JP6519098B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to an air conditioner provided with a refrigerant circuit configured by connecting a compressor, a radiator, and an evaporator.

  BACKGROUND Conventionally, there is an air conditioner provided with a refrigerant circuit configured by connecting a compressor, a radiator, and an evaporator. Then, R22 has often been used as a refrigerant to be filled in the refrigerant circuit of such an air conditioner before the regulation of CFCs, but at present, R410A, which is the alternative refrigerant, is often used. At the time of switching to alternative refrigerants due to such fluorocarbon regulations, there was concern about the problem of erroneous filling of the refrigerant. On the other hand, as shown in Patent Document 1 (Japanese Patent Application Laid-Open No. 10-111052), the refrigerant circuit is saturated under certain outside temperature conditions before the operation of the compressor after the refrigerant is filled in the refrigerant circuit. The pressure of the refrigerant in the refrigerant circuit (that is, the saturation pressure at a certain saturation temperature condition) is detected, and the detected saturation pressure is compared with the planned saturation pressure which is the saturation pressure of the refrigerant to be charged. There has been proposed a method of detecting the presence or absence of the erroneous filling based on the magnitude of.

  By the way, recently, there has been a movement to further switch R410A, which is often used at present, to R32. For this reason, there is a possibility that the misfilling of R410A and R32 may occur, that is, the air conditioning apparatus using R410A may be filled with R32 or the air conditioning apparatus using R32 may be filled with R410A.

  However, for such incorrect filling of R410A and R32, it is not possible to use the method of detecting incorrect filling based on the difference in saturation pressure before the operation of the compressor as in Patent Document 1. This is because R410A and R32 have substantially the same saturation pressure under the same saturation temperature condition, and no pressure difference appears between the two refrigerants.

  Thus, in the method of detecting an incorrect filling based on the difference in saturation pressure before the operation of the compressor as in Patent Document 1, an incorrect filling between refrigerants having substantially the same saturation pressure such as an incorrect filling of R410A and R32 Can not respond to. For this reason, even if it is between the refrigerant | coolants with substantially the same saturation pressure, the method of being able to detect the presence or absence of incorrect filling is desired.

  An object of the present invention is to provide an air conditioner provided with a refrigerant circuit configured by connecting a compressor, a radiator, and an evaporator, even if the saturation pressures of the refrigerants are substantially the same among the refrigerants. To provide a method capable of detecting the presence or absence of

  The air conditioner according to the first aspect is an air conditioner including a refrigerant circuit configured by connecting a compressor, a radiator, and an evaporator. Then, here, the refrigerant misfill detection operation is performed to control the components including the compressor so that the refrigerant filled in the refrigerant circuit is in a predetermined circulation state, and the refrigerant circuit is circulated in the refrigerant misfill detection operation. A refrigerant misfilling determination is performed to determine whether the refrigerant charged in the refrigerant circuit is the same as the refrigerant to be charged, based on the state quantities of the refrigerant or the constituent devices.

  The air conditioning apparatus according to the second aspect is the air conditioning apparatus according to the first aspect, wherein the refrigerant misfilling determination is an actual measurement that is a state quantity of the refrigerant or component that circulates through the refrigerant circuit during the refrigerant misfilling detection operation. The state quantity is compared with the predicted state quantity, which is the state quantity of the refrigerant or component that circulates in the refrigerant circuit that is predicted when the refrigerant circuit is filled with the refrigerant to be charged.

  In the case where misfilling occurs between refrigerants having substantially the same saturation pressure, the method of detecting misfilling based on the difference in saturation pressure before the operation of the conventional compressor can not detect the presence or absence of misfilling. . However, even if the saturation pressure is substantially the same among the refrigerants, all physical properties are not the same, so the state quantities of the refrigerant or component equipment circulating in the refrigerant circuit during operation were attributed to the physical properties of both refrigerants A difference will appear.

  Therefore, here, unlike the method of detecting the erroneous filling based on the difference in saturation pressure before the operation of the conventional compressor, as described above, the refrigerant erroneous filling detection operation including the operation of the compressor or the like is performed A predetermined circulation state is obtained, and the refrigerant misfilling determination is performed based on the state amount at the time of the refrigerant misfilling detection operation. Here, as the refrigerant misfilling determination based on the state amount in the refrigerant misfill detection operation, as described above, when the actual state amount in the refrigerant misfill detection operation and the refrigerant circuit to be filled in the refrigerant circuit are filled. The comparison with the predicted state quantity to be predicted can be adopted.

  Thereby, here, even if the saturation pressure of the refrigerant is substantially the same among the refrigerants, it is possible to detect the presence or absence of the erroneous filling.

  The air conditioner according to the third aspect is the air conditioner according to the second aspect, wherein the refrigerant misfill detection operation performs control to make the high pressure in the refrigerant circuit constant at the target high pressure, and the refrigerant misfill detection The target high pressure during operation is set in the direction in which the difference between the measured state quantity and the predicted state quantity becomes large.

  An air conditioner according to a fourth aspect of the present invention is the air conditioner according to the second or third aspect, wherein the refrigerant misfilling determination is performed by using the refrigerant discharged from the compressor during the refrigerant misfill detection operation as the measured state quantity. The actual discharge temperature, which is the temperature, is used, and the predicted discharge temperature, which is the temperature of the refrigerant discharged from the compressor, predicted when the refrigerant circuit is filled with the refrigerant to be filled is used as the predicted state quantity.

