Air conditioner, control method thereof and computer readable storage medium

Abstract

The invention provides an air conditioner, a control method thereof and a computer readable storage medium. The control method comprises the steps that when the air conditioner runs in a refrigeration mode, at least one set of actual measurement data of the indoor environment temperature, the indoor unit fan rotating speed and the fan power factor actual measurement value are obtained, and according to a pre-stored fitting function, the power factor fitting value corresponding to the indoor environment temperature and the fan rotating speed is calculated; determining a correction coefficient of the fitting function according to the relation between the power factor measured value and the power factor fitting value; the indoor environment temperature, the fan rotating speed and the power factor monitoring value of the fan of the indoor environment are obtained in real time, power factor fitting values corresponding to the indoor environment temperature and the fan rotating speed are calculated according to the fitting function, and the power factor fitting values are corrected into power factor correction values according to the correction coefficient; and the defrosting strategy of the air conditioner is determined according to the relation between the power factor monitoring value and the power factor correction value. The problems that frosting and freezing detection of an existing air conditioner is not accurate, and opportunities of shutdown defrosting are not reasonable are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an air conditioner and a control method thereof, and a computer-readable storage medium. Background Art

[0002] When existing air conditioners are operating in cooling mode, the indoor unit typically runs at low fan speeds when both the outdoor and indoor ambient temperatures are low. This degrades the heat exchange efficiency of the indoor unit's heat exchanger, leading to incomplete evaporation of the refrigerant, which may flow back into the compressor in a semi-liquid state, damaging it. This also reduces the compressor's suction pressure and evaporation temperature, causing the heat exchanger's evaporation temperature to drop below zero degrees Celsius, leading to frost or even ice. Severe frost and ice can completely block the heat exchanger with frozen water, resulting in a loss of cooling efficiency and even freezing the drain pan.

[0003] Therefore, the air conditioner needs to be shut down and defrosted at the appropriate time to remove frost and ice. Existing control schemes monitor the temperature of the indoor heat exchanger coils. When the coil temperature falls below a preset temperature, the air conditioner stops cooling and performs defrosting to prevent freezing. If this preset temperature is set too low, the air conditioner will be shut down and defrosted too late, causing severe frost on the indoor heat exchanger. The frost or ice layer may even extend to the drain pan, causing it to clog and overflow. If the preset temperature is set too high, the air conditioner will be shut down and defrosted too early, potentially shutting down the air conditioner when the indoor heat exchanger is lightly frosted or frost-free. This will cause the air conditioner to start and stop frequently, causing the indoor ambient temperature to fluctuate and compromising comfort. Summary of the Invention

[0004] An object of the present invention is to provide a method for controlling an air conditioner, an air conditioner, and a computer-readable storage medium that can overcome the above problems or at least partially solve the above problems.

[0005] The purpose of the present invention is to solve the problems of inaccurate frost and ice detection of existing air conditioners and unreasonable selection of the timing for stopping and defrosting.

[0006] In one aspect, the present invention provides a method for controlling an air conditioner, comprising:

[0007] When the air conditioner is in cooling operation, obtaining at least one set of measured data of the indoor ambient temperature, the fan speed of the indoor unit, and the fan power factor measured value, and calculating the power factor fitting value corresponding to the indoor ambient temperature and the fan speed according to a pre-stored fitting function;

[0008] Determining a correction coefficient of the fitting function according to a relationship between the measured power factor value and the fitted power factor value;

[0009] Acquiring the indoor ambient temperature, fan speed, and power factor monitoring values ​​of the indoor environment in real time, calculating the power factor fitting value corresponding to the indoor ambient temperature and fan speed according to the fitting function, and correcting the power factor fitting value to a power factor correction value according to the correction coefficient; and

[0010] A defrost strategy for the air conditioner is determined according to a relationship between the power factor monitoring value and the power factor correction value.

[0011] Optionally, “determining a correction coefficient of the fitting function according to a relationship between the measured value of the wind turbine power factor and the fitted value of the power factor” includes:

[0012] Determine whether (Py-P1) / Py, (Py-P2) / Py...(Py-Pn) / Py are all less than a preset deviation rate;

[0013] If so, set A=1;

[0014] If not, let A=1-B, B=((Py-P1) / Py+(Py-P2) / Py+...+(Py-Pn) / Py) / n;

[0015] Where A is the correction coefficient, B is the mean of the deviation rates, P1, P2, ..., Pn are the measured values ​​of the power factors, Py is the fitted value of the power factor, and n is the number of groups of measured data, where n ≥ 1.

