JP2022069305A - Air conditioner - Google Patents

Abstract

To provide an air conditioner capable of estimating a refrigerant quantity remaining in a refrigerant circuit even when the air conditioner is actually operated.SOLUTION: An air conditioner has a refrigerant circuit formed by connecting an indoor unit having an indoor heat exchanger to an outdoor unit having a compressor, an outdoor heat exchanger and an expansion valve by refrigerant piping, wherein the refrigerant circuit is filled with a prescribed quantity of refrigerant. The air conditioner has: an acquisition portion for periodically acquiring an operation state quantity in an air conditioning operating; a storage portion for storing the acquired operation state quantity; an estimation model for estimating a residual refrigerant quantity remaining in the refrigerant circuit by using the operation state quantity; a detection portion for detecting a first operation state quantity as an operation state quantity in a state that the refrigerant circuit satisfies a first stabilization condition, or a second operation state quantity as an operation state quantity in a state that the refrigerant circuit satisfies a second stabilization condition different from the first stabilization condition, from the storage portion; and a control portion for estimating the residual refrigerant quantity of the refrigerant circuit by using the estimation model and the detected operation state quantity.SELECTED DRAWING: Figure 3

Description

The present invention relates to an air conditioner.

An air conditioner that determines the amount of refrigerant using the amount of operating state that can be detected by the refrigerant circuit has been proposed (for example, Patent Document 1). In Patent Document 1, for example, in order to limit the refrigerant flowing through the liquid pipe of the refrigerant circuit during the cooling cycle to only the liquid refrigerant (so that the gas refrigerant does not exist), the degree of refrigerant superheat at the outlet of the evaporator and the pressure of the evaporator The amount of refrigerant is determined using the degree of refrigerant supercooling at the outlet of the condenser in the adjusted state (hereinafter referred to as the default state).

Japanese Unexamined Patent Publication No. 2006-23072

When the air conditioner is actually in operation, it is difficult to obtain the default state, which is a precondition of Patent Document 1, and it is difficult to estimate the amount of the refrigerant.

In view of such a problem, it is an object of the present invention to provide an air conditioner capable of estimating the amount of refrigerant remaining in the refrigerant circuit even when the air conditioner is actually in operation.

The air conditioner of one embodiment has a refrigerant circuit formed by connecting an indoor unit having an indoor heat exchanger to an outdoor unit having a compressor, an outdoor heat exchanger and an expansion valve with a refrigerant pipe. An air conditioner in which a refrigerant circuit is filled with a predetermined amount of refrigerant. The air conditioner has an acquisition unit, a storage unit, an estimation model, a detection unit, and a control unit. The acquisition unit periodically acquires the operating state quantity during the air-conditioned operation. The storage unit stores the operating state amount acquired by the acquisition unit. The estimation model estimates the amount of residual refrigerant remaining in the refrigerant circuit using the operating state amount. From the storage unit, the detection unit is a first operating state quantity, which is an operating state quantity in a state where the refrigerant circuit satisfies the first stabilizing condition, or a first stable condition in which the refrigerant circuit is different from the first stabilizing condition. The second operating state amount, which is the operating state amount in the state where the stability condition of 2 is satisfied, is detected. The control unit estimates the residual refrigerant amount of the refrigerant circuit by using the estimation model and the operating state amount detected by the detection unit.

As one aspect, the amount of residual refrigerant remaining in the refrigerant circuit can be estimated even when the air conditioner is actually in operation.

FIG. 1 is an explanatory diagram showing an example of the air conditioner of this embodiment. FIG. 2 is an explanatory diagram showing an example of an outdoor unit and an indoor unit. FIG. 3 is a block diagram showing an example of a control circuit of an outdoor unit. FIG. 4 is a Moriel diagram showing a state of change in the refrigerant of the air conditioner. FIG. 5 is a flowchart showing an example of the processing operation of the control circuit related to the acquisition processing. FIG. 6 is a flowchart showing an example of the processing operation of the control circuit related to the detection processing. FIG. 7 is a flowchart showing an example of the processing operation of the control circuit related to the estimation processing. FIG. 8 is an explanatory diagram showing an example of the air conditioning system of the second embodiment.

Hereinafter, examples of the air conditioner and the like disclosed in the present application will be described in detail with reference to the drawings. The disclosed technique is not limited by the present embodiment. In addition, each of the examples shown below may be appropriately modified as long as it does not cause a contradiction.

<Structure of air conditioner>
FIG. 1 is an explanatory diagram showing an example of the air conditioner 1 of the present embodiment. The air conditioner 1 shown in FIG. 1 is, for example, a home-use air conditioner having one outdoor unit 2 and one indoor unit 3. The outdoor unit 2 is connected to the indoor unit 3 by a liquid pipe 4 and a gas pipe 5. Then, the outdoor unit 2 and the indoor unit 3 are connected by a refrigerant pipe such as a liquid pipe 4 and a gas pipe 5, so that the refrigerant circuit 6 of the air conditioner 1 is formed.

<Outdoor unit configuration>
FIG. 2 is an explanatory diagram showing an example of the outdoor unit 2 and the indoor unit 3. The outdoor unit 2 includes a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, an expansion valve 14, an accumulator 15, an outdoor unit fan 16, and a control circuit 17. Using these compressor 11, four-way valve 12, outdoor heat exchanger 13, expansion valve 14, and accumulator 15, outdoor refrigerants that are interconnected by each refrigerant pipe described in detail below and form a part of the refrigerant circuit 6. Form a circuit.

The compressor 11 is, for example, a high-pressure container-type variable capacity compressor whose operating capacity can be changed according to the drive of a motor (not shown) whose rotation speed is controlled by an inverter. The refrigerant discharge side of the compressor 11 is connected to the first port 12A of the four-way valve 12 by a discharge pipe 21. Further, the refrigerant suction side of the compressor 11 is connected to the refrigerant outflow side of the accumulator 15 by a suction pipe 22.

The four-way valve 12 is a valve for switching the flow direction of the refrigerant in the refrigerant circuit 6, and includes a first port 12A to a fourth port 12D. The first port 12A is connected to the refrigerant discharge side of the compressor 11 by a discharge pipe 21. The second port 12B is connected to one of the refrigerant inlets / outlets of the outdoor heat exchanger 13 (corresponding to the first outdoor heat exchange port 13A described later) by the outdoor refrigerant pipe 23. The third port 12C is connected to the refrigerant inflow side of the accumulator 15 by an outdoor refrigerant pipe 26. The fourth port 12D is connected to the indoor heat exchanger 51 by an outdoor gas pipe 24.

The outdoor heat exchanger 13 exchanges heat between the refrigerant and the outside air taken into the outdoor unit 2 by the rotation of the outdoor unit fan 16. The outdoor heat exchanger 13 includes a first outdoor heat exchange port 13A as one of the refrigerant inlets and outlets, a second outdoor heat exchange port 13B as the other refrigerant inlet and outlet, and the first outdoor heat exchange port 13A. It has an outdoor heat exchange intermediate portion 13C connecting between the second outdoor heat exchange port portion 13B. The first outdoor heat exchange port 13A is connected to the second port 12B of the four-way valve 12 by an outdoor refrigerant pipe 23. The second outdoor heat exchange port 13B is connected to the expansion valve 14 by the outdoor liquid pipe 25. The outdoor heat exchange intermediate portion 13C is connected to the first outdoor heat exchange port 13A and the second outdoor heat exchange port 13B. The outdoor heat exchanger 13 functions as a condenser when the air conditioner 1 performs a cooling operation, and functions as an evaporator when the air conditioner 1 performs a heating operation.

