JP4606394B2 - Refrigerant leak detection method, refrigerant leak detection device, and air conditioner - Google Patents

Description

  The present invention relates to a refrigerant leakage detection method capable of detecting refrigerant leakage accurately and stably over a long period of time, a refrigerant leakage detection device that executes the method, and an air conditioner including the device.

  Conventionally, in an indoor / outdoor separation type air conditioner in which an indoor unit and an outdoor unit are separated, a hydrofluorocarbon (hereinafter referred to as “HFC”) material is used as a refrigerant, and R32 or R152a is used as the HFC material. Some have flammability.

  Therefore, for example, when the pipe in the air conditioner breaks and the refrigerant leaks, the leaked refrigerant may ignite, so the air conditioner uses the refrigerant leak detection method or the refrigerant leak detection device. It was requested.

  Therefore, conventionally, an air conditioner has been proposed in which a refrigerant sensor is attached and the refrigerant sensor detects refrigerant leaking from the refrigerant circuit (for example, Patent Document 1).

  However, since the refrigerant sensor used in the invention described in Patent Document 1 is likely to change over time, there is a problem in that refrigerant leakage is erroneously detected due to long-time use. In addition, since the refrigerant sensor is expensive, an air conditioner equipped with the refrigerant sensor has a problem that the manufacturing cost increases and it is difficult to accept it in the market.

Then, the air conditioner which detects the leakage of the refrigerant | coolant from a refrigerant circuit was proposed by attaching a temperature sensor instead of a refrigerant | coolant sensor, and a temperature sensor detecting the rise or fall of the temperature of a heat exchanger (for example, Patent Document 2). That is, in the invention described in Patent Document 2, when the refrigerant that causes an increase or decrease in the temperature of the heat exchanger is filled in the refrigerant circuit, the temperature of the heat exchanger is increased or decreased by the refrigerant. On the other hand, if there is a shortage of refrigerant in the refrigerant circuit, the temperature of the heat exchanger will not rise or fall, so the refrigerant leaks from the refrigerant circuit based on the rise or fall of the heat exchanger temperature. It is something to be judged. The invention described in Patent Document 2 can suppress an increase in the manufacturing cost of the air conditioner by using an inexpensive temperature sensor instead of an expensive refrigerant sensor, and the temperature sensor is less likely to change over time than the refrigerant sensor. This is in response to market demands in that leakage of refrigerant from the refrigerant circuit can be detected even after long-term use.
JP-A-8-327195 JP 2000-81258 A

  However, since the temperature of the heat exchanger may change depending on the temperature around the refrigerant circuit including the heat exchanger, for example, the refrigerant is satisfied even though the refrigerant is satisfied in the refrigerant circuit. When the heat around the circuit is transferred to the heat exchanger and prevents the temperature of the heat exchanger from rising or falling, in the invention described in Patent Document 2, there is actually no refrigerant leakage, but the refrigerant There is a problem in that it is erroneously detected that the leakage is occurring.

  The present invention has been made in view of such circumstances. The object of the present invention is to set the temperature range of the heat exchanger within a predetermined time, the temperature of the heat exchanger when the predetermined time is reached, and the refrigerant. Refrigerant capable of accurately and stably detecting refrigerant leakage over a long period of time while suppressing manufacturing cost by detecting refrigerant leakage from the refrigerant circuit based on the temperature difference between the temperatures around the circuit It is providing the leak detection method, the refrigerant | coolant leak detection apparatus which performs the said method, and an air conditioner provided with the said apparatus.