[0016] Optionally, “correcting the power factor fitting value to a power factor correction value according to the correction coefficient” includes:

[0017] The power factor correction value P0 is calculated according to the following formula: P0 = A*Py.

[0018] Optionally, “determining a defrost strategy for the air conditioner according to a relationship between the power factor monitoring value and the power factor correction value” includes:

[0019] Each time the power factor monitoring value P is obtained, the attenuation ratio H thereof compared to the corresponding power factor correction value Py is calculated, where H=(P0-P) / P;

[0020] A defrost strategy for the air conditioner is determined according to the attenuation ratio.

[0021] Optionally, “determining a defrost strategy for the air conditioner according to the attenuation ratio” includes:

[0022] When the attenuation ratio H is greater than a preset first attenuation ratio and gradually increases, and the coil temperature of the indoor unit is lower than a second preset temperature, the air conditioner is controlled to operate in a defrost mode;

[0023] Continuously monitoring the attenuation ratio H;

[0024] When the attenuation ratio H is less than the preset second attenuation ratio and the coil temperature of the indoor unit is greater than a third preset temperature, the air conditioner is controlled to exit the defrost mode and return to the cooling mode.

[0025] Optionally, the defrost mode includes: shutting down the outdoor unit of the air conditioner and keeping the fan of the indoor unit running.

[0026] Optionally, the second preset temperature is less than 0°C, and the third preset temperature is greater than 0°C.

[0027] Optionally, “determining a defrost strategy for the air conditioner according to the attenuation ratio” further includes:

[0028] Calculate the duration of each defrost mode;

[0029] If the duration is less than the first preset time, increasing the value of the first attenuation ratio;

[0030] If the duration is greater than a second preset time, the value of the first attenuation ratio is reduced, and the second preset time is greater than or equal to the first preset time.

[0031] Optionally, the value of the first attenuation ratio is set between a lower limit value and an upper limit value.

[0032] Optionally, the air conditioner control method further includes keeping the value of the first attenuation ratio unchanged if the duration is greater than or equal to a first preset time and less than or equal to a second preset time, and the second preset time is greater than the first preset time.

[0033] Optionally, before “obtaining at least one set of measured data of the indoor ambient temperature, the fan speed of the indoor unit, and the power factor measured value of the fan, and calculating the power factor fitting value under the indoor ambient temperature and the fan speed according to a pre-stored fitting function”, the following is further included:

[0034] The coil temperature of the indoor unit is acquired in real time, and it is determined that the coil temperature is less than a first preset temperature.

[0035] Optionally, the power factor is the product of the wind turbine power and a preset coefficient.

[0036] On the other hand, the present invention also provides an air conditioner, comprising an indoor unit and a controller, the indoor unit having a fan, the controller comprising a memory and a processor, the memory storing a computer program, and the computer program being used to implement the control method according to any one of the above items when executed by the processor.

[0037] In another aspect, the present invention further provides a computer-readable storage medium storing a computer program, wherein the computer program implements any one of the control methods described above when executed by a processor.

[0038] In the air conditioner and its control method of the present invention, the inventors recognized that when the indoor unit heat exchanger is frosted or frozen, the indoor unit's fan resistance increases, the air volume decreases, and the fan power will decrease. Furthermore, the fan power is very sensitive to frost and ice. Based on this, the present invention incorporates fan power into the considerations of the air conditioner's defrost strategy. Before the air conditioner leaves the factory, the fitting function of the fan power factor, the indoor ambient temperature, and the fan speed is pre-tested and saved. By comparing the power factor monitoring value of the air conditioner during actual cooling operation in the user's room with the power factor correction value calculated based on the fitting function, the change in power factor is determined, and a reasonable defrost strategy is then formulated. This breaks through the drawback of most traditional solutions that only consider coil temperature, making the detection of frost and ice more accurate and the timing of stopping the unit for defrosting more reasonable, so that the situation of stopping the unit for defrosting too early or too late will not occur.

[0039] The air conditioner and its control method of the present invention not only take into account the influence of the fan speed on the fan power, but also particularly consider the influence of the indoor ambient temperature on the fan power, and incorporate the indoor ambient temperature into the fitting function, so that the calculated power factor fitting value is closer to the true value of the fan power factor when the air conditioner is actually running in a frost-free state, making the detection of frost and ice more accurate.