The expansion valve 14 is an electronic expansion valve provided in the outdoor liquid pipe 25 and driven by a pulse motor (not shown). The opening degree of the expansion valve 14 is adjusted according to the number of pulses given to the pulse motor, so that the amount of refrigerant flowing from the expansion valve 14 into the refrigerant circuit 6 (flowing from the outdoor heat exchanger 13 into the indoor heat exchanger 51). The amount of refrigerant to be applied or the amount of refrigerant flowing from the indoor heat exchanger 51 to the outdoor heat exchanger 13) is adjusted. The opening degree of the expansion valve 14 is adjusted so that the discharge temperature (refrigerant discharge temperature) of the refrigerant of the compressor 11 reaches a target discharge temperature which is a predetermined temperature.

The accumulator 15 has its refrigerant inflow side connected to the third port 12C of the four-way valve 12 by an outdoor refrigerant pipe 26. Further, the accumulator 15 is connected to the refrigerant inflow side of the compressor 11 by a suction pipe 22 on the refrigerant outflow side. The accumulator 15 separates the refrigerant flowing into the accumulator 15 from the outdoor refrigerant pipe 26 into a gas refrigerant and a liquid refrigerant, and causes only the gas refrigerant to be sucked into the compressor 11.

The outdoor unit fan 16 is made of a resin material and is arranged in the vicinity of the outdoor heat exchanger 13. The outdoor unit fan 16 takes in outside air from a suction port (not shown) into the inside of the outdoor unit 2 in response to the rotation of a fan motor (not shown), and exchanges heat with the refrigerant in the outdoor heat exchanger 13 from an outlet (not shown) to the outside. It is released to the outside of the machine 2.

Further, a plurality of sensors are arranged in the outdoor unit 2. A discharge temperature sensor 31 for detecting the temperature of the refrigerant discharged from the compressor 11, that is, the refrigerant discharge temperature is arranged in the discharge pipe 21. In the outdoor liquid pipe 25 between the outdoor heat exchanger 13 and the expansion valve 14, the temperature of the refrigerant flowing into the second outdoor heat exchange port 13B among the heat exchanger temperatures, or the second outdoor heat exchange port An outdoor heat exchange outlet sensor 32 for detecting the temperature of the refrigerant flowing out from the unit 13B is arranged. Further, an outside air temperature sensor 33 for detecting the temperature of the outside air flowing into the inside of the outdoor unit 2, that is, the outside air temperature is arranged near the suction port (not shown) of the outdoor unit 2.

The control circuit 17 controls the outdoor unit 2 in response to an instruction from the control circuit 18 of the indoor unit 3 described later. The control circuit 17 of the outdoor unit 2 has a communication unit (not shown), a storage unit, and a control unit. The communication unit is a communication interface for communicating with the communication unit 41 described later of the indoor unit 3. The storage unit is, for example, a flash memory, which is an operating state amount such as a detection value corresponding to a control program of the outdoor unit 2 and detection signals from various sensors, a driving state of the compressor 11 and the outdoor unit fan 16, and an outdoor unit. The rated capacity of 2 and the required capacity of each indoor unit 3 are stored.

<Composition of indoor unit>
As shown in FIG. 2, the indoor unit 3 has an indoor heat exchanger 51, a gas pipe connecting portion 52, a liquid pipe connecting portion 53, an indoor unit fan 54, and a control circuit 18. The indoor heat exchanger 51, the gas pipe connecting portion 52, and the liquid pipe connecting portion 53 are connected to each other by each refrigerant pipe described later to form an indoor unit refrigerant circuit forming a part of the refrigerant circuit 6.

The indoor heat exchanger 51 exchanges heat between the refrigerant and the indoor air taken into the interior of the indoor unit 3 from a suction port (not shown) due to the rotation of the indoor unit fan 54. The indoor heat exchanger 51 has a first indoor heat exchange port 51A as one refrigerant inlet / outlet, a second indoor heat exchange port 51B as the other refrigerant inlet / outlet, and a first indoor heat exchange port 51A and a second. It has an indoor heat exchange intermediate portion 51C that connects between the indoor heat exchange port portion 51B and the indoor heat exchange port 51B. The first indoor heat exchange port 51A is connected to the gas pipe connecting portion 52 by the indoor gas pipe 56. The second indoor heat exchange port 51B is connected to the liquid pipe connecting portion 53 by the indoor liquid pipe 57. The indoor heat exchange intermediate portion 51C is connected to the first indoor heat exchange port 51A and the second indoor heat exchange port 51B. The indoor heat exchanger 51 functions as a condenser when the air conditioner 1 performs a heating operation, and functions as an evaporator when the air conditioner 1 performs a cooling operation.

The indoor unit fan 54 is made of a resin material and is arranged in the vicinity of the indoor heat exchanger 51. The indoor unit fan 54 is rotated by a fan motor (not shown) to take indoor air into the indoor unit 3 from a suction port (not shown), and an outlet (not shown) that exchanges heat with the refrigerant in the indoor heat exchanger 51. Is released into the room.

The indoor unit 3 is provided with various sensors. In the indoor heat exchange intermediate portion 51C, an indoor heat exchange intermediate sensor 58 for detecting the temperature of the refrigerant passing through the indoor heat exchange intermediate portion 51C among the heat exchanger temperatures, that is, the indoor heat exchange intermediate temperature is arranged.

The control circuit 18 controls the entire air conditioner 1. FIG. 3 is a block diagram showing an example of the control circuit 18 of the indoor unit 3. The control circuit 18 includes a communication unit 41, an acquisition unit 42, a detection unit 43, a storage unit 44, and a control unit 45. The communication unit 41 is a communication interface for communicating with the communication unit of the outdoor unit 2. The acquisition unit 42 acquires an operating state quantity such as a detection value according to a detection signal from the various sensors described above. The storage unit 44 is, for example, a flash memory, and has an operating state amount such as a detection value corresponding to a control program of the indoor unit 3 and detection signals from various sensors, a drive state of the indoor unit fan 54, and transmission from the outdoor unit 2. The operation information to be performed (for example, the operation / stop information of the compressor 11, the driving state of the outdoor unit fan 16, etc.), the rated capacity of the outdoor unit 2, the required capacity of each indoor unit 3, and the like are stored.

The storage unit 44 has an operation state amount memory 61, a first operation state amount memory 61A, and a second operation state amount memory 61B. The operating state amount memory 61 stores all the operating state quantities acquired by the acquisition unit 42. The operating state quantity is, for example, the operating state quantity of the compressor 11, the opening degree of the expansion valve 14, the refrigerant discharge temperature of the compressor 11, the outdoor heat exchange outlet temperature, and the outside air temperature during the cooling operation, for example. , The operating state quantities of the rotation speed of the compressor 11, the opening degree of the expansion valve 14, the refrigerant discharge temperature of the compressor 11, and the indoor heat exchange intermediate temperature during the heating operation.