  In the case where the refrigerant misfilling determination is performed by comparing the actual state amount and the predicted state amount, it is preferable to perform the refrigerant misfilling detection operation so that the difference between the two state amounts is as large as possible. At this time, the difference between the measured state quantity and the predicted state quantity is susceptible to the pressure difference between the high pressure and the low pressure in the refrigerant circuit. Here, when the temperature of the refrigerant discharged from the compressor is adopted as the state quantity used for the refrigerant misfilling determination as described above, the larger the pressure difference between the high pressure and the low pressure in the refrigerant circuit, the actual measurement The difference between the state quantity and the predicted state quantity tends to be large.

  Therefore, here, as described above, in the refrigerant misfill detection operation, control is performed to make the high pressure in the refrigerant circuit constant at the target high pressure, and the target high pressure is the direction in which the difference between the measured state amount and the predicted state amount becomes large. It is set to. Here, as in the case where the temperature of the refrigerant discharged from the compressor is employed as the state quantity used for the refrigerant misfill determination, the larger the pressure difference between the high pressure and the low pressure in the refrigerant circuit, the larger the measured state quantity and the predicted state quantity In the case of adopting a state quantity in which the difference between the two becomes large, the actual state quantity and the prediction are set by setting the target high pressure at the time of refrigerant misfill detection operation so as to be higher than the high pressure in the refrigerant circuit at the time of normal operation. Make the difference with the state quantity larger.

  Hereby, the presence or absence of the erroneous filling can be detected with high accuracy.

  In the air conditioning apparatus according to the fifth aspect, in any of the air conditioning apparatuses according to the first to fourth aspects, the refrigerant misfilling determination is used to determine the presence or absence of the misfilling of R410A and R32. Ru.

  Since R410A and R32 have substantially the same saturation pressure of the refrigerant, it is not possible to use a method for detecting an erroneous charge based on the difference in saturation pressure before the operation of the conventional compressor. For this reason, the erroneous refrigerant charge detection operation including the operation of the compressor or the like and the erroneous refrigerant charge determination based on the state amount at the time of the refrigerant erroneous charge detection operation are particularly effective.

  An air conditioning apparatus according to a sixth aspect of the present invention is the air conditioning apparatus according to any of the first to fifth aspects, wherein the refrigerant circulating in the refrigerant circuit is determined based on the state quantity of the component or component after the refrigerant misfilling determination. The refrigerant overfill determination is performed to determine whether the refrigerant filled in the refrigerant circuit is excessively filled.

  Here, as described above, the refrigerant overfill determination is performed to determine whether the refrigerant charged in the refrigerant circuit is excessively charged based on the state quantities of the refrigerant circulating through the refrigerant circuit or the component devices. I have to. However, at this time, it is meaningless to perform the refrigerant overfill determination in a state where the refrigerant is incorrectly charged.

  Therefore, in this case, after confirming that the refrigerant to be charged is charged without erroneous charging by the erroneous refrigerant charging determination, the refrigerant overcharging determination is performed.

  Thereby, here, the refrigerant misfilling determination and the refrigerant overfilling determination can be performed in an appropriate order.

  As described above, according to the present invention, the following effects can be obtained.

  In the air conditioners according to the first and second aspects, the presence or absence of erroneous filling can be detected even when the saturation pressures of the refrigerants are substantially the same.

  In the air conditioners according to the third and fourth aspects, the presence or absence of erroneous filling can be detected with high accuracy.

  In the air conditioning apparatus according to the fifth aspect, the refrigerant misfilling determination based on the state amount in the refrigerant misfilling detection operation including the operation of the compressor or the like and the refrigerant misfilling detection operation is particularly effective.

  In the air conditioner according to the sixth aspect, the refrigerant misfilling determination and the refrigerant overfilling determination can be performed in an appropriate order.

It is a schematic block diagram of the air conditioning apparatus concerning one Embodiment of this invention. It is a control block diagram of an air conditioning apparatus. It is a figure which shows the relationship between the high voltage | pressure in a refrigerant | coolant circuit, and the temperature of the refrigerant | coolant discharged from a compressor about the cooling operation in the case where R410A is used as a refrigerant | coolant, and R32. It is a flowchart which shows trial operation including a refrigerant | coolant incorrect charge detection driving | operation and a refrigerant | coolant incorrect charge determination. It is a flowchart which shows the principal part (refrigerant overcharge determination) of the test run concerning a modification <A>.

  Hereinafter, an embodiment of an air conditioner according to the present invention will be described based on the drawings. In addition, the specific structure of embodiment of the air conditioning apparatus concerning this invention is not restricted to following embodiment and its modification, It can change in the range which does not deviate from the summary of invention.

(1) Configuration of Air Conditioning Apparatus FIG. 1 is a schematic configuration diagram of an air conditioning apparatus 1 according to an embodiment of the present invention. The air conditioning apparatus 1 is an apparatus used for indoor air conditioning of a building or the like by performing a vapor compression refrigeration cycle operation. The air conditioner 1 is mainly configured by connecting an outdoor unit 2 and a plurality of (in this case, two) indoor units 4 and 5. Here, the outdoor unit 2 and the plurality of indoor units 4 and 5 are connected via the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7. That is, the vapor compression type refrigerant circuit 10 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the plurality of indoor units 4 and 5 via the refrigerant communication pipes 6 and 7.

<Indoor unit>
The indoor units 4 and 5 are installed indoors. The indoor units 4 and 5 are connected to the outdoor unit 2 via the refrigerant communication pipes 6 and 7, and constitute a part of the refrigerant circuit 10.

  Next, the configuration of the indoor units 4 and 5 will be described. In addition, since the indoor unit 5 has the same configuration as the indoor unit 4, only the configuration of the indoor unit 4 will be described here, and the configuration of the indoor unit 5 will be denoted by reference numeral 40 that indicates each part of the indoor unit 4. The series is replaced with the 50s, and the explanation of each part is omitted.