[0040] Moreover, the present invention does not simply decide whether to enter the shutdown defrosting time based on the comparison result between the power factor monitoring value and the calculated power factor fitting value, because the inventors realize that the fitting function is obtained by testing before the air conditioner leaves the factory. After the air conditioner leaves the factory, various environmental conditions including the ambient humidity are different, and the heat exchanger may also be dirty and blocked. These factors that appear later will cause the power factor calculated by the fitting function to deviate from the true value. Therefore, in the solution of the present invention, before the air conditioner determines the defrosting strategy, at least one set of data (indoor ambient temperature, indoor unit fan speed and fan power factor measured value) is retested, and the correction coefficient of the fitting function is determined based on the relationship between the power factor measured value and the power factor fitting value. In the later judgment, the power factor fitting value is corrected to the power factor correction value according to the correction coefficient. The corrected power factor correction value is closer to the true value, so that the detection of frost and ice can be adaptively adjusted to cope with different environmental conditions, and the detection results are more accurate and intelligent.

[0041] Furthermore, the air conditioner and its control method of the present invention incorporate the numerical value and change trend of the attenuation ratio of the power factor monitoring value compared to the power factor correction value and the indoor unit coil temperature into the judgment and determination factors of the defrost strategy, and the factors considered are more comprehensive and reasonable, close to the actual environmental conditions, and make the detection of frost and ice more accurate. In addition, the present invention reasonably adjusts the value of the subsequent first attenuation ratio according to the duration of the last defrost mode. When the duration is less than the first preset time, it indicates that the frosting is not serious, then the value of the first attenuation ratio is increased, and the threshold for entering the defrost mode next time is increased. If the duration is greater than the second preset time, it indicates that the frosting is more serious, then the value of the first attenuation ratio is increased, and the threshold for entering the defrost mode next time is lowered to avoid untimely defrosting. It can be seen that the present invention can timely and adaptively adjust the threshold for entering the defrost mode, so that the entry into the defrost mode is more in line with the actual needs of the air conditioner, and the timing of stopping for defrosting is more reasonable.

[0042] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0044] Figure 1 is a schematic diagram of a vapor compression refrigeration cycle system of an air conditioner according to one embodiment of the present invention;

[0045] Figure 2 is a schematic block diagram of an air conditioner according to an embodiment of the present invention;

[0046] Figure 3 is a schematic block diagram of a computer-readable storage medium according to one embodiment of the present invention;

[0047] Figure 4 is a schematic diagram of a method for controlling an air conditioner according to an embodiment of the present invention;

[0048] Figure 5 FIG. 1 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] Refer to the following Figures 1 to 5 The air conditioner and its control method and computer-readable storage medium according to the embodiments of the present invention are described.

[0050] The flowchart provided in this embodiment is not intended to indicate that the operations of the method will be performed in any particular order, or that all operations of the method are included in all every case. In addition, the method may include additional operations. Within the scope of the technical ideas provided by the method of this embodiment, additional changes can be made to the above method.

[0051] It should be noted here that the logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or equipment (such as a computer-based system, a system including a processor or other system that can fetch instructions from an instruction execution system, device or equipment and execute instructions), or used in combination with these instruction execution systems, devices or equipment.

[0052] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and the part of the module, program segment or instruction includes one or more executable instructions for realizing the logical function of the specification. In some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the function or action of the specification, or can be implemented with a combination of dedicated hardware and computer instructions.

[0053] An embodiment of the present invention provides an air conditioner for conditioning indoor air, including adjusting the temperature, humidity, and air quality of the air, humidifying and dehumidifying the indoor air, and introducing fresh air.

[0054] Figure 1 FIG. 1 is a schematic diagram of a vapor compression refrigeration cycle system of an air conditioner according to an embodiment of the present invention. Figure 1 Arrows indicate the flow of refrigerant during the refrigeration cycle.

[0055] like Figure 1As shown, the air conditioner of the embodiment of the present invention utilizes a vapor compression refrigeration cycle system for cooling and heating. The vapor compression refrigeration cycle system comprises a compressor 100, a four-way valve 600, an outdoor unit heat exchanger 500, a throttling device 400, an indoor unit heat exchanger 300, a gas-liquid separator 200, and other necessary components connected by piping. The operating principle of the vapor compression refrigeration cycle system is well known to those skilled in the art and will not be elaborated upon here.

[0056] The air conditioner in the embodiment of the present invention may be a household split-type air conditioner, a multi-split air conditioner or other forms. The embodiment of the present invention does not impose any limitation on the form of the air conditioner.

