JP2009024923A - Refrigerant leakage detecting device, air conditioner, and refrigerant leakage detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerant leakage detecting device capable of correctly detecting the leakage of a refrigerant. <P>SOLUTION: A control portion 2 (refrigerant leakage detecting device ) judges the leakage of the refrigerant from a refrigerant circuit 1 when the temperature difference ΔTa between a maximum temperature and a minimum temperature of an indoor-side heat exchanger 11 within a prescribed judgment time is less than a judgment value Tp. Further the judgment time or the judgment value Tp is corrected according to the number of rotation Z within a prescribed time, of a compressor 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigerant leakage detection device, an air conditioner, and a refrigerant leakage detection method that can accurately detect refrigerant leakage over a long period of time.

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

  If the refrigerant leaks due to a pipe breakage or the like in the air conditioner, the performance of cooling or heating deteriorates, and sufficient heating or cooling cannot be performed. For this reason, Patent Document 1 discloses an air conditioner provided with a refrigerant sensor including a gas detector that detects refrigerant leaked from the refrigerant circuit.

  However, since the refrigerant sensor used in this air conditioner is likely to change over time, there is a disadvantage in that refrigerant leakage may be erroneously detected due to long-term use. In addition, since the refrigerant sensor is expensive, an air conditioner equipped with the refrigerant sensor has a disadvantage that the manufacturing cost increases.

  Patent Document 2 discloses an air conditioner that detects refrigerant leakage using a temperature sensor instead of a refrigerant sensor. The air conditioner includes a compressor, an indoor heat exchanger and an outdoor heat exchanger connected to the compressor, and a temperature sensor attached to the indoor heat exchanger.

  In this air conditioner, refrigerant leakage is detected based on the temperature difference of the indoor air conditioner between when the compressor starts to be driven and when a predetermined time has elapsed. That is, it is determined that the refrigerant leaks when a predetermined time elapses after the compressor is driven and the indoor heat exchanger has not been heated (heating operation) or cooled (cooling operation) more than a predetermined temperature difference. To do.

When the refrigerant that causes an increase or decrease in temperature is satisfied in the refrigerant circuit, the indoor heat exchanger increases or decreases by a predetermined temperature due to the refrigerant. On the other hand, when the refrigerant is insufficient in the refrigerant circuit, the temperature of the indoor heat exchanger is unlikely to rise or fall. Therefore, it is possible to detect refrigerant leakage based on the temperature difference of the indoor air conditioner between when the compressor starts to drive and when a predetermined time has elapsed.
JP-A-8-327195 JP-A-1-95255

  However, according to the air conditioner described in Patent Document 2, the temperature of the heat exchanger may change under the influence of the rotation speed of the compressor for circulating the refrigerant in the refrigerant circuit. For example, when the room temperature is close to the target temperature set for the air conditioner, the rotational speed of the compressor is suppressed. Thereby, even if it is a case where the refrigerant | coolant is satisfy | filled within a refrigerant circuit, the raise or fall of the temperature of a heat exchanger may be prevented.

  Thus, in the said patent document 2 which detects a refrigerant | coolant leak with the temperature difference of a heat exchanger, even if it is a case where the refrigerant | coolant leak does not arise, it may be misdetected that the refrigerant | coolant leak has arisen. There is a problem.

  An object of the present invention is to provide a refrigerant leakage detection device, an air conditioner, and a refrigerant leakage detection method that can accurately detect refrigerant leakage.

  In order to achieve the above object, a refrigerant leakage detection device according to the present invention is a refrigerant leakage detection device that detects refrigerant leakage from a refrigerant circuit including a heat exchanger and a compressor, and detects heat within a predetermined determination time. When the first temperature difference between the maximum temperature and the minimum temperature of the exchanger is smaller than the first determination temperature, it is determined that the refrigerant is leaking from the refrigerant circuit, and compression is performed for circulating the refrigerant in the refrigerant circuit. The determination time or the first determination temperature is corrected according to the number of rotations of the machine or the rotation amount within a predetermined time.

  According to this configuration, the refrigerant is circulated in the refrigerant circuit by the compressor and the heat exchanger is driven. The determination time or the first determination temperature is corrected according to the rotation speed of the compressor or the rotation amount within a predetermined time. When the first temperature difference between the maximum temperature and the minimum temperature of the heat exchanger within a predetermined determination time is smaller than the first determination temperature, it is determined that the refrigerant is leaking from the refrigerant circuit.