The first operating state amount memory 61A stores the first operating state amount among the operating state quantities. The first operating state quantity is a state in which the first stable condition is satisfied under the condition that the high pressure and low pressure values in the refrigerant circuit 6 are stable and the refrigerant is stably circulated in the refrigerant circuit 6. It is an operating state quantity indicating an operating state during air-conditioned operation. The first stable condition is a state in which the fluctuation of the rotation speed of the compressor 11 continues within the first predetermined range for the first predetermined period or more, and the refrigerant discharge temperature and the target discharge temperature of the compressor 11. It is a state in which the absolute value of the difference from the above value is equal to or less than a predetermined value and continues for the first predetermined period or more. The first operating state amount is, for example, that the fluctuation of the rotation speed of the compressor 11 is within ± 1 rps in 5 minutes after 8 minutes have passed from the start of the compressor 11, and the refrigerant discharge temperature and the target discharge temperature of the compressor 11 It is an operating state quantity acquired when the absolute value of the difference from the above is within ± 2 ° C. in 5 minutes.

The second operating state amount memory 61B stores the second operating state amount among the operating state quantities. The second operating state quantity is the operating state during air conditioning operation in a state where the refrigerant is stably circulated in the refrigerant circuit 6 and the second stable condition different from the first stable condition is satisfied. It is an operating state quantity indicating. The second stability condition is a second stability condition in which the fluctuation of the rotation speed of the compressor 11 exceeds the first predetermined range and is within the second predetermined range, and exceeds the first predetermined period or exceeds the first predetermined period. It is in a state of continuing for a predetermined period or longer. The second operating state quantity is, for example, the operating state quantity acquired when the fluctuation of the rotation speed of the compressor 11 is within ± 5 rps in 12 minutes after 8 minutes have elapsed from the start of the compressor 11. Since the second stable condition is a condition in which the variation in the rotation speed of the compressor 11 is relaxed as compared with the first stable condition, the second operating state quantity acquired under the second stable condition is , The variation becomes larger than that of the first operating state amount earned under the first stable condition.

The detection unit 43 detects the first operating state amount from the operating state amount stored in the operating state amount memory 61, and stores the detected first operating state amount in the first operating state amount memory 61A. Further, the detection unit 43 detects the second operating state amount from the operating state amount stored in the operating state amount memory 61, and stores the detected second operating state amount in the second operating state amount memory 61B. ..

Further, the storage unit 44 stores an estimation model for estimating the amount of residual refrigerant remaining in the refrigerant circuit 6. The estimation model has an estimation model 62A for cooling and an estimation model 62B for heating. The cooling estimation model 62A is a model for estimating the amount of residual refrigerant in the refrigerant circuit 6 during cooling operation. Further, the heating estimation model 62B is a model for estimating the amount of residual refrigerant in the refrigerant circuit 6 during the heating operation.

The control unit 45 periodically (for example, every 30 seconds) captures the detected values of various sensors. The control unit 45 controls the entire air conditioner 1 based on the various input information. Further, the control unit 45 estimates the amount of residual refrigerant using each of the estimation models described above.

Further, the control unit 45 counts the number of detected first operating state quantities within a predetermined period, and when the number of detected first operating state quantities is equal to or greater than the predetermined number, the first operating state quantity and each estimation model. Is used to estimate the amount of residual refrigerant in the refrigerant circuit 6. When the number of detected first operating state quantities is less than a predetermined number within a predetermined period, the control unit 45 estimates the residual refrigerant amount of the refrigerant circuit 6 by using the second operating state quantity and each estimation model. The control unit 45 uses the first operating state amount and each estimated model when the number of detected first operating state quantities is a predetermined number, for example, 50 or more, for a predetermined period, for example, the amount of residual refrigerant per day. To estimate. Further, the control unit 45 estimates the residual refrigerant amount using the second operating state amount and each estimation model when the number of detected first operating state quantities is less than 50 per day.

The control unit 45 of the refrigerant circuit 6 of the previous day uses either the first operating state amount or the second operating state amount acquired in the 24 hours of the previous day at a predetermined time of the day, for example, 1:00 am. Estimate the amount of residual refrigerant. When the number of detected first operating state quantities is equal to or greater than a predetermined number, the amount of residual refrigerant is estimated using the acquired first operating condition quantity and the estimation model, and the number of detected first operating condition quantities is a predetermined number. If it is less than, the amount of residual refrigerant is estimated using the acquired second operating state amount and estimation model. A specific method for estimating the amount of residual refrigerant per day will be described later.

<Operation of refrigerant circuit>
Next, the flow of the refrigerant and the operation of each part in the refrigerant circuit 6 during the air conditioning operation of the air conditioner 1 in the present embodiment will be described.

When the air conditioner 1 performs the heating operation, the four-way valve 12 switches so that the first port 12A and the fourth port 12D communicate with each other, and the second port 12B and the third port 12C communicate with each other. (The state shown by the solid line in FIG. 2). As a result, the refrigerant circuit 6 becomes a heating cycle in which the indoor heat exchanger 51 functions as a condenser and the outdoor heat exchanger 13 functions as an evaporator. For convenience of explanation, the flow of the refrigerant during the heating operation is indicated by the solid arrow shown in FIG.

When the compressor 11 is driven in this state of the refrigerant circuit 6, the refrigerant discharged from the compressor 11 flows through the discharge pipe 21 and flows into the four-way valve 12, flows from the four-way valve 12 through the outdoor gas pipe 24, and is a gas. It flows into the pipe 5. The refrigerant flowing through the gas pipe 5 flows into the indoor unit 3 via the gas pipe connecting portion 52. The refrigerant that has flowed into the indoor unit 3 flows through the indoor gas pipe 56 and flows into the indoor heat exchanger 51. The refrigerant flowing into the indoor heat exchanger 51 is condensed by exchanging heat with the indoor air taken into the indoor unit 3 by the rotation of the indoor unit fan 54. That is, the indoor heat exchanger 51 functions as a condenser, and the indoor unit 3 is blown into the room from an outlet (not shown) heated by heat exchange with the refrigerant in the indoor heat exchanger 51. The installed room is heated.

The refrigerant that has flowed from the indoor heat exchanger 51 into the indoor liquid pipe 57 flows out to the liquid pipe 4 via the liquid pipe connecting portion 53. The refrigerant that has flowed into the liquid pipe 4 flows into the outdoor unit 2. The refrigerant that has flowed into the outdoor unit 2 flows through the outdoor liquid pipe 25, passes through the expansion valve 14, and is depressurized. The refrigerant decompressed by the expansion valve 14 flows through the outdoor liquid pipe 25 and flows into the outdoor heat exchanger 13, and heat exchanges with the outside air flowing in from the suction port (not shown) of the outdoor unit 2 by the rotation of the outdoor unit fan 16. Evaporates. The refrigerant flowing out from the outdoor heat exchanger 13 to the outdoor refrigerant pipe 26 flows into the four-way valve 12, the outdoor refrigerant pipe 26, the accumulator 15 and the suction pipe 22 in this order, is sucked into the compressor 11, is compressed again, and is compressed again. It flows out to the outdoor gas pipe 24 via the first port 12A and the fourth port 12D of the twelve.

