condition is met (i.e., when the discharge temperature reaches an abnormal temperature in a short time), it is determined that the cause of the abnormality in the refrigeration cycle device 10 is the sticking of the expansion valve 240. On the other hand, when the third specific condition is not met (i.e., when the discharge temperature does not reach an abnormal temperature in a short time), it is determined that the cause of the abnormality is a refrigerant leak.

[0064] [Third Embodiment] Next, the operation of the air conditioner 10A equipped with the refrigeration cycle device 10 of the third embodiment will be described with reference to Figures 1, 2, and 5. Figure 5 is a flowchart illustrating the operation of the air conditioner 10A of the third embodiment.

[0065] As shown in Figure 5, steps S301 to S313 are executed in the air conditioner 10A. Steps S301 to S311 are the same as steps S101 to S111 shown in Figure 3, so their respective explanations will be omitted.

[0066] If the second specific condition is not met in step S310 (No in step S310), the process proceeds to step S312.

[0067] In step S312, the discrimination unit 218 determines whether the count N satisfies the fourth specific condition. The fourth specific condition is part of the specific conditions, and is that the count N exceeds the threshold count N2. The threshold count N2 is smaller than the threshold count N1. The threshold count N2 is a reference value indicating that the refrigerant in the refrigeration cycle device 10 is decreasing. The threshold count N2 is stored in the storage unit 217 and is an example of the "second threshold count" in the present invention.

[0068] If the fourth specific condition is not met (No in step S312), the process proceeds to step S308. On the other hand, if the fourth specific condition is met (Yes in step S312), the process proceeds to step S313.

[0069] In step S313, the outdoor control unit 210 notifies the indoor control unit 110 that the refrigerant is decreasing in the refrigeration cycle device 10. The indoor control unit 110 causes the display unit of the remote control 105 to display that the refrigerant is decreasing via the remote control transmitting / receiving unit 120. The outdoor control unit 210 updates the threshold count N2 in the storage unit 217 by count N. The outdoor control unit 210 and indoor control unit 110 in step S313 are examples of the "notification / update unit" in the present invention. Also, count N is an example of the "determination count" in the present invention. After the execution of step S313, the process proceeds to step S308.

[0070] In this embodiment, although the number of cycles N has not reached the threshold cycle N1, it can be determined that the refrigerant in the refrigeration cycle device 10 is decreasing because it exceeds the threshold cycle N2.

[0071] [Fourth Embodiment] Next, the operation of the air conditioner 10A equipped with the refrigeration cycle device 10 of the fourth embodiment will be described with reference to Figures 1, 2, and 6. Figure 6 is a flowchart illustrating the operation of the air conditioner 10A of the fourth embodiment.

[0072] As shown in Figure 6, steps S401 to S416 are executed in the air conditioner 10A. Steps S401, S402, S404 to S411 are the same as steps S101, S102, S104 to S111 shown in Figure 3, so their respective explanations are omitted. In the second embodiment, the threshold count N1 is, for example, 4.

[0073] In step S403, the counting unit 219 sets the number of counts N and Nt to initial values.

[0074] Step S412 is executed if the first specific condition is satisfied in step S406. In step S412, the outdoor control unit 210 determines whether or not the fifth specific condition is satisfied. The fifth specific condition is that the absolute value of the difference between time T and the time reference value T3 is less than or equal to the threshold time T4. The initial value of the time reference value T3 is predetermined and stored in the storage unit 217. The threshold time T4 is predetermined and is a value close to zero.

[0075] If the fifth specific condition is not met (No in step S412), the process proceeds to step S413. On the other hand, if the fifth specific condition is met (Yes in step S412), the process proceeds to step S414.

[0076] In step S413, the outdoor control unit 210 updates the time reference value T3 at time T. After step S413 is completed, the process proceeds to step S409.

[0077] In step S414, the outdoor control unit 210 determines whether the number of times Nt satisfies the sixth specific condition using the discrimination unit 218 (S414). The sixth specific condition is that the number of times Nt exceeds the threshold number of times N3. The threshold number of times N3 can be predefined in the computer program and is a criterion for determining whether or not the expansion valve 240 is stuck.

[0078] If the sixth specific condition is met (Yes in step S414), the process proceeds to S415. If the sixth specific condition is not met (No in step S414), the process proceeds to step S416.

[0079] In step S415, the discrimination unit 218 performs the same processing as in step S215 in Figure 4.

[0080] In step S416, the outdoor control unit 210 increments the count Nt by 1 using the discrimination unit 218. The process then proceeds to step S408.

[0081] In this embodiment, if the time T from the start of operation of the compressor 230 until a high-temperature discharge error is determined is close to Nt consecutive times, it is determined that the expansion valve 240 is stuck.