[0057] The air conditioner according to an embodiment of the present invention includes an indoor unit and an outdoor unit. A heat exchanger 500 is disposed within the outdoor unit. The outdoor unit also includes a fan 510 for promoting forced convection heat exchange between the outdoor air and the heat exchanger 500. An outdoor ambient temperature detection device 520 is used to detect the outdoor ambient temperature to assist in control. A heat exchanger 300 is disposed within the indoor unit. The indoor unit also includes a fan 310 for promoting forced convection heat exchange between the indoor air and the heat exchanger 300. Cooling and heating the indoor environment are achieved by outputting cold / hot air through the fan 310. The indoor ambient temperature detection device 320 is used to detect the indoor ambient temperature. The indoor unit coil temperature detection device 330 is used to detect the coil temperature of the heat exchanger 300.

[0058] Figure 2 is a schematic block diagram of an air conditioner according to an embodiment of the present invention.

[0059] like Figure 2 As shown, the air conditioner according to the embodiment of the present invention further includes a controller 800. The controller 800 is electrically connected to the compressor 100, the fan 310, the throttling device 400, the four-way valve 600, the outdoor ambient temperature detection device 520, the outdoor ambient temperature detection device 520, and the indoor unit coil temperature detection device 330 to implement relevant control functions.

[0060] The controller 800 includes a processor 810 and a memory 820 . The memory 820 stores a computer program 821 . When the computer program 821 is executed by the processor 810 , it is used to implement the air conditioner control method according to any of the following embodiments of the present invention.

[0061] The processor 810 can be a central processing unit (CPU), a digital processing unit, or the like. The processor 810 sends and receives data via a communication interface. The memory 820 is used to store programs executed by the processor 810. The memory 820 is any medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, and can also be a combination of multiple memories. The above-mentioned computer program 821 can be downloaded from a computer-readable storage medium to a corresponding computing / processing device or downloaded and installed to the controller 800 via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network).

[0062] An embodiment of the present invention also provides a computer-readable storage medium.

[0063] Figure 3 is a schematic block diagram of a computer-readable storage medium according to an embodiment of the present invention.

[0064] like Figure 3 As shown, the computer-readable storage medium 700 of the embodiment of the present invention stores a computer program 821, and when the computer program 821 is executed, the device where the computer-readable storage medium 700 is located executes the air conditioner control method of any embodiment of the present invention.

[0065] The computer-readable storage medium 700 of the embodiment of the present invention can be an electronic memory such as a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), an EPROM, a hard disk, or a ROM. The computer-readable storage medium 700 has storage space for a computer program 821 for executing any method steps in the air conditioner control method according to the embodiment of the present invention. These computer programs 821 can be read from or written to one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disk (CD), a memory card, or a floppy disk. When the device containing the computer-readable storage medium 700 runs the computer program 821, the various steps of the method described in the present invention can be executed.

[0066] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0067] An embodiment of the present invention further provides a method for controlling an air conditioner.

[0068] The air conditioner is any of the above embodiments of the present invention. The control method of any embodiment of the present invention is described from the perspective of the controller 800, that is, the controller 800 executes the relevant steps of the control method, which will not be emphasized below.

[0069] Figure 4 FIG. 4 is a schematic diagram of a method for controlling an air conditioner according to an embodiment of the present invention.

[0070] like Figure 4 As shown, the air conditioner control method according to the embodiment of the present invention may generally include the following steps:

[0071] Step S402: When the air conditioner is in cooling operation, obtain at least one set of measured data including the indoor ambient temperature, the fan speed of the indoor unit fan 310, and the fan power factor measured value, and calculate the power factor fitting value corresponding to the indoor ambient temperature and the fan speed according to a pre-stored fitting function.

[0072] Step S404: determining a correction coefficient of the fitting function according to the relationship between the measured power factor value and the fitted power factor value.

[0073] Step S406: Acquire the indoor ambient temperature, fan speed and power factor monitoring value of the indoor environment in real time, calculate the power factor fitting value corresponding to the indoor ambient temperature and fan speed according to the fitting function, and correct the power factor fitting value to the power factor correction value according to the correction coefficient.

[0074] Step S408: determining the defrost strategy of the air conditioner according to the relationship between the power factor monitoring value and the power factor correction value.

[0075] In step S402, the air conditioner cooling operation refers to the cooling operation of the air conditioner when it is actually operating in the user's room. The indoor ambient temperature is detected by the indoor ambient temperature detection device 320. The air conditioner may obtain the measured values ​​of the indoor ambient temperature, fan speed, and fan power factor only once, or may obtain the measured values ​​of the indoor ambient temperature, fan speed, and fan power factor multiple times, for example, every preset time interval (e.g., 1 second, 2 seconds, etc.). Each time the three parameters are obtained, the measured values ​​of the indoor ambient temperature, fan speed, and fan power factor constitute a set of data.