Further, when the air conditioner 1 performs the cooling operation, the four-way valve 12 communicates with the first port 12A and the second port 12B, and communicates with the third port 12C and the fourth port 12D. (The state shown by the broken line in FIG. 2). As a result, the refrigerant circuit 6 becomes a cooling cycle in which the indoor heat exchanger 51 functions as an evaporator and the outdoor heat exchanger 13 functions as a condenser. For convenience of explanation, the flow of the refrigerant during the cooling operation is indicated by the broken line arrow shown in FIG.

When the compressor 11 is driven in this state of the refrigerant circuit 6, the refrigerant discharged from the compressor 11 flows through the discharge pipe 21 and flows into the four-way valve 12, flows from the four-way valve 12 through the outdoor refrigerant pipe 23, and is outdoors. It flows into the heat exchanger 13. The refrigerant flowing into the outdoor heat exchanger 13 is condensed by exchanging heat with the outdoor air taken into the inside of the outdoor unit 2 by the rotation of the outdoor unit fan 16. That is, the outdoor heat exchanger 13 functions as a condenser, and the outdoor air heated by the refrigerant in the outdoor heat exchanger 13 is blown out to the outside from an outlet (not shown).

The refrigerant flowing from the outdoor heat exchanger 13 to the outdoor liquid pipe 25 passes through the expansion valve 14 and is depressurized. The refrigerant decompressed by the expansion valve 14 flows through the liquid pipe 4 and flows into the indoor unit 3. The refrigerant that has flowed into the indoor unit 3 flows through the indoor liquid pipe 57 and flows into the indoor heat exchanger 51, and heat exchanges with the indoor air that has flowed in from the suction port (not shown) of the indoor unit 3 by rotating the indoor unit fan 54. Evaporates. That is, the indoor heat exchanger 51 functions as an evaporator, and the indoor unit 3 is blown into the room from an outlet (not shown) cooled by heat exchange with the refrigerant in the indoor heat exchanger 51. The installed room is cooled.

The refrigerant flowing from the indoor heat exchanger 51 to the gas pipe 5 via the gas pipe connecting portion 52 flows into the outdoor gas pipe 24 of the outdoor unit 2 and flows into the fourth port 12D of the four-way valve 12. The refrigerant that has flowed into the fourth port 12D of the four-way valve 12 flows into the refrigerant inflow side of the accumulator 15 from the third port 12C. The refrigerant that has flowed in from the refrigerant inflow side of the accumulator 15 flows in through the suction pipe 22, is sucked into the compressor 11, and is compressed again.

When the air conditioner 1 is performing the cooling operation or the heating operation described above, the acquisition unit 42 in the control circuit 18 sets the sensor values of the discharge temperature sensor 31, the outdoor heat exchange outlet sensor 32, and the outside air temperature sensor 33. Acquired via the control circuit 17 of the outdoor unit 2. Further, the acquisition unit 42 acquires the sensor values of the indoor heat exchange intermediate sensor 58 and the suction temperature sensor 59 of the indoor unit 3.

FIG. 4 is a Moriel diagram showing the refrigeration cycle of the air conditioner 1. As described above, the outdoor heat exchanger 13 functions as a condenser and the indoor heat exchanger 51 functions as an evaporator during the cooling operation of the air conditioner 1, and the outdoor heat exchanger 1 functions as an evaporator during the heating operation of the air conditioner 1. The heat exchanger 13 functions as an evaporator and the indoor heat exchanger 51 functions as a condenser.

The compressor 11 compresses the low-temperature low-pressure gas refrigerant (refrigerant in the state of point A in FIG. 4) flowing from the evaporator and discharges the high-temperature and high-pressure gas refrigerant (refrigerant in the state of point B in FIG. 4). do. The temperature of the gas refrigerant discharged by the compressor 11 is the refrigerant discharge temperature, and the refrigerant discharge temperature is detected by the discharge temperature sensor 31.

The condenser heat-exchanges high-temperature and high-pressure gas refrigerant from the compressor 11 with air to condense it. At this time, in the condenser, after all the gas refrigerant becomes a liquid refrigerant due to the latent heat change, the temperature of the liquid refrigerant drops due to the sensible heat change and the state becomes overcooled (state of point C in FIG. 4). The temperature at which the gas refrigerant changes to a liquid refrigerant due to a latent heat change is the condensation temperature, and the temperature of the overcooled refrigerant at the outlet of the condenser is the heat exchange outlet temperature. Of the heat exchanger temperatures, the heat exchange outlet temperature is detected by the outdoor heat exchange outlet sensor 32 during the cooling operation. During the heating operation, the flow of the refrigerant is opposite to that during the cooling operation, and the outdoor heat exchanger 13 functions as an evaporator. During the heating operation, the outdoor heat exchange outlet sensor 32 is used to detect the temperature of the outdoor heat exchanger 13 to detect freezing and to control the defrosting operation.

The expansion valve 14 depressurizes the low-temperature and high-pressure refrigerant flowing out of the condenser. The refrigerant decompressed by the expansion valve 14 is a gas-liquid two-phase refrigerant in which gas and liquid are mixed (refrigerant in the state of point D in FIG. 4).

The evaporator heat-exchanges the inflowing gas-liquid two-phase refrigerant with air to evaporate. At this time, in the evaporator, after all the gas-liquid two-phase refrigerant becomes a gas refrigerant due to the latent heat change, the temperature of the gas refrigerant rises due to the sensible heat change and becomes an overheated state (state of point A in FIG. 4), and is compressed. It is sucked into the machine 11. The temperature at which the liquid refrigerant changes to the gas refrigerant due to the latent heat change is the evaporation temperature. The evaporation temperature is the indoor heat exchange intermediate temperature detected by the indoor heat exchange intermediate sensor 58 during the cooling operation. Further, the temperature of the refrigerant that is overheated by the evaporator and sucked into the compressor 11 is the suction temperature. During the heating operation, the flow of the refrigerant is opposite to that during the cooling operation, and the indoor heat exchanger 51 functions as a condenser. The detection result of the indoor heat exchange intermediate sensor 58 is used to calculate the target discharge temperature.

<Structure of estimation model>
The estimation model is generated by a multiple regression analysis method, which is a kind of regression analysis method, using an arbitrary operating state quantity (feature quantity) among a plurality of operating state quantities. In the multiple regression analysis method, the test result using an actual air conditioner (hereinafter referred to as the actual machine) (what kind of value is the operating state amount when the amount of the refrigerant remaining in the refrigerant circuit is changed by using the actual machine). Regression obtained from the results of multiple simulations (results of reproducing the refrigerant circuit by numerical calculation and calculating the value of the operating state amount with respect to the remaining amount of refrigerant). Of the equations, the P value (value indicating the degree of influence of the operating state amount on the accuracy of the generated estimated model (predetermined weight parameter)) is the smallest, and the correction value R2 (indicating the accuracy of the generated estimated model). A regression equation having a value) of 0.9 or more and 1.0 or less is selected and generated as an estimation model. Here, the P value and the correction value R2 are values related to the accuracy of the estimation model when the estimation model is generated by the multiple regression analysis method, and the smaller the P value, the more the correction value R2 is 1.0. The closer the value is to, the more accurate the generated estimation model will be.

The estimation model has an estimation model 62A for cooling and an estimation model 62B for heating. In this embodiment, each of these estimation models is generated using test results using an actual machine as described later, and is stored in advance in the control circuit 18 of the air conditioner 1.