  The indoor unit 4 mainly includes an indoor-side refrigerant circuit 10a (in the indoor unit 5, an indoor-side refrigerant circuit 10b) which constitutes a part of the refrigerant circuit 10. The indoor refrigerant circuit 10 a mainly includes an indoor expansion valve 41 and an indoor heat exchanger 42.

  The indoor expansion valve 41 is an indoor flow control valve that depressurizes the refrigerant flowing through the indoor refrigerant circuit 10a to adjust the flow rate of the refrigerant. The indoor expansion valve 41 is an electric expansion valve connected to the liquid side of the indoor heat exchanger 42.

  The indoor heat exchanger 42 is, for example, a cross fin type fin and tube heat exchanger. In the vicinity of the indoor heat exchanger 42, an indoor fan 43 for sending indoor air to the indoor heat exchanger 42 is provided. By blowing indoor air to the indoor heat exchanger 42 by the indoor fan 43, in the indoor heat exchanger 42, heat exchange is performed between the refrigerant and the indoor air. The indoor fan 43 is rotationally driven by the indoor fan motor 43a. Thereby, the indoor heat exchanger 42 functions as a radiator of the refrigerant and an evaporator of the refrigerant. The indoor fan motor 43a can change the air volume of the indoor fan 43 by changing the rotation speed.

  The indoor unit 4 is also provided with various sensors. On the liquid side of the indoor heat exchanger 42, a liquid-side temperature sensor 44 is provided which detects the temperature Trla of the refrigerant in the liquid state or the gas-liquid two-phase state (Trlb in the outdoor unit 5). On the gas side of the indoor heat exchanger 42, a gas side temperature sensor 45 is provided which detects the temperature Trga of the gas state refrigerant (Trgb in the outdoor unit 5). Further, the indoor unit 4 has an indoor side control unit 47 that controls the operation of each part constituting the indoor unit 4. The indoor control unit 47 includes a microcomputer, a memory, and the like provided to control the indoor unit 4, and a remote controller (not shown) for individually operating the indoor unit 4. It is possible to exchange control signals and the like between them and exchange control signals and the like with the outdoor unit 2.

<Outdoor unit>
The outdoor unit 2 is installed outdoors. The outdoor unit 2 is connected to the indoor units 4 and 5 via the refrigerant communication pipes 6 and 7, and constitutes a part of the refrigerant circuit 10.

  Next, the configuration of the outdoor unit 2 will be described.

  The outdoor unit 2 mainly includes an outdoor side refrigerant circuit 10 c which constitutes a part of the refrigerant circuit 10. The outdoor refrigerant circuit 10 c mainly includes a compressor 21, a switching mechanism 22, an outdoor heat exchanger 23, and an outdoor expansion valve 24.

  The compressor 21 is a sealed compressor in which a compressor element 21 (not shown) and a compressor motor 21a for rotationally driving the compressor element are housed in a casing. The electric power is supplied to the compressor motor 21a through an inverter device (not shown), and the operating capacity can be varied by changing the frequency (ie, the number of revolutions) of the inverter device. ing.

  The switching mechanism 22 is a four-way switching valve for switching the flow direction of the refrigerant. During the cooling operation as one of the normal operations, the switching mechanism 22 functions as a radiator of the refrigerant compressed by the compressor 21 and the indoor heat exchangers 42 and 52 as the outdoor heat exchanger 23 during the cooling operation as one of the normal operations. In order to function as an evaporator for the refrigerant that has dissipated heat, connect the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 23 and connect the suction side of the compressor 21 and the gas refrigerant communication pipe 7 In the heat release switching state, see the solid line of the switching mechanism 22 of FIG. 1), and in the heating operation as one of the normal operations, the indoor heat exchangers 42 and 52 serve as a radiator of the refrigerant compressed in the compressor 21 and In order to cause the outdoor heat exchanger 23 to function as an evaporator for the refrigerant that has dissipated heat in the indoor heat exchangers 42, 52, the discharge side of the compressor 21 and the gas refrigerant communication pipe 7 are connected together with the suction side of the compressor 21. Outdoors It is possible to connect the gas side of the exchanger 23 (evaporator switching state, see dashed switching mechanism 22 in FIG. 1). The switching mechanism 22 may be configured not to be a four-way switching valve, but to perform the same function by combining a three-way valve, an electromagnetic valve, and the like.

  The outdoor heat exchanger 23 is, for example, a cross fin type fin and tube heat exchanger. In the vicinity of the outdoor heat exchanger 23, an outdoor fan 25 for sending outdoor air to the outdoor heat exchanger 23 is provided. By blowing outdoor air to the outdoor heat exchanger 23 by the outdoor fan 25, in the outdoor heat exchanger 23, heat exchange is performed between the refrigerant and the outdoor air. The outdoor fan 25 is rotationally driven by the outdoor fan motor 25a. Thereby, the outdoor heat exchanger 23 functions as a radiator of the refrigerant and an evaporator of the refrigerant. In addition, the outdoor fan motor 25a can change the air volume of the outdoor fan 25 by changing the rotational speed.

  The outdoor expansion valve 24 is a valve that reduces the pressure of the refrigerant flowing through the outdoor refrigerant circuit 10c. The outdoor expansion valve 24 is an electric expansion valve connected to the liquid side of the outdoor heat exchanger 23.