Refrigerant leakage detection method according to the present invention in order to solve the above described problems is the method for detecting refrigerant leakage from a refrigerant circuit including a heat exchanger, the heat exchanger in the time or these predetermined time starting temperature When the temperature range is calculated from the maximum temperature and the minimum temperature of the heat exchanger that are repeatedly detected, and the calculated temperature range is determined to be within the predetermined range, the refrigerant leaks from the refrigerant circuit. It is judged that it is.
Furthermore, refrigerant leakage detection method according to the present invention is a method for detecting refrigerant leakage from a refrigerant circuit including a heat exchanger, repeatedly detects the temperature of the heat exchanger within a predetermined time when starting or al, A temperature range is calculated from the highest temperature and the lowest temperature of the heat exchanger repeatedly detected, and when the temperature reaches a predetermined time, the temperature around the refrigerant circuit is detected, and the temperature difference between the heat exchanger and the refrigerant circuit is detected. And when it is determined that the calculated temperature range is within a predetermined range and the calculated temperature difference does not exceed a predetermined value, it is determined that the refrigerant is leaking from the refrigerant circuit. It is characterized by.

The refrigerant leakage detection device according to the present invention is a refrigerant leakage detection device comprising a refrigerant circuit including a heat exchanger and leakage detection means for detecting leakage of the refrigerant from the refrigerant circuit, the temperature of the heat exchanger. comprising a temperature detection means for detecting, timing means, and calculating means for calculating the temperature range of the maximum and minimum temperatures of the repeated detected temperature by said temperature detecting means to start or these within a predetermined time, the The leakage detection unit is configured to output a signal indicating that the refrigerant is leaking from the refrigerant circuit when the temperature range calculated by the calculation unit is determined to be within a predetermined range. To do.
The refrigerant leakage detection device according to the present invention is a refrigerant leakage detection device comprising a refrigerant circuit including a heat exchanger and leakage detection means for detecting leakage of the refrigerant from the refrigerant circuit, the temperature of the heat exchanger. a first temperature detecting means for detecting a second temperature detecting means for detecting the temperature around the refrigerant circuit, timer means and repeatedly detected temperature by said first temperature detecting means when starting or these within a predetermined time maximum temperature and a calculation means for calculating the temperature range of the heat exchanger and a minimum temperature, the temperature of the heat exchanger detected by the first temperature detecting means upon reaching a predetermined time at or we start and the second Determining means for determining whether or not a temperature difference between the temperatures around the refrigerant circuit detected by the temperature detecting means exceeds a predetermined value, and the leakage detecting means has a temperature range calculated by the calculating means within a predetermined range. Where the temperature If a is determined not to exceed a predetermined value, characterized in that the refrigerant from the refrigerant circuit are to output a signal indicating that is leaking.

Furthermore, the air conditioner according to the present invention includes the refrigerant leakage detection device described above and means for stopping operation in response to a signal indicating that the refrigerant output from the refrigerant leakage detection device is leaking. It is characterized by providing.

  In the present invention, if the temperature range of the heat exchanger is within the predetermined range and the temperature difference between the heat exchanger and the temperature around the refrigerant circuit does not exceed the predetermined value when the predetermined time is reached, both refrigerants Is based on a phenomenon that occurs when the temperature of the heat exchanger is less likely to increase or decrease due to shortage in the refrigerant circuit, it is determined that the refrigerant is leaking. On the other hand, if the temperature range of the heat exchanger is larger than the predetermined range, or if the temperature difference between the heat exchanger and the temperature around the refrigerant circuit exceeds a predetermined value when the predetermined time is reached, at least One is not a phenomenon that occurs when there is a shortage of refrigerant in the refrigerant circuit, so that it is not determined that the refrigerant is leaking to avoid erroneous detection of refrigerant leakage. Further, since the temperature sensor is used for determining the leakage of the refrigerant, the leakage of the refrigerant from the refrigerant circuit is stably detected even when used for a long time as compared with the refrigerant sensor. In addition, since an inexpensive temperature sensor is used to determine the leakage of the refrigerant, an increase in the manufacturing cost of the air conditioner is suppressed as compared with the case where an expensive refrigerant sensor is used.

  In the present invention, the leakage of the refrigerant can be accurately detected without erroneous detection due to the influence of the temperature around the refrigerant circuit. Moreover, in this invention, even when an air conditioner is used for a long time using a temperature sensor with little secular change, the leakage of the refrigerant from the refrigerant circuit can be detected stably. Furthermore, in the present invention, an inexpensive temperature sensor can be used to suppress the manufacturing cost of the air conditioner and smoothly accept it in the market.