  In the refrigerant leakage detection device, it is preferable to reduce the first determination temperature when the rotation speed or the rotation amount within a predetermined time is smaller than a predetermined value.

  In the refrigerant leakage detection device, it is preferable that the determination time is lengthened when the rotation speed of the compressor or the rotation amount within a predetermined time is smaller than a predetermined value.

  In the refrigerant leak detection device, the first temperature difference is smaller than the first determination temperature, and the second temperature difference between the temperature of the heat exchanger and the temperature around the refrigerant circuit when the determination time has elapsed is the second temperature difference. When the temperature is lower than the determination temperature, it is determined that the refrigerant is leaking from the refrigerant circuit, and the first determination temperature and the second determination temperature are corrected according to the rotation speed of the compressor or the rotation amount within a predetermined time. Is preferred.

  In the refrigerant leakage detection device, it is preferable that the first determination temperature and the second determination temperature are decreased when the rotation speed of the compressor or the rotation amount within a predetermined time is smaller than a predetermined value.

  In the refrigerant leak detection device, the first temperature difference is smaller than the first determination temperature, and the second temperature difference between the temperature of the heat exchanger and the temperature around the refrigerant circuit when the determination time has elapsed is the second temperature difference. It is preferable to determine that the refrigerant is leaking from the refrigerant circuit when the temperature is lower than the determination temperature, and to correct the determination time according to the rotation speed of the compressor or the rotation amount within a predetermined time.

  In the refrigerant leakage detection device, it is preferable that the determination time is lengthened when the rotation speed of the compressor or the rotation amount within a predetermined time is smaller than a predetermined value.

  The air conditioner of this invention is provided with the said refrigerant | coolant leak detection apparatus, and the refrigerant circuit containing a heat exchanger and a compressor.

  In the air conditioner, the heat exchanger is preferably composed of an indoor heat exchanger disposed indoors during heating operation.

  In the above air conditioner, it is preferable that the heat exchanger is an outdoor heat exchanger disposed outside the room during cooling operation.

  The refrigerant leakage detection method of the present invention is a refrigerant leakage detection method for detecting refrigerant leakage from a refrigerant circuit including a heat exchanger and a compressor, wherein the maximum temperature and the minimum temperature of the heat exchanger within a predetermined determination time. Determining that the refrigerant is leaking from the refrigerant circuit when the first temperature is lower than the first determination temperature, and the rotation speed of the compressor for circulating the refrigerant in the refrigerant circuit or within a predetermined time And a step of correcting the determination time or the first determination temperature in accordance with the amount of rotation.

  According to this invention, when the first temperature difference between the maximum temperature and the minimum temperature of the heat exchanger within a predetermined determination time is smaller than the first determination temperature, it is determined that the refrigerant is leaking from the refrigerant circuit. Thus, when the refrigerant is not leaking, the first temperature difference is larger than the first determination temperature, so it can be determined whether the refrigerant is leaking from the refrigerant circuit.

  Further, by correcting the determination time or the first determination temperature using the rotation speed of the compressor or the rotation amount within a predetermined time, for example, the room temperature is close to the target set temperature of the air conditioner, and the rotation speed of the compressor Alternatively, the determination time or the first determination temperature can be corrected to an appropriate value even when the amount of rotation within the predetermined time is suppressed and the temperature of the heat exchanger is difficult to change. Thereby, it can be judged correctly whether the refrigerant is leaking from the refrigerant circuit.

  Further, by determining whether or not the refrigerant leaks from the refrigerant circuit using the temperature of the heat exchanger, the refrigerant leaks from the refrigerant circuit using a temperature sensor or the like without using a refrigerant sensor that easily changes over time. It can be determined whether or not. Thereby, it can suppress over a long time that it misdetects that the refrigerant | coolant has leaked, and it can suppress that manufacturing cost rises.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing an overall configuration of an air conditioner 100 according to a first embodiment of the present invention. As shown in FIG. 1, the air conditioner 100 includes a refrigerant circuit 1 and a control unit 2. The refrigerant circuit 1 includes an indoor heat exchanger 11, an expansion valve 12, an outdoor heat exchanger 13, a switching valve 14, and a compressor 15. One end of the indoor heat exchanger 11 and the outdoor heat exchanger 13 is connected to the compressor 15 that operates the refrigeration cycle via the switching valve 14. The other ends of the indoor side heat exchanger 11 and the outdoor side heat exchanger 13 are connected via an expansion valve 12.

