WO2018220758A1 - Air-conditioning apparatus - Google Patents

Abstract

This air-conditioning apparatus is provided with: at least one indoor unit which air-conditions a space to be air-conditioned; at least one outdoor unit which functions as a heat source; a refrigerant circuit in which the indoor unit and the outdoor unit are connected via refrigerant piping and through which a refrigerant is circulated; a refrigerant detection device which is disposed within the indoor unit or in the space to be air-conditioned by the indoor unit and which detects leakage of refrigerant from the refrigerant circuit; and a control device which determines that refrigerant leakage has occurred in the case when a detection value of the refrigerant detection device exceeds a threshold value C1 all the time during a determination period ΔTa, or in the case when the detection value of the refrigerant detection device exceeds the threshold value C1 for a period equal to or longer than a standard time during the determination period ΔTa.

Description

Air conditioner

The present invention relates to refrigerant leakage detection of an air conditioner.

In current air conditioners such as multi air conditioners for buildings, the total length of the refrigerant pipe connecting the outdoor unit and the indoor unit may be several hundred meters, and as a result, the amount of refrigerant charged in the refrigerant circuit is very large. It is increasing. In such an air conditioner, a large amount of refrigerant may leak into one room when refrigerant leakage occurs.

Also, in recent years, conversion to a refrigerant having a low global warming potential is required from the viewpoint of global warming, but many refrigerants having a low global warming potential are flammable. In the future, when the transition to refrigerants with a low global warming potential progresses, further consideration for safety will be required.

In order to solve such a problem, a technology has been proposed in which a shutoff valve for shutting off the flow of the refrigerant is provided in the refrigerant circuit to reduce the amount of refrigerant leakage when the refrigerant leaks (for example, Patent Documents). 1).

In addition, a refrigerant detection sensor that detects the leaked refrigerant is installed in an indoor unit or air-conditioned space, and a technology for operating the shut-off valve appropriately using the refrigerant detection sensor, a method for reducing the number of refrigerant detection sensors installed, and optimum A technique relating to an appropriate installation position has also been proposed (see, for example, Patent Document 2).

JP 2000-97527 A Japanese Patent No. 3744330

However, the market for air conditioners equipped with refrigerant detection sensors is still limited, and refrigerants are generated not only by electrical noise but also by miscellaneous gases such as organic compound systems in the air caused by disinfectants and cleaning agents. There was a possibility of false detection of leakage. In addition, in order to suppress misdetection of refrigerant leakage by the refrigerant detection sensor, some measures such as protecting the sensor part with a filter capable of chemically adsorbing miscellaneous gas are taken, but enough There was a problem that false detection of refrigerant leakage could not be suppressed.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an air conditioner that can suppress erroneous detection of refrigerant leakage.

In the air conditioner according to the present invention, one or a plurality of indoor units that air-condition an air-conditioned space, one or a plurality of outdoor units that function as a heat source, and the indoor unit and the outdoor unit are refrigerant pipes. A refrigerant circuit that circulates the refrigerant, a refrigerant detection device that is provided in the indoor unit or in an air-conditioned space in which the indoor unit performs air conditioning, and that detects refrigerant leakage from the refrigerant circuit, and the refrigerant detection When the detected value of the apparatus always exceeds the threshold value C1 during the determination time ΔTa, or when the detected value of the refrigerant detection apparatus exceeds the threshold value C1 during the determination time ΔTa, the refrigerant leakage occurs. And a control device for determining that.

According to the air conditioner of the present invention, the control device is configured such that the detected value of the refrigerant detection device always exceeds the threshold C1 during the determination time ΔT, or the detection value of the refrigerant detection device is between the determination time ΔT. When the threshold value C1 is exceeded for the reference time or more, it is determined that refrigerant leakage has occurred, so that erroneous detection of refrigerant leakage can be avoided.

It is the schematic which shows the 1st example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 2nd example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 3rd example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 4th example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 5th example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 6th example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 7th example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows the 8th example of a structure of the air conditioning apparatus which concerns on embodiment of this invention. It is the schematic which shows an example of the refrigerant circuit structure of the air conditioning apparatus which concerns on embodiment of this invention. It is a functional block of the air harmony device concerning an embodiment of the invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the cooling only operation of the air conditioning apparatus which concerns on embodiment of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the all heating operation of the air conditioning apparatus 100 which concerns on embodiment of this invention. It is a figure explaining an example of the false detection operation of the refrigerant leak of the conventional air harmony device. It is a figure explaining the false detection avoidance operation | movement of the refrigerant | coolant leakage of the air conditioning apparatus which concerns on embodiment of this invention. It is a figure which shows the 1st example of the control flow of the detection operation | movement of the refrigerant | coolant leakage of the air conditioning apparatus which concerns on embodiment of this invention. It is a figure which shows the 2nd example of the control flow of the detection operation | movement of the refrigerant | coolant leakage of the air conditioning apparatus which concerns on embodiment of this invention. It is a figure which shows the 3rd example of the control flow of the detection operation of the refrigerant | coolant leakage of the air conditioning apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the air conditioning apparatus 100 of the present invention will be described with reference to the drawings. In addition, the form of drawing is an example and does not limit this invention. Moreover, what attached | subjected the same code | symbol in each figure is the same, or is equivalent to this, and this is common in the whole text of a specification. Furthermore, in the following drawings, the relationship between the sizes of the constituent members may be different from the actual one.

Embodiment.
FIG. 1 is a schematic diagram illustrating a first example of the configuration of an air-conditioning apparatus 100 according to an embodiment of the present invention.
Hereinafter, the structure of the air conditioning apparatus 100 which concerns on this Embodiment is demonstrated.
The air conditioner 100 circulates a refrigerant in a refrigerant circuit 101 to be described later, and performs air conditioning using a refrigeration cycle. Further, the air conditioner 100 can select a cooling only operation in which all indoor units to be operated cool, and a heating only operation in which all indoor units to be operated are heated, such as a building multi-air conditioner. .

As shown in FIG. 1, the air conditioner 100 includes one outdoor unit 1 and two indoor units 2a and 2b (hereinafter collectively referred to as an indoor unit 2), and the outdoor unit 1 and the indoor unit 2a. 2b is connected by the refrigerant | coolant piping 3, respectively. In this embodiment, the case where two indoor units 2 are connected to the outdoor unit 1 is shown as an example. However, the present invention is not limited to this, and a plurality of outdoor units 1 may be used. One or three or more may be used.

