JP2010007997A - Refrigerant amount determining method of air conditioning device, and air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerant amount determining method of an air conditioning device, and the air conditioning device in which the refrigerant amount determining method is realized to perform a refrigerant amount determining operation under a condition to minimize error in detection. <P>SOLUTION: In this refrigerant amount determining method for determining the adequacy or inadequacy of the refrigerant amount in a refrigerant circuit in a trial operation of the air conditioning device 1 comprising a heat source unit 2 having a compressor 21, a heat source-side heat exchanger 23 and a cooling heat source adjusting means 27, an utilization unit 4 having an utilization-side heat exchanger 41, an expanding mechanism 33, and the refrigerant circuit 10 including a liquid refrigerant communication pipe 6 and a gas refrigerant communication pipe 7, and capable of performing at least a cooling operation, at least one of that the determination of adequacy/inadequacy of the refrigerant amount is not performed, that the fact that the present condition is not proper to determine the adequacy/inadequacy of the refrigerant amount, is notified, and that a proper condition to determine the adequacy/inadequacy of the refrigerant amount is notified, is performed as the refrigerant amount adequacy/inadequacy disapproval control, when environmental conditions after the lapse of a prescribed time from a memorizing step is out of a range of a first condition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a function for determining the suitability of the amount of refrigerant charged in the refrigerant circuit of the air conditioner, in particular, in the refrigerant circuit of the air conditioner in which the heat source unit and the utilization unit are connected via a refrigerant communication pipe. It is related with the function which determines the suitability of the refrigerant | coolant amount with which it filled.

2. Description of the Related Art Conventionally, there is an air conditioner that performs a trial operation such as a refrigerant amount determination operation that determines a refrigerant amount based on the degree of supercooling of a condenser (see Patent Document 1).
JP 2006-23072 A

  However, in the air conditioner described in Patent Document 1, when environmental conditions such as the outside air temperature are different, the refrigerant amount determination operation is not performed under the same conditions, which results in a detection error. there is a possibility.

  The subject of this invention is providing the refrigerant | coolant amount determination method of the air conditioning apparatus which performs refrigerant | coolant amount determination driving | running conditions on the conditions which a detection error does not occur as much as possible, and the air conditioning apparatus which implement | achieved it.

  A refrigerant amount determination method for an air conditioner according to a first aspect of the present invention includes a heat source unit having a compressor capable of adjusting an operating capacity and a heat source side heat exchanger, a utilization unit having a utilization side heat exchanger, an expansion mechanism, A liquid refrigerant communication pipe and a gas refrigerant communication pipe connecting the heat source unit and the utilization unit, the heat source side heat exchanger as a refrigerant condenser to be compressed in the compressor, and the utilization side heat exchanger as the heat source In the air conditioner having a refrigerant circuit capable of performing at least a cooling operation for functioning as an evaporator of refrigerant condensed in the side heat exchanger, a refrigerant amount determination method for determining suitability of the refrigerant amount in the refrigerant circuit. And an initial operation step, a storage step, and a condition determination step. In the initial operation step, from the normal operation mode in which the heat source unit and each device of the utilization unit are controlled according to the operation load of the utilization unit, the refrigerant superheat degree at the outlet of the utilization side heat exchanger is positive after the previous cooling operation. While controlling the expansion mechanism to detect, the degree of supercooling of the refrigerant at the outlet of the heat source side heat exchanger or the fluctuation in the degree of supercooling is detected, and the degree of supercooling is greater than or equal to the first predetermined value Alternatively, a stable state in which the operating state quantity is equal to or greater than the second predetermined value is set. In the storage step, the compressor frequency in the stable state is set as the first frequency, the superheat degree of the refrigerant at the outlet of the use side heat exchanger in the stable state is set as the first superheat degree, and the degree of supercooling or the operating state quantity in the stable state is calculated. As the index value, the environmental condition in the initial operation step is stored as the first condition. In the condition determining step, the first frequency stored in the storing step is set when the environmental condition after the lapse of a predetermined period from the storing step is within a first condition range that is a range converted based on the first condition. In which the compressor is controlled and the expansion mechanism is controlled so that the first superheat degree is reached, and the refrigerant is subcooled at the outlet of the heat source side heat exchanger, or the operation fluctuates according to the fluctuation of the supercooling degree. The state quantity is detected as a detected value, the index value is compared with the detected value, and the refrigerant quantity is determined to be appropriate to determine the appropriateness of the refrigerant quantity charged in the refrigerant circuit. When the environmental condition is not within the first condition range, the refrigerant amount suitability determination is not performed, and it is reported that the refrigerant amount suitability determination is not an appropriate condition. Report, no Performing a refrigerant quantity adequacy Call control at least one of.

  In the refrigerant amount determination method of the present invention, the heat source unit and the utilization unit are connected via a refrigerant communication pipe to form a refrigerant circuit, and the method is performed in a separate type air conditioner capable of at least cooling operation. is there. Here, “at least” is because the air conditioner to which the present invention can be applied includes one that can perform another operation such as a heating operation in addition to the cooling operation. In this air conditioner, it is possible to switch between a normal operation such as a cooling operation (hereinafter referred to as a normal operation mode) and a refrigerant amount determination operation mode in which the use unit is forcibly cooled. Detecting the degree of refrigerant subcooling at the outlet of the heat source side heat exchanger or the amount of operating state that fluctuates in accordance with the fluctuation of the degree of supercooling and determining the suitability of the refrigerant amount charged in the refrigerant circuit Can do.

  Thus, in the refrigerant amount determination method of the air conditioner that determines the suitability of the refrigerant amount, the environmental condition after the elapse of a predetermined period from the storing step is within a first condition range that is a range converted based on the first condition. In this case, the compressor is controlled so as to have the first frequency stored in the storing step, and the expansion mechanism is controlled so as to become the first superheat degree, and the refrigerant at the outlet of the heat source side heat exchanger is controlled. The degree of supercooling or the amount of operating state that varies according to the degree of supercooling is detected as a detected value, and the index value is compared with the detected value to determine whether the refrigerant amount charged in the refrigerant circuit is appropriate. The refrigerant amount suitability determination is performed, and when the environmental condition after the lapse of a predetermined period from the storage step is not within the first condition range, the refrigerant amount suitability determination is not performed, and the refrigerant amount suitability determination is not an appropriate condition. To report, cold Report the appropriate conditions to carry out the amount appropriateness determination, performed as the refrigerant quantity adequacy Call control at least one of.

  Therefore, the suitability of the refrigerant amount can be determined within the range of environmental conditions where detection errors do not occur as much as possible, so that detection errors can be reduced. Also, if it is recognized that the detection error is within the range of environmental conditions, the refrigerant amount propriety determination is not performed, and the refrigerant amount propriety is reported to the user that the refrigerant amount propriety determination is not appropriate. Since at least one of reporting appropriate conditions to be judged is controlled as refrigerant quantity propriety control, measures should be taken so that the user can judge the refrigerant quantity suitability even if the refrigerant quantity suitability cannot be judged. Therefore, it is possible to determine whether or not the refrigerant amount is appropriate under the condition that the detection error is small.

  A refrigerant amount determination method for an air conditioner according to a second aspect of the present invention is the refrigerant amount determination method for an air conditioner according to the first aspect of the present invention, wherein the environmental conditions are acquired from the outside temperature, the outside temperature based on the calendar, and the outside. Including at least one of the weather conditions.

  In the present invention, as the environmental condition, at least one of an outside temperature, an outside temperature based on a calendar, and a weather condition acquired from the outside is employed. Therefore, it is possible to flexibly determine whether or not the refrigerant amount suitability can be determined according to each environmental condition.

  A refrigerant amount determination method for an air conditioner according to a third aspect of the present invention is the refrigerant amount determination method for an air conditioner according to the first or second aspect of the present invention, wherein the first condition includes at least an outside air temperature. In the first condition range, a first range width that is the width of the range is determined based on the outside air temperature. The first range width has a positive correlation with the outside air temperature.