  When the cooling operation is started in the air conditioner 100, the switching valve 14 is switched as shown by a solid line in the figure. The refrigerant is compressed to a high pressure by the compressor 15 and conveyed to the outdoor heat exchanger 13 via the switching valve 14 as indicated by an arrow A. Then, the refrigerant condenses while radiating heat to the outdoor air in the outdoor heat exchanger 13 and is conveyed to the expansion valve 12.

  After the refrigerant is expanded by the expansion valve 12, the refrigerant is conveyed to the indoor heat exchanger 11 and further evaporated while absorbing the indoor air in the indoor heat exchanger 11. Then, the refrigerant is conveyed to the compressor 15 via the switching valve 14 and is compressed again by the compressor 15. The cold air generated by the circulation of the refrigerant is sent into the room by a blower fan (not shown, the same applies hereinafter) arranged near the indoor heat exchanger 11 to cool the room air. The refrigerant is an HFC refrigerant.

  When the heating operation is started in the air conditioner 100, the switching valve 14 is switched as indicated by a broken line in the figure. The refrigerant is compressed to a high pressure by the compressor 15 and conveyed to the indoor heat exchanger 11 through the switching valve 14 as indicated by an arrow B. Then, the refrigerant condenses while radiating heat to the indoor air in the indoor heat exchanger 11 and is conveyed to the expansion valve 12.

  The refrigerant is expanded by the expansion valve 12, then conveyed to the outdoor heat exchanger 13, and further evaporated while absorbing outdoor air by the outdoor heat exchanger 13. Then, the refrigerant is conveyed to the compressor 15 via the switching valve 14 and is compressed again by the compressor 15. The warm air generated by the circulation of the refrigerant is sent into the room by a blower fan arranged in the vicinity of the indoor heat exchanger 11 and warms the room air.

  FIG. 2 shows the configuration of the control unit 2. The control unit 2 controls each unit of the air conditioner 100 and constitutes a refrigerant leakage detection device that detects refrigerant leakage from the refrigerant circuit 1. Further, the control unit 2 includes a temperature sensor interface 20, a rotation amount detection circuit 21 that detects a rotation amount Z of the compressor 15 (see FIG. 1), a ROM 22, a RAM 23, a timer 24, an operation unit 25, The display unit 26, the CPU 27, and a bus 28 for connecting them are configured.

  The temperature sensor interface 20 is connected to the temperature sensors 16, 17 and 18. The temperature sensor interface 20 is configured to receive a temperature signal detected by the temperature sensors 16, 17, and 18 and send it to the CPU 27.

  The temperature sensors 16 and 17 are, for example, thermistors, and are attached to the indoor heat exchanger 11 and the outdoor heat exchanger 13 (see FIG. 1), respectively. The temperature sensors 16 and 17 detect the temperature X inside the indoor heat exchanger 11 and the outdoor heat exchanger 13. Further, the temperature X signal detected by the temperature sensors 16 and 17 is sent to the CPU 27 via the temperature sensor interface 20.

  The temperature sensor 18 is a thermistor, for example, and is disposed around the refrigerant circuit 1. Further, the temperature sensor 18 detects the temperature Y (the temperature around the air conditioner 100, the room temperature, the outdoor temperature, etc.) around the refrigerant circuit 1 that rises or falls regardless of the evaporation or condensation of the refrigerant. The temperature Y signal detected by the temperature sensor 18 is sent to the CPU 27 via the temperature sensor interface 20.

  The rotation amount detection circuit 21 detects the rotation amount Z of the compressor 15, and a signal of the detected rotation amount Z is sent to the CPU 27.

  The ROM 22 stores a control program for the air conditioner 100 and the like. The ROM 22 is configured to be read as appropriate in response to a read request from the CPU 27.

  The RAM 23 is configured by SRAM, flash memory, or the like. The RAM 23 stores data generated when the CPU 27 executes a program, setting data, and the like.

  The timer 24 is provided for timing the timing for calculating and determining temperature differences ΔTa and ΔTb, which will be described later. The timer 24 receives a timing start instruction from the CPU 27 and counts time according to the received instruction. Further, the signal of the time counted by the timer 24 is sequentially sent to the CPU 27.