  Hereinafter, a refrigerant leakage detection method, a refrigerant leakage detection device, and an air conditioner according to the present invention will be described based on the drawings showing embodiments. FIG. 1 is a schematic diagram showing a configuration of an air conditioner according to the present invention, and FIG. 2 is a schematic diagram showing a configuration of a control unit.

  In FIG. 1, the air conditioner includes a refrigerant leakage detection device including a refrigerant circuit 1 and a control unit 2. The refrigerant circuit 1 is composed of an indoor heat exchanger 11, an expansion valve 12, an outdoor heat exchanger 13, a four-way switching valve 14, and a compressor 15, which are sequentially piped by a pipe 16. The control unit 2 controls the refrigerant circuit 1 and is connected to a temperature sensor 21 attached to the indoor heat exchanger 11 and / or the outdoor heat exchanger 13 and a temperature sensor 22 arranged around the refrigerant circuit 1. Then, a temperature signal detected by the connected temperature sensor 21 or the like is received.

  Here, the operation of the refrigerant circuit 1 will be described. When the cooling operation is performed by the air conditioner, as indicated by an arrow A, the refrigerant in the pipe 16 is compressed (vaporized) to a high pressure by the compressor 15, and the outdoor heat exchanger 13 is passed through the four-way switching valve 14. The air is compressed (liquefied) while dissipating heat to the outdoor air in the outdoor heat exchanger 13, is transferred to the expansion valve 12, is expanded by the expansion valve 12, and is then expanded through the pipe 16 to the indoor heat exchanger 11. Further, the room-side heat exchanger 11 evaporates (vaporizes) the room air while absorbing heat, is conveyed to the compressor 15 via the four-way switching valve 14, and is compressed (vaporized) again by the compressor 15. . And the cold air produced | generated by the circulation of such a refrigerant | coolant is sent indoors by the ventilation fan (not shown, and it is the same below) arrange | positioned in the indoor side heat exchanger 11 vicinity, and cools indoor air.

  When heating operation is performed with an air conditioner, as indicated by an arrow B, the refrigerant in the pipe 16 is compressed (vaporized) to a high pressure by the compressor 15 and is transferred to the indoor heat exchanger 11 via the four-way switching valve. It is conveyed, compressed (liquefied) while radiating heat to indoor air in the indoor heat exchanger 11, conveyed to the expansion valve 12, expanded by the expansion valve 12, and then to the outdoor heat exchanger 13 through the pipe 16. Then, the outdoor air heat exchanger 13 evaporates (vaporizes) the outdoor air while absorbing heat, transports it to the compressor 15 via the four-way switching valve 14, and compresses (vaporizes) again with the compressor 15. And the warm air produced | generated by the circulation of such a refrigerant | coolant is sent indoors with the ventilation fan arrange | positioned in the indoor side heat exchanger 11 vicinity, and warms indoor air.

  Next, the configuration of the control unit 2 will be described. The control unit 2 includes a temperature sensor interface 20, a ROM 23, a RAM 24, a timer 25, an operation unit 26, a display unit 27, a CPU 28, and the like connected to the temperature sensors 21, 21,. And a bus 29 for connecting the two.

  The temperature sensor interface 20 is connected to the temperature sensors 21, 21,... And the temperature sensor 22, receives a temperature signal detected by the temperature sensor 21, and sends it to the CPU 28.

  The temperature sensors 21, 21,... Are, for example, thermistors, which are attached to the indoor side heat exchanger 11 and / or the outdoor side heat exchanger 13, and rise or fall due to evaporation or compression of the refrigerant. The internal temperature X is detected, and the detected temperature X is generated as a signal and sent to the CPU 28 via the temperature sensor interface 20.