[0076] The controller 800 or the cloud platform has a pre-stored fitting function. This fitting function is tested and saved before the air conditioner leaves the factory. Specifically, the fitting function represents the relationship between the power factor and the indoor ambient temperature and fan speed, assuming the heat exchanger 300 of the indoor unit is free of frost and ice. The power factor is the dependent variable, and the indoor ambient temperature and fan speed are the independent variables. Substituting the indoor ambient temperature and fan speed data into the fitting function yields the power factor calculated, which is called the fitted power factor value.

[0077] Step S404 is used to correct the fitting function. The reason for the correction is that the inventors realize that the fitting function is obtained by testing before the air conditioner leaves the factory. After the air conditioner leaves the factory, various environmental conditions including ambient humidity are different, and the heat exchanger may also accumulate dirt and blockage. These factors that appear later will cause the power factor calculated by the fitting function to deviate from the true value. Therefore, in an embodiment of the present invention, before the air conditioner determines the defrost strategy, at least one set of data is retested (each set of data includes the indoor ambient temperature, the fan speed of the indoor unit and the actual value of the fan power factor), and the correction coefficient of the fitting function is determined based on the relationship between the actual value of the power factor and the fitted value of the power factor. During the later judgment, the power factor fitting value is corrected to the power factor correction value according to the correction coefficient. The corrected power factor correction value is closer to the true power factor of the air conditioner in the frost-free state under the conditions of the indoor ambient temperature and fan speed, making the detection of frost and ice more accurate. The present invention can adaptively adjust the fitting function to cope with different environments and working conditions, and the detection results are more accurate and intelligent.

[0078] In the section "Determining a correction coefficient for the fitting function based on the relationship between the measured power factor value and the fitted power factor value," the specific method for determining the correction coefficient can be determined at the discretion of the technician. For example, when the measured power factor value is greater than the fitted power factor value, a correction coefficient greater than 1 can be determined and the fitted power factor value can be multiplied by this coefficient to appropriately amplify the fitted power factor value and obtain the corrected power factor value. When the measured power factor value is less than the fitted power factor value, a correction coefficient less than 1 can be determined and the fitted power factor value can be multiplied by this coefficient to appropriately reduce the fitted power factor value and obtain the corrected power factor value.

[0079] In step S406, the indoor environment temperature, fan speed and power factor monitoring values ​​are obtained multiple times in a row, for example, once every 10 seconds.

[0080] In step S408, the air conditioner's defrost strategy is determined based on the relationship between the power factor monitoring value and the power factor correction value. Frost or ice on the indoor unit heat exchanger 300 increases the wind resistance of the fan 310, reduces air volume, and therefore reduces power. Therefore, when the power factor monitoring value is less than the power factor correction value and the difference reaches a certain level sufficient to eliminate interference from other factors, it is sufficient to determine that the heat exchanger 300 is frosted or frozen, and the air conditioner can enter defrost mode. Otherwise, it indicates that the heat exchanger 300 is not frosted or frozen, or the condition is not severe, and defrost mode is not required.

[0081] In some embodiments, the power factor is the product of the fan power and a preset coefficient. The preset coefficient can be 2, 4, 10, 15, 20, and so on. This configuration makes the power factor larger than the power, making it easier to intuitively reflect power changes when comparing numerical values. In other embodiments, fan power can be converted into a power factor through other methods to achieve the purpose of amplifying the value. Of course, the preset coefficient can also be 1.

[0082] In the embodiment of the present invention, the inventors recognized that when the indoor unit heat exchanger 300 is frosted or iced, the wind resistance of the indoor unit fan 310 increases, the air volume decreases, and the power will decrease. Power is very sensitive to frost and ice. Based on this, the embodiment of the present invention incorporates fan power into the consideration of the air conditioner defrost strategy. Before the air conditioner leaves the factory, a fitting function of the fan power factor, the indoor ambient temperature, and the fan speed is pre-tested and saved. By comparing the power factor monitoring value of the air conditioner during actual cooling operation in the user's room with the power factor correction value calculated according to the fitting function, the change in power factor is determined, and then a reasonable defrost strategy is formulated. This overcomes the drawback of most traditional solutions that only consider coil temperature, making the detection of frost and ice more accurate and the timing of stopping the air conditioner for defrosting more reasonable, so that the situation of stopping the air conditioner for defrosting too early or too late will not occur.

[0083] The embodiment of the present invention not only takes into account the influence of the fan speed on the fan power, but also specifically considers the influence of the indoor ambient temperature on the fan power, and incorporates the indoor ambient temperature into the fitting function, so that the calculated power factor fitting value is closer to the true value of the fan power factor when the air conditioner is actually running in a frost-free state, making the detection of frost and ice more accurate.