  As the outside air temperature increases, the amount of change in the degree of supercooling or the amount of operating state tends to increase. Further, for example, when a margin for the amount of change in the degree of subcooling or the amount of operating state for detecting refrigerant leakage is detected to detect that the amount of refrigerant in the refrigerant circuit has decreased by 10% from 100% to 90%, the outside air temperature Since the detection range in which the refrigerant amount when the outside air temperature is higher than that when the outside air temperature is high is large, the range of the outside air temperature where the change in the refrigerant amount can be detected increases as the outside air temperature increases.

  Therefore, as in the present invention, by determining the first range width based on the outside air temperature so that the first range width and the outside air temperature have a positive correlation, for example, the outside air temperature and the first temperature range are By storing in advance data associated with the first range width for determination and determining the first temperature range based on the data, it is possible to accurately determine whether the refrigerant amount is appropriate. Become.

  A refrigerant amount determination method for an air conditioner according to a fourth aspect of the present invention is the refrigerant amount determination method for an air conditioner according to any one of the first to third aspects of the invention, wherein the condition determination step is a lapse of a predetermined period from the storage step. It will be done regularly later. Then, in the condition determining step, when the environmental condition after the lapse of a predetermined period from the storing step is within the first condition range, the environmental condition at that time is stored as the second environmental condition and converted based on the second environmental condition. The second condition range is derived, and in the next condition determination step, if the environmental condition at that time is within the expanded condition range including the first condition range and the second condition range, the refrigerant amount is appropriate. When the environmental condition at that time is not within the expanded condition range obtained by adding the first condition range and the second condition range, the refrigerant amount propriety control is performed.

  In the present invention, when the first condition range serving as a reference in the condition determining step is within the first condition range, the environmental condition detected in the condition determining step periodically performed after the lapse of a predetermined period from the storing step. The second environmental condition range is further derived based on the environmental condition at that time, and in the condition determination step performed next time, the environmental condition at that time is within the expanded condition range obtained by adding the first condition range and the second condition range. If there is, the refrigerant amount suitability determination is performed, and if there is no environmental condition at that time, the refrigerant suitability disabling control is performed. In addition, when the refrigerant amount suitability determination is performed, the degree of supercooling or the operating state amount under the environmental condition that is the basis of the condition range including the environmental condition at that time within the expanded condition range is appropriate for the refrigerant amount. It becomes an index value in the determination.

  Accordingly, in the second and subsequent condition determination steps after the initial operation step, if the environmental conditions are within the temperature range in which the refrigerant amount suitability determination is to be performed in all steps, the refrigerant amount suitability determination is in the temperature range in which the refrigerant amount suitability determination is to be performed. A new temperature range will be added based on the environmental conditions that exist, and by accumulating such information, it will be possible to determine the suitability of the refrigerant amount under various environmental conditions, It is possible to efficiently determine the suitability of the refrigerant amount.

  A refrigerant amount determination method for an air conditioner according to a fifth aspect of the present invention is the refrigerant amount determination method for an air conditioner according to the third aspect of the present invention, wherein the second condition includes at least an outside air temperature. In the second condition range, a second range width that is the width of the range is determined based on the outside air temperature. The second range width has a positive correlation with the outside air temperature.

  As the outside air temperature increases, the amount of change in the degree of supercooling or the amount of operating state tends to increase. Further, for example, when a margin for the amount of change in the degree of subcooling or the amount of operating state for detecting refrigerant leakage is detected to detect that the amount of refrigerant in the refrigerant circuit has decreased by 10% from 100% to 90%, the outside air temperature Since the detection range in which the refrigerant amount when the outside air temperature is higher than that when the outside air temperature is high is large, the range of the outside air temperature where the change in the refrigerant amount can be detected increases as the outside air temperature increases.

  Accordingly, as in the present invention, by determining the second range width based on the outside air temperature so that the second range width and the outside air temperature have a positive correlation, for example, the outside air temperature and the second temperature range can be determined. If data relating to the second range width for determination is stored in advance and the second temperature range is determined based on the data, it is possible to accurately determine whether the refrigerant amount is appropriate. Become.

  An air conditioner according to a sixth aspect of the present invention includes a refrigerant circuit, initial operation means, storage means, and condition determination means. The refrigerant circuit includes a heat source unit, a utilization unit, an expansion mechanism, a liquid refrigerant communication pipe and a gas refrigerant communication pipe. The heat source unit includes a compressor capable of adjusting an operation capacity and a heat source side heat exchanger. The utilization unit has a utilization side heat exchanger. The liquid refrigerant communication pipe and the gas refrigerant communication pipe connect the heat source unit and the utilization unit. Further, the refrigerant circuit is a cooling operation in which the heat source side heat exchanger functions as a condenser for refrigerant compressed in the compressor, and the use side heat exchanger functions as an evaporator for refrigerant condensed in the heat source side heat exchanger. Can be performed at least. Then, the initial operation means starts from the normal operation mode in which the heat source unit and each device of the utilization unit are controlled in accordance with the operation load of the utilization unit, and the refrigerant is superheated at the outlet of the utilization side heat exchanger in the previous cooling operation. While controlling the expansion mechanism to be a value, the degree of subcooling of the refrigerant at the outlet of the heat source side heat exchanger or the amount of operating state that fluctuates according to the fluctuation of the degree of subcooling is detected, and the degree of subcooling is a first predetermined value. Or a stable state in which the operating state quantity is equal to or greater than the second predetermined value. The storage means uses the compressor frequency in the stable state as the first frequency, sets the superheat degree of the refrigerant at the outlet of the use side heat exchanger in the stable state as the first superheat degree, and determines the degree of supercooling or the operating state quantity in the stable state. As the index value, the environmental condition in the initial operation step is stored as the first condition. The condition determination means has the first frequency stored in the storage step when the environmental condition after a predetermined period has elapsed from the storage step is within a first condition range that is a range converted based on the first condition. In which the compressor is controlled and the expansion mechanism is controlled so that the first superheat degree is reached, and the refrigerant is subcooled at the outlet of the heat source side heat exchanger, or the operation fluctuates according to the fluctuation of the supercooling degree. The state quantity is detected as a detected value, the index value is compared with the detected value, and the refrigerant quantity is determined to be appropriate to determine the appropriateness of the refrigerant quantity charged in the refrigerant circuit. When the environmental condition is not within the first condition range, the refrigerant amount suitability determination is not performed, and it is reported that the refrigerant amount suitability determination is not an appropriate condition. To report Kutomo performed as one refrigerant quantity adequacy not control.

  Therefore, the suitability of the refrigerant amount can be determined within the range of environmental conditions where detection errors do not occur as much as possible, so that detection errors can be reduced. Also, if it is recognized that the detection error is within the range of environmental conditions, the refrigerant amount propriety determination is not performed, and the refrigerant amount propriety is reported to the user that the refrigerant amount propriety determination is not appropriate. Since at least one of reporting appropriate conditions to be judged is controlled as refrigerant quantity propriety control, measures should be taken so that the user can judge the refrigerant quantity suitability even if the refrigerant quantity suitability cannot be judged. Therefore, it is possible to determine whether or not the refrigerant amount is appropriate under the condition that the detection error is small.

  In the refrigerant quantity determination method for an air conditioner according to the first aspect of the invention, it is possible to determine the suitability of the refrigerant quantity within a range of environmental conditions where detection errors do not occur as much as possible. Also, if it is recognized that the detection error is within the range of environmental conditions, the refrigerant amount propriety determination is not performed, and the refrigerant amount propriety is reported to the user that the refrigerant amount propriety determination is not appropriate. Since at least one of reporting appropriate conditions to be judged is controlled as refrigerant quantity propriety control, measures should be taken so that the user can judge the refrigerant quantity suitability even if the refrigerant quantity suitability cannot be judged. Therefore, it is possible to determine whether or not the refrigerant amount is appropriate under the condition that the detection error is small.

  In the refrigerant amount determination method for the air conditioner according to the second aspect of the present invention, it is possible to determine whether or not the refrigerant amount suitability can be flexibly determined according to each environmental condition.