The indoor units 2a and 2b are installed in air-conditioned spaces 4a and 4b (hereinafter collectively referred to as air-conditioned spaces 4), respectively, and perform air conditioning of the air-conditioned spaces 4a and 4b. In the branch portions 3a and 3b of the refrigerant pipe 3 connecting the outdoor unit 1 and the indoor units 2a and 2b, shut-off devices 7a and 7b (hereinafter referred to as “refrigerants”) for blocking the refrigerant flow and suppressing the refrigerant leak when the refrigerant leaks. Are collectively referred to as a shut-off device 7). Further, in the air-conditioned spaces 4a and 4b, alarm devices 6a and 6b (hereinafter collectively referred to as alarm device 6) for notifying the user of the refrigerant leak when the refrigerant leaks, and the leaked refrigerant are exhausted outside the air-conditioned spaces 4a and 4b. Ventilators 8a and 8b (hereinafter collectively referred to as a ventilator 8) are provided.

The indoor unit 2a or the air-conditioned space 4a and the indoor unit 2b or the air-conditioned space 4b are provided with refrigerant detection devices 5a and 5b (hereinafter collectively referred to as the refrigerant detection device 5) for detecting refrigerant leakage. Yes. In the present embodiment, the refrigerant detection device 5a is provided in the indoor unit 2a and the refrigerant detection device 5b is provided in the air-conditioned space 4b. However, the present invention is not limited to this. The refrigerant detection device 5a may be installed in at least one of the indoor unit 2a or the air-conditioned space 4a, and the refrigerant detection device 5b may be installed in at least one of the indoor unit 2b or the air-conditioned space 4b. Good.

The refrigerant detection device 5, the alarm device 6, the shut-off device 7, and the ventilation device 8 are provided as a safety measure when the refrigerant leaks from the air conditioner 100. Hereinafter, a generic term for the refrigerant detection device 5, the alarm device 6, the shut-off device 7, and the ventilation device 8 is referred to as a safety measure device.

In the air conditioning apparatus 100 according to the present embodiment, when refrigerant leakage is detected by the refrigerant detection device 5, a refrigerant leakage output signal is output toward the alarm device 6, the cutoff device 7, and the ventilation device 8. . And all or at least one of them operates based on the outputted refrigerant leakage output signal, so that the safety of the air-conditioned space 4 is ensured.

Therefore, since the refrigerant detection device 5, the alarm device 6, the shut-off device 7, and the ventilation device 8 are provided as a safety measure when the refrigerant leaks from the air conditioner 100, a normal cooling operation or heating operation is performed. It does not perform any function when done. Therefore, when the maximum concentration at the time of refrigerant leakage calculated from the amount of refrigerant filled in the air conditioner 100 and the volume of the air-conditioned space 4 does not become a concentration that affects the human body, the refrigerant detector 5, the alarm device 6, The blocking device 7 and the ventilation device 8 may not be installed.

FIG. 2 is a schematic diagram showing a second example of the configuration of the air-conditioning apparatus 100 according to the embodiment of the present invention, and FIG. 3 shows the second configuration of the air-conditioning apparatus 100 according to the embodiment of the present invention. FIG. 4 is a schematic diagram showing a third example, FIG. 4 is a schematic diagram showing a fourth example of the configuration of the air-conditioning apparatus 100 according to the embodiment of the present invention, and FIG. 5 is an embodiment of the present invention. FIG. 6 is a schematic diagram illustrating a sixth example of the configuration of the air-conditioning apparatus 100 according to the embodiment of the present invention. FIG. 7 is a schematic diagram showing a seventh example of the configuration of the air-conditioning apparatus 100 according to the embodiment of the present invention.

In addition, any one or more of the alarm device 6, the shut-off device 7, and the ventilation device 8 may be installed. The case where one or two of these are installed is shown in FIGS.

FIG. 2 shows the air conditioner 100 when the alarm devices 6a and 6b are provided in the air-conditioned spaces 4a and 4b, respectively, as a safety measure. FIG. 3 shows the air conditioner 100 when the shut-off devices 7a and 7b are provided in the branch portions 3a and 3b of the refrigerant pipe 3 as safety measures. FIG. 4 shows the air conditioner 100 when the ventilators 8a and 8b are provided in the conditioned spaces 4a and 4b, respectively, as a safety measure. In FIG. 5, as safety measures, the alarm devices 6 a and 6 b are provided in the air-conditioned spaces 4 a and 4 b, respectively, and the shut-off devices 7 a and 7 b are provided in the branch portions 3 a and 3 b of the refrigerant pipe 3, respectively. It is the harmony device 100.

FIG. 6 shows the air conditioner 100 when the alarm devices 6a and 6b and the ventilation devices 8a and 8b are provided in the air-conditioned spaces 4a and 4b, respectively, as safety measures. FIG. 7 shows the air conditioner 100 when the shutoff device 7 is provided in the refrigerant pipe 3 inside the outdoor unit 1 as a safety measure. In addition, since the interruption | blocking apparatus 7 should just be provided in the exterior of air- conditioning space 4a, 4b, as shown in FIG. 7, you may be provided in the inside of the outdoor unit 1. FIG.

FIG. 8 is a schematic diagram showing an eighth example of the configuration of the air-conditioning apparatus 100 according to the embodiment of the present invention.
As shown in FIG. 8, in the air conditioning apparatus 100 according to the present embodiment, a plurality of indoor units 2a and 2b may be installed in the same conditioned space 4. In this case, as a safety measure, for example, the alarm device 6 is provided in the air-conditioned space 4, and the shut-off devices 7a and 7b are provided in the branch portions 3a and 3b of the refrigerant pipe 3, respectively.

Next, the configuration of the refrigerant circuit 101 of the air-conditioning apparatus 100 according to the present embodiment will be described.
FIG. 9 is a schematic diagram showing an example of the configuration of the refrigerant circuit 101 of the air-conditioning apparatus 100 according to the embodiment of the present invention.
As shown in FIG. 9, the air conditioner 100 according to the present embodiment includes a compressor 10, a refrigerant flow switching device 11, a heat source side heat exchanger 12, expansion devices 41a and 41b, a load side heat exchanger 40a, 40b, The accumulator 13 is connected by the refrigerant | coolant piping 3 sequentially, and the refrigerant circuit 101 through which a refrigerant | coolant circulates is provided. Hereinafter, the expansion devices 41a and 41b are collectively referred to as the expansion device 41, and the load side heat exchangers 40a and 40b are collectively referred to as the load side heat exchanger 40.