[0084] Moreover, the embodiment of the present invention does not simply decide whether to enter the shutdown defrosting time based on the comparison result between the power factor monitoring value and the calculated power factor fitting value, because the inventors realize that the fitting function is obtained by testing before the air conditioner leaves the factory. After the air conditioner leaves the factory, various environmental conditions including ambient humidity are different, and the heat exchanger 300 may also accumulate dirt and blockage. These factors that appear later will cause the power factor calculated by the fitting function to deviate from the true value. Therefore, in the embodiment of the present invention, before the air conditioner determines the defrosting strategy, at least one set of data (indoor ambient temperature, indoor unit fan speed and fan power factor measured value) is retested, and the correction coefficient of the fitting function is determined based on the relationship between the power factor measured value and the power factor fitting value. In the later judgment, the power factor fitting value is corrected to the power factor correction value according to the correction coefficient. The corrected power factor correction value is closer to the true value, so that the detection of frost and ice can be adaptively adjusted to cope with different environments and working conditions, and the detection results are more accurate and intelligent.

[0085] In some embodiments, the aforementioned step S402, i.e., the step of "obtaining at least one set of measured data of the indoor ambient temperature, the fan speed of the indoor unit, and the power factor measured value of the fan, and calculating the power factor fitting value under the indoor ambient temperature and fan speed according to a pre-stored fitting function", also includes: obtaining the coil temperature of the indoor unit in real time, and determining that the coil temperature is less than the first preset temperature.

[0086] Specifically, statistical data on the coil temperature at the onset of frosting can be determined experimentally to determine a reasonable value for the first preset temperature. When the coil temperature is greater than or equal to the first preset temperature, it indicates that the risk of frosting or icing on the heat exchanger 300 is low, and the frosting or icing determination steps (steps S404-S406) are not required, thereby reducing the number of invalid determinations. The first preset temperature can be a value such as 1°C, 0°C, or -1°C, and can be determined experimentally.

[0087] In some embodiments, the aforementioned step S404, i.e., "determining a correction coefficient of the fitting function based on the relationship between the actual measured value of the wind turbine power factor and the fitted value of the power factor," may specifically include:

[0088] Determine whether (Py-P1) / Py, (Py-P2) / Py...(Py-Pn) / Py are all less than a preset deviation rate;

[0089] If so, set A=1;

[0090] If not, let A=1-B, B=((Py-P1) / Py+(Py-P2) / Py+...+(Py-Pn) / Py) / n.

[0091] Where A is the correction coefficient, B is the mean of the deviation rates, P1, P2, ..., Pn are the measured values ​​of the power factors, Py is the fitted value of the power factor, and n is the number of groups of measured data, where n ≥ 1.

[0092] The steps of “correcting the power factor fitting value to the power factor correction value according to the correction coefficient” include:

[0093] The power factor correction value P0 is calculated according to the following formula: P0 = A*Py.

[0094] In the above steps, (Py-P1) / Py indicates the deviation rate of P1 compared to Py, reflecting the degree of deviation of P1 compared to Py. Similarly, the same is true for (Py-P2) / Py and even (Py-Pn) / Py. The aforementioned preset deviation rate is the maximum tolerable deviation preset by the system. When (Py-P1) / Py is less than the preset deviation rate, it indicates that the deviation of P1 compared to Py is small enough, and it is considered to be a measurement error rather than a deviation caused by working conditions or humidity. Therefore, A=1, that is, P0=Py. The preset deviation rate can be set to reasonable values ​​such as 1%, 2%, 3%, 4%, etc., and can be reasonably set according to experiments. When the deviation rate of (Py-P1) / Py, (Py-P2) / Py...(Py-Pn) / Py is greater than or equal to the preset deviation rate at least once, it is considered that the deviation is indeed caused by the difference between the current environmental conditions and the air conditioner when it leaves the factory. Py needs to be corrected so that A=1-B, B=((Py-P1) / Py+(Py-P2) / Py+...+(Py-Pn) / Py) / n, and B is the average of each deviation rate. Taking into account the results of multiple tests, the obtained A value is more reasonable.

[0095] In some embodiments, the aforementioned step S408, i.e., "determining the defrost strategy of the air conditioner according to the relationship between the power factor monitoring value and the power factor correction value," may specifically include:

[0096] Each time the power factor monitoring value P is obtained, its attenuation ratio H compared to the corresponding power factor correction value Py is calculated, where H = (P0-P) / P; the defrost strategy of the air conditioner is determined based on the attenuation ratio.