  In the refrigerant amount determination method for the air conditioner according to the third aspect of the invention, the first range width is determined based on the outside air temperature so that the first range width and the outside air temperature have a positive correlation, for example, outside air. If data that associates the temperature with the first range for determining the first temperature range is stored in advance, and the first temperature range is determined based on the data, the suitability of the refrigerant amount can be accurately determined. A determination can be made.

  In the refrigerant quantity determination method for an air conditioner according to the fourth aspect of the present invention, in the second and subsequent condition determination steps after the initial operation step, the environmental conditions are within the temperature range where the refrigerant quantity suitability determination should be performed at all steps. In addition, a new temperature range will be added based on the environmental conditions that were within the temperature range where the refrigerant amount suitability should be determined, and by accumulating such information, even under various environmental conditions The refrigerant amount suitability determination can be performed, and the refrigerant amount suitability determination can be efficiently performed.

  In the refrigerant quantity determination method for the air conditioner according to the fifth aspect of the present invention, the second range width is determined based on the outside air temperature so that the second range width and the outside air temperature have a positive correlation. If data that associates the temperature with the second range width for determining the second temperature range is stored in advance, and the second temperature range is determined based on the data, the suitability of the refrigerant amount can be accurately determined. A determination can be made.

  In the air conditioner according to the sixth aspect of the present invention, it is possible to determine the suitability of the refrigerant amount within the range of environmental conditions where detection errors do not occur as much as possible. Therefore, detection errors can be reduced. Also, if it is recognized that the detection error is within the range of environmental conditions, the refrigerant amount propriety determination is not performed, and the refrigerant amount propriety is reported to the user that the refrigerant amount propriety determination is not appropriate. Since at least one of reporting appropriate conditions to be judged is controlled as refrigerant quantity propriety control, measures should be taken so that the user can judge the refrigerant quantity suitability even if the refrigerant quantity suitability cannot be judged. Therefore, it is possible to determine whether or not the refrigerant amount is appropriate under the condition that the detection error is small.

  Hereinafter, embodiments of an air-conditioning apparatus according to the present invention will be described based on the drawings.

(1) Configuration of Air Conditioner FIG. 1 is a schematic refrigerant circuit diagram of an air conditioner 1 according to an embodiment of the present invention. The air conditioner 1 is a device used for indoor air conditioning such as a building by performing a vapor compression refrigeration cycle operation. The air conditioner 1 mainly includes one outdoor unit 2, an indoor unit 4, a liquid refrigerant communication pipe 6 and a gas refrigerant communication pipe 7 that connect the outdoor unit 2 and the indoor unit 4. That is, the vapor compression refrigerant circuit 10 of the air conditioner 1 of the present embodiment is configured by connecting the outdoor unit 2, the indoor unit 4, the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7. ing.

<Indoor unit>
The indoor unit 4 is installed by embedding or hanging on a ceiling of a room such as a building or by hanging on a wall surface of the room. The indoor unit 4 is connected to the outdoor unit 2 via a liquid refrigerant communication pipe 6 and a gas refrigerant communication pipe 7 and constitutes a part of the refrigerant circuit 10.

  Next, the configuration of the indoor unit 4 will be described.

  The indoor unit 4 mainly has an indoor refrigerant circuit 11 that constitutes a part of the refrigerant circuit 10. This indoor refrigerant circuit 11 mainly has an indoor heat exchanger 41 as a use side heat exchanger.

  In the present embodiment, the indoor heat exchanger 41 is a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant evaporator during cooling operation. It is a heat exchanger that cools indoor air and functions as a refrigerant condenser during heating operation to heat indoor air. In the present embodiment, the indoor heat exchanger 41 is a cross-fin type fin-and-tube heat exchanger, but is not limited thereto, and may be another type of heat exchanger.

  In the present embodiment, the indoor unit 4 sucks indoor air into the unit, exchanges heat with the refrigerant in the indoor heat exchanger 41, and then supplies the indoor fan 42 as a blower fan to be supplied indoors as supply air. have. The indoor fan 42 is a fan capable of changing the air volume supplied to the indoor heat exchanger 41. In this embodiment, the indoor fan 42 is a centrifugal fan or a multiblade fan driven by a motor 42m such as a DC fan motor. Etc.

  The indoor unit 4 is provided with an indoor temperature sensor 43 that detects the temperature of indoor air flowing into the unit (that is, the indoor temperature) on the indoor air inlet side of the indoor unit 4. In the present embodiment, the room temperature sensor 43 is a thermistor. The indoor unit 4 also has an indoor side control unit 44 that controls the operation of each part constituting the indoor unit 4. And the indoor side control part 44 has the microcomputer, memory, etc. which were provided in order to control the indoor unit 4, and is with the remote control (not shown) for operating the indoor unit 4 separately. Control signals and the like can be exchanged between them, and control signals and the like can be exchanged with the outdoor unit 2 via the transmission line 8a.

<Outdoor unit>
The outdoor unit 2 is installed outside a building or the like, and is connected to the indoor unit 4 via a liquid refrigerant communication pipe 6 and a gas refrigerant communication pipe 7, and constitutes a refrigerant circuit 10 together with the indoor unit 4. .

  Next, the configuration of the outdoor unit 2 will be described. The outdoor unit 2 mainly has an outdoor refrigerant circuit 12 that constitutes a part of the refrigerant circuit 10. The outdoor refrigerant circuit 12 mainly includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23 as a heat source side heat exchanger, an outdoor expansion valve 33 as an expansion mechanism, an accumulator 24, A liquid side closing valve 25 and a gas side closing valve 26 are provided.

  The compressor 21 is a compressor whose operating capacity can be varied. In the present embodiment, the compressor 21 is a positive displacement compressor driven by a motor 21m whose rotation speed is controlled by an inverter. In addition, in this embodiment, although the compressor 21 is only one unit, it is not limited to this, Two or more compressors may be connected in parallel according to the number of connected indoor units or the like. .

  The four-way switching valve 22 is a valve for switching the flow direction of the refrigerant. During the cooling operation, the outdoor heat exchanger 23 is used as a refrigerant condenser compressed by the compressor 21 and the indoor heat exchanger 41. Is connected to the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 23 and to the suction side of the compressor 21 (specifically, in order to function as an evaporator of refrigerant condensed in the outdoor heat exchanger 23) Connects the accumulator 24) and the gas refrigerant communication pipe 7 side (cooling operation state: refer to the solid line of the four-way switching valve 22 in FIG. 1), and compresses the indoor heat exchanger 41 by the compressor 21 during heating operation. In order for the outdoor heat exchanger 23 to function as a refrigerant evaporator to be condensed in the indoor heat exchanger 41, the discharge side of the compressor 21 and the gas refrigerant communication pipe 7 side are Connecting It is possible to together connect the gas side of the suction side and the outdoor heat exchanger 23 of the compressor 21 (the heating operation state: see the broken lines of the four-way switching valve 22 in FIG. 1).

  In the present embodiment, the outdoor heat exchanger 23 is a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant condenser during cooling operation. It is a heat exchanger that functions as a refrigerant evaporator during heating operation. The outdoor heat exchanger 23 has a gas side connected to the four-way switching valve 22 and a liquid side connected to the liquid refrigerant communication pipe 6. In the present embodiment, the outdoor heat exchanger 23 is a cross-fin fin-and-tube heat exchanger, but is not limited to this, and may be another type of heat exchanger.

  In the present embodiment, the outdoor expansion valve 33 is configured to perform outdoor heat exchange in the refrigerant flow direction in the refrigerant circuit 10 during the cooling operation in order to adjust the pressure, flow rate, and the like of the refrigerant flowing in the outdoor refrigerant circuit 12. It is an electric expansion valve disposed on the downstream side of the vessel 23 (connected to the liquid side of the outdoor heat exchanger 23 in this embodiment).