  The operation unit 25 includes various operation buttons (not shown) for receiving operation instructions from the user. In addition, the operation unit 25 is configured to receive instructions such as selection of cooling operation or heating operation, setting of a target temperature, change of wind direction, setting of a predetermined time, and the like. The instruction received by the operation unit 25 is sent to the RAM 23. Note that the operation unit 25 is not only installed in the air conditioner 100 main body, but may be separately connected by wire or wirelessly controlled.

  The display unit 26 includes a liquid crystal display (not shown). Operation status of the air conditioner 100 by the display unit 26, setting information set via the operation unit 25, information to be notified to the user (for example, a warning that the refrigerant is leaking from the refrigerant circuit 1) Etc. are displayed.

  The CPU 27 controls each part of the hardware configured by the control unit 2 by the control program read from the ROM 22. Moreover, CPU27 controls each part of the hardware which the refrigerant circuit 1 comprises, and controls the refrigerant circuit 1 to air_conditionaing | cooling operation or heating operation. Further, the CPU 27 converts the signal received by the temperature sensor interface 20 into temperature information.

  Further, the CPU 27 determines the temperature difference ΔTa between the maximum temperature and the minimum temperature of the indoor heat exchanger 11 within the determination time (from the start of operation until the determination time elapses), and the temperature of the indoor heat exchanger 11 when the determination time elapses. A temperature difference ΔTb between X and the temperature Y around the refrigerant circuit 1 is calculated.

  Further, the CPU 27 is configured to determine whether or not the temperature differences ΔTa and ΔTb are smaller than predetermined determination values Tp and Tq, respectively. Further, the CPU 27 is configured to execute a process for detecting whether or not the refrigerant is leaking from the refrigerant circuit 1.

  Further, the CPU 27 is configured to calculate the rotation amount Z of the compressor 15 within a predetermined time. Further, the CPU 27 corrects the determination values Tp and Tq to be small when the rotation amount Z of the compressor 15 within a predetermined time is smaller than a predetermined value (for example, 16500 rotations).

  Next, the temperature change at the time of starting with the heating operation of the air conditioner 100 is demonstrated. FIG. 3 is a view showing a temperature change inside the indoor heat exchanger 11 of the air conditioner 100. FIG. 4 is a diagram illustrating a change in temperature difference between the indoor heat exchanger 11 of the air conditioner 100 and the periphery of the refrigerant circuit 1. In these drawings, C indicates a case where the refrigerant is operating normally without leakage. D indicates the case where the refrigerant is leaking from the refrigerant circuit 1.

  When the air conditioner 100 is operating normally without leakage of refrigerant from the refrigerant circuit 1 (see FIG. 1), the liquefaction remaining in the indoor heat exchanger 11 (see FIG. 1) in the previous operation. The refrigerant evaporates while absorbing heat. Therefore, as shown in FIG. 3C, the temperature X of the indoor heat exchanger 11 drops to the minimum value Xmin from the time t1 to the time t2.

  Then, the liquefied refrigerant remaining during the previous operation disappears from the time t2 until the calculation time t3 when a predetermined time has elapsed, and the refrigerant condenses in the indoor heat exchanger 11 while releasing heat. For this reason, the temperature X of the indoor heat exchanger 11 rises to the maximum value Xmax within the determination time (t3-t1).

  Further, as shown in FIG. 4C, at the start time t1, the temperature X of the indoor heat exchanger 11 is slightly higher than the temperature Y around the refrigerant circuit 1. And the temperature X of the indoor side heat exchanger 11 falls between the time t1 and time t2, and is lower than the temperature Y around the refrigerant circuit 1 by the time t2. Then, the temperature X rises from the time t2 to the calculation time t3, and is higher than the temperature Y around the refrigerant circuit 1 before reaching the calculation time t3. In this case, it can be seen that the temperature X has a minimum value at time t2.

  On the other hand, when the refrigerant is leaking from the refrigerant circuit 1, the refrigerant becomes insufficient in the refrigerant circuit 1 as shown in D of FIG. 3, and the temperature X of the indoor heat exchanger 11 is hardly increased. Therefore, the temperature difference ΔTa = a between the maximum temperature and the minimum temperature of the temperature X within the determination time (t3−t1), which is smaller than the temperature difference ΔTa = b in the normal operation.

  Further, as shown in D of FIG. 4, the refrigerant that causes the temperature X to rise or fall is insufficient in the refrigerant circuit 1, and the temperature X of the indoor heat exchanger 11 is difficult to rise. For this reason, the temperature difference ΔTb = c between the temperature X and the temperature Y when the determination time (t3−t1) has elapsed since the start of operation is smaller than the temperature difference ΔTb = d in the normal operation.