  In addition, the outdoor unit 2 is provided with various sensors. The outdoor unit 2 includes a suction pressure sensor 31 that detects a suction pressure Ps of the compressor 21, a discharge pressure sensor 32 that detects a discharge pressure Pd of the compressor 21, and a suction temperature that detects a suction temperature Ts of the compressor 21. A sensor 33 and a discharge temperature sensor 34 for detecting the discharge temperature Td of the compressor 21 are provided. The outdoor heat exchanger 23 is provided with an outdoor heat exchange temperature sensor 35 that detects the temperature Tol of the refrigerant in the gas-liquid two-phase state. Further, on the liquid side of the outdoor heat exchanger 23, there is provided a liquid side temperature sensor 36 for detecting the temperature Toll of the refrigerant in the liquid state or the gas-liquid two-phase state. In addition, the outdoor unit 2 includes an outdoor control unit 37 that controls the operation of each part that constitutes the outdoor unit 2. The outdoor side control unit 37 includes a microcomputer provided to control the outdoor unit 2, a memory, an inverter device for controlling the compressor motor 21a, and the like. It is possible to exchange control signals with the control units 47 and 57.

<Refrigerant communication tube>
The refrigerant communication pipes 6 and 7 are refrigerant pipes installed on site when the air conditioner 1 is installed, and various lengths and pipe diameters according to the installation conditions of the outdoor unit 2 and the indoor units 4 and 5 Are used.

<Control unit>
As shown in FIG. 1, the indoor side control units 47 and 57 of the indoor units 4 and 5 and the outdoor side control unit 37 of the outdoor unit 2 constitute a control unit 8 that performs operation control of the entire air conditioning apparatus 1 ing. The control part 8 is connected so that the detection signal of various sensors 31-36, 44, 45, 54, 55 grade | etc., Can be received, as shown in FIG. Then, the control unit 8 controls the various devices and the valves 21a, 22, 24, 26, 41, 51, 43a, 53a based on the detection signals and the like to perform normal operation (cooling operation and heating operation) and the like. It is comprised so that the various driving | operations of can be performed. Further, the control unit 8 is connected to a warning display unit 9 for displaying various failures, abnormalities, and the like in the air conditioner 1. Here, FIG. 2 is a control block diagram of the air conditioner 1.

  As described above, the air conditioner 1 has the refrigerant circuit 10 configured by connecting the indoor units 4 and 5 to the outdoor unit 2. The refrigerant circuit 10 mainly includes a compressor 21, an outdoor heat exchanger 23 or indoor heat exchangers 42, 52 as a radiator, and an indoor heat exchanger 42, 52 or outdoor heat exchanger 23 as an evaporator. It is configured by being connected. Then, in the air conditioning apparatus 1, the control unit 8 performs various operations such as the following normal operation (cooling operation and heating operation).

(2) Normal Operation of the Air Conditioning Device Next, the normal operation (cooling operation and heating operation) of the air conditioning device 1 will be described using FIGS. 1 and 2.

<Cooling operation>
When an instruction for cooling operation is issued from a remote controller (not shown) or the like, the switching mechanism 22 is switched to the heat radiation operation state (the state shown by the solid line of the switching mechanism 22 in FIG. 1), The fan 25 and the indoor fans 43, 53 are activated.

  Then, the low pressure gas refrigerant in the refrigerant circuit 10 is drawn into the compressor 21 and compressed to be a high pressure gas refrigerant. The high pressure gas refrigerant is sent to the outdoor heat exchanger 23 via the switching mechanism 22. The high-pressure gas refrigerant sent to the outdoor heat exchanger 23 is condensed by performing heat exchange with the outdoor air supplied by the outdoor fan 25 and cooling in the outdoor heat exchanger 23 functioning as a refrigerant radiator. It becomes a high pressure liquid refrigerant. The high pressure liquid refrigerant is sent from the outdoor unit 2 to the indoor units 4 and 5 via the outdoor expansion valve 24 and the liquid refrigerant communication pipe 6.

  The high pressure liquid refrigerant sent to the indoor units 4 and 5 is decompressed by the indoor expansion valves 41 and 51 to be a low pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant is sent to the indoor heat exchangers 42, 52. The low-pressure gas-liquid two-phase refrigerant sent to the indoor heat exchangers 42, 52 is the indoor air supplied by the indoor fans 43, 53 in the indoor heat exchangers 42, 52 functioning as evaporators of the refrigerants and By performing heat exchange and heating, it evaporates to become a low pressure gas refrigerant. The low pressure gas refrigerant is sent from the indoor units 4 and 5 to the outdoor unit 2 via the gas refrigerant communication pipe 7.

  The low-pressure gas refrigerant sent to the outdoor unit 2 is again sucked into the compressor 21 via the switching mechanism 22.

<Heating operation>
When an instruction for heating operation is issued from a remote controller (not shown) or the like, the switching mechanism 22 is switched to the evaporation operation state (state shown by the broken line of the switching mechanism 22 in FIG. 1), The fan 25 and the indoor fans 43, 53 are activated.

  Then, the low pressure gas refrigerant in the refrigerant circuit 10 is drawn into the compressor 21 and compressed to be a high pressure gas refrigerant. The high pressure gas refrigerant is sent from the outdoor unit 2 to the indoor units 4 and 5 via the switching mechanism 22 and the gas refrigerant communication pipe 7.

  The high-pressure gas refrigerant sent to the indoor units 4 and 5 is sent to the indoor heat exchangers 42 and 52. The high-pressure gas refrigerant sent to the indoor heat exchangers 42, 52 exchanges heat with the indoor air supplied by the indoor fans 43, 53 in the indoor heat exchangers 42, 52 functioning as a refrigerant radiator. It condenses by being cooled and becomes a high pressure liquid refrigerant. The high pressure liquid refrigerant is depressurized by the indoor expansion valves 41 and 51. The refrigerant decompressed by the indoor expansion valves 41 and 51 is sent from the indoor units 4 and 5 to the outdoor unit 2 via the liquid refrigerant communication pipe 6.