  In the present embodiment, the outdoor unit 2 has an outdoor fan 27 as a blower fan for sucking outdoor air into the unit, exchanging heat with the refrigerant in the outdoor heat exchanger 23, and then discharging the air outside. ing. The outdoor fan 27 is a fan capable of changing the air volume supplied to the outdoor heat exchanger 23. In the present embodiment, the outdoor fan 27 is a propeller fan or the like driven by a motor 27m such as a DC fan motor. .

  The accumulator 24 is connected between the four-way selector valve 22 and the compressor 21 and is a container capable of storing surplus refrigerant generated in the refrigerant circuit 10 in accordance with fluctuations in the operating load of the indoor unit 4. It is.

  The liquid side shutoff valve 25 and the gas side shutoff valve 26 are valves provided at connection ports with external devices and pipes (specifically, the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7). The liquid side closing valve 25 is connected to the outdoor heat exchanger 23. The gas side closing valve 26 is connected to the four-way switching valve 22.

  The outdoor unit 2 is provided with various sensors. Specifically, the outdoor unit 2 includes an evaporation pressure sensor 28 that detects the pressure of the gas refrigerant flowing from the indoor heat exchanger 41, and a condensation pressure sensor that detects the condensation pressure condensed by the outdoor heat exchanger 23. 29, a suction temperature sensor 30 for detecting the suction temperature of the compressor 21, and a liquid side temperature sensor 31 for detecting the temperature of the refrigerant in the liquid state or the gas-liquid two-phase state on the liquid side of the outdoor heat exchanger 23. Is provided. An outdoor temperature sensor 32 that detects the temperature of the outdoor air flowing into the unit (that is, the outdoor temperature) is provided on the outdoor air inlet side of the outdoor unit 2. In this embodiment, the suction temperature sensor 30, the liquid side temperature sensor 31, and the outdoor temperature sensor 32 are thermistors. In addition, the outdoor unit 2 includes an outdoor control unit 34 that controls the operation of each unit constituting the outdoor unit 2. The outdoor control unit 34 includes a microcomputer provided for controlling the outdoor unit 2, a memory, an inverter circuit for controlling the motor 21m, and the like. Control signals and the like can be exchanged between them. That is, the control part 8 which performs operation control of the whole air conditioning apparatus 1 is comprised by the transmission line 8a which connects between the indoor side control part 44, the outdoor side control part 34, and the control parts 34 and 44. FIG.

  As described above, the refrigerant circuit 10 of the air conditioner 1 is configured by connecting the indoor-side refrigerant circuit 11, the outdoor-side refrigerant circuit 12, and the refrigerant communication pipes 6 and 7. The air conditioner 1 of the present embodiment performs the operation by switching between the cooling operation and the heating operation by the four-way switching valve 22, and each of the outdoor unit 2 and the indoor unit 4 according to the operation load of the indoor unit 4. The device is controlled.

(2) Operation | movement of an air conditioning apparatus Next, operation | movement of the air conditioning apparatus 1 of this embodiment is demonstrated.

  As the operation mode of the air conditioner 1 of the present embodiment, the normal operation mode for controlling each device of the outdoor unit 2 and the indoor unit 4 according to the operation load of the indoor unit 4 and the cooling of all the indoor units 4 are performed. There is a refrigerant quantity determination operation mode in which the degree of refrigerant subcooling at the outlet of the outdoor heat exchanger 23 that functions as a condenser while operating is detected to determine whether the refrigerant quantity filled in the refrigerant circuit 10 is appropriate. The normal operation mode includes a cooling operation and a heating operation, and the refrigerant amount determination operation mode includes a refrigerant leakage detection operation.

  Hereinafter, the operation | movement in each operation mode of the air conditioning apparatus 1 is demonstrated.

<Normal operation mode>
First, the cooling operation in the normal operation mode will be described.

  During the cooling operation, the four-way switching valve 22 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the gas side of the outdoor heat exchanger 23 and the suction side of the compressor 21 is the indoor heat. It is in a state connected to the gas side of the exchanger 41. Here, the liquid side closing valve 25 and the gas side closing valve 26 are in an open state. The opening of the outdoor expansion valve 33 is adjusted so that the degree of supercooling of the refrigerant at the outlet of the outdoor heat exchanger 23 becomes a predetermined value. In the present embodiment, the degree of refrigerant supercooling at the outlet of the outdoor heat exchanger 23 is determined by using the refrigerant pressure (condensation pressure) value on the outlet side of the outdoor heat exchanger 23 detected by the condensation pressure sensor 29 as the saturation temperature value of the refrigerant. And is detected by subtracting the refrigerant temperature value detected by the liquid side temperature sensor 31 from the saturation temperature value of the refrigerant.

  When the compressor 21 and the outdoor fan 27 are started in the state of the refrigerant circuit 10, the low-pressure gas refrigerant is sucked into the compressor 21 and compressed to become high-pressure gas refrigerant. Thereafter, the high-pressure gas refrigerant is sent to the outdoor heat exchanger 23 via the four-way switching valve 22 and is condensed by exchanging heat with outdoor air supplied by the outdoor fan 27. Become. The high-pressure liquid refrigerant is decompressed by the outdoor expansion valve 33 to become a low-pressure gas-liquid two-phase refrigerant, and is sent to the indoor unit 4 via the liquid-side closing valve 25 and the liquid refrigerant communication pipe 6. Here, since the outdoor expansion valve 33 controls the flow rate of the refrigerant flowing in the outdoor heat exchanger 23 so that the degree of supercooling at the outlet of the outdoor heat exchanger 23 becomes a predetermined value, the outdoor heat exchanger 23 is controlled. The high-pressure liquid refrigerant condensed in step 1 has a predetermined degree of supercooling.

  The low-pressure gas-liquid two-phase refrigerant sent to the indoor unit 4 is sent to the indoor heat exchanger 41, where it is evaporated by exchanging heat with indoor air in the indoor heat exchanger 41 to become a low-pressure gas refrigerant. . And the refrigerant | coolant of the flow volume according to the driving | running load requested | required in the air-conditioning space in which the indoor unit 4 was installed flows through the indoor heat exchanger 41.

  This low-pressure gas refrigerant is sent to the outdoor unit 2 via the gas refrigerant communication pipe 7 and flows into the accumulator 24 via the gas-side closing valve 26 and the four-way switching valve 22. Then, the low-pressure gas refrigerant that has flowed into the accumulator 24 is again sucked into the compressor 21. Here, according to the operating load of the indoor unit 4, for example, when the operating load of the indoor unit 4 is small or when it is stopped, excess refrigerant is accumulated in the accumulator 24.

  Here, the distribution state of the refrigerant in the refrigerant circuit 10 during the cooling operation in the normal operation mode is as follows. As shown in FIG. 2, the refrigerant is in the liquid state (the hatched portion in FIG. 2), the gas-liquid The two-phase states (lattice hatched portions in FIG. 2) and gas states (hatched hatched portions in FIG. 2) are distributed and distributed. Specifically, the portion from the vicinity of the outlet of the outdoor heat exchanger 23 to the outdoor expansion valve 33 is filled with a liquid refrigerant. The intermediate portion of the outdoor heat exchanger 23 and the portion between the outdoor expansion valve 33 and the vicinity of the inlet of the indoor heat exchanger 41 are filled with the gas-liquid two-phase refrigerant. In addition, the portion from the middle portion of the indoor heat exchanger 41 to the portion excluding a part of the gas refrigerant communication pipe 7 and the accumulator 24 and the vicinity of the inlet of the outdoor heat exchanger 23 via the compressor 21 is in a gas state. Filled with refrigerant. Note that some of the accumulators excluded here may contain liquid refrigerant that has accumulated as excess refrigerant. Here, FIG. 2 is a schematic diagram showing a state of the refrigerant flowing in the refrigerant circuit 10 in the cooling operation.

  Next, the heating operation in the normal operation mode will be described.

  During the heating operation, the four-way switching valve 22 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the gas side of the indoor heat exchanger 41, and the suction side of the compressor 21 is the outdoor heat. It is connected to the gas side of the exchanger 23. The degree of opening of the outdoor expansion valve 33 is adjusted so as to reduce the refrigerant flowing into the outdoor heat exchanger 23 to a pressure at which the refrigerant can evaporate in the outdoor heat exchanger 23 (that is, evaporation pressure). . Moreover, the liquid side closing valve 25 and the gas side closing valve 26 are opened.