  Therefore, when the refrigerant is insufficient in the refrigerant circuit 1 and the temperature X of the indoor heat exchanger 11 is hardly increased, the temperature differences ΔTa and ΔTb are smaller than the predetermined determination values Tp and Tq, respectively. Similarly, in the cooling operation, if the refrigerant is insufficient, the temperature X of the indoor heat exchanger 11 is less likely to drop. Therefore, similarly, the temperature difference ΔTa between the maximum temperature and the minimum temperature of the temperature X within the determination time (t3−t1) and the temperature difference ΔTb between the temperature X and the temperature Y when the determination time (t3−t1) has elapsed are respectively It becomes smaller than predetermined judgment values Tp and Tq.

  FIG. 5 is a flowchart showing the operation of the air conditioner 100. Here, the case where the air conditioner 100 is started in the heating operation will be described.

  When the start of operation of the air conditioner 100 is instructed by the user, the compressor 15 (see FIG. 1) is driven in step # 1. In step # 2, the CPU 27 (see FIG. 2) of the control unit 2 starts accepting various signals.

  Specifically, the timer 24 (see FIG. 2) starts timing, and the CPU 27 starts accepting timing signals sequentially sent from the timer 24. Further, the rotation amount detection circuit 21 (see FIG. 2) starts detecting the rotation amount Z of the compressor 15, and the CPU 27 starts receiving the rotation amount signal sequentially sent from the rotation amount detection circuit 21. Further, the temperature sensors 16 to 18 (see FIG. 2) start detecting the temperature around the indoor heat exchanger 11, the outdoor heat exchanger 13 (see FIG. 1) and the refrigerant circuit 1, and the CPU 27 18 starts accepting temperature signals sequentially sent from 18. Then, the time signal, the rotation amount Z of the compressor 15 and the temperature signal that are sequentially sent are stored in the RAM 23 (see FIG. 2).

  In step # 3, the process waits until a predetermined time (for example, 5 minutes) elapses. When the predetermined time elapses, the process proceeds to step # 4.

  In step # 4, the CPU 27 calculates the rotation amount Z of the compressor 15 within a predetermined time. Thereafter, in step # 5, it is determined whether or not the amount of rotation Z within a predetermined time is smaller than, for example, 16500 rotations (= 3300 rpm × 5 minutes as a reference).

  If it is determined in step # 5 that the rotation amount Z within the predetermined time is smaller than 16500 rotations, the process proceeds to step # 6. In step # 6, the determination value Tp for determining the temperature difference ΔTa and the determination value Tq for determining the temperature difference ΔTb are corrected to appropriate values, and the process proceeds to step # 7. At this time, the determination values Tp and Tq are corrected to be small (for example, if the original determination value Tp is 4 ° C., the determination value Tp is reduced by 1 ° C. to 3 ° C.). If it is determined in step # 5 that the rotation amount Z within the predetermined time is not smaller than 16500 rotations (16500 rotations or more), the process proceeds to step # 7.

  In step # 7, the CPU 27 calculates the temperature difference ΔTa between the maximum temperature and the minimum temperature within the determination time of the indoor heat exchanger 11 (from the start of operation until the determination time elapses). In step # 8, it is determined whether or not the temperature difference ΔTa of the indoor heat exchanger 11 is smaller than the determination value Tp.

  If the temperature difference ΔTa is not smaller than the determination value Tp, it is determined that there is no refrigerant leakage and the indoor heat exchanger 11 is operating normally, and the process proceeds to step # 21. In step # 21, the memory of the refrigerant leakage error described later is cleared, and normal operation is performed in step # 22. If the temperature difference ΔTa is smaller than the determination value Tp, the process proceeds to step # 9.

  In step # 9, the CPU 27 calculates the temperature difference ΔTb. In step # 10, it is determined whether or not the temperature difference ΔTb is smaller than the determination value Tq.

  If the temperature difference ΔTb is not smaller than the determination value Tq, it is determined that there is no refrigerant leakage and the indoor heat exchanger 11 is operating normally, and the process proceeds to step # 21. In step # 21, the memory of the refrigerant leakage error described later is cleared, and normal operation is performed in step # 22. When it is determined that the temperature difference ΔTb is smaller than the determination value Tq, it is determined that the refrigerant is leaking, and the process proceeds to step # 11.