The cooling estimation model 62A is a first method capable of estimating the amount of residual refrigerant during cooling operation with high accuracy by using an operating state amount during cooling operation, for example, a first operating state amount or a second operating state amount. It is a regression equation.

It is assumed that the coefficients α1 to α6 are determined at the time of generating the estimation model. The control unit 45 is the rotation speed of the compressor 11 and the expansion valve in the first operating state amount or the second operating state amount detected by the detection unit 43 in the 24 hours of the previous day at a predetermined time in the day. When the first operating state amount or the second operating state amount is detected by substituting the opening degree 14, the refrigerant discharge temperature of the compressor 11, the heat exchange outlet temperature, and the outside air temperature into the first regression equation, respectively. The amount of residual refrigerant in the refrigerant circuit 6 of the above is calculated. Then, the control unit 45 determines the average value of the residual refrigerant amount calculated by using the first operating state amount at each time point, or the residual refrigerant amount calculated by using the second operating state amount at each time point. One of the average values is used as the estimated value of the residual refrigerant amount on the previous day. The reason for substituting the number of revolutions of the compressor 11, the opening degree of the expansion valve, the refrigerant discharge temperature of the compressor 11, the outdoor heat exchange outlet temperature, and the outside air temperature is the feature amount used when the estimation model 62A for cooling was generated. To use. The rotation speed of the compressor 11 is detected by, for example, a rotation speed sensor (not shown) of the compressor 11. For the opening degree of the expansion valve, for example, the number of pulses of the pulse signal input from the control unit 45 to the stepping motor (not shown) of the expansion valve is used. The refrigerant discharge temperature of the compressor 11 is detected by the discharge temperature sensor 31. The heat exchange outlet temperature is detected by the outdoor heat exchange outlet sensor 32. The outside air temperature is detected by the outside air temperature sensor 33.

The estimation model 62B for heating uses a second operating state amount during heating operation, for example, a first operating state amount or a second operating state amount, to estimate the amount of residual refrigerant during heating operation with high accuracy. It is a regression equation.

It is assumed that the coefficients α11 to α15 are determined at the time of generating the estimation model. The control unit 45 is the rotation speed of the compressor 11 and the expansion valve in the first operating state amount or the second operating state amount detected by the detection unit 43 in the 24 hours of the previous day at a predetermined time in the day. By substituting the opening degree of 14 and the refrigerant discharge temperature of the compressor 11 and the indoor heat exchange intermediate temperature into the second regression equation, the refrigerant at the time when the first operating state amount or the second operating state amount is detected is detected. The amount of residual refrigerant in the circuit 6 is calculated. Then, the control unit 45 determines the average value of the residual refrigerant amount calculated by using the first operating state amount at each time point, or the residual refrigerant amount calculated by using the second operating state amount at each time point. One of the average values is used as the estimated value of the residual refrigerant amount on the previous day. The reason for substituting the rotation speed of the compressor 11, the opening degree of the expansion valve 14, the refrigerant discharge temperature of the compressor 11 and the indoor heat exchange intermediate temperature is that the feature amount used when the estimation model 62B for heating is generated is used. Because. The rotation speed of the compressor 11 is detected by a rotation speed sensor (not shown) of the compressor 11. For the opening degree of the expansion valve, for example, the number of pulses of the pulse signal input from the control unit 45 to the stepping motor (not shown) of the expansion valve is used. The refrigerant discharge temperature of the compressor 11 is detected by the discharge temperature sensor 31. Of the heat exchanger temperatures, the indoor heat exchange intermediate temperature is detected by the indoor heat exchange intermediate sensor 58.

As described above, during the cooling operation, the amount of residual refrigerant is estimated using the first regression equation. Further, during the heating operation, the amount of residual refrigerant is estimated using the second regression equation.

<Method of generating regression equation>
Next, the features used to generate the first regression equation and the second regression equation will be described. In the cooling operation using the first regression equation, as the feature quantities used when generating the first regression equation by the multiple regression analysis method, in this embodiment, the rotation speed of the compressor 11 and the expansion valve 14 are used. The operating state quantities of the opening degree, the refrigerant discharge temperature of the compressor 11, the outdoor heat exchange outlet temperature, and the outside air temperature are used. Then, for each of these operating state quantities, the test results using the actual machine are used. Further, in the heating operation using the second regression equation, as feature quantities used when generating the second regression equation by multiple regression analysis, in this embodiment, the number of revolutions of the compressor 11 and the expansion valve are used. Each operating state amount of the opening degree of 14, the refrigerant discharge temperature of the compressor 11, and the room heat exchange intermediate temperature is used. Then, for each of these operating state quantities, the test results using the actual machine are used. When the first regression equation of the cooling estimation model 62A and the second regression equation of the heating estimation model 62B are generated, the second one detected when the first stability condition is satisfied. The operating state quantity of 1 is used.

Specifically, at the design stage of the air conditioner 1, as an example, when the indoor unit 3 is operating, the air conditioner 1 is subjected to a test operation with different outside air temperature, indoor temperature and refrigerant filling amount. Obtain the relationship between the amount and the refrigerant shortage rate. As a condition for performing the test operation, for example, the outside air temperature is changed to 20 ° C, 25 ° C, 30 ° C, 35 ° C and 40 ° C. When performing the test operation, other parameters of the outside air temperature may be added.

Of the multiple operating state quantities, any operating condition quantity (feature amount) used in the estimation model will be obtained from the test results (hereinafter referred to as teacher data) showing the relationship between the plurality of operating condition quantities and the refrigerant filling amount. Become. Specifically, the teacher data is data that links the amount of residual refrigerant changed by changing the amount of refrigerant to be filled in the refrigerant circuit and the amount of each operating state when operating with the amount of residual refrigerant (in the multiple regression analysis method). Teacher data used to generate an estimated model).

In the multiple regression analysis method, for example, a test operation is performed with different refrigerant filling amounts, each operating state amount different for each outside air temperature is acquired for each refrigerant filling amount, and the data is classified into data for each refrigerant filling amount. The operating state amount used for the teacher data includes, for example, the operating state amount of the compressor 11, the indoor unit 3, and the outdoor unit 2. The operating state amount of the compressor 11 includes, for example, a rotation speed, a target rotation speed, an operation time, a refrigerant discharge temperature, a target discharge temperature, an output voltage, and the like. The operating state quantity of the indoor unit 3 includes, for example, the rotation speed of the indoor unit fan 54, the target rotation speed, the heat exchanger intermediate sensor temperature, and the like. The operating state amount of the outdoor unit 2 includes, for example, the rotation speed and target rotation speed of the outdoor unit fan 16, the opening degree of the expansion valve 14, the condenser outlet sensor temperature, and the like. Then, by performing machine learning using the data for each refrigerant filling amount as teacher data, an arbitrary operating state amount (feature amount) for estimating the residual refrigerant amount is extracted and a coefficient is derived to generate an estimation model. do.

<Operation of operation status acquisition processing>
Next, the operation when the operating state quantity is acquired by the air conditioner 1 of the first embodiment will be described. FIG. 5 is a flowchart showing an example of the processing operation of the control circuit 18 related to the acquisition of the operating state quantity. In FIG. 5, the acquisition unit 42 of the control circuit 18 determines whether or not it is a predetermined timing for acquiring the operating state quantity (step S11). The predetermined timing is, for example, the timing of a 5-minute cycle for acquiring the operating state quantity. When the timing is predetermined (step S11: Yes), the acquisition unit 42 acquires the operating state quantity of the air conditioner 1 (step S12). After acquiring the operating state amount of the air conditioner 1, the acquisition unit 42 stores the operating state amount in the operating state amount memory 61 (step S13), and returns the process to step S11. If the timing is not the predetermined timing in step S11 (step S11: No), the acquisition unit 42 returns the process to step S11.