[Outdoor unit 1]
The outdoor unit 1 functions as a heat source, and includes a compressor 10, a refrigerant flow switching device 11, a heat source side heat exchanger 12, and an accumulator 13. In addition, an outdoor blower 14 that blows air to the heat source side heat exchanger 12 is provided in the vicinity of the heat source side heat exchanger 12.

The compressor 10 sucks low-temperature and low-pressure refrigerant and compresses the refrigerant to bring it into a high-temperature and high-pressure state, and is composed of an inverter compressor and the like whose capacity can be controlled. The refrigerant flow switching device 11 switches the refrigerant flow during the cooling operation and the refrigerant flow during the heating operation, and includes a four-way valve or the like.

The heat source side heat exchanger 12 functions as a condenser during the cooling operation, functions as an evaporator during the heating operation, and performs heat exchange between the air supplied from the outdoor blower 14 such as a fan and the refrigerant. .

Further, the outdoor unit 1 is provided with a first pressure detection device 20 and a second pressure detection device 21 that detect pressure. The first pressure detection device 20 is provided in the refrigerant pipe 3 that connects the discharge side of the compressor 10 and the refrigerant flow switching device 11, and the pressure of the high-temperature and high-pressure refrigerant that is compressed and discharged by the compressor 10 is measured. It is something to detect. The second pressure detection device 21 is provided in the refrigerant pipe 3 that connects the refrigerant flow switching device 11 and the suction side of the compressor 10, and detects the pressure of the low-temperature and low-pressure refrigerant sucked into the compressor 10. To do.

In addition, the outdoor unit 1 is provided with a first temperature detection device 22 that detects the temperature. The first temperature detection device 22 is provided in the refrigerant pipe 3 that connects the discharge side of the compressor 10 and the refrigerant flow switching device 11, and the temperature of the high-temperature and high-pressure refrigerant that is compressed and discharged by the compressor 10 is measured. It is to be detected and is composed of a thermistor or the like.

[ Indoor units 2a, 2b]
Indoor unit 2a, 2b air-conditions air-conditioned space 4a, 4b, and is equipped with load side heat exchangers 40a, 40b and expansion devices 41a, 41b, respectively. Further, in the vicinity of the load side heat exchangers 40a and 40b, indoor fans 42a and 42b (hereinafter collectively referred to as the indoor fan 42) for blowing air to the load side heat exchangers 40a and 40b are respectively provided. . Moreover, the indoor units 2a and 2b are connected to the outdoor unit 1 via the refrigerant pipe 3, and the refrigerant flows in and out.

The load-side heat exchanger 40 functions as an evaporator during the cooling operation, functions as a condenser during the heating operation, and performs heat exchange between the air supplied from the indoor blower 42 such as a fan and the refrigerant, and is thus conditioned space. The air for heating or the air for cooling to supply to 4 is produced | generated. The expansion device 41 has a function as a pressure reducing valve and an expansion valve, expands the refrigerant by depressurizing it, and is configured by a device whose opening degree can be variably controlled, for example, an electronic expansion valve.

The indoor units 2a and 2b include second temperature detection devices 50a and 50b (hereinafter collectively referred to as the second temperature detection device 50) for detecting temperature, and third temperature detection devices 51a and 51b (hereinafter referred to as generic names). A third temperature detection device 51) and fourth temperature detection devices 52a and 52b (hereinafter collectively referred to as a fourth temperature detection device 52).

The second temperature detection device 50 is provided in the refrigerant pipe 3 connecting the expansion device 41 and the load side heat exchanger 40, and detects the temperature of the refrigerant flowing into the load side heat exchanger 40 during the cooling operation. is there. Further, the third temperature detection device 51 is provided in the refrigerant pipe 3 on the opposite side of the expansion device 41 with respect to the load side heat exchanger 40, and the refrigerant that flows out of the load side heat exchanger 40 during the cooling operation. It detects temperature. Furthermore, the fourth temperature detection device 52 is provided in the air suction portion of the load-side heat exchanger 40 and detects the air temperature in the conditioned space 4.

The second temperature detection device 50, the third temperature detection device 51, and the fourth temperature detection device 52 are composed of a thermistor or the like.

[Control device 30]
The outdoor unit 1 also includes a control device 30. The control device 30 includes, for example, dedicated hardware or a CPU (also referred to as a central processing unit, a central processing device, a processing device, an arithmetic device, a microprocessor, a microcomputer, or a processor) that executes a program stored in a memory. Has been.

FIG. 10 is a functional block of the air conditioning apparatus 100 according to the embodiment of the present invention.
As shown in FIG. 10, the control device 30 includes a main control unit 31, a timer unit 32, a storage unit 33, and a drive unit 34.
The main control unit 31 turns on / off the alarm device 6, opens / closes the shut-off device 7, and rotates the ventilation device 8 (ON) based on detection values of various detection devices and instructions from a remote controller (not shown). / Off), the frequency of the compressor 10, the rotational speed of the outdoor fan 14 of the heat source side heat exchanger 12 (including ON / OFF), switching of the refrigerant flow switching device 11, opening of the expansion device 41, and load The drive unit 34 is instructed to control the rotational speed (including ON / OFF) of the indoor blower 42 of the side heat exchanger 40.

The various detection devices include the refrigerant detection device 5, the first pressure detection device 20, the second pressure detection device 21, the first temperature detection device 22, the second temperature detection device 50, the third temperature detection device 51, and A fourth temperature detection device 52 is included.

The timer unit 32 measures time. The storage unit 33 stores various information such as a threshold value C1 described later.
Based on instructions from the main control unit 31, the drive unit 34 turns on / off the alarm device 6, opens / closes the shut-off device 7, the rotational speed (including ON / OFF) of the ventilation device 8, the frequency of the compressor 10, and the heat source The rotational speed (including ON / OFF) of the outdoor fan 14 of the side heat exchanger 12, the switching of the refrigerant flow switching device 11, the opening degree of the expansion device 41, and the rotational speed of the indoor fan 42 of the load side heat exchanger 40 (Including ON / OFF).