  When the compressor 21 and the outdoor fan 27 are started in the state of the refrigerant circuit 10, the low-pressure gas refrigerant is sucked into the compressor 21 and compressed to become a high-pressure gas refrigerant, and the four-way switching valve 22 and the gas side closing are performed. It is sent to the indoor unit 4 via the valve 26 and the gas refrigerant communication pipe 7.

  Then, the high-pressure gas refrigerant sent to the indoor unit 4 is condensed by exchanging heat with indoor air in the indoor heat exchanger 41, and then becomes high-pressure liquid refrigerant, and then passes through the liquid refrigerant communication pipe 6. Sent to the outdoor unit 2.

  The high-pressure liquid refrigerant is reduced in pressure by the outdoor expansion valve 33 via the liquid-side closing valve 25 to become a low-pressure gas-liquid two-phase refrigerant and flows into the outdoor heat exchanger 23. The low-pressure gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 23 exchanges heat with outdoor air supplied by the outdoor fan 27 to evaporate into a low-pressure gas refrigerant, and the four-way switching valve 22. And flows into the accumulator 24. Then, the low-pressure gas refrigerant that has flowed into the accumulator 24 is again sucked into the compressor 21. Here, according to the operation load of the indoor unit 4, for example, when the surplus refrigerant amount is generated in the refrigerant circuit 10 as in the case where the operation load of the indoor unit 4 is small, as in the cooling operation, Excess refrigerant is accumulated in the accumulator 24.

<Refrigerant amount judgment operation mode>
In the refrigerant amount determination operation mode, the refrigerant leakage detection operation is performed, and the operation that is performed only after the air conditioner 1 is installed (hereinafter referred to as the initial setting operation) and the second and subsequent operations ( Hereinafter, the driving method is different from that of the determination operation. For this reason, the first setting operation and the determination operation will be described below separately.

(Initial setting operation)
In the field, after the refrigerant unit 10 is configured by connecting the outdoor unit 2 pre-filled with the refrigerant and the indoor unit 4 via the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7, a remote controller (not shown) Through or directly to the indoor side control unit 44 of the indoor unit 4 and the outdoor side control unit 34 of the outdoor unit 2 to perform an automatic refrigerant charging operation which is one of the refrigerant quantity determination operation modes. Then, the initial setting operation is performed in the following steps S1 to S7 (see FIG. 3). In FIG. 3, the relative supercooling degree is expressed as relative SC for simplification.

-Step S1, cooling the indoor unit (maximum outdoor fan airflow)-
First, in step S1, when an instruction to start the initial setting operation is made, the refrigerant circuit 10 is in a state (cooling operation state) in which the four-way switching valve 22 of the outdoor unit 2 is indicated by a solid line in FIG. Then, the compressor 21 and the outdoor fan 27 are activated, and the cooling operation is forcibly performed for all the indoor units 4 (the control method of the outdoor fan 27 is different from the cooling operation in the normal operation mode). At this time, the rotational speed of the motor 27m is maximized in the outdoor fan 27 so that the air volume is maximized. In step S1, since the air volume of the outdoor fan 27 is maximized in the cooling operation state, the heat transfer efficiency on the air side of the heat exchange efficiency performed by the outdoor heat exchanger 23 can be maximized, and the influence of disturbance can be reduced. Can be reduced. The verification of this effect will be described later. Further, the “disturbance” referred to here is contamination of the outdoor heat exchanger 23, installation status of the outdoor unit 2, presence or absence of wind and rain, and the like. Then, when the air volume of the outdoor fan 27 becomes maximum, the process proceeds to the next step S2.

-Step S2, temperature reading-
In step S2, the indoor temperature Tb detected by the indoor temperature sensor 43 and the outdoor temperature Ta detected by the outdoor temperature sensor are read. When the indoor temperature Tb and the outdoor temperature Ta are detected, the process proceeds to the next step S3.

-Step S3, determination of whether or not the detection range-
In step S3, the detected indoor temperature Tb and outdoor temperature Ta are set to a predetermined temperature range suitable for the preset refrigerant amount determination operation mode (for example, the indoor temperature Tb is in the range of 15 ° C. to 35 ° C., outdoor It is determined whether or not the temperature Ta is within the range of 0 ° C. to 50 ° C. In step S3, when the indoor temperature Tb and the outdoor temperature Ta are within the predetermined temperature range, the indoor temperature Tb at that time is stored as the first indoor temperature Tb1, and the outdoor temperature Ta at that time is stored in the first outdoor temperature. After storing the temperature Ta1, the process proceeds to the next step S4, and if it is not within the predetermined temperature range, the cooling operation of step S1 is continued.

-Step S4, Determination of whether the relative SC is equal to or greater than a predetermined value
In step S4, a relative supercooling degree value is derived, and it is determined whether or not the relative supercooling degree value is a predetermined value or more (for example, 0.3 or more). Here, the “relative supercooling value” refers to a value obtained by dividing the supercooling value at the outlet of the outdoor heat exchanger 23 by a value obtained by subtracting the outdoor temperature from the condensation temperature value. In the drawing, the relative supercooling degree is expressed as relative SC. The “relative supercooling degree value” will be described in detail later. In the present embodiment, the condensation temperature value is a value obtained by converting the outlet pressure (condensation pressure) value of the outdoor heat exchanger 23 detected by the condensation pressure sensor 29 into the refrigerant saturation temperature. If it is determined in step S4 that the relative supercooling value is less than the predetermined value, the process proceeds to the next step S5, and if it is determined that the relative subcooling value is less than the predetermined value, the process proceeds to step S6.

-Step S5, control of relative SC-
In step S5, since the relative supercooling degree value is less than the predetermined value, the rotational frequency of the compressor 21 and the superheating degree at the outlet of the indoor heat exchanger 41 are set so that the relative supercooling degree value is equal to or greater than the predetermined value. Control. For example, the cooling operation in step S1 is performed with the rotational frequency of the compressor 21 being 40 Hz and the degree of superheat at the outlet of the indoor heat exchanger 41 being 5 ° C., and whether or not the relative supercooling degree value is equal to or higher than a predetermined value. judge. In this operating state, when the relative supercooling degree value is less than the predetermined value, the superheating degree of the refrigerant at the outlet of the indoor heat exchanger 41 is increased by 5 ° C. while maintaining the rotational frequency of the compressor 21 to 10 ° C. Thus, a relative supercooling degree value is derived, and it is determined whether or not the relative supercooling degree value is equal to or greater than a predetermined value. When the relative supercooling degree value is less than the predetermined value, this is repeated, and the relative supercooling degree value is less than the predetermined value even if the superheating degree of the refrigerant at the outlet of the indoor heat exchanger 41 is increased. In this case, the rotational frequency of the compressor 21 is increased from 40 Hz to, for example, 50 Hz, the superheat degree of the refrigerant at the outlet of the indoor heat exchanger 41 is lowered to 5 ° C., and the relative supercool degree value is equal to or higher than a predetermined value. It is determined whether or not. Then, as described above, the degree of relative supercooling is controlled to be equal to or higher than a predetermined value by repeatedly increasing the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger 41 by 5 ° C. again. And if a relative supercooling degree value becomes more than predetermined value, it will transfer to Step S6. Control of the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger 41 (for example, control for increasing the degree of superheat by 5 ° C. from 5 ° C.) is controlled by narrowing the outdoor expansion valve 33 from the open state. ing. Further, the control of the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger 41 is not limited to this, and may be performed by controlling the air volume of the indoor fan 42, or the control of the valve opening degree of the outdoor expansion valve 33. And control of the air volume of the indoor fan 42 may be performed in combination. Here, the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger 41 is converted from the refrigerant temperature value detected by the suction temperature sensor 30 to the evaporation pressure value detected by the evaporation pressure sensor 28 into the saturation temperature value of the refrigerant. The detected value is detected by subtracting.