<Operation of operation state quantity detection processing>
FIG. 6 is a flowchart showing an example of the processing operation of the control circuit 18 related to the detection of the operating state quantity. In FIG. 6, the detection unit 43 of the control circuit 18 refers to the operation state amount stored in the operation state amount memory 61 at a predetermined time of the day (for example, 1:00 am described above), and starts from the start of the compressor 11. It is determined whether or not the operating state amount acquired after 8 minutes has elapsed is in the operating state amount memory 61 (step S21). When the detection unit 43 has an operating state quantity acquired 8 minutes after the start of the compressor 11 (step S21: Yes), the fluctuation of the rotation speed of the compressor 11 is within the second predetermined range, for example, ± 5 rps. Whether or not the operating state amount acquired when the second predetermined period continues in the state of, for example, 12 minutes or more, that is, when the second stable condition is satisfied, is in the operating state amount memory 61. Determination (step S22). A time stamp indicating the acquired time is attached to the operating state amount acquired at the timing of a 5-minute cycle and stored in the operating state amount memory 61, and the detection unit 43 assigns the operating state amount to the operating state amount. By referring to the set time stamp, it can be determined whether or not there is an acquired operating state quantity in the time zone in which the second stability condition is satisfied.

The detection unit 43 is in the case where the operating state amount acquired when the fluctuation of the rotation speed of the compressor 11 continues within the second predetermined range for the second predetermined period or more is not in the operating state amount memory 61 (step). S22: No), the operating state amount acquired when the fluctuation of the rotation speed of the compressor 11 continues within the first predetermined range, for example, ± 1 rps for the first predetermined period, for example, 5 minutes or more, is the operation. It is determined whether or not it is in the state quantity memory 61 (step S23). The detection unit 43 is in the case where the operating state amount acquired when the fluctuation of the rotation speed of the compressor 11 continues for the first predetermined period or more in the state within the first predetermined range is in the operating state amount memory 61 (step). S23: Yes), the first predetermined period when the absolute value of the difference between the refrigerant discharge temperature of the compressor 11 and the target discharge temperature is a predetermined value, for example, 2 ° C. or less in the operating state quantity satisfying the condition of step S23. It is determined whether or not there is an operating state quantity acquired when the above is continued (step S24). That is, the detection unit 43 determines whether or not the operating state amount acquired when the first stability condition is satisfied is in the operating state amount memory 61 by performing the determination in step S23 and the determination in step S24. To judge. The detection unit 43 can determine whether or not there is an acquired operating state amount in the time zone in which the first stability condition is satisfied by referring to the time stamp given to the operating state amount.

When the detection unit 43 continues for a first predetermined period or longer in a state where the absolute value of the difference between the refrigerant discharge temperature of the compressor 11 and the target discharge temperature is equal to or less than a predetermined value within the operating state quantity satisfying the condition of step S23. When there is an acquired operating state amount in (step S24: Yes), the corresponding operating state amount is detected as the first operating state amount (step S25). Further, the detection unit 43 stores the first operating state quantity detected in step S25 in the first operating state quantity memory 61A (step S26), and returns the process to step S21.

Further, when the operating state amount acquired by the detection unit 43 when the fluctuation of the rotation speed of the compressor 11 continues within the second predetermined range for the second predetermined period or longer is in the operating state amount memory 61. (Step S22: Yes), the corresponding operating state amount is detected as the second operating state amount (step S27). The detection unit 43 stores the second operating state quantity detected in step S27 in the second operating state quantity memory 61B (step S28), and proceeds to the process in step S23.

Further, when the operating state amount acquired 8 minutes after the start of the compressor 11 is not in the operating state amount memory 61 (step S21: No), the detection unit 43 returns the process to step S21. Further, when the operation state amount acquired by the detection unit 43 when the fluctuation of the rotation speed of the compressor 11 continues within the first predetermined range for the first predetermined period or longer is not in the operation state amount memory 61. (Step S23: No), the process returns to step S21. Further, the detection unit 43 continues for a first predetermined period or longer in a state where the absolute value of the difference between the refrigerant discharge temperature of the compressor 11 and the target discharge temperature is equal to or less than a predetermined value in the operating state amount satisfying the condition of step S23. If there is no operating state quantity acquired at that time (step S24: No), the process is returned to step S21.

<Operation of estimation processing of residual refrigerant amount>
FIG. 7 is a flowchart showing an example of the processing operation of the control circuit 18 related to the estimation of the residual refrigerant amount. In FIG. 7, the control unit 45 of the control circuit 18 determines whether or not the timing is estimated (step S31). The estimated timing is a predetermined time in the above-mentioned day, for example, 1:00 am. When the estimation timing is reached (step S31: Yes), the control unit 45 counts the number (detection number) of the first operating state quantity acquired in a predetermined period, for example, one day of the previous day (step S32). It is determined whether or not the number of detected first operating state quantities within the predetermined period is a predetermined number, for example, 50 or more (step S33).

When the number of detected first operating state quantities within a predetermined period is equal to or greater than a predetermined number (step S33: Yes), the control unit 45 uses the first operating state quantity and each estimation model to acquire the first operating state quantity. The amount of residual refrigerant in the refrigerant circuit 6 is calculated for each operating state amount (step S34). For example, the control unit 45 during the cooling operation calculates the residual refrigerant amount of the refrigerant circuit 6 for each acquired first operating state amount by using the first operating state amount and the cooling estimation model 62A. Further, the control unit 45 during the heating operation calculates the residual refrigerant amount of the refrigerant circuit 6 for each acquired first operating state amount by using the first operating state amount and the heating estimation model 62B.

When the number of detected first operating state quantities within a predetermined period is not equal to or greater than the predetermined number (step S33: No), that is, when the detected number is less than the predetermined number, the control unit 45 has a second operating state quantity and an estimation model. Is used to calculate the amount of residual refrigerant in the refrigerant circuit 6 for each acquired second operating state amount (step S35). For example, the control unit 45 during the cooling operation calculates the residual refrigerant amount of the refrigerant circuit 6 for each acquired second operating state amount by using the second operating state amount and the cooling estimation model 62A. Further, the control unit 45 during the heating operation calculates the residual refrigerant amount of the refrigerant circuit 6 for each acquired second operating state amount by using the second operating state amount and the heating estimation model 62B.

Next, the control unit 45 calculates the average value of each residual refrigerant amount calculated in step S34 or each residual refrigerant amount calculated in step S35 (step S36), and the calculated average value of each residual refrigerant amount is less than a predetermined value. (Step S37). Here, the predetermined value means that if the amount of the refrigerant filled in the refrigerant circuit 6 is less than this predetermined value, the air conditioning capacity exhibited by the air conditioner 1 will be hindered in a test or the like conducted in advance. It is a known value, and is, for example, 60% of the amount of the refrigerant filled in the refrigerant circuit 6 when the air conditioner 1 is installed.