In the present embodiment, an example in which the control device 30 is provided in the outdoor unit 1 is shown. However, the present invention is not limited thereto, and the control device 30 may be provided separately for each unit of the outdoor unit 1 and the indoor units 2a and 2b. Alternatively, it may be provided in either the outdoor unit 1 or the indoor units 2a and 2b. Further, although the control device 30 includes the timer unit 32 and the storage unit 33, the configuration is not limited thereto, and the timer unit 32 and the storage unit 33 may be provided separately from the control device 30. Good.

The shutoff device 7 shuts off the flow of the refrigerant pipe 3 in order to suppress the refrigerant leak from the outdoor unit 1 to the air-conditioned space 4 when the refrigerant leaks from the indoor unit 2 or the vicinity thereof. . Accordingly, the blocking device 7 may be any device as long as it can block the refrigerant flow in the refrigerant circuit 101. For example, the blocking device 7 may be controlled only to open or close like an electromagnetic valve, or like an electronic expansion valve. The opening may be variably controllable.

[Cooling only]
FIG. 11 is a refrigerant circuit 101 diagram showing the refrigerant flow during the cooling only operation of the air-conditioning apparatus 100 according to the embodiment of the present invention. In FIG. 11, the flow direction of the refrigerant is indicated by solid line arrows. The refrigerant flow switching device 11 is switched so that the discharge side of the compressor 10 and the heat source side heat exchanger 12 are connected. In this FIG. 11, the cooling only operation of the air conditioner 100 will be described by taking as an example a case where a cooling load is generated in the load side heat exchangers 40a and 40b.

In the case of the cooling only operation, the low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 through the refrigerant flow switching device 11. The high-temperature and high-pressure gas refrigerant that has flowed into the heat source side heat exchanger 12 is condensed while dissipating heat to the outdoor air, and becomes high-pressure liquid refrigerant. Then, the high-pressure liquid refrigerant that has flowed out of the heat source side heat exchanger 12 flows out of the outdoor unit 1, passes through the refrigerant pipe 3, and flows into the indoor units 2a and 2b. At this time, the blocking devices 7a and 7b are in an open state so as not to hinder the refrigerant flow.

The high-pressure liquid refrigerant that has flowed into the indoor units 2a and 2b is decompressed by the expansion devices 41a and 41b into a low-temperature and low-pressure two-phase refrigerant, and then flows into the load- side heat exchangers 40a and 40b that act as evaporators. By absorbing heat from the air, the indoor air is cooled and becomes a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant that has flowed out of the load- side heat exchangers 40 a and 40 b flows into the outdoor unit 1 through the refrigerant pipe 3. The refrigerant flowing into the outdoor unit 1 passes through the refrigerant flow switching device 11 and the accumulator 13 and is sucked into the compressor 10.

The control device 30 makes the superheat (superheat degree) obtained as a difference between the temperature detected by the second temperature detection devices 50a and 50b and the temperature detected by the third temperature detection devices 51a and 51b constant. In addition, the opening degree of the expansion devices 41a and 41b is controlled. By doing so, the capability according to the thermal load of air-conditioned space 4a, 4b can be exhibited, and efficient driving | operation becomes possible.

[All heating operation]
FIG. 12 is a refrigerant circuit 101 diagram illustrating the refrigerant flow during the heating only operation of the air-conditioning apparatus 100 according to the embodiment of the present invention. In FIG. 12, the flow direction of the refrigerant is indicated by solid line arrows. The refrigerant flow switching device 11 is switched so that the discharge side of the compressor 10 and the shut-off devices 7a and 7b are connected. In FIG. 12, the heating operation of the air conditioner 100 will be described by taking as an example a case where a thermal load is generated in the load- side heat exchangers 40a and 40b.

In the case of the all-heating operation, the low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the indoor units 2a and 2b through the refrigerant pipe 3 via the refrigerant flow switching device 11. At this time, the blocking devices 7a and 7b are in an open state so as not to hinder the refrigerant flow.

The high-temperature and high-pressure gas refrigerant that has flowed into the indoor units 2a and 2b radiates heat to the indoor air in the load- side heat exchangers 40a and 40b, becomes high-pressure liquid refrigerant, and flows into the expansion devices 41a and 41b. Then, after the pressure is reduced to the low-temperature and low-pressure two-phase refrigerant by the expansion devices 41 a and 41 b, the indoor units 2 a and 2 b flow out, and the refrigerant pipe 3 flows into the outdoor unit 1.

The low-temperature and low-pressure two-phase refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12 and absorbs heat from the outdoor air to become a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant exiting the heat source side heat exchanger 12 passes through the refrigerant flow switching device 11 and the accumulator 13 and is sucked into the compressor 10.

The control device 30 is a subcool (supercooling degree) obtained as a difference between the saturated liquid temperature of the refrigerant calculated from the pressure detected by the first pressure detection device 20 and the temperature detected by the second temperature detection device 50. Is controlled so that the opening degree of the expansion devices 41a and 41b is constant. By doing so, the capability according to the thermal load of air-conditioned space 4a, 4b can be exhibited, and efficient driving | operation becomes possible.

Next, the misdetection avoidance operation of the refrigerant leakage of the air conditioning apparatus 100 according to the present embodiment will be described.
FIG. 13 is a diagram for explaining an example of an erroneous detection operation for refrigerant leakage of a conventional air conditioner, and FIG. 14 illustrates an erroneous detection avoidance operation for refrigerant leakage of the air conditioner 100 according to the embodiment of the present invention. It is a figure explaining.
2. Description of the Related Art Conventionally, a control device for an air conditioner has a refrigerant concentration threshold value, and when a detection value (refrigerant concentration) detected by the refrigerant leakage device exceeds the threshold value, a method of determining that refrigerant leakage has been common. there were. However, with this method, as shown in FIG. 13, even if the refrigerant concentration temporarily exceeds the threshold value due to miscellaneous gas, noise, etc., it is determined that the refrigerant is leaking, and erroneous detection of refrigerant leakage has occurred. It was.

Therefore, the control device 30 of the air conditioning apparatus 100 according to the present embodiment is characterized by having a refrigerant leakage determination function for avoiding the erroneous detection of the refrigerant leakage as described above.
Hereinafter, the refrigerant leakage determination function will be described in detail.

[Refrigerant leak judgment function]
The refrigerant leakage determination function of the control device 30 of the air conditioner 100 is a function of determining whether refrigerant leakage has occurred using two of the refrigerant leakage determination time and the refrigerant concentration threshold.