  The refrigerant sent to the outdoor unit 2 is sent to the outdoor expansion valve 24 and is decompressed by the outdoor expansion valve 24 to become a low pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant is sent to the outdoor heat exchanger 23. The low-pressure gas-liquid two-phase refrigerant sent to the outdoor heat exchanger 23 is heated by exchanging heat with the outdoor air supplied by the outdoor fan 25 in the outdoor heat exchanger 23 functioning as an evaporator of the refrigerant. As a result, it evaporates to become a low pressure gas refrigerant. The low pressure gas refrigerant is again sucked into the compressor 21 via the switching mechanism 22.

(3) Trial operation including the erroneous refrigerant charge detection operation and the erroneous refrigerant charge determination The air conditioner 1 performing the above-described normal operation is filled with refrigerant at the time of on-site shipping or on-site construction and sealed in the refrigerant circuit 10. Here, there is no problem if the refrigerant filled in the refrigerant circuit 10 is the same as the refrigerant to be filled, but there is a possibility that the refrigerant different from the refrigerant to be filled may be erroneously filled.

  At this time, as in the case of misfilling of R22 and R410A, if misfilling between refrigerants having different saturation pressures, the refrigerant is detected by a method of detecting misfilling based on the difference in saturation pressure before the operation of the conventional compressor. Misfilling of can be detected.

  However, in the case where the saturation pressure is a misfill between the refrigerants having almost the same condition like the misfill of R410A and R32, the method of detecting the misfill based on the difference of the saturation pressure before the operation of the conventional compressor , Can not detect the incorrect filling of the refrigerant.

  However, even if the saturation pressures are substantially the same among refrigerants, not all physical properties are the same, so the state quantities of the refrigerant or component equipment circulating through the refrigerant circuit 10 during operation are attributed to the physical properties of both refrigerants Differences will appear. For example, in FIG. 3, in the case of using R410A as the refrigerant and in the case of using R32, the high pressure in the refrigerant circuit 10 (here, the corresponding condensation temperature Tc) and the refrigerant discharged from the compressor 21 And the discharge temperature Td). According to FIG. 3, the discharge temperature Td is about 10 ° C. (when the high pressure is 30 ° C.) to about 20 ° C. (when the high pressure is 50 ° C.) in the cases where R410A and R32 are used as the refrigerant. It turns out that the difference appears. For this reason, the measured state quantity (here, the measured value of the discharge temperature Td, hereinafter referred to as the "measured discharge temperature Tda"), which is the state amount of the refrigerant or component that circulates the refrigerant circuit 10 during operation, A predicted state quantity (here, a predicted value of the discharge temperature Td shown in FIG. 3), which is a state quantity of the refrigerant or component that circulates through the refrigerant circuit 10 predicted when the refrigerant scheduled to be filled is filled with 10; By comparing the “prediction with the output temperature Tdp”, it is possible to detect the presence or absence of the erroneous filling of the refrigerant. However, the predicted discharge temperature Td in FIG. 3 is such that the low pressure in the refrigerant circuit 10 (here, the corresponding evaporation temperature Te) is 0.degree. C., and the degree of superheat of the refrigerant at the outlet of each indoor heat exchanger 42, 52. This value is obtained when the cooling operation is performed such that SHra and SHrb become 5 ° C. For this reason, when obtaining the measured state quantity (here, the measured discharge temperature Tda), a predetermined circulation is assumed for the refrigerant filled in the refrigerant circuit 10 to obtain the predicted state quantity (predicted discharge temperature Tdp). State (here, the cooling operation is performed so that the low pressure in the refrigerant circuit 10 is 0 ° C. and the degree of superheat SHra and SHrb of the refrigerant at the outlet of each indoor heat exchanger 42, 52 is 5 ° C.) It is necessary to control the components including the compressor 21 so that

  Therefore, in this case, in the test run after the refrigerant circuit 10 is filled with the refrigerant, the refrigerant erroneous charge detection driving operation is performed to control components including the compressor 21 such that the refrigerant filled in the refrigerant circuit 10 is in a predetermined circulation state. To determine whether the refrigerant charged in the refrigerant circuit 10 is the same as the refrigerant to be charged, based on the state quantities of the refrigerant or constituent devices circulating in the refrigerant circuit 10 during the refrigerant misfill detection operation. It is made to make an erroneous filling judgment. That is, here, unlike the method of detecting the erroneous filling based on the difference in saturation pressure before the operation of the conventional compressor 21, as described above, the refrigerant erroneous filling detection operation including the operation of the compressor 21 etc. Then, a predetermined circulation state is obtained, and the refrigerant misfilling determination is performed based on the state amount in the refrigerant misfilling detection operation.

  Next, trial operation including the refrigerant misfilling detection operation and the refrigerant misfilling determination will be described using FIGS. 1 to 4. Here, FIG. 4 is a flowchart showing a test run including the refrigerant misfill detection operation and the refrigerant misfill determination. The control at the time of trial operation including the refrigerant erroneous charge detection operation and the refrigerant erroneous charge determination is performed by the control unit 8.