  Since the degree of superheat is controlled to be a positive value in step S5, as shown in FIG. 4, the accumulator 24 is in a state where no excess refrigerant is accumulated, and the refrigerant accumulated in the accumulator 24 is subjected to outdoor heat exchange. It will move to the container 23.

-Step S6, storing relative SC-
In step S6, the relative supercooling degree value that is equal to or greater than the predetermined value in step S4 or step S6 is stored as the initial relative supercooling degree value, and the process proceeds to the next step S7.

-Step S7, parameter storage-
In step S7, the rotational frequency of the compressor 21, the rotational frequency of the indoor fan 42, the outdoor temperature Ta, and the indoor temperature Tb in the operating state at the supercooling degree value stored in step S6 are stored. End the initial setting operation.

(Judgment operation)
Next, a determination operation that is an operation that is periodically performed after the initial setting operation is performed in the refrigerant amount determination operation mode will be described with reference to FIG. Here, FIG. 5 is a flowchart at the time of determination operation. In FIG. 5, the relative supercooling degree is expressed as relative SC for simplification.

  This judgment operation is switched from the cooling operation or the heating operation in the normal operation mode periodically (for example, when a load is not required for the air-conditioned space once every year) after the initial setting operation is performed. This is an operation for detecting whether or not the refrigerant in the refrigerant circuit has leaked to the outside due to the cause.

-Step S11, determination of whether or not the normal operation mode has passed a certain time-
First, it is determined whether or not the operation in the normal operation mode such as the cooling operation or the heating operation has elapsed for a certain period of time, and when the operation in the normal operation mode has elapsed for a certain period of time, the process proceeds to the next step S12.

-Step S12, indoor unit cooling operation-
When the operation in the normal operation mode has passed for a certain period of time, the refrigerant circuit 10 and the four-way switching valve 22 of the outdoor unit 2 are in the state indicated by the solid line in FIG. Then, the compressor 21 and the outdoor fan 27 are activated, and the cooling operation is forcibly performed for all the indoor units 4.

-Step S13, temperature reading-
In step S13, the room temperature and the outdoor temperature are read in the same manner as in step S2 of the initial setting operation. When the indoor temperature Tb and the outdoor temperature Ta are detected, the process proceeds to the next step S14.

-Step S14, determination of whether or not it is in a detectable range-
In step S14, similarly to step S3 of the initial setting operation described above, a range in which the detected indoor temperature Tb and outdoor temperature Ta are determined based on the first indoor temperature Tb1 and the first outdoor temperature Ta1 (for example, It is determined whether the temperature is within a range of ± 5 ° C. from the indoor temperature Tb and the outdoor temperature Tb detected by the initial setting operation (hereinafter referred to as a first temperature range ar1). In step S14, when the indoor temperature Tb and the outdoor temperature Ta are within the first temperature range ar1, the indoor temperature Tb at that time is stored as the second indoor temperature Tb2, and the outdoor temperature Ta at that time is stored as the second outdoor temperature Ta. After storing as the outdoor temperature Ta2, the process proceeds to the next step S15, and if it is not within the first temperature range ar1, the cooling operation of step S12 is continued. In the second and subsequent determination operations, the reference temperature range is stored by the first indoor temperature Tb1 and the first outdoor temperature Ta1 stored by the initial setting operation and immediately before the second and subsequent determination operations. Based on the room temperature and the outdoor temperature (stored in steps S4 and S14), all the temperatures (in each of the room temperature and the outdoor temperature) are expanded to a range of ± 5 ° C. For example, assuming that the point A in FIG. 6 is a plot of the first indoor temperature Tb1 and the first outdoor temperature Ta1, the temperature range (first temperature range ar1) serving as a reference in step S14 during the first determination operation. Is the range surrounded by a solid line. FIG. 6 is a graph showing a reference temperature range obtained based on the plotted points of the relationship between the indoor temperature Tb and the outdoor temperature Ta detected in step S3 or step S14. If the second indoor temperature Tb2 and the second outdoor temperature Ta2 are detected in the first temperature range ar1 in step S14, the reference temperature range (second temperature range ar2 in step S14 in the second determination operation). ) Is a range obtained by adding a temperature range surrounded by a broken line based on the second indoor temperature Tb2 and the second outdoor temperature Ta2 (point B). In FIG. 6, the frame of the first temperature range ar1 specified based on the point A and the frame of the second temperature range ar2 specified based on the point B are congruent. Thus, in the second and subsequent determination operations, each temperature condition when the temperature is within the predetermined temperature range is stored, and the predetermined temperature range is expanded accordingly.

-Control to the conditions in step S15, initial setting operation-
In step S15, the compressor 21 and the indoor fan 42 are controlled based on the rotation frequency of the compressor 21 and the rotation frequency of the indoor fan 42 stored in step S7 of the initial setting operation. Thereby, it can be considered that the state of the refrigerant | coolant inside the refrigerant circuit 10 is the same state as an initial setting driving | operation. That is, if the amount of refrigerant in the refrigerant circuit 10 has not changed, the conditions of the cooling operation performed in the initial setting operation are reproduced as the same, and the supercooling degree value and the like are set to substantially the same value. it can. When step S15 ends, the process proceeds to the next step S16.

-Step S16, determination of appropriateness of refrigerant amount-
In step S16, the degree of relative supercooling is derived as in step S4 of the initial setting operation. Then, it is determined whether or not a value obtained by subtracting the relative supercooling degree from the initial relative supercooling degree (hereinafter referred to as a relative supercooling degree difference) is equal to or greater than a second predetermined value. If it is determined in step S16 that the relative subcooling degree difference is less than the second predetermined value, the second indoor temperature Tb2 and the second room temperature Tb2 stored in step S14 with the relative supercooling degree area as the second relative supercooling degree value are stored. 2 The outdoor temperature Ta2 is stored in association with each other, the determination operation is terminated, and if it is determined that the relative subcooling degree difference is equal to or greater than the second predetermined value, the process proceeds to step S17. In the second and subsequent determination operations, the relative supercooling degree value associated with the indoor temperature and the outdoor temperature that are the basis of the expanded predetermined temperature range is compared. In this case, if there are a plurality of relative supercooling degree values to be used as a reference, one of them may be used as a reference.

-Step S17, warning display-
In step S <b> 17, it is determined that the refrigerant has leaked, and after performing a warning display notifying that the refrigerant leak has been detected, the determination operation is terminated.

<Relative SC value>
The relative subcooling value will be described with reference to FIGS.

  First, FIG. 7 is a graph showing the condensation temperature Tc and the outdoor heat exchanger outlet temperature Tl when the outdoor temperature Ta is constant with respect to the outdoor fan air volume. Referring to FIG. 7, under the condition where the outdoor temperature Ta is constant, the condensation temperature Tc and the outdoor heat exchanger outlet temperature Tl decrease as the outdoor fan air volume increases. The drop of the decrease is that the condensation temperature Tc is larger than the outdoor heat exchanger outlet temperature Tl. That is, it is understood that when the outdoor fan air volume increases, the degree of supercooling, which is the difference between the condensation temperature Tc and the outdoor heat exchanger outlet temperature Tl, decreases.

  Here, it can be seen from FIG. 8 that is a graph showing the distribution of the supercooling degree value with respect to the outdoor fan air volume, as the outdoor fan air volume increases, the supercooling degree value decreases. In FIG. 8, the variation in the degree of supercooling is greater when the outdoor fan air volume is smaller than when the outdoor fan air volume is large. This is because when the outdoor fan airflow is small, it is more susceptible to disturbances such as dirt from the outdoor heat exchanger, outdoor unit installation, and wind and rain, and when the outdoor fan airflow is large, it is more susceptible to disturbances. This is thought to be because it is difficult. For this reason, by maximizing the outdoor fan air volume, it is possible to suppress variations in the detected supercooling degree value and reduce detection errors.