Hereinafter, a more specific description regarding the refrigerant leakage determination function will be given. When refrigerant leakage occurs, the time ΔT (s) from when the refrigerant leakage occurs until the refrigerant concentration in the conditioned space 4 reaches C (kg / m ³ ) is expressed by the following equation.

[Equation 1]
ΔT = C × A × H / G (1)

In Equation 1, A is the floor area (m ² ) of the conditioned space 4, H is the ceiling height (m) of the conditioned space 4, and G is the refrigerant leakage rate (kg / s).

If the refrigerant concentration threshold is C1 (kg / m ³ ), the time ΔT1 (s) from the occurrence of refrigerant leakage until the threshold C1 is reached is expressed by the following equation.

[Equation 2]
ΔT1 = C1 × A × H / G (2)

Further, if the refrigerant leakage is detected before the refrigerant concentration in the conditioned space 4 becomes LFL / 2 (kg / m ³ ) using the lower combustion limit LFL (kg / m ³ ), there is a problem in the conditioned space 4. The flammable area that cannot be obtained is described by Risk Association of Mildly Refrigerators Final Report 2016 (March 2017) published by the Japan Society of Refrigeration and Air Conditioning, page 221 (http://www.jsrae.orte.jp/bite final_report_2016r1_en.pdf).

Therefore, if the refrigerant leakage is detected before the refrigerant concentration in the air-conditioned space 4 reaches LFL / 2 (kg / m ³ ) and the safety countermeasure device is operated, ignition in the air-conditioned space 4 can be suppressed. it can. Here, the time ΔT2 (s) from when the refrigerant leakage occurs until the refrigerant concentration in the air-conditioned space 4 becomes LFL / 2 is expressed by the following equation.

[Equation 3]
ΔT2 = (LFL / 2) × A × H / G (3)

As described above, when the safety countermeasure device operates immediately, the control device 30 detects the refrigerant concentration at the threshold C1 after ΔT1 seconds by the refrigerant detection device 5 with reference to the time when the refrigerant leakage occurs, and the conditioned space 4 If it is determined that the refrigerant leakage has occurred before ΔT2 seconds after the refrigerant concentration becomes LFL / 2, the safety is ensured.

The determination time ΔTa (s), which is the maximum time allowed until the control device 30 determines that the refrigerant leaks after the refrigerant leakage occurs, is expressed by the following equation.

[Equation 4]
ΔTa = ΔT2−ΔT1 = ((LFL / 2) −C1) × A × H / G (4)

The refrigerant leakage occurs due to cracks in the refrigerant pipe 3 and corrosion of the heat exchanger in the indoor unit 2. That is, once the refrigerant leakage occurs, the hole through which the refrigerant leaks is not blocked, and thus the refrigerant leakage continues until the refrigerant in the air conditioner 100 decreases. On the other hand, sterilization spray or the like that causes erroneous detection of refrigerant leakage is sprayed in a short time.

Therefore, in order to suppress erroneous detection of refrigerant leakage, the refrigerant is detected when the refrigerant concentration exceeding the threshold C1 is detected for a certain period of time after the refrigerant detection device 5 detects the refrigerant concentration exceeding the threshold C1. A method of determining a leak is conceivable. However, although there is a possibility that a transmission error of the detection signal from the refrigerant detection device 5 may occur, even if a transmission error of the signal occurs, it is a small percentage, so the time exceeding the threshold C1 is a predetermined percentage or more. If there is a criterion, signal transmission errors can be suppressed.

In other words, the refrigerant concentration detected by the refrigerant detection device 5 always exceeds the threshold C1 or exceeds the threshold C1 until the determination time ΔTa (s) elapses after the refrigerant leakage occurs. By performing the refrigerant leakage determination based on the determination criterion that the exceeding time is equal to or greater than a predetermined ratio, it is possible to suppress erroneous detection of refrigerant leakage.

The refrigerant leakage determination does not necessarily have to wait until the determination time ΔTa (s) elapses after the refrigerant detection device 5 detects the refrigerant concentration exceeding the threshold C1, and if the refrigerant detection device 5 has high reliability, The refrigerant leakage determination may be performed before the determination time ΔTa (s) elapses.

The control interval of the control device 30 of the air conditioner 100 is 10 seconds or more even if it is short, and it is necessary to detect refrigerant leakage a plurality of times at this control interval in order to suppress erroneous detection of refrigerant leakage. In addition, the spraying time of the disinfecting spray or the like seems to be about several seconds at most. Therefore, detecting the refrigerant concentration exceeding the threshold C1 continuously for 20 seconds or more by the refrigerant detection device 5 is the shortest refrigerant leakage determination time, and the determination time ΔTa needs to be a value of 20 (s) or more. There is.

In addition, since it is necessary to determine the leakage of the refrigerant before all the refrigerant filled in the refrigerant circuit 101 leaks, the refrigerant amount M (kg) filled in the refrigerant circuit 101 satisfies the following equation: There is a need.

[Equation 5]
M ≧ ΔT2 × G (5)

In addition, 221 pages (http: // www. Then, the leakage rate of the refrigerant in the indoor unit of the air conditioner is 10 (kg / h) = 10/3600 (kg / s). Further, considering that the standard indoor ceiling height is 2.2 (m), Expressions (1) to (5) are respectively expressed as follows.

[Formula 1A]
ΔT = C × A × H / G
= C x A x 2.2 / (10/3600)
= 792 × C × A (6)

[Formula 2A]
ΔT1 = C1 × A × H / G
= C1 * A * 2.2 / (10/3600)
= 792 × C1 × A (7)

[Formula 3A]
ΔT2 = (LFL / 2) × A × H / G
= (LFL / 2) x A x 2.2 / (10/3600)
= 396 x LFL x A (8)

[Formula 4A]
ΔTa = ((LFL / 2) −C1) × A × H / G
= ((LFL / 2) -C1) × A × 2.2 / (10/3600)
= 792 x (LFL / 2-C1) x A (9)
[Formula 5A]
M ≧ ΔT2 × G
= (LFL / 2) x A x (H / G) x G
= 396 x LFL x A x G
= (LFL / 2) x A x H
= (LFL / 2) x A x 2.2
= 1.1 x LFL x A (10)

As an example, the refrigerant filled in the refrigerant circuit 101 is R32 refrigerant, the floor area A of the air-conditioned space 4 is 9 (m ² ), and the threshold C1 of the refrigerant detector 5 is 0.0307 (kg / m ³ ). Then, since the LFL of the R32 refrigerant is 0.307 (kg / m ³ ), ΔT1 is about 219 seconds (≈3.7 minutes), ΔT2 is about 1094 seconds (≈18.2 minutes), and ΔTa is about 875. Second (≈14.5 minutes), M is about 3.0 (kg).