[0082] Embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings schematically show each component in order to make them easy to understand, and the thickness, length, number, spacing, etc. of each component shown may differ from the actual dimensions due to the convenience of drawing creation. Also, the material, shape, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various modifications are possible without substantially departing from the effects of the present invention.

[0083] (1) In the fourth embodiment, step S415 was performed after step S414. However, the process is not limited to this, and as shown in Figure 7, steps S211 to S213 shown in Figure 4 may be performed between step S414 and step S415. This improves the reliability of the determination that the expansion valve 240 is stuck. [Industrial applicability]

[0084] This invention has industrial applicability as a method for generating abnormalities in refrigeration cycle systems. [Explanation of Symbols]

[0085] 10: Refrigeration cycle equipment 10A: Air conditioner 21: Outdoor control unit 29: Outdoor control unit 100: Indoor unit 105: Remote control 110: Indoor Control Unit 111: Indoor Operation Control Unit 112: Indoor command transmission unit 120: Remote control transmitter / receiver unit 130: Indoor fan motor 160: Indoor heat exchanger 200: Outdoor unit 210: Outdoor control unit 211: Outdoor Operation Control Unit 212: Outdoor command transmission unit 213: Adjustment section 214: Drive Control Unit 216:Temperature judgment section 217: Storage section 218: Discrimination section 219: Counting Department 219a: Timing section 219b: Warning section 220: Outdoor fan motor 230: Compressor 240: Expansion valve 250: Four-way valve 260: Suction solenoid valve 273: Discharge temperature sensor 274: Suction temperature sensor 280:Outdoor heat exchanger 291: Two-way valve 292: Three-way valve

Claims

1. A refrigeration cycle device, An expansion valve that expands the refrigerant, A compressor for compressing the aforementioned refrigerant, An adjustment unit for adjusting the opening degree of the expansion valve, A drive control unit that controls the operation of the compressor, A detection unit for detecting the discharge temperature of the compressor and Equipped with, When the discharge temperature reaches an abnormal temperature, the drive control unit stops the operation of the compressor. The aforementioned refrigeration cycle device further, A timing unit that measures the time from the start of operation of the compressor until the discharge temperature reaches the abnormal temperature, A counting unit that counts the number of times the discharge temperature reaches the abnormal temperature, A determination unit that determines the cause of the abnormality in the refrigeration cycle device when specific conditions based on the aforementioned time and number of times are met. Equipped with, If the above specific conditions are not met, the adjustment unit changes the opening degree of the expansion valve, and then the drive control unit restarts the operation of the compressor. The aforementioned specific condition is that the number of determinations in which the time it takes for the discharge temperature to reach the abnormal temperature is determined to be within a threshold time reaches a first threshold number of determinations, in a refrigeration cycle device.

2. The refrigeration cycle apparatus according to claim 1, wherein when the number of determinations reaches the first threshold number, the determination unit determines that the cause of the abnormality is at least one of refrigerant leakage and sticking of the expansion valve.

3. The refrigeration cycle apparatus according to claim 1, wherein when the number of determinations reaches the first threshold number, the adjustment unit increases the opening of the expansion valve, and after the drive control unit restarts the operation of the compressor, if the discharge temperature becomes the abnormal temperature, the determination unit determines that the cause of the abnormality is the sticking of the expansion valve.

4. A storage unit that stores the second threshold number of times, The refrigeration cycle apparatus according to claim 1, further comprising a notification and update unit that, when the number of determinations has not reached the first threshold number, exceeds the second threshold number stored in the storage unit, notifies the user of the decrease in the refrigerant and updates the second threshold number stored in the storage unit with the number of determinations.

5. The refrigeration cycle apparatus according to claim 1, wherein if the time difference between the time measured by the timing unit when the discharge temperature became abnormally high this time and the time measured by the timing unit when the discharge temperature became abnormally high last time is less than or equal to a threshold time difference, the discrimination unit determines that the cause of the abnormality is the sticking of the expansion valve.

6. A method for determining the cause of an abnormality used in a refrigeration cycle system equipped with a compressor for compressing a refrigerant, The step of stopping the operation of the compressor when the discharge temperature of the compressor reaches an abnormal temperature, A step of measuring the time from the start of operation of the compressor until the discharge temperature reaches the abnormal temperature, The steps include counting the number of times the discharge temperature reached the abnormal temperature, A step of determining the cause of the abnormality in the refrigeration cycle device based on the fact that the aforementioned time is within the threshold time and that the aforementioned number of times has reached the threshold number of times. A method for determining the cause of an anomaly, including the above.

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