<Step ST1: Refrigerant Misfilling Detection Operation>
Specifically, first, in step ST1, a refrigerant misfilling detection operation is performed to control components including the compressor 21 such that the refrigerant charged in the refrigerant circuit 10 is in a predetermined circulation state. Here, in the predetermined circulation state, the indoor heat exchangers 42, 52 which forcibly perform cooling operation (hereinafter referred to as "all indoor units operation") for all the indoor units 4, 5 and function as an evaporator. The indoor expansion valves 41 and 51 are controlled (hereinafter referred to as “superheat control”) such that the degree of superheat SHra and SHrb of the target becomes constant at the target degree of superheat SHras and SHrbs, and the low pressure in the refrigerant circuit 10 The operating capacity of the compressor 21 is controlled (hereinafter referred to as "low pressure control") so that the target low pressure Tes becomes constant, and the high pressure (condensing temperature Tc) in the refrigerant circuit 10 becomes constant at the target high pressure Tcs. The air volume of the outdoor fan 25 is controlled (hereinafter referred to as "high-pressure control") and stabilized. For example, when target superheat degrees SHras and SHrbs in superheat degree control are 5 ° C. and target low pressure Tes in low pressure control is stabilized at 0 ° C., the high pressure (condensing temperature Tc) of FIG. It becomes possible to obtain the relationship with the temperature (discharge temperature Td). Then, a predicted value (predicted discharge temperature Tdp as a predicted state quantity) of the temperature Td of the refrigerant discharged from the compressor 21 can be obtained according to the type of refrigerant to be charged and the target high pressure Tcs in high pressure control. It becomes possible to compare with the actual measurement value (the actual measurement discharge temperature Tda as the actual measurement state amount) of the temperature Td of the refrigerant discharged from the machine 21 (here, the refrigerant actually filled). Thus, in the predetermined circulation state, the state quantity of the refrigerant or component equipment circulating in the refrigerant circuit 10 used for the refrigerant misfilling determination (here, the actual discharge temperature Tda) is a predicted state as shown in FIG. This is a state in which the components including the compressor 21 are controlled and stabilized so as to achieve the circulation state assumed when obtaining the amount (here, the predicted discharge temperature Tdp). And here, in order to obtain a predetermined circulation state, the above-mentioned indoor unit 100% operation, the superheat degree control, the low pressure control, and the refrigerant erroneous charge detection operation accompanied with the high pressure control are performed. As the low pressure (evaporation temperature Te) in the refrigerant circuit 10, the suction pressure Ps of the compressor 21 detected by the suction pressure sensor 31 is converted to the saturation temperature of the refrigerant, or the liquid side temperature sensors 44, 54 The temperatures Trla, Trlb of the refrigerant on the liquid side of the indoor heat exchangers 42, 52 to be detected can be used. The high pressure (condensing temperature Tc) in the refrigerant circuit 10 is detected by converting the discharge pressure Pd of the compressor 21 detected by the discharge pressure sensor 32 into the saturation temperature of the refrigerant, or detected by the outdoor heat exchange temperature sensor 35 The temperature Tol of the refrigerant in the outdoor heat exchanger 23 can be used. The low pressure (evaporation temperature Te) in the refrigerant circuit 10 is subtracted from the refrigerant temperatures Trga and Trgb on the gas side of the indoor heat exchangers 42 and 52 detected by the gas side temperature sensors 45 and 55 as the superheat degrees SHra and SHrb. The resulting temperature difference can be used.

  Moreover, in the high pressure control of the refrigerant misfill detection operation, the target high pressure Tcs is increased in the direction in which the difference between the measured state amount (here, the measured discharge temperature Tda) and the predicted state amount (here, the predicted discharge temperature Tdp) increases. It is set. For example, in erroneous filling of R410A and R32, as shown in FIG. 3, the difference ΔTd between the discharge temperatures Td of both refrigerants tends to become larger as the high pressure Tc becomes higher. For this reason, the target high pressure Tcs at the time of the refrigerant misfill detection operation is set to be higher (40 ° C. or higher) than the high pressure Tc of the refrigerant circuit 10 at the normal operation.

<Steps ST2 to ST5: Judgment of Incorrect Charge of Refrigerant>
Next, in steps ST2 and ST3, the refrigerant filled in the refrigerant circuit 10 is based on the state quantity (here, the discharge temperature Td) of the refrigerant or constituent devices circulating in the refrigerant circuit 10 at the time of refrigerant misfill detection operation. A refrigerant misfilling determination is performed to determine whether it is the same as the refrigerant to be charged. Here, the refrigerant misfilling determination is performed by filling the refrigerant circuit 10 with the measured state quantity (here, the measured discharge temperature Tda), which is the state amount of the refrigerant or component that circulates through the refrigerant circuit 10 during the refrigerant misfill detection operation. This is performed by comparison with the predicted state quantity (here, the predicted discharge temperature Tdp) which is the state quantity of the refrigerant or component that circulates in the refrigerant circuit 10 predicted when the scheduled refrigerant is charged.

  First, in step ST2, it is determined whether the difference between the measured state amount and the predicted state amount (here, the difference ΔTd between the measured discharge temperature Tda and the predicted discharge temperature Tdp) is within the first predetermined range ΔTd1. That is, in the case where the refrigerant circuit 10 is filled with the refrigerant to be charged, if there is no failure such as a failure of the compressor 21, the measured state amount should almost coincide with the predicted state amount. Therefore, here, it is determined whether or not the absolute value of ΔTd is equal to or less than ΔTd1, and if the absolute value of ΔTd satisfies the condition of equal to or less than ΔTd1, the refrigerant circuit 10 is filled with the refrigerant to be charged It is determined that the refrigerant misfilling detection operation and the refrigerant misfilling determination process are ended, and when the absolute value of .DELTA.Td does not satisfy the condition of .DELTA.Td1 or less, the process proceeds to step ST3. When this process is used to determine the presence or absence of erroneous filling of R410A and R32, the first predetermined range ΔTd1 is about 10 ° C. (high pressure is required when R410A is used as a refrigerant and when R32 is used) It is set to about 3 to 7 ° C. in consideration of the difference in discharge temperature Td (see FIG. 3) from 30 ° C.) to about 20 ° C. (when the high pressure is 50 ° C.). At this time, the value of the first predetermined range ΔTd1 may be changed according to the target high pressure Tcs.