When the calculated average value of each residual refrigerant amount is less than a predetermined value (step S37: Yes), the control unit 45 outputs the calculated average value as an estimated value of the residual refrigerant amount (step S38) and processes in step S31. Return. Here, the output of the estimated value of the residual refrigerant amount is, for example, to transmit the estimated value of the residual refrigerant amount to a remote controller (not shown) for operating the indoor unit 3 or a mobile terminal of the user of the air conditioner 1, and the residual refrigerant amount is output. On the remote controller or the neglected terminal that has received the estimated amount, the estimated value of the residual refrigerant received is displayed on each display unit.

If the timing is not estimated in step S31 (step S31: No), the control unit 45 returns the process to step S31. Further, when the average value of each residual refrigerant amount calculated in step S37 is not less than a predetermined value (step S37: No), the control unit 45 returns the process to step S31.

<Effect of Example 1>
The air conditioner 1 of the first embodiment has a first operating state amount indicating an operating state during an air conditioning operation in a state where the refrigerant circuit 6 satisfies the first stabilizing condition, and a cooling operation / heating operation. Using each estimation model, the amount of residual refrigerant remaining in the refrigerant circuit 6 is estimated. If the first operating state amount is used for estimating the residual refrigerant amount, the residual refrigerant amount can be accurately estimated because the first operating state amount is also used for generating each estimation model. Further, when the first stable condition is not satisfied, that is, when it is difficult to obtain a stable state of the refrigerant circuit 6, the operating state at the time of air conditioning operation in the state where the refrigerant circuit 6 satisfies the second stable condition. The amount of residual refrigerant remaining in the refrigerant circuit 6 is estimated by using the second operating state amount showing the above and each estimation model for cooling operation / heating operation. If the second operating state amount is used for estimating the residual refrigerant amount, the accuracy of each estimation is lower than when the first operating state amount is used, but the second operating state amount is the first operating state amount. Since more can be obtained, the accuracy of estimating the amount of residual refrigerant can be ensured by averaging the individual estimation results and using this average value as the estimated value of the amount of residual refrigerant.

The control unit 45 estimates the amount of residual refrigerant by using the first operating state amount and the estimation model when the number of detected first operating state quantities is equal to or greater than the predetermined number within a predetermined period. When the number of detected first operating state quantities is less than the predetermined number within a predetermined period, the amount of residual refrigerant is estimated using the second operating condition amount and the estimation model. As a result, when estimating the amount of residual refrigerant, the first operating state amount or the second operating state amount can be used properly.

When the control unit 45 estimates the residual refrigerant amount using the second operating state amount and the estimation model at each predetermined timing, the control unit 45 sets the average value of the residual refrigerant amount estimated at each predetermined timing within the predetermined period for a predetermined period. It is output as the amount of residual refrigerant in. As a result, the amount of residual refrigerant can be estimated with high accuracy.

In the first embodiment, the fluctuation of the rotation speed of the compressor 11 is continued within the first predetermined range for the first predetermined period or more, and the refrigerant discharge temperature and the target discharge temperature of the compressor 11 are maintained. When the absolute value of the difference from the above value is equal to or less than a predetermined value and the temperature continues for the first predetermined period or longer, the first stability condition is satisfied. However, the first stability condition may be satisfied only when the fluctuation of the rotation speed of the compressor 11 is within the first predetermined range and continues for the first predetermined period or longer, and can be changed as appropriate. Is.

In the first embodiment, it is assumed that the fluctuation of the rotation speed of the compressor 11 is within the second predetermined range exceeding the first predetermined range, and continues for the second predetermined period exceeding the first predetermined period. The state where the second stability condition was satisfied was set. However, even if it does not continue for the second predetermined period or longer, the second stable condition is that the fluctuation of the rotation speed of the compressor 11 continues for the first predetermined period or longer within the second predetermined range. May be satisfied, and can be changed as appropriate.

In the first embodiment, the case where the residual refrigerant amount is estimated at predetermined timings is illustrated, but it is not necessary to estimate it periodically, and it can be changed as appropriate.

In the first embodiment, each operating state amount is obtained by the test operation of the air conditioner 1 at the design stage of the air conditioner 1, and the estimation model obtained by learning the test result by a terminal such as a server having a learning function is controlled. The case where the circuit 18 is stored in advance is illustrated. Instead of this, the estimated model obtained by acquiring each operating state quantity by simulation and learning the acquired result may be stored in advance. Further, there is a server 120 connected to the air conditioner 1 by a communication network 110, and the server 120 generates a first regression equation and a second regression equation and transmits them to the air conditioner 1. You may. This embodiment will be described below.

<Structure of air conditioning system>
FIG. 8 is an explanatory diagram showing an example of the air conditioning system 100 of the second embodiment. The same configuration as that of the air conditioner 1 of the first embodiment is designated by the same reference numeral, and the description of the overlapping configuration and operation will be omitted. The air conditioner system 100 shown in FIG. 8 has an air conditioner 1, a communication network 110, and a server 120 described in the first embodiment, and the air conditioner 1 can communicate with the server 120 via the communication network 110. It is connected to the.

The server 120 has a generation unit 121 and a transmission unit 122. The generation unit 121 generates an estimation model by a multiple regression analysis method using the operating state amount related to the estimation of the residual refrigerant amount of the refrigerant filled in the refrigerant circuit 6. The estimation model includes, for example, the cooling estimation model 62A and the heating estimation model 62B described in the first embodiment. The transmission unit 122 transmits each estimation model generated by the generation unit 121 to the air conditioner 1 via the communication network 110. The control circuit 18 in the air conditioner 1 calculates the amount of residual refrigerant in the refrigerant circuit 6 of the air conditioner 1 using each of the received estimation models.

The generation unit 121 in the server 120 is an operating state amount during cooling operation periodically from a standard machine of the air conditioner 1 (installed in a test room of a manufacturer or the like) that can actually measure the amount of residual refrigerant in the refrigerant circuit 6. Is collected, and the estimation model 62A for cooling is generated or updated by using the comparison result between the residual refrigerant amount estimated by each estimation model and the measured residual refrigerant amount and the collected operating state amount. Then, the transmission unit 122 in the server 120 periodically transmits the generated or updated cooling estimation model 62A to the air conditioner 1. As in the first embodiment, the operating state quantity used for generating each estimated model may be obtained by simulation, and the operating state quantity obtained by the generation unit 121 in the simulation may be used to generate each estimated model.

The generation unit 121 in the server 120 periodically collects the operating state amount during the heating operation from the standard machine of the air conditioner 1 described above, and compares the residual refrigerant amount estimated by the estimation model with the measured residual refrigerant amount. The estimation model 62B for heating is generated by using the result and the collected operating state quantity. Then, the transmission unit 122 in the server 120 periodically transmits the generated estimation model 62B for heating to the air conditioner 1. As in the first embodiment, the operating state quantity used for generating each estimated model may be obtained by simulation, and the operating state quantity obtained by the generation unit 121 in the simulation may be used to generate each estimated model.

<Effect of Example 2>
The server 120 of the second embodiment uses the multiple regression analysis method using the operating state amount related to the estimation of the residual refrigerant amount of the refrigerant circuit 6 to generate an estimation model for estimating the residual refrigerant amount, and the generated estimation model. Is transmitted to the air conditioner 1. The air conditioner 1 estimates the amount of residual refrigerant by using the estimation model received from the server 120 and the current operating state amount. As a result, even in the household air conditioner 1, the current amount of residual refrigerant can be estimated using a highly accurate estimation model.