  FIG. 9 is a graph showing the distribution of the relative supercooling degree value with respect to the outdoor fan air volume. As described above, the relative supercooling degree value is a value obtained by dividing the supercooling degree value by the value obtained by subtracting the outdoor temperature from the condensation temperature value. Referring to FIG. 9, it can be seen that regardless of the magnitude of the outdoor fan air volume, the value is approximately between 0.3 and 0.4 and there is little variation. Therefore, by using this relative supercooling degree value as an index when determining the suitability of the refrigerant amount, it is possible to determine the suitability of the refrigerant amount without being affected by disturbance as much as possible, and to suppress detection errors. Can do. Therefore, it is useful to use the relative supercooling degree value for determining the suitability of the refrigerant amount.

(3) Features of the Air Conditioner In the present embodiment, in step S14, the detected indoor temperature Tb and outdoor temperature Ta are detected as the first indoor temperature Tb1 and the first outdoor temperature, as in step S3 of the initial setting operation. It is determined whether or not it is within a range determined based on the temperature Ta1 (for example, a range of ± 5 ° C. from the indoor temperature Tb and the outdoor temperature Tb detected by the initial setting operation). In step S14, when the indoor temperature Tb and the outdoor temperature Ta are within the above-described temperature range, the indoor temperature Tb at that time is stored as the second indoor temperature Tb2, and the outdoor temperature Ta at that time is stored as the first outdoor temperature Ta. After storing as the two outdoor temperatures Ta2, the process proceeds to the next step S15, and if it is not within the predetermined temperature range, the cooling operation of step S12 is continued.

  In the second and subsequent determination operations, the reference temperature range is stored by the first indoor temperature Tb1 and the first outdoor temperature Ta1 stored by the initial setting operation and immediately before the second and subsequent determination operations. Based on the room temperature and the outdoor temperature (stored in steps S4 and S14), all the temperatures (in each of the room temperature and the outdoor temperature) are expanded to a range of ± 5 ° C. Thus, in the second and subsequent determination operations, each temperature condition when the temperature is within the predetermined temperature range is stored, and the predetermined temperature range is expanded accordingly.

  Therefore, the suitability of the refrigerant amount can be determined within a range of environmental conditions in which detection errors do not occur as much as possible, and detection errors can be reduced. Also, if it is recognized that the detection error is within the range of environmental conditions, the refrigerant amount propriety determination is not performed, and the refrigerant amount propriety is reported to the user that the refrigerant amount propriety determination is not appropriate. Since at least one of reporting appropriate conditions to be judged is controlled as refrigerant quantity propriety control, measures should be taken so that the user can judge the refrigerant quantity suitability even if the refrigerant quantity suitability cannot be judged. Therefore, it is possible to determine whether or not the refrigerant amount is appropriate under the condition that the detection error is small.

(4) Modification 1
In step S14 during the determination operation of the present embodiment, a range of ± 5 ° C. from the indoor temperature Tb and the outdoor temperature Ta detected by the initial setting operation as the first temperature range ar1, and the indoor temperature Tb and the outdoor temperature Ta Although the range width ΔT of the temperature range is uniformly determined from both, the present invention is not limited to this, and the range width ΔT of the first temperature range ar1 may be determined from at least the outdoor temperature Ta, and the temperature range When the outdoor temperature Ta is large, the range width ΔT at that time may be changed so as to be positively correlated with the outdoor temperature Ta which is the outdoor temperature.

  For example, the range width of the first temperature range ar1 when the outdoor temperature Ta is 11 ° C. is the first range width ΔT1 of ± 4 ° C., and the range width of the first temperature range ar1 when the outdoor temperature Ta is 26 ° C. is ± The first temperature range ar1 may be determined so that the range width ΔT has a positive correlation with the change in the outdoor temperature Ta so that the second range width ΔT2 is 10 ° C. (see FIG. 10).

  Here, FIG. 11 shows the amount of change in the degree of relative supercooling (hereinafter referred to as the amount of change in relative SC) and the outdoor temperature Ta when the amount of refrigerant charged in the refrigerant circuit 10 changes from 100% to 90%. It is the graph which showed the relationship. FIG. 12 is a graph showing the relationship between the relative supercooling value and the outdoor temperature Ta. When the refrigerant amount filled in the refrigerant circuit 10 is 100%, the refrigerant amount filled in the refrigerant circuit 10 is 90%. % Is shown. According to FIG. 11, the relative SC change amount tends to increase as the outdoor temperature Ta increases. Furthermore, as shown in FIG. 12, the margin of the relative supercooling degree value for refrigerant leakage detection for detecting that the refrigerant amount in the refrigerant circuit 10 has decreased by 10% from 100% to 90% (the first step in step S16). 2 corresponding to a predetermined value), since the second detectable range ΔT2a when the outdoor temperature Ta is higher than the first detectable range ΔT1a when the outdoor temperature Ta is low, the outdoor temperature Ta is It can be seen that the range of the outdoor temperature Ta in which the change in the refrigerant amount can be detected increases as the value increases. Accordingly, when data relating the outdoor temperature Ta and the range width ΔT for determining the first temperature range ar1 is stored in advance, the first temperature range ar1 is determined based on the data. Thus, it is possible to determine the suitability of the refrigerant amount with higher accuracy than in the above embodiment. From this, it can be said that it is desirable to apply the modification (1) from the viewpoint of accuracy of the refrigerant amount. This can be said not only for the first temperature range ar1 but also for the second temperature range ar2.

(5) Modification 2
In step S14 during the determination operation of the present embodiment, when the indoor temperature Tb and the outdoor temperature Ta are not within the first temperature range, the cooling operation in step S12 is continued, but not limited thereto. The user may be informed that the indoor temperature Tb and the outdoor temperature Ta at that time are not within the first temperature range, and the user can determine what value range is within the first temperature range. May be notified.

(6) Modification 3
In the present embodiment, the degree of refrigerant supercooling at the outlet of the outdoor heat exchanger 23 is the refrigerant pressure (corresponding to the condensation pressure) value on the outlet side of the outdoor heat exchanger 23 detected by the condensation pressure sensor 29. Although converted into a temperature value and detected by subtracting the refrigerant temperature value detected by the liquid side temperature sensor 31 from the saturation temperature value of the refrigerant, the present invention is not limited to this.

  For example, an outdoor heat exchange sensor capable of detecting the temperature of the refrigerant in the outdoor heat exchanger 23 is provided to detect the condensation temperature value as the saturation temperature value of the refrigerant, and the refrigerant temperature value detected by the liquid-side temperature sensor 31 is the refrigerant temperature value. It may be detected by subtracting from the saturation temperature value.

(7) Modification 4
In the present embodiment, the relative supercooling value is used as an index for determining the suitability of the refrigerant amount. It does not matter as an indicator.

(8) Modification 5
In the present embodiment, as shown in FIG. 5 and the description thereof, a case where control is performed to switch between the normal operation mode and the refrigerant amount determination operation mode at a constant time interval is given as an example. Is not to be done.

  For example, instead of being controlled, the air conditioner 1 is provided with a switch or the like for switching to the refrigerant amount determination operation mode, and a serviceman or facility manager operates the switch or the like locally. The refrigerant leakage detection operation may be performed periodically.

(9) Other Embodiments Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments and can be changed without departing from the gist of the invention. It is.

  For example, in the above-described embodiment, an example in which the present invention is applied to an air conditioner capable of switching between heating and cooling has been described. However, the present invention is not limited thereto, and can be applied to a separate type air conditioner, and is a pair type The present invention may be applied to an air conditioner, an air conditioner dedicated to cooling, or an air conditioner capable of simultaneous cooling and heating.

  By using the present invention, in a separate type air conditioner in which a heat source unit and a utilization unit are connected via a refrigerant communication pipe, it is possible to accurately determine the suitability of the amount of refrigerant charged in the refrigerant circuit. can do.