  Next, in step ST3, it is determined whether the difference between the measured state amount and the predicted state amount (here, the difference ΔTd between the measured discharge temperature Tda and the predicted discharge temperature Tdp) is within the second predetermined range ΔTd2. That is, when the refrigerant circuit 10 is not filled with the refrigerant to be charged, the difference between the measured state amount and the predicted state amount (here, ΔTd) is calculated if there is no failure such as a failure of the compressor 21. It should be approximately equal to the difference between the state quantity when the scheduled refrigerant is charged and the state quantity when the suspected coolant is charged. Therefore, here, it is determined whether or not the absolute value of ΔTd is equal to or less than ΔTd2, and if the absolute value of ΔTd satisfies the condition of ΔTd2 or less, it is determined that erroneous filling has occurred, The process proceeds to step ST4, and if the absolute value of ΔTd does not satisfy the condition of ΔTd2 or less, it is determined that a failure such as a failure of the compressor 21 is occurring, and the process proceeds to step ST6. . Here, when this process is used to determine the presence or absence of erroneous filling of R410A and R32, the second predetermined range ΔTd2 is approximately 10 ° C. when R410A is used as a refrigerant and when R32 is used. It is set to about 17 ° C. to 27 ° C. in consideration of the difference in discharge temperature Td from (when the high pressure is 30 ° C.) to about 20 ° C. (when the high pressure is 50 ° C.). At this time, the value of the first predetermined range ΔTd1 may be changed according to the target high pressure Tcs.

  Then, if it is determined in steps ST2 and ST3 that the erroneous filling of the refrigerant is occurring, in step ST4, after displaying that the erroneous filling of the refrigerant is occurring on the warning display unit 9, The process proceeds to step ST5 to stop the operation. If it is determined in steps ST2 and ST3 that a failure such as a failure of the compressor 21 is occurring, the warning display unit 9 is displayed on the warning display unit 9 that the erroneous refrigerant charge determination can not be performed in step ST6. , Shift to the process of step ST5, and stop the operation.

(4) Characteristics of Air Conditioning Device The air conditioning device 1 of the present embodiment has the following features.

<A>
In the method of detecting the incorrect filling based on the difference in the saturation pressure before the operation of the conventional compressor 21 when the incorrect filling occurs between the refrigerants with almost the same saturation pressure as in the incorrect filling of R410A and R32 , Can not detect the presence of incorrect filling. However, even if the saturation pressures are substantially the same among refrigerants, not all physical properties are the same, so the state quantities of the refrigerant or component equipment circulating through the refrigerant circuit 10 during operation are attributed to the physical properties of both refrigerants Differences will appear.

  Here, as described above, unlike the method of detecting the erroneous filling based on the difference in saturation pressure before the operation of the conventional compressor 21, as described above, the erroneous refrigerant filling including the operation of the compressor 21 or the like as described above The detection operation is performed to obtain a predetermined circulation state, and the refrigerant misfilling determination is performed based on the state amount in the refrigerant misfilling detection operation. In this predetermined circulation state, the state quantity (for example, the actual discharge temperature Tda) of the refrigerant or the component that circulates the refrigerant circuit 10 used for the refrigerant misfilling determination is a predicted state quantity (for example, the prediction shown in FIG. 3) This is a state in which the components including the compressor 21 are controlled and stabilized so as to achieve the circulation state assumed when obtaining the discharge temperature Tdp). In addition, here, in order to obtain a predetermined circulation state, the above-mentioned indoor unit 100% operation, the superheat degree control, the low pressure control, and the refrigerant misfilling detection operation with the high pressure control are performed. In addition, as described above, the refrigerant misfilling determination based on the state amount in the refrigerant misfill detection operation includes the actual state amount in the refrigerant misfill detection operation and the case where the refrigerant circuit is filled with the refrigerant scheduled to be filled. The comparison with the predicted state quantity to be predicted can be adopted.

  Thereby, here, even if the saturation pressure of the refrigerant is substantially the same among the refrigerants, it is possible to detect the presence or absence of the erroneous filling.

<B>
In the case where the refrigerant misfilling determination is performed by comparing the actual state amount and the predicted state amount, it is preferable to perform the refrigerant misfilling detection operation so that the difference between the two state amounts is as large as possible. At this time, the difference between the measured state quantity and the predicted state quantity is easily affected by the pressure difference between the high pressure Tc and the low pressure Te in the refrigerant circuit 10. Here, as described above, when the temperature Td of the refrigerant discharged from the compressor 21 is adopted as the state quantity used for the refrigerant misfill determination, the pressure difference between the high pressure Tc and the low pressure Te in the refrigerant circuit 10 The larger the value of, the larger the difference between the measured state quantity and the predicted state quantity.

  Therefore, here, as described above, in the refrigerant misfill detection operation, control is performed to make the high pressure Tc in the refrigerant circuit 10 constant at the target high pressure Tcs, and the target high pressure Tcs is the difference between the measured state amount and the predicted state amount Is set to be larger. Here, as in the case where the temperature Td of the refrigerant discharged from the compressor 21 is employed as the state amount used for the refrigerant misfill determination, the measured state amount increases as the pressure difference between the high pressure Tc and the low pressure Te in the refrigerant circuit 10 increases. In the case of adopting a state quantity in which the difference between the value and the predicted state quantity is large (see FIG. 3), the target in the refrigerant misfilling detection operation is higher than the high pressure Tc in the refrigerant circuit 10 in normal operation. The difference between the measured state quantity and the predicted state quantity is increased by setting the high pressure Tcs or the like.

  Hereby, the presence or absence of the erroneous filling can be detected with high accuracy.