  The temperature sensor 22 is, for example, a thermistor, and detects the temperature Y around the refrigerant circuit 1 that rises or falls regardless of the evaporation or compression of the refrigerant (including the temperature around the air conditioner, the room temperature, or the outdoor temperature). Then, the detected temperature Y is generated as a signal and sent to the CPU 28 via the temperature sensor interface 20.

  The ROM 23 is, for example, a conversion program that converts a signal received via the temperature interface 20 into temperature information, a calculation program that calculates a temperature range from the converted temperature information, and whether a temperature difference obtained from a plurality of temperature information exceeds a predetermined value. A determination program for determining whether or not, a detection program for detecting whether or not refrigerant is leaking from the refrigerant circuit 1 based on temperature information, a control program for controlling each part of hardware included in the air conditioner, and other various programs Are stored and read as appropriate in response to a read request from the CPU.

  The RAM 24 is configured by SRAM, flash memory, or the like. Data generated when the CPU 28 executes the program, for example, a received time or temperature signal, a calculated temperature range, and a user input via the operation unit 26. The predetermined time, the predetermined range, the predetermined value, etc. are stored.

  The timer 25 calculates a temperature range and measures a predetermined time which is a timing for determining a predetermined value. The timer 25 receives a timing start instruction from the CPU 28, counts the time from the timing start according to the received instruction, and measures the time. A time signal is sequentially sent to the CPU.

  The operation unit 26 includes various operation buttons for receiving operation instructions from a user, and selects a cooling operation or a heating operation, setting a target temperature, changing a wind direction, setting a predetermined time, setting a predetermined range, An instruction for setting a predetermined value is received and sent to the RAM 24. The operation unit 26 may be installed not only in the air conditioner main body but also separately connected by wire, or may be remotely controlled by radio.

  The display unit 27 includes a liquid crystal display. The operating state of the air conditioner, setting information set via the operation unit 26, information to be notified to the user (for example, refrigerant leaks from the refrigerant circuit 1). Warning) and the like.

  The CPU 28 controls not only the hardware components configured by the control unit 2 by the control program read from the ROM 23, but also controls the hardware components configured by the refrigerant circuit 1 so that the refrigerant passes through the refrigerant circuit 1 with the arrows A or B. Control to circulate in the direction. Further, the CPU 28 converts a signal received by the temperature interface 20 into temperature information by the conversion program read from the ROM 23, calculates a temperature range from the temperature information by the calculation program, and a difference obtained from the plurality of temperature information by the determination program is predetermined. It is determined whether or not the value is exceeded, and processing for detecting whether or not the refrigerant is leaking from the refrigerant circuit 1 is executed by the detection program.

  Next, the refrigerant leak detection method according to the present invention will be described. FIG. 3 is a graph showing the temperature range of the heat exchanger detected by the refrigerant leak detection method according to the present invention, and FIG. 4 is a graph showing the temperature around the heat exchanger and the refrigerant circuit detected by the refrigerant leak detection method according to the present invention. It is a graph which shows a temperature difference. In the present embodiment, a case where the air conditioner is activated in the heating operation will be described.

When the air conditioner is operating normally without leakage of refrigerant from the refrigerant circuit 1, as shown in FIG. 3, during the previous operation, the indoor heat exchanger from the start (time measurement start) t ₁ to the time t ₂ Since the liquefied refrigerant remaining in 11 evaporates (vaporizes) while absorbing heat, the temperature X of the indoor heat exchanger 11 drops to the minimum value Xmin. Then, from the time t ₂ to the time t ₃ when the predetermined time is reached, the liquefied refrigerant remaining at the previous operation disappears, and the refrigerant is compressed (liquefied) while releasing heat in the indoor heat exchanger 11. The temperature X of the vessel 11 rises to the maximum value Xmax. As described above, the temperature sensor 21 generates the temperature X sequentially detected from the time of start (time measurement start) t ₁ to the time t ₃ when it reaches the predetermined time, and sends it to the CPU 28 via the temperature sensor interface 20. The CPU 28 calculates the temperature range b based on the received signal.