1 is a schematic refrigerant circuit diagram of an air-conditioning apparatus according to an embodiment of the present invention. It is a schematic diagram which shows the state of the refrigerant | coolant which flows through the inside of the refrigerant circuit in air_conditionaing | cooling operation. It is a flowchart of initial setting operation. It is a schematic diagram which shows the state of the refrigerant | coolant which flows through the inside of a refrigerant circuit in refrigerant | coolant amount determination operation mode (initial setting operation and determination operation). It is a flowchart of determination driving | operation. It is a graph showing the temperature range derived | led-out from indoor temperature and outdoor temperature. It is a graph showing the condensation temperature Tc and the outdoor heat exchanger outlet temperature Tl when the outdoor temperature Ta is constant with respect to the outdoor fan air volume. It is a graph showing distribution of the supercooling degree value with respect to outdoor fan air volume. It is a graph showing distribution of the relative supercooling degree value with respect to outdoor fan air volume. It is an example of the 1st temperature range derived | led-out from the outdoor temperature in the determination driving | operation which concerns on a modification (1). It is the graph which showed the relationship between the variation | change_quantity of the relative supercooling degree value and the outdoor temperature Ta when the refrigerant | coolant amount with which the refrigerant circuit 10 is filled changes from 100% to 90%. It is a graph showing the relationship between a relative supercooling degree value and outdoor temperature Ta.

Explanation of symbols

1 Air conditioner 2 Outdoor unit (heat source unit)
4 Indoor units (units used)
6 Liquid refrigerant communication pipe 7 Gas refrigerant communication pipe 10 Refrigerant circuit 21 Compressor 23 Outdoor heat exchanger (heat source side heat exchanger)
27 Outdoor fan (cooling heat source adjustment means)
33 Outdoor expansion valve (expansion mechanism)
41 user side heat exchanger ar1 first temperature range ar2 second temperature range

Claims (6)

A heat source unit (2) having a compressor (21) and a heat source side heat exchanger (23) capable of adjusting the operating capacity, a utilization unit (4) having a utilization side heat exchanger (41), an expansion mechanism ( 33), a liquid refrigerant communication pipe (6) and a gas refrigerant communication pipe (7) for connecting the heat source unit and the utilization unit, and the heat source side heat exchanger of the refrigerant compressed in the compressor In an air conditioner having a refrigerant circuit (10) capable of performing at least a cooling operation as a condenser and causing the use side heat exchanger to function as an evaporator of refrigerant condensed in the heat source side heat exchanger. A refrigerant amount determination method for determining the suitability of the refrigerant amount in the refrigerant circuit,
From the normal operation mode in which the heat source unit and each device of the utilization unit are controlled in accordance with the operation load of the utilization unit, the refrigerant superheat degree at the outlet of the utilization side heat exchanger is positive after the previous cooling operation. In this way, while controlling the expansion mechanism, the degree of subcooling of the refrigerant at the outlet of the heat source side heat exchanger or the operating state quantity that varies according to the fluctuation of the degree of subcooling is detected, and the degree of subcooling is the first. An initial operation step of making a stable state equal to or greater than a predetermined value or the operation state quantity being equal to or greater than a second predetermined value;
The frequency of the compressor in the stable state is a first frequency, the degree of superheat of the refrigerant at the outlet of the use side heat exchanger in the stable state is a first superheat degree, and the degree of supercooling or the operation in the stable state A storage step of storing the environmental condition in the initial operation step as a first condition using the state quantity as an index value;
When the environmental condition after the elapse of a predetermined period from the storing step is within the first condition range (ar1) that is a range converted based on the first condition, the first frequency stored in the storing step is set to the first frequency. The compressor is controlled so that the first superheat degree is controlled, and the expansion mechanism is controlled so that the first superheat degree is reached, and the degree of supercooling of the refrigerant at the outlet of the heat source side heat exchanger or the degree of supercooling is controlled. A refrigerant amount propriety determination is performed by detecting, as a detected value, an operating state variable that varies according to the fluctuation, comparing the index value and the detected value, and determining whether the refrigerant amount charged in the refrigerant circuit is appropriate. When the environmental condition after a predetermined period has elapsed from the storage step is not within the first condition range, the refrigerant amount suitability determination is not performed, and the refrigerant amount suitability determination is not an appropriate condition. Report Report the appropriate conditions to perform the refrigerant quantity adequacy determination, the conditional step of performing a refrigerant quantity adequacy Call control at least one of,
A method for determining the amount of refrigerant in an air conditioner comprising: The environmental condition includes at least one of an outside air temperature, an outside air temperature based on a calendar, and a weather condition acquired from the outside.
The refrigerant | coolant amount determination method of the air conditioning apparatus of Claim 1. The first condition includes at least an outside air temperature,
The first condition range is determined based on the outside air temperature, a first range width that is a width of the range,
The first range width is positively correlated with the outside air temperature.
The refrigerant | coolant amount determination method of the air conditioning apparatus of Claim 1 or 2. The condition determining step is periodically performed after the predetermined period from the storing step,
In the condition determining step, when an environmental condition after a predetermined period has elapsed from the storing step is within the first condition range, the environmental condition at that time is stored as a second condition, and converted based on the second condition. A second condition range (ar2) that is a range to be determined, and in the condition determination step performed next time, the environmental condition at that time is within the expanded condition range obtained by adding the first condition range and the second condition range In this case, the refrigerant quantity suitability determination is performed, and when there is no environmental condition at that time within the expanded condition range obtained by adding the first condition range and the second condition range, the refrigerant quantity suitability control is performed.
The refrigerant | coolant amount determination method of the air conditioning apparatus in any one of Claim 1 to 3. The second condition includes at least an outside air temperature,
The second condition range is determined based on the outside air temperature, a second range width that is the width of the range,
The second range width is positively correlated with the outside air temperature.
The refrigerant | coolant amount determination method of the air conditioning apparatus of Claim 3. A heat source unit (2) having a compressor (21) and a heat source side heat exchanger (23) with adjustable operating capacity, a utilization unit (4) having a utilization side heat exchanger, and an expansion mechanism (33) And a liquid refrigerant communication pipe (6) and a gas refrigerant communication pipe (7) connecting the heat source unit and the utilization unit, and the heat source side heat exchanger is used as a refrigerant condenser to be compressed in the compressor. And a refrigerant circuit (10) capable of performing at least a cooling operation for causing the use side heat exchanger to function as an evaporator of refrigerant condensed in the heat source side heat exchanger;
From the normal operation mode in which the heat source unit and each device of the utilization unit are controlled in accordance with the operation load of the utilization unit, the refrigerant superheat degree at the outlet of the utilization side heat exchanger is positive after the previous cooling operation. In this way, while controlling the expansion mechanism, the degree of subcooling of the refrigerant at the outlet of the heat source side heat exchanger or the operating state quantity that varies according to the fluctuation of the degree of subcooling is detected, and the degree of subcooling is the first. An initial operation means for achieving a stable state in which the operation state quantity is equal to or greater than a predetermined value or greater than a second predetermined value;
The frequency of the compressor in the stable state is a first frequency, the degree of superheat of the refrigerant at the outlet of the use side heat exchanger in the stable state is a first superheat degree, and the degree of supercooling or the operation in the stable state Storage means for storing the environmental condition in the initial operation step as a first condition using the state quantity as an index value;
When the environmental condition after the lapse of a predetermined period from the storing step is within a first condition range that is a range converted based on the first condition, the first frequency stored in the storing step is set to be the first frequency. Depending on the degree of subcooling of the refrigerant at the outlet of the heat source side heat exchanger or the variation of the degree of supercooling while controlling the compressor and controlling the expansion mechanism so as to achieve the first degree of superheating. Detecting an operating state amount that fluctuates as a detection value, comparing the index value and the detection value, and performing a refrigerant amount propriety determination to determine the propriety of the refrigerant amount charged in the refrigerant circuit, When the environmental condition after the lapse of a predetermined period from the storage step is not within the first condition range, it is reported that the refrigerant amount suitability determination is not performed and the refrigerant amount suitability determination is not an appropriate condition. The refrigerant A condition judging means for performing a propriety Report appropriate conditions to make a determination, at least one refrigerant quantity adequacy Call control of,
An air conditioner (1) comprising:

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