In the example of the R32 refrigerant described above, the determination time ΔTa (s), which is the maximum time allowed from the detection of the refrigerant concentration exceeding the threshold C1 to the determination of refrigerant leakage, is set to about 875 seconds. However, the safety of the air-conditioned space 4 can be secured. Naturally, the determination time ΔTa (s) is the maximum allowable time, and may be set to a smaller value in actual operation.

Since the amount of refrigerant charged in the refrigerant circuit 101 is determined in advance, the LFL of the refrigerant that leaks is known in advance. Further, the threshold C1 is also determined in advance by the refrigerant detection device 5 used. Therefore, LFL and C1 in equation (9) can be set as constants, and when R32 refrigerant is used and threshold C1 is 0.0307 (kg / m ³ ), equation (9) is expressed by the following equation: Therefore, ΔTa can be calculated using only the floor area A.

[Formula 4B]
ΔTa = ((LFL / 2) −C1) × A × H / G
= 792 x (0.307 / 2-0.037) x A
= 92.268 × A (11)

The air conditioning load L of the general air conditioned space 4 takes a value such as 0.1 (kW / m ² ). Since the air conditioning capability Q (kW) of the indoor unit 2 is stored in the storage unit 33 of the control device 30, the floor area A can be obtained by using the air conditioning capability Q and the air conditioning load L of the indoor unit 2, ΔTa can also be calculated by the following equation. That is, ΔTa can be calculated using only the value of the air conditioning capability Q of the indoor unit 2. When a plurality of indoor units 2 are installed in one air-conditioned space 4, the total air conditioning capacity of the plurality of indoor units 2 may be Q.

[Formula 4C]
ΔTa = ((LFL / 2) −C1) × (Q / L) × H / G
= 792 x (0.307 / 2-0.037) x (Q / 0.1)
= 922.68 × Q (12)

Further, when equation (9) is rewritten, the following equation is obtained, and ΔTa may be defined by the value calculated by equation (13).

[Formula 4D]
ΔTa = ((LFL / 2) −C1) × (Q / L) × H / G
= 792 × ((LFL / 2) −C1) × (Q / 0.1)
= 7920 × ((LFL / 2) −C1) × Q (13)

Similarly, when equation (10) is rewritten, the following equation is obtained, and M may be defined by the value calculated by equation (14).

[Formula 5B]
M ≧ ΔT2 × G
= (LFL / 2) x (Q / L) x (H / G) x G
= (LFL / 2) x (Q / L) x H
= (LFL / 2) x (Q / 0.1) x 2.2
= 11 x LFL x Q (14)

Therefore, as shown in FIG. 14, the control device 30 may detect the refrigerant concentration exceeding the threshold value C1 by the refrigerant detection device 5 using electrical noise and other gases including organic compound system in the air. It is not immediately determined that the refrigerant has leaked. Then, the control device 30 can determine whether or not refrigerant leakage has actually occurred from the detection value Cd of the refrigerant detection device 5 during the determination time ΔTa (s), and suppress erroneous detection of refrigerant leakage. It becomes possible to do.

Next, a specific example regarding a method for suppressing erroneous detection of refrigerant leakage will be described. The following measures can be taken as a method for suppressing erroneous detection of refrigerant leakage using the determination time ΔTa (s).
The condition for determining that the refrigerant leakage has occurred is always the threshold value until the determination time ΔTa (s) elapses after the detection value Cd by the refrigerant detection device 5 exceeds the threshold value C1 (kg / m ³ ). Under the condition that it exceeds C1, erroneous detection of refrigerant leakage due to miscellaneous gas in the air can be suppressed.

In addition, the condition for determining that a refrigerant leak has occurred is that the detection value Cd by the refrigerant detection device 5 exceeds the threshold value C1 (kg / m ³ ) until the determination time ΔTa (s) elapses. In the meantime, even if the ratio that the threshold value C1 is exceeded is a predetermined ratio or more, erroneous detection of refrigerant leakage due to miscellaneous gas in the air can be suppressed.

As another determination condition, the detection value Cd by the refrigerant detection device 5 is sampled at regular intervals, and the detection value Cd by the refrigerant detection device 5 continues for the reference number of times until the determination time ΔTa (s) elapses. If the threshold value C1 is exceeded, it may be determined that refrigerant leakage has occurred.

In the present embodiment, in the description of the above-described refrigerant leakage determination function, the refrigerant filled in the refrigerant circuit 101 is R32 refrigerant, which is a flammable refrigerant, and the refrigerant lower combustion limit LFL is used. . However, the refrigerant filled in the refrigerant circuit 101 is not limited to the flammable refrigerant, but may be a nonflammable refrigerant or a toxic refrigerant, and the refrigerant concentration limit RCL (Refrigerant Concentration Limit) of the nonflammable refrigerant and the toxic refrigerant may be used. The same effect can be obtained.

FIG. 15 is a diagram illustrating a first example of a control flow of the refrigerant leakage detection operation of the air-conditioning apparatus 100 according to the embodiment of the present invention.
Next, a first example of the control flow of the refrigerant leak detection operation of the air-conditioning apparatus 100 according to the present embodiment will be described with reference to FIG.

First, the main control unit 31 determines whether or not the detection value Cd detected by the refrigerant detection device 5 exceeds the threshold value C1 stored in the storage unit 33 (step S1A).

When the main control unit 31 determines that the detected value Cd exceeds the threshold C1 (YES in step S1A), the main control unit 31 starts measuring the time t by the timer unit 32 (step S2A).

After step S2A, the main control unit 31 determines whether the time t exceeds the determination time ΔTa stored in the storage unit 33 (step S3A).

When the main control unit 31 determines that the time t does not exceed the determination time ΔTa (NO in step S3A), the main control unit 31 determines whether the detection value Cd exceeds the threshold C1 (step S4A).

In step S4A, when the main control unit 31 determines that the detection value Cd does not exceed the threshold value C1 (NO in step S4A), the process ends.