Further, as shown in FIG. 4, the temperature X of the indoor heat exchanger 11 detected by the temperature sensor 21 at the start (time measurement start) t ₁ is slightly higher than the temperature Y around the refrigerant circuit 1 detected by the temperature sensor 22. It is in. The temperature X of the indoor side heat exchanger 11 rapidly drops due to the refrigerant from the time of start (time measurement start) t ₁ to time t _2, and the temperature X of the indoor side heat exchanger 11 is the refrigerant. It becomes lower than the temperature Y around the circuit 1. Then, during the period from time t ₂ to arrival time t ₃ , the temperature rises rapidly due to the refrigerant, and the temperature X of the indoor side exchanger 11 becomes higher than the temperature Y around the refrigerant circuit 1. As described above, the temperature sensor 21 (and 22) generates the temperature X (and Y) detected at the time t ₃ when the predetermined time has been reached as a signal and sends it to the CPU 28 via the temperature sensor interface 20. The CPU 28 calculates the temperature difference d based on the received signal. The value d in the present embodiment is a positive number (the temperature X of the indoor side exchanger 11> the temperature Y around the refrigerant circuit 1).

  When the temperature range b is larger than the predetermined range i or the temperature difference d exceeds the predetermined value j, the CPU 28 has insufficient refrigerant in the refrigerant circuit. Therefore, it is determined that there is no refrigerant leakage from the refrigerant circuit 1.

  On the other hand, when the refrigerant is leaking from the refrigerant circuit 1, the temperature sensor 21 sequentially detects the decrease and increase in the temperature X of the indoor heat exchanger 11 as in the normal operation. The temperature range a of the temperature X of the indoor heat exchanger 11 that is finally calculated by the CPU 28 is, because the factor refrigerant is insufficient in the refrigerant circuit 1 and the temperature X of the indoor heat exchanger 11 is difficult to rise. smaller than b (see FIG. 3).

  As in the normal operation, the temperature sensor 21 (and 22) detects the temperature X of the indoor heat exchanger 11 (and the temperature Y around the refrigerant circuit 1). The refrigerant X becomes insufficient in the refrigerant circuit 1 and it becomes difficult for the temperature X of the indoor heat exchanger 11 to rise. Therefore, the CPU 28 finally calculates the temperature X of the indoor heat exchanger 11 and the vicinity of the refrigerant circuit 1. The temperature difference c of the temperature Y is also smaller than d (see FIG. 4).

  When the temperature range a is within the predetermined range i (including the value i) and the temperature difference c does not exceed the predetermined value j (including the value j), the CPU 28 uses the refrigerant circuit 1 as the refrigerant. This is a phenomenon that occurs when the temperature of the indoor heat exchanger 11 is not easily increased or decreased, so that the refrigerant leaks from the refrigerant circuit 1 and is determined to be operating abnormally.

  As described above, when the air conditioner is started in the heating operation and the refrigerant that causes the temperature X of the indoor heat exchanger 11 to increase is insufficient in the refrigerant circuit 1, the indoor heat Since it is difficult for the temperature X of the exchanger 11 to increase, it is possible to determine whether or not the refrigerant is insufficient by paying attention to the increase of the temperature X. However, immediately after the start of the air conditioner, there is an irregularity that the temperature X temporarily drops due to the liquefied refrigerant remaining in the indoor heat exchanger 11 in the previous operation. Therefore, in the present embodiment, the determination is made not by focusing on the direction of increase or decrease of the temperature X but by focusing on the size of the temperature range of the temperature X.