Further, in this embodiment, the case of estimating the amount of the residual refrigerant remaining in the refrigerant circuit 6 has been described. However, the present invention is not limited to this, and specifically, it is the ratio of the amount of refrigerant leaked to the outside from the refrigerant circuit 6 to the filling amount (initial value) when the refrigerant circuit 6 is filled with the refrigerant. The refrigerant shortage rate may be estimated. Further, the estimated amount of the refrigerant shortage may be multiplied by the initial value to provide the amount of the refrigerant leaked from the refrigerant circuit 6 to the outside. Further, an estimation model for estimating the absolute amount of refrigerant leaked to the outside from the refrigerant circuit 6 or the absolute amount of refrigerant remaining in the refrigerant circuit 6 may be generated, and the estimation result by this estimation model may be provided. .. When generating an estimation model for estimating the absolute amount of refrigerant leaked to the outside from the refrigerant circuit 6 or the absolute amount of refrigerant remaining in the refrigerant circuit 6, in addition to each operating state amount described so far, the outdoor The volume of the heat exchanger 13 and the indoor heat exchanger 51 and the volume of the liquid pipe 4 may be taken into consideration.

Further, the refrigerant shortage rate is the ratio of the decrease with respect to the specified amount, where 100% is the case where the specified amount of the refrigerant is filled. Instead of this, the refrigerant shortage rate may be estimated immediately after the refrigerant circuit 6 is filled with the specified amount of the refrigerant, and the estimation result may be set to 100%. For example, when the refrigerant shortage rate estimated immediately after the refrigerant circuit 6 is filled with the specified amount of the refrigerant is 90%, that is, when the amount of the refrigerant filled in the refrigerant circuit 6 is estimated to be 10% less than the specified amount of the refrigerant is filled. The amount of the refrigerant, which is 10% less than the specified amount of filling, may be set to 100%. By matching the amount of the refrigerant to 100% with the estimation result in this way, the subsequent refrigerant shortage rate can be estimated more accurately.

<Modification example>
In this embodiment, the case where the control circuit 18 provided in the indoor unit 3 controls the entire air conditioner 1 is illustrated, but the control circuit 18 may be provided in the outdoor unit 2 or the cloud side. In this embodiment, the case where the estimation model is generated by the server 120 is illustrated, but a person may calculate the estimation model from the simulation result instead of the server 120. Further, in this embodiment, the case where the control circuit 18 of the indoor unit 3 estimates the amount of the refrigerant by using the estimation model is illustrated, but the server 120 that generates the estimation model may estimate the amount of the refrigerant. Further, in this embodiment, the case where each estimation model is generated by using the multiple regression analysis method is illustrated, but SVR (Support Vector Regression), NN (Neural Network), etc., which are machine learning methods that can perform general regression analysis methods, etc. May be used to generate an estimation model. At that time, in selecting the feature amount, instead of the P value and the correction value R2 used in the multiple regression analysis method, a general method (Forward Feature Selection method, Backward feature Elimination) in which the feature amount is selected so as to improve the accuracy of the estimation model is used. Etc.).

Further, each component of each of the illustrated parts does not necessarily have to be physically configured as shown in the figure. That is, the specific form of distribution / integration of each part is not limited to the one shown in the figure, and all or part of them may be functionally or physically distributed / integrated in any unit according to various loads and usage conditions. Can be configured.

Further, various processing functions performed by each device are performed on a CPU (Central Processing Unit) (or a microcomputer such as an MPU (Micro Processing Unit) or an MCU (Micro Controller Unit)) in whole or in any part thereof. You may try to do it. Further, the various processing functions may be executed in whole or in any part on a program to be analyzed and executed by a CPU (or a microcomputer such as an MPU or MCU) or on hardware by wired logic. Needless to say.

1 Air conditioner 2 Outdoor unit 3 Indoor unit 11 Compressor 18 Control circuit 42 Acquisition unit 43 Detection unit 44 Storage unit 45 Control unit 61A First operating state quantity memory 61B Second operating condition quantity memory 62A Estimated model for cooling 62B Estimated model for heating

Claims (7)

An outdoor unit having a compressor, an outdoor heat exchanger and an expansion valve is provided with a refrigerant circuit formed by connecting an indoor unit having an indoor heat exchanger with a refrigerant pipe, and the refrigerant circuit is filled with a predetermined amount of refrigerant. It ’s an air conditioner
The air conditioner is
An acquisition unit that periodically acquires the amount of operating conditions during air-conditioned operation,
A storage unit that stores the operating state quantity acquired by the acquisition unit, and a storage unit.
An estimation model that estimates the amount of residual refrigerant remaining in the refrigerant circuit using the operating state amount, and an estimation model.
From the storage unit, a first operating state quantity, which is an operating state quantity in a state where the refrigerant circuit satisfies the first stabilizing condition, or a second stabilizing condition in which the refrigerant circuit is different from the first stabilizing condition. A detection unit that detects a second operating state amount, which is an operating state amount in a state that satisfies
A control unit that estimates the amount of residual refrigerant in the refrigerant circuit using the estimation model and the amount of operating state detected by the detection unit.
An air conditioner characterized by having. The air conditioner according to claim 1, wherein the second stabilizing condition is a condition relaxed from the first stabilizing condition. The control unit
When the number of detected first operating state quantities detected by the detection unit within a predetermined period is equal to or greater than a predetermined number, the residual refrigerant amount is estimated using the first operating state quantity and the estimation model. With
When the number of detected first operating state quantities detected by the detection unit within the predetermined period is less than the predetermined number, the residual refrigerant amount is estimated using the second operating condition amount and the estimation model. The air conditioner according to claim 1 or 2, wherein the air conditioner is characterized by the above. The detector is
The operation detected when the state in which the fluctuation of the rotation speed of the compressor is within the first predetermined range is a state in which the state is continued for the first predetermined period or more and the first stability condition is satisfied. The state quantity is defined as the first operating state quantity.
The state in which the fluctuation of the rotation speed of the compressor exceeds the first predetermined range and is within the second predetermined range continues for the first predetermined period or longer or the second predetermined period exceeding the first predetermined period. Any of claims 1 to 3, wherein the operating state amount detected when the second stability condition is satisfied is defined as the second operating state amount. The air conditioner described in one. The detector is
In addition to the first stability condition, in which the absolute value of the difference between the refrigerant discharge temperature of the compressor and the target discharge temperature is equal to or less than the predetermined value and continues for the first predetermined period or longer, the first stability condition is the same. The air conditioner according to claim 4, wherein the operating state amount detected when the stable condition is satisfied is set as the first operating state amount. The detector is
While detecting the first operating state quantity,
The air conditioner according to any one of claims 1 to 5, wherein the second operating state quantity is detected. The control unit
When the amount of the residual refrigerant is estimated using the second operating state amount and the estimation model at each predetermined timing, the average value of the residual refrigerant amount estimated at each predetermined timing within a predetermined period is set as the predetermined value. The air conditioner according to any one of claims 1 to 6, wherein the air conditioner is output as the amount of the residual refrigerant within the period.

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