On the other hand, when the main control unit 31 determines that the detection value Cd exceeds the threshold value C1 (YES in step S4A), the process returns to step S3A.

In step S3A, when the main control unit 31 determines that the time t exceeds the determination time ΔTa (YES in step S3A), the drive unit 34 operates the safety measure device. That is, the main control unit 31 turns on the alarm device 6, opens the shut-off device 7, and turns on the ventilation device 8 (step S <b> 5 </ b> A).

As described above, the main control unit 31 repeats the processes of steps S3A and S4A while the detection value Cd exceeds the threshold value C1, and if the detection value Cd always exceeds the threshold value C1 during the determination time ΔTa, The countermeasure device is operating.

FIG. 16 is a diagram illustrating a second example of a control flow of the refrigerant leakage detection operation of the air-conditioning apparatus 100 according to the embodiment of the present invention.
Next, a second example of the control flow of the refrigerant leak detection operation of the air-conditioning apparatus 100 according to the present embodiment will be described with reference to FIG.

First, the main control unit 31 starts measuring the time t by the timer unit 32, and resets the on time Δton and the off time Δtoff to 0 (step S1B). Here, the on-time Δton is the total time that the detected value Cd exceeds the threshold value C1, and the off-time Δtoff is the total time that the detected value Cd does not exceed the threshold value C1. Next, the main control unit 31 determines whether or not the detection value Cd by the refrigerant detection device 5 exceeds the threshold value C1 stored in the storage unit 33 (step S2B).

When the main control unit 31 determines that the detection value Cd exceeds the threshold C1 (YES in step S2B), the main control unit 31 adds time to the on-time Δton (step S3B), and proceeds to step S5B.

On the other hand, when the main control unit 31 determines that the detection value Cd does not exceed the threshold C1 (NO in step S2B), the main control unit 31 adds time to the off time Δtoff (step S4B), and proceeds to step S5B. Note that the process of step S4B can be omitted.

Here, in steps S3B and S4B, the time to be added to the on time Δton or the off time Δtoff is the time from the determination process in the previous step S2B to the current step S2B. For example, when the main control unit 31 performs the determination process in step S2B every second, the time to add is 1 second.

In step S5B, the main control unit 31 determines whether or not the time t exceeds the determination time ΔTa stored in the storage unit 33.

When the main control unit 31 determines that the time t exceeds the determination time ΔTa (YES in step S5B), the process proceeds to step S6B.

On the other hand, when the main control unit 31 determines that the time t does not exceed the determination time ΔTa (NO in step S5B), the main control unit 31 returns to step S2B. That is, the main control unit 31 repeats the processes of steps S2B to S5B until the time t exceeds the determination time ΔTa. Then, during the determination time ΔTa, the detection value Cd does not exceed the threshold value C1 during the Δon time ton, which is the sum of the times when the detection value Cd exceeds the threshold value C1, and the determination time ΔTa. The off time Δtoff, which is the total time, is obtained.

In step S6B, the main control unit 31 determines whether or not the on-time Δton exceeds the reference time xΔTa stored in the storage unit 33. Here, for the reference time xΔTa, for example, when the determination time ΔTa is 30 seconds and the preset ratio x is 80%, the reference time xΔTa is 30 × (8/10) = 24 seconds.

When the main control unit 31 determines that the on-time Δton exceeds the reference time xΔTa (YES in step S6B), the main control unit 31 causes the drive unit 34 to operate the safety measure device. That is, the main control unit 31 turns on the alarm device 6, turns it off on the shut-off device 7, and turns it on on the ventilation device 8 (step S 7 B).

On the other hand, when the main control unit 31 determines that the on-time Δton does not exceed the reference time xΔTa (NO in step S6B), the process is terminated.

From the above, the main control unit 31 measures the total time when the detected value Cd exceeds the threshold value C1 during the determination time ΔTa, and when the total measured time is equal to or greater than the reference time xΔTa, the safety measure device Is operating.

FIG. 17 is a diagram illustrating a third example of the control flow of the refrigerant leak detection operation of the air-conditioning apparatus 100 according to the embodiment of the present invention.
Next, a third example of the control flow of the refrigerant leak detection operation of the air-conditioning apparatus 100 according to the present embodiment will be described with reference to FIG.

First, the main control unit 31 starts measuring the time t by the timer unit 32, and resets the counter K to 0 (step S1C). Next, the main control unit 31 determines whether or not the detection value Cd detected by the refrigerant detection device 5 exceeds the threshold value C1 stored in the storage unit 33 (step S2C).

When the main control unit 31 determines that the detected value Cd exceeds the threshold value C1 (YES in step S2C), the main control unit 31 adds 1 to the counter K (step S3C), and proceeds to step S5C.

On the other hand, if the main control unit 31 determines that the detected value Cd does not exceed the threshold C1 (NO in step S2C), the main control unit 31 resets the counter K (step S4C), and proceeds to step S5C.

In step S5C, the main control unit 31 determines whether the value of the counter K has reached the reference number Ka stored in the storage unit 33.

When the main control unit 31 determines that the value of the counter K has reached the reference number Ka (YES in step S5C), the main control unit 31 causes the drive unit 34 to operate the safety measure device. That is, the main control unit 31 turns on the alarm device 6, opens the shut-off device 7, and turns on the ventilation device 8 (step S <b> 7 </ b> C).

On the other hand, if the main control unit 31 determines that the value of the counter K has not reached the reference number Ka (NO in step S5C), the process proceeds to step S6C.

In step S6C, the main control unit 31 determines whether the time t exceeds the determination time ΔTa stored in the storage unit 33.

The main control part 31 complete | finishes a process, when it determines with the time t exceeding the determination time (DELTA) Ta (YES of step S6C).

On the other hand, when determining that the time t does not exceed the determination time ΔTa (NO in step S6C), the main control unit 31 returns to step S2C. That is, the main control unit 31 repeats the processes of steps S2C to S5C until the time t exceeds the determination time ΔTa, and the detection value Cd exceeds the threshold C1 continuously for the reference number Ka during the determination time ΔTa. It is determined whether or not.

As described above, the main control unit 31 measures the number of times that the detected value Cd continuously exceeds the threshold value C1 during the determination time ΔTa, and when the measured number is equal to or greater than the reference number Ka, the main control unit 31 It is operating.