  Furthermore, since the size of the temperature range of the temperature X may be affected by the temperature Y around the refrigerant circuit 1, for example, the refrigerant is satisfied in the refrigerant circuit 1 even though the refrigerant is satisfied in the refrigerant circuit 1. When the heat around the circuit 1 is transferred to the indoor heat exchanger 11 and prevents the temperature of the heat exchanger from rising or falling, it is erroneously detected that the refrigerant has leaked even though the refrigerant has not actually leaked. Resulting in. Further, the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1 are, for example, when the refrigerant is satisfied in the refrigerant circuit 1, the temperature X of the indoor heat exchanger 11 due to the refrigerant. Suddenly rises or falls, a temperature difference occurs between the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1, while the refrigerant is insufficient in the refrigerant circuit 1. As a result, the temperature X of the indoor heat exchanger 11 is unlikely to rise or fall, so that there is almost no temperature difference between the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1. Therefore, in this embodiment, the determination is made not only on the temperature range of the temperature X but also on the temperature difference between the temperature X and the temperature Y.

  Next, the refrigerant leakage detection process by the air conditioner according to the present invention will be specifically described. FIG. 5 is a flowchart for explaining the procedure of refrigerant leakage detection processing by the air conditioner according to the present invention. In the present embodiment, a case where the air conditioner is activated in the heating operation will be described.

  With the activation of the air conditioner, the CPU 28 of the control unit 2 sends a time measurement start instruction to the timer 25 via the bus 29 (step S101). The timer 25 that has received the timing start instruction starts timing and sequentially transmits signals of the measured times.

  The CPU 28 sequentially receives the time signal sent from the timer 25 (step S102), and also receives the signal of the temperature X of the indoor heat exchanger 11 sent from the temperature sensor 21 (step S103), and the sequentially received signal. Among these, the minimum value Xmin of the temperature X and the maximum value Xmax of the temperature X are stored in the RAM 24 (S104).

  The CPU 28 determines whether or not the time indicated by the signal sent from the timer 25 has reached a predetermined time (for example, 5 minutes) read from the RAM 24 (step S105), and determines that the time has not reached (NO in step S105), the process returns to step S102 and steps S102 to S105 are repeated.

  On the other hand, when the CPU 28 determines that the time indicated by the signal sent from the timer 25 has reached the predetermined time read from the RAM 24 (YES in step S105), the CPU 28 obtains the temperature X determined by the maximum value Xmax-the minimum value Xmin. A temperature range is calculated (step S106), and it is determined whether or not the calculated temperature range of the temperature X is within a predetermined range (for example, 2 ° C.) read from the RAM 24 (step S107), and is not within the predetermined range. (NO in step S107), it is determined that the refrigerant has not leaked from the refrigerant circuit 1 (step S108), and the refrigerant leakage detection process is terminated.

  On the other hand, if the CPU 28 determines that the temperature is within the predetermined range (YES in step S107), the temperature X (and the refrigerant circuit) of the indoor heat exchanger 11 received from the temperature sensor 21 (and the temperature sensor 22) when the predetermined time is reached. 1, the temperature difference between the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1, which is obtained by the temperature X−temperature Y, is calculated (step S 108), and the calculated temperature It is determined whether or not the difference exceeds a predetermined value (for example, 3 ° C.) read from the RAM 24 (step S109). When it is determined that the difference exceeds the predetermined value (YES in step S109), the refrigerant is supplied from the refrigerant circuit 1. Is not leaked (step S112), and the refrigerant leak detection process is terminated.

  On the other hand, if the CPU 28 determines that the predetermined value is not exceeded (NO in step 109), the CPU 28 determines that the refrigerant is leaking from the refrigerant circuit 1 (step S110), and outputs a signal to that effect to the outside (step S110). Step S111), the refrigerant leakage detection process is terminated.

  The CPU 28 may be controlled to output a signal indicating that the refrigerant is leaking from the refrigerant circuit 1 via the display unit 27 to notify the user.

  In addition, when the CPU 28 outputs a signal indicating that the refrigerant is leaking from the refrigerant circuit 1 (step S111), for example, the compressor 15 is stopped to stop the operation of the air conditioner for ensuring safety. The corresponding processing may be executed.