  In step # 11, the refrigerant leakage error is stored in the RAM 23 (see FIG. 2). In step # 12, the compressor 15 is stopped. In step # 13, it is determined whether or not the refrigerant leak detection in steps # 1 to # 12 has been performed a predetermined number of times (N times). Since it may be possible that the refrigerant leakage detection in steps # 1 to # 12 is a false detection, the same determination is made by repeating a plurality of times.

  If it is determined in step # 13 that refrigerant leakage has not been detected a predetermined number of times (N times (for example, 4 times)), the process proceeds to step # 14. In step # 14, the process waits for a predetermined time. When the predetermined time has elapsed, the process returns to step # 1, and steps # 1 to # 14 are repeated. The predetermined time in step # 14 may be the same time (for example, 5 minutes) as the predetermined time in step # 3, or may be a different time (for example, 3 minutes). When step # 1 to # 14 is repeated and the process proceeds to step # 21 based on the determination in step # 8 or # 10, the storage of the refrigerant leakage error is cleared.

  If it is determined in step # 13 that the refrigerant leakage has been detected a predetermined number of times (N times (for example, 4 times)), it is determined that the refrigerant leakage is not a false detection, and the process proceeds to step # 31. In step # 31, the occurrence of refrigerant leakage is notified by the display unit 26 (see FIG. 2). Thereafter, in step # 32, the notification state of the display unit 26 is maintained and the entire air conditioner 100 is stopped.

  According to the present embodiment, when the temperature difference ΔTa between the maximum temperature and the minimum temperature of the indoor heat exchanger 11 detected within the determination time is smaller than the determination value Tp, the refrigerant leaks from the refrigerant circuit 1. By determining, when the refrigerant is not leaking, the temperature difference ΔTa becomes larger than the determination value Tp, so it can be determined whether the refrigerant is leaking from the refrigerant circuit 1 or not.

  Further, when the temperature difference ΔTb between the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1 is smaller than the determination value Tq, it is determined that the refrigerant is leaking from the refrigerant circuit 1 accurately. It can be determined whether the refrigerant is leaking from the refrigerant circuit 1. That is, the temperature difference ΔTa is smaller than the determination value Tp because the heat around the refrigerant circuit 1 is transmitted to the indoor heat exchanger 11 and the temperature X of the indoor heat exchanger 11 is prevented from rising. However, if the refrigerant is sufficient, a temperature difference ΔTb equal to or greater than the determination value Tq is generated between the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1. Thereby, it can be determined that the refrigerant has not leaked from the indoor heat exchanger 11. Although the determination accuracy slightly decreases, the determination based on ΔTb may be omitted.

  Further, by reducing both of the determination values Tp and Tq using the rotation amount Z of the compressor 15 within a predetermined time, for example, the room temperature is close to the target set temperature of the air conditioner 100 and the rotation amount of the compressor 15 Even when Z is suppressed and the temperature X of the indoor heat exchanger 11 is difficult to change, the determination values Tp and Tq can be corrected to appropriate values. Thereby, it can be judged more accurately whether the refrigerant is leaking from the refrigerant circuit 1.

  Further, by using the temperature X of the indoor heat exchanger 11 and the temperature Y around the refrigerant circuit 1 to determine whether the refrigerant is leaking from the refrigerant circuit 1, it is possible to use a refrigerant sensor that does not easily change over time. Whether or not the refrigerant is leaking from the refrigerant circuit 1 can be determined using the temperature sensors 16 and 18. Thereby, it can suppress over a long time that it misdetects that the refrigerant | coolant has leaked, and it can suppress that manufacturing cost rises.

(Second Embodiment)
FIG. 6 is a flowchart showing the operation of the air conditioner 100 according to the second embodiment of the present invention. In the second embodiment, unlike the first embodiment, when the rotation amount Z of the compressor 15 within a predetermined time is smaller than a predetermined value (for example, 16500 rotations), determination until the temperature differences ΔTa and ΔTb are calculated. The time is extended. The structure of the second embodiment is the same as that of the first embodiment shown in FIGS. In FIG. 6, steps # 1 to # 4 and steps # 7 to # 32 are the same as those in the first embodiment, and a description thereof will be omitted.

  In step # 5, it is determined whether or not the rotation amount Z of the compressor 15 is smaller than 16500 rotations. If it is not smaller, the process proceeds to step # 6. If it is smaller, the process waits until it reaches 16500 revolutions or more.