<C>
Since the saturation pressure of the refrigerant is almost the same as that of R410A and R32, it is not possible to use a method for detecting an erroneous filling based on the difference in saturation pressure before the operation of the conventional compressor 21. Therefore, the erroneous refrigerant charge detection operation including the operation of the compressor 21 or the like and the erroneous refrigerant charge determination based on the state amount at the time of the refrigerant erroneous charge detection operation are particularly effective.

(5) Modifications <A>
In the air conditioning apparatus, a refrigerant overfill determination may be performed to determine whether the refrigerant charged in the refrigerant circuit is excessively charged based on the state quantities of the refrigerant circulating in the refrigerant circuit or the constituent devices. For this reason, it is conceivable to perform the refrigerant overfill determination also in the air conditioner 1 of the above embodiment.

  However, it is meaningless to perform the refrigerant overfill determination in the state where the refrigerant is erroneously charged.

  Therefore, here, as shown in FIG. 5, in the air conditioning apparatus 1 of the above embodiment, after confirming that the refrigerant to be charged is filled without erroneous filling by the processing of the refrigerant misfilling determination in step ST2, The refrigerant overfill determination in step ST7 is performed.

  Here, although various things can be used as the state quantities of the refrigerant or constituent devices circulating in the refrigerant circuit 10 that can be used for the refrigerant overfill determination, here, the refrigerant at the outlet of the outdoor heat exchanger 23 It is preferred to use a degree of subcooling SC. Because, here, the refrigerant circuit 10 is stabilized in the predetermined circulation state filled with the refrigerant circuit 10 by the 100% indoor unit operation at step ST1, the superheat degree control, the low pressure control, and the refrigerant erroneous charge detection operation with the high pressure control. In this state, excess or deficiency of the refrigerant charged in the refrigerant circuit 10 appears in the amount of refrigerant present in the outdoor heat exchanger 23. Therefore, in the refrigerant overfill determination in step ST7, it is determined whether the degree of subcooling SC of the refrigerant at the outlet of the outdoor heat exchanger 23 is within the predetermined degree of subcooling range SCs1 to SCs2. The subcooling degree SC is a temperature difference obtained by subtracting the temperature Toll of the refrigerant on the liquid side of the outdoor heat exchanger 23 detected by the liquid side temperature sensor 36 from the high pressure (condensing temperature Tc) in the refrigerant circuit 10 It can be used.

  Thereby, here, the refrigerant misfilling determination and the refrigerant overfilling determination can be performed in an appropriate order. Moreover, since the refrigerant overfill determination can be performed using the state stabilized in the predetermined circulation state by the refrigerant misfill detection operation in step ST1, two determination processes can be smoothly performed.

<B>
Although the present invention is applied to the air conditioner 1 capable of switching between the cooling operation and the heating operation in the above embodiment and the modification thereof, the present invention is not limited to this, and air dedicated to cooling may be used. The present invention may be applied to a conditioner.

<C>
Although the present invention is applied to the air conditioning apparatus 1 in which the plurality of indoor units 4 and 5 are connected to the outdoor unit 2 in the above embodiment and the modification thereof, the present invention is not limited to this. The present invention may be applied to an air conditioner in which the indoor unit is connected to the outdoor unit.

  The present invention is widely applicable to an air conditioner provided with a refrigerant circuit configured by connecting a compressor, a radiator and an evaporator.

1 air conditioner 10 refrigerant circuit 21 compressor 23 outdoor heat exchanger (dissipator)
42, 52 indoor heat exchanger (evaporator)

Japanese Patent Application Laid-Open No. 10-111052

Claims (4)

In an air conditioner comprising a refrigerant circuit (10) configured by connecting a compressor (21), a radiator (23) and an evaporator (42, 52),
Performing an erroneous refrigerant charge detection operation of controlling components including the compressor so that the refrigerant charged in the refrigerant circuit is in a predetermined circulation state;
The refrigerant error which determines whether the refrigerant charged in the refrigerant circuit is the same as the refrigerant to be charged, based on the amount of state of the refrigerant circulating in the refrigerant circuit or the component equipment during the refrigerant misfill detection operation Make a filling judgment,
The refrigerant misfilling determination is performed when the refrigerant circulating through the refrigerant circuit during the refrigerant misfilling detection operation or the measured state amount, which is the state amount of the component, and the refrigerant circuit to be filled with the refrigerant circuit. It is performed by comparison with the refrigerant circulating through the refrigerant circuit to be predicted or the predicted state amount which is the state amount of the component device,
In the refrigerant misfill detection operation, control is performed to make the high pressure in the refrigerant circuit constant at the target high pressure, make the low pressure in the refrigerant circuit constant at the target low pressure, and make the superheat degree of the evaporator constant at the target superheat degree. Going,
The refrigerant misfilling determination uses the actual discharge temperature which is the temperature of the refrigerant discharged from the compressor during the refrigerant misfilling detection operation as the actual state amount, and the refrigerant circuit is scheduled to be filled as the predicted state amount. The predicted discharge temperature, which is the temperature of the refrigerant discharged from the compressor, predicted when the refrigerant is charged
Air conditioner (1). The target high pressure at the time of the refrigerant misfill detection operation is set in the direction in which the difference between the actual measured state quantity and the predicted state quantity becomes large.
An air conditioner (1) according to claim 1. The refrigerant misfilling determination is used to determine whether there is a misfilling of R410A and R32.
An air conditioner (1) according to claim 1 or 2 . After the refrigerant misfilling determination, the refrigerant circulating in the refrigerant circuit (10) or the refrigerant that determines whether the refrigerant charged in the refrigerant circuit is excessively charged based on the state quantities of the component devices Perform overfill determination,
The air conditioning apparatus (1) according to any one of claims 1 to 3 .

Images