  When the CPU 28 outputs a signal indicating that the refrigerant is leaking from the refrigerant circuit 1 (step S111), the CPU 15 operates the compressor 15 from the normal operation to the low speed operation (for example, the first three minutes at 1800 rpm, and the remaining The refrigerant leakage determination detection process is repeated several times, and if it is determined that “refrigerant is leaking from the refrigerant circuit 1” in all the processes, the compressor 15 is operated at a low speed. From this, it is possible to execute a corresponding process such as stopping completely and stopping the operation of the air conditioner.

It is a schematic diagram which shows the structure of the air conditioner which concerns on this invention. It is a schematic diagram which shows the structure of a control part. It is a graph which shows the temperature range of the heat exchanger detected with the refrigerant | coolant leak detection method which concerns on this invention. It is a graph which shows the temperature difference of the temperature around the heat exchanger and refrigerant circuit detected with the refrigerant leak detection method concerning the present invention. It is a flowchart explaining the procedure of the refrigerant | coolant leak detection process by the air conditioner which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerant circuit 11 Indoor side heat exchanger 12 Expansion valve 15 Compressor 21 Temperature sensor 22 Temperature sensor 25 Timer 28 CPU

Claims (5)

In a method for detecting leakage of refrigerant from a refrigerant circuit including a heat exchanger,
Start or these repeatedly detects the temperature of the heat exchanger within a predetermined time,
Calculate the temperature range from the highest temperature and the lowest temperature of the heat exchanger detected repeatedly,
A refrigerant leakage detection method, wherein, when it is determined that the calculated temperature range is within a predetermined range, it is determined that the refrigerant is leaking from the refrigerant circuit. In a method for detecting leakage of refrigerant from a refrigerant circuit including a heat exchanger,
Start or these repeatedly detects the temperature of the heat exchanger within a predetermined time,
Calculate the temperature range from the highest temperature and the lowest temperature of the heat exchanger detected repeatedly,
When the predetermined time is reached, the temperature around the refrigerant circuit is detected, and the temperature difference between the heat exchanger and the refrigerant circuit is calculated.
When it is determined that the calculated temperature range is within a predetermined range and the calculated temperature difference does not exceed a predetermined value, it is determined that the refrigerant is leaking from the refrigerant circuit. Refrigerant leak detection method. In a refrigerant leakage detection device comprising a refrigerant circuit including a heat exchanger and leakage detection means for detecting leakage of the refrigerant from the refrigerant circuit,
Temperature detecting means for detecting the temperature of the heat exchanger;
Timekeeping means,
And a calculating means for calculating the temperature range of the maximum and minimum temperatures of the start or in these repeated detected temperature by said temperature detecting means within a predetermined time,
The leakage detection unit is configured to output a signal indicating that the refrigerant is leaking from the refrigerant circuit when the temperature range calculated by the calculation unit is determined to be within a predetermined range. A refrigerant leakage detection device. In a refrigerant leakage detection device comprising a refrigerant circuit including a heat exchanger and leakage detection means for detecting leakage of the refrigerant from the refrigerant circuit,
First temperature detecting means for detecting the temperature of the heat exchanger;
Second temperature detecting means for detecting a temperature around the refrigerant circuit;
Timekeeping means,
A calculating means for calculating the temperature range of the heat exchanger to the start or in these within a predetermined time after repeatedly detected temperature maximum and minimum temperatures and in the first temperature detecting means,
Whether the temperature difference between the temperature around the refrigerant circuit detected at startup or these predetermined time temperature of the heat exchanger detected by the first temperature detecting means at the time of arrival and the second temperature detection means exceeds a predetermined value not Determination means for determining whether or not
The leakage detection means indicates that the refrigerant is leaking from the refrigerant circuit when it is determined that the temperature range calculated by the calculation means is within a predetermined range and the temperature difference does not exceed a predetermined value. A refrigerant leakage detection device characterized in that a signal is output. The refrigerant leakage detection device according to claim 3 or 4,
An air conditioner comprising: means for stopping operation in response to a signal indicating that the refrigerant output from the refrigerant leakage detection device is leaking.

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