  In step # 6, the elapsed time from the start of operation is substituted for the determination time until the temperature differences ΔTa and ΔTb are calculated. That is, if it takes time until the rotation amount Z of the compressor 15 reaches 16500 rotations or more in step # 5, the determination time until the temperature differences ΔTa and ΔTb are calculated is extended. Specifically, when the rotation amount Z of the compressor 15 does not reach 16,500 rotations when the predetermined time has elapsed in step # 3, the predetermined rotation speed Z is determined from the rotation amount Z of the compressor 15 when the predetermined time has elapsed in step # 3. Thus, the time required to reach 16500 rotations, which is the amount of rotation, is extended.

  Then, similarly to the first embodiment, refrigerant leakage is determined based on ΔTa and ΔTb.

  According to the present embodiment, when the rotation amount Z of the compressor 15 within a predetermined time is smaller than a predetermined amount (for example, 16500 rotations), the determination time until the temperature differences ΔTa and ΔTb are calculated is lengthened, whereby the refrigerant Can be further suppressed from being erroneously detected as leaking. That is, for example, since the room temperature is close to the target set temperature of the air conditioner 100 and the compressor 15 does not need to be rotated at a high speed, the rotation amount Z of the compressor 15 is suppressed, and the temperature of the indoor heat exchanger 11 Even when X is less likely to change, it can be determined whether the refrigerant is leaking from the refrigerant circuit 1 in a state where the refrigerant is sufficiently circulated by the compressor 15.

  In this embodiment, the determination time is extended by waiting until the rotation amount Z of the compressor 15 reaches 16500 rotations or more in step # 5, but the rotation amount Z of the compressor 15 in step # 5. May be configured to extend the determination time by, for example, 2 minutes, and to proceed to step # 7 if the extended determination time elapses.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

  Although the example which comprised the refrigerant | coolant leak detection apparatus by the control part 2 was shown in 1st, 2nd embodiment, this invention is not limited to this. For example, the refrigerant leakage detection device may be configured by the control unit 2 and the refrigerant circuit 1. Moreover, you may comprise a refrigerant | coolant leak detection apparatus by the indoor side heat exchanger (or outdoor side heat exchanger) in which the control part was incorporated.

  In the first and second embodiments, the temperature difference ΔTa between the highest temperature and the lowest temperature of the indoor heat exchanger 11 within the determination time during the heating operation, and the temperature of the indoor heat exchanger 11 when the determination time has elapsed. Although the example in which the refrigerant leakage is detected using the temperature difference ΔTb between X and the temperature Y around the refrigerant circuit 1 is shown, the present invention is not limited to this. For example, the temperature difference between the highest temperature and the lowest temperature of the outdoor heat exchanger 13 within the determination time during the heating operation, and the temperature of the outdoor heat exchanger 13 and the temperature around the refrigerant circuit 1 when the determination time has elapsed. The leakage of the refrigerant may be detected using the temperature difference. Moreover, the temperature difference between the highest temperature and the lowest temperature of the indoor heat exchanger 11 within the determination time during the cooling operation, and the temperature of the indoor heat exchanger 11 and the temperature around the refrigerant circuit 1 when the determination time has elapsed. The leakage of the refrigerant may be detected using the temperature difference. Moreover, the temperature difference between the highest temperature and the lowest temperature of the outdoor heat exchanger 13 within the determination time during the cooling operation, and the temperature of the outdoor heat exchanger 13 and the temperature around the refrigerant circuit 1 when the determination time elapses. The leakage of the refrigerant may be detected using the temperature difference.

  During the heating operation, the indoor heat exchanger 11 is temporarily lowered due to low temperature refrigerant flowing in, and it takes time to increase the temperature, while the outdoor heat exchanger 13 is temporarily lowered because the temperature is lowered by the operation of the compressor 15. There is not much temperature drop. For this reason, if the temperature of the outdoor heat exchanger 13 is detected during the heating operation, the temperature change can be detected quickly, and the leakage of the refrigerant can be detected quickly.

  Moreover, since the outdoor temperature is high during the cooling operation, the temperature change in the indoor heat exchanger 11 is larger than that in the outdoor heat exchanger 13. For this reason, it is more preferable to determine the refrigerant leak using the temperature of the indoor heat exchanger 11 during the cooling operation.