[0097] As previously mentioned, when frosting or ice forms on heat exchanger 300, the wind resistance of fan 310 increases, air volume decreases, and power is reduced. Therefore, a larger attenuation ratio H indicates more severe frost or ice formation. Taking the attenuation ratio H into account when developing a defrost strategy—that is, factoring in the degree of frost or ice formation—can lead to a more efficient defrost strategy.

[0098] For example, "Determining the defrost strategy of the air conditioner based on the attenuation ratio" includes:

[0099] When the attenuation ratio H is greater than a preset first attenuation ratio and gradually increases, and the indoor unit's coil temperature is less than a second preset temperature, the air conditioner is controlled to enter defrost mode. While in defrost mode, the attenuation ratio is continuously monitored. When the attenuation ratio H is less than a preset second attenuation ratio and the indoor unit's coil temperature is greater than a third preset temperature, the air conditioner exits defrost mode and returns to cooling mode. Otherwise, defrost mode remains in effect.

[0100] In this step, if the decay ratio H is greater than the preset first decay ratio, it indicates that H is sufficiently large, and H is gradually increasing, indicating that frost or ice formation is ongoing and defrosting is necessary. The first decay ratio can be reasonably determined based on experiments and can be set to 9%, 10%, 11%, etc. The second preset temperature is less than 0°C, because the risk of frost or ice formation is greater below 0°C. The specific value can be reasonably determined based on experiments, for example, it can be set to -11°C, -10°C, -9°C, etc.

[0101] The defrost mode may specifically include shutting down the outdoor unit of the air conditioner to stop cooling and achieve defrost. Simultaneously, the indoor unit's fan 310 remains in operation to accelerate defrost. Of course, active heating of the heat exchanger 300 may also be employed in defrost mode to achieve defrost, but details will not be repeated here.

[0102] In this step, if the decay ratio H is less than the second decay ratio, it indicates that it is sufficiently small. Furthermore, the coil temperature is sufficiently high, indicating that the frost layer has essentially disappeared, and therefore, cooling mode can be re-entered. The second decay ratio can be determined experimentally and can be set to 1%, 2%, 3%, etc. The third preset temperature is greater than 0°C, as temperatures above 0°C indicate a low probability of freezing of the heat exchanger 300. The specific value can be determined experimentally and can be set to, for example, 4°C, 5°C, 6°C, etc.

[0103] The embodiment of the present invention incorporates the numerical value and change trend of the attenuation ratio of the power factor monitoring value compared to the power factor correction value and the indoor unit coil temperature into the determination factors of the defrost strategy. The factors considered are more comprehensive and reasonable, closer to the actual working conditions, and the detection of frost and ice is more accurate.

[0104] In some embodiments, “determining a defrost strategy for an air conditioner according to a decay ratio” further includes:

[0105] Calculate the duration of each defrost mode;

[0106] If the duration is less than the first preset time, the value of the first attenuation ratio is increased. If the duration is greater than the second preset time, the value of the first attenuation ratio is decreased, and the second preset time is greater than or equal to the first preset time.

[0107] In this step, after the current defrost mode ends, the system continues to obtain the power factor monitoring value P and the power factor correction value Py, calculates the decay ratio H, and compares the decay ratio H with the first decay ratio to determine whether to enter defrost mode a second time. The first decay ratio at this point is the value corrected in the previous step. Similarly, during the second defrost mode, the duration is calculated and the first decay ratio is further corrected based on the duration. Of course, the first decay ratio is kept between a lower limit and an upper limit. Once the first decay ratio correction reaches the lower limit or upper limit, no further correction is made to avoid overcorrection. The lower and upper limits can be reasonably determined based on experimental results. Specifically, the lower limit can be 5%, 6%, or 7%, while the upper limit can be 15%, 16%, or 17%. The values ​​of the first and second preset times can also be reasonably determined based on experimental results. For example, the first preset time can be 2 minutes, 3 minutes, 4 minutes, or 5 minutes, and the second preset time can be 19 minutes, 20 minutes, or 21 minutes, etc.

[0108] Furthermore, the second preset time may be greater than the first preset time. Thus, in the aforementioned steps, if the duration is greater than or equal to the first preset time and less than or equal to the second preset time, the value of the first attenuation ratio remains unchanged.