As described above, in the air conditioning apparatus 100 according to the present embodiment, the refrigerant detection device 5 that detects refrigerant leakage from the refrigerant circuit 101, and the detection value Cd of the refrigerant detection device 5 always exceeds the threshold C1 during the determination time ΔT. Or a control device 30 that determines that refrigerant leakage has occurred when the detection value Cd of the refrigerant detection device 5 exceeds the threshold C1 for a reference time xΔTa or more during the determination time ΔT. .

According to the air conditioner 100 according to the present embodiment, the control device 30 detects that the detection value Cd of the refrigerant detection device 5 always exceeds the threshold C1 during the determination time ΔT, or the detection of the refrigerant detection device 5. When the value Cd exceeds the threshold value C1 for the determination time ΔT or more than the reference time xΔTa, it is determined that the refrigerant leakage has occurred, so that erroneous detection of the refrigerant leakage can be suppressed.

In addition, the air conditioner 100 according to the present embodiment includes at least one of the alarm device 6, the ventilation device 8, and the shut-off device 7, and when the control device 30 determines that refrigerant leakage has occurred, the alarm device 6 At least one of the ventilation device 8 and the shut-off device 7 is operated.

According to the air conditioner 100 according to the present embodiment, when it is determined that refrigerant leakage has occurred, the safety countermeasure device is operated, so that ignition in the air-conditioned space 4 can be suppressed, and the safety of the air-conditioned space 4 Can be secured.

Moreover, in the air conditioning apparatus 100 according to the present embodiment, the control device 30 samples the detection value of the refrigerant detection device 5 at regular intervals, and the detection value of the refrigerant detection device 5 is the reference number of times during the determination time ΔTa. When Ka exceeds the threshold value C1 continuously, it is determined that refrigerant leakage has occurred.

According to the air conditioner 100 according to the present embodiment, the control device 30 samples the detection value of the refrigerant detection device 5 at regular intervals, and the detection value of the refrigerant detection device 5 is the reference number of times during the determination time ΔTa. When the threshold value C1 is continuously exceeded for Ka, it is determined that refrigerant leakage has occurred, so that erroneous detection of refrigerant leakage can be suppressed.

1 outdoor unit, 2 indoor unit, 2a indoor unit, 2b indoor unit, 3 refrigerant pipe, 3a branching unit, 3b branching unit, 4 air conditioning space, 4a air conditioning space, 4b air conditioning space, 5 refrigerant detection device, 5a refrigerant detection device, 5b refrigerant detection device, 6 alarm device, 6a alarm device, 6b alarm device, 7 block device, 7a block device, 7b block device, 8 ventilator, 8a ventilator, 8b ventilator, 10 compressor, 11 refrigerant flow switching Device, 12 heat source side heat exchanger, 13 accumulator, 14 outdoor fan, 20 first pressure detection device, 21 second pressure detection device, 22 first temperature detection device, 30 control device, 31 main control unit, 32 timer unit, 33 storage unit, 34 drive unit, 40 load side heat exchanger, 40a load side heat exchanger, 40b load side heat exchanger, 41 , 41a throttle device, 41b throttle device, 42 indoor blower, 42a indoor blower, 42b indoor blower, 50 second temperature detection device, 50a second temperature detection device, 50b second temperature detection device, 51 third temperature detection device , 51a third temperature detection device, 51b third temperature detection device, 52 fourth temperature detection device, 52a fourth temperature detection device, 52b fourth temperature detection device, 100 air conditioner, 101 refrigerant circuit.

Claims (9)

1. One or more indoor units that air-condition the air-conditioned space;
   One or more outdoor units that function as heat sources;
   A refrigerant circuit in which the indoor unit and the outdoor unit are connected by a refrigerant pipe and the refrigerant circulates;
   A refrigerant detector provided in the indoor unit or in an air-conditioned space in which the indoor unit performs air conditioning, and detects refrigerant leakage from the refrigerant circuit;
   When the detection value of the refrigerant detection device always exceeds the threshold value C1 during the determination time ΔTa, or when the detection value of the refrigerant detection device exceeds the threshold value C1 during the determination time ΔTa, the refrigerant leakage And an air conditioner comprising:
2. It includes at least one of an alarm device that informs the user of refrigerant leakage, a ventilation device that exhausts the leaked refrigerant, and a blocking device that blocks the flow of the refrigerant,
   The air conditioning apparatus according to claim 1, wherein the control device operates at least one of the alarm device, the ventilation device, and the shut-off device when it is determined that refrigerant leakage has occurred.
3. ^3. The air according to claim 1, wherein the determination time ΔTa is a value obtained using a lower combustion limit LFL (kg / m ³ ) when the refrigerant charged in the refrigerant circuit is a combustible refrigerant. Harmony device.
4. The floor area of the air-conditioned space in which the indoor unit is installed is A (m ² ),
   The ceiling height of the air-conditioned space where the indoor unit is installed is H (m),
   G (kg / s) is a leakage rate of the refrigerant filled in the refrigerant circuit,
   The total air conditioning capacity of the indoor unit is Q (kW),
   When the air conditioning load of the air conditioned space where the indoor unit is installed is L (kW / m ² ),
   The determination time ΔTa is less than a value calculated by ((LFL / 2) −C1) × A × H / G or ((LFL / 2) −C1) × (Q / L) × H / G. The air conditioning apparatus according to claim 3.
5. The amount of refrigerant charged in the refrigerant circuit is equal to or greater than a value calculated by (LFL / 2) × A × H or (LFL / 2) × (Q / L) × H. Air conditioner.
6. The leakage rate is G = 10/3600 (kg / s), the ceiling height is H = 2.2 (m), and the air conditioning load is L = 0.1 (kW / m ² ). The air conditioning apparatus according to 4 or 5.
7. The determination time ΔTa is a value obtained by using a refrigerant concentration limit RCL (kg / m ³ ) when the refrigerant filled in the refrigerant circuit is an incombustible refrigerant or a toxic refrigerant. The air conditioning apparatus described.
8. The air conditioner according to any one of claims 1 to 7, wherein the determination time ΔTa is 20 seconds or more.
9. The control device samples the detection value of the refrigerant detection device at regular intervals, and if the detection value of the refrigerant detection device exceeds the threshold value C1 for the reference number of times during the determination time ΔTa, refrigerant leakage occurs. The air conditioner according to any one of claims 1 to 8, wherein it is determined that the air has occurred.

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