  Moreover, although the example which judged whether the refrigerant | coolant has leaked using the rotation amount Z within the predetermined time of the compressor 15 was shown, a refrigerant | coolant leaks using the rotation speed of the compressor 15 in predetermined time. It may be determined whether or not.

  Moreover, although the example which provided the temperature sensors 16 and 17 in both the indoor side heat exchanger 11 and the outdoor side heat exchanger 13 was shown, a temperature sensor is one side of the indoor side heat exchanger 11 and the outdoor side heat exchanger 13. You may provide only.

It is the schematic diagram which showed the whole structure of the air conditioner by 1st Embodiment of this invention. It is the schematic diagram which showed the structure of the control part by 1st Embodiment of this invention. It is the figure which showed the temperature change inside the heat exchanger of the air conditioner by 1st Embodiment of this invention. It is the figure which showed the change of the temperature difference of the heat exchanger of the air conditioner by 1st Embodiment of this invention, and a refrigerant circuit periphery. It is the flowchart which showed operation | movement of the air conditioner by 1st Embodiment of this invention. It is the flowchart which showed operation | movement of the air conditioner by 2nd Embodiment of this invention.

Explanation of symbols

1 Refrigerant Circuit 2 Control Unit (Refrigerant Leak Detection Device)
11 Indoor heat exchanger (heat exchanger)
13 Outdoor heat exchanger (heat exchanger)
15 Compressor 100 Air conditioner ΔTa Temperature difference (first temperature difference)
ΔTb temperature difference (second temperature difference)
Tp judgment value (first judgment temperature)
Tq judgment value (second judgment temperature)

Claims (9)

A refrigerant leakage detection device for detecting refrigerant leakage from a refrigerant circuit including a heat exchanger and a compressor,
When the first temperature difference between the maximum temperature and the minimum temperature of the heat exchanger within a predetermined determination time is smaller than the first determination temperature, it is determined that the refrigerant is leaking from the refrigerant circuit;
The refrigerant leakage detection device, wherein the determination time or the first determination temperature is corrected in accordance with a rotation speed of the compressor for circulating the refrigerant in the refrigerant circuit or a rotation amount within a predetermined time.   2. The refrigerant leakage detection device according to claim 1, wherein the first determination temperature is decreased when a rotation speed of the compressor or a rotation amount within a predetermined time is smaller than a predetermined value.   The refrigerant leakage detection device according to claim 1, wherein the determination time is lengthened when a rotation speed of the compressor or a rotation amount within a predetermined time is smaller than a predetermined value. The first temperature difference is smaller than the first determination temperature, and the second temperature difference between the temperature of the heat exchanger and the temperature around the refrigerant circuit when the determination time has elapsed is smaller than the second determination temperature. In case the refrigerant is leaking from the refrigerant circuit,
The refrigerant leakage detection device according to claim 1, wherein the first determination temperature and the second determination temperature are corrected according to a rotation speed of the compressor or a rotation amount within a predetermined time.   5. The refrigerant leakage detection device according to claim 4, wherein the first determination temperature and the second determination temperature are decreased when the rotation speed of the compressor or the rotation amount within a predetermined time is smaller than a predetermined value. The first temperature difference is smaller than the first determination temperature, and the second temperature difference between the temperature of the heat exchanger and the temperature around the refrigerant circuit when the determination time has elapsed is smaller than the second determination temperature. In case the refrigerant is leaking from the refrigerant circuit,
The refrigerant leakage detection device according to claim 1, wherein the determination time is corrected in accordance with a rotation speed of the compressor or a rotation amount within a predetermined time.   The refrigerant leakage detection device according to claim 6, wherein the determination time is lengthened when a rotation speed of the compressor or a rotation amount within a predetermined time is smaller than a predetermined value. The refrigerant leakage detection device according to any one of claims 1 to 7,
An air conditioner comprising: a refrigerant circuit including a heat exchanger and a compressor. A refrigerant leakage detection method for detecting refrigerant leakage from a refrigerant circuit including a heat exchanger and a compressor,
Determining that the refrigerant is leaking from the refrigerant circuit when the first temperature of the maximum temperature and the minimum temperature of the heat exchanger within a predetermined determination time is lower than the first determination temperature;
The refrigerant leakage comprising: a step of correcting the determination time or the first determination temperature according to a rotation speed of the compressor for circulating the refrigerant in the refrigerant circuit or a rotation amount within a predetermined time. Detection method.

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