[0109] The embodiment of the present invention rationally adjusts the value of the subsequent first attenuation ratio based on the duration of the previous defrost mode. If the duration is less than a first preset time, indicating that frosting is not severe, the value of the first attenuation ratio is increased, raising the threshold for entering the defrost mode next time. If the duration is greater than a second preset time, indicating that frosting is severe, the value of the first attenuation ratio is increased, lowering the threshold for entering the defrost mode next time, thereby preventing untimely defrosting. The present invention can timely and adaptively adjust the threshold for entering the defrost mode, ensuring that entry into the defrost mode is more in line with the actual needs of the air conditioner and that the timing of defrosting during shutdown is more reasonable.

[0110] In some optional embodiments, higher technical effects can be achieved by further optimizing and configuring the above steps. The control method of the embodiment of the present invention is described in detail below in combination with an introduction to an optional execution process of the embodiment of the present invention. This embodiment is only an example of the execution process. During specific implementation, the execution order and operating conditions of some steps can be modified according to specific implementation requirements.

[0111] Figure 5 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present invention;

[0112] like Figure 5 As shown, a method for controlling an air conditioner according to a preferred embodiment of the present invention sequentially performs the following steps:

[0113] Step S502: The air conditioner operates in cooling mode.

[0114] Step S504: Acquire the indoor coil temperature.

[0115] Step S506: Determine whether the coil temperature is less than the first preset temperature. If so, proceed to step S508. If not, return to step S504.

[0116] Step S508: obtaining at least one set of measured data of the indoor ambient temperature, the fan speed of the indoor unit and the fan power factor measured value, and calculating the power factor fitting value corresponding to the indoor ambient temperature and the fan speed according to a pre-stored fitting function.

[0117] Step S510: Determine whether (Py-P1) / Py, (Py-P2) / Py ... (Py-Pn) / Py are all less than a predetermined deviation rate. If so, proceed to step S512. If not, proceed to step S514.

[0118] Step S512: Set A=1, and then execute step S516.

[0119] Step S514: Let A=1-B, B=((Py-P1) / Py+(Py-P2) / Py+...+(Py-Pn) / Py) / n, and then execute step S516.

[0120] Step S516: Calculate the power factor correction value P0: P0 = A*Py.

[0121] Step S518: Acquire the indoor environment temperature, fan speed and fan power factor monitoring value P in real time.

[0122] Step S520: After each power factor monitoring value P is obtained, the attenuation ratio H thereof compared to the corresponding power factor correction value Py is calculated, where H=(P0-P) / P.

[0123] Step S522: Determine whether the attenuation ratio H is greater than the first attenuation ratio and gradually increases, and whether the coil temperature is less than the second preset temperature. If so, proceed to step S524. If not, return to step S518.

[0124] Step S524: Run the defrost mode and continuously monitor the attenuation ratio H.

[0125] Step S526: Determine whether the attenuation ratio H is less than the second attenuation ratio and the coil temperature is greater than the third preset temperature. If so, proceed to step S528. If not, return to step S524.

[0126] Step S528: Exit the defrost mode, and then continue to execute step S502 to run the cooling mode.

[0127] Further details of the above steps have been introduced above and will not be repeated here.

[0128] At this point, those skilled in the art will recognize that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A method for controlling an air conditioner, comprising: When the air conditioner is in cooling operation, obtaining at least one set of measured data of the indoor ambient temperature, the fan speed of the indoor unit, and the fan power factor measured value, and calculating the power factor fitting value corresponding to the indoor ambient temperature and the fan speed according to a pre-stored fitting function; Determining a correction coefficient of the fitting function according to a relationship between the measured power factor value and the fitted power factor value; Acquire the indoor ambient temperature, fan speed, and power factor monitoring values ​​of the indoor environment in real time, calculate the power factor fitting value corresponding to the indoor ambient temperature and fan speed according to the fitting function, and correct the power factor fitting value to a power factor correction value according to the correction coefficient; as well as A defrost strategy for the air conditioner is determined according to a relationship between the power factor monitoring value and the power factor correction value.

2. The air conditioner control method according to claim 1, wherein "determining the correction coefficient of the fitting function based on the relationship between the measured value of the fan power factor and the fitted value of the power factor" comprises: Determine whether (Py-P1) / Py, (Py-P2) / Py...(Py-Pn) / Py are all less than a preset deviation rate; If so, set A=1; If not, let A=1-B, B=((Py-P1) / Py+(Py-P2) / Py+...+(Py-Pn) / Py) / n; Where A is the correction coefficient, B is the mean of the deviation rates, P1, P2, ..., Pn are the measured values ​​of the power factors, Py is the fitted value of the power factor, and n is the number of groups of measured data, where n ≥ 1.

3. The air conditioner control method according to claim 2, wherein "correcting the power factor fitting value to a power factor correction value according to the correction coefficient" comprises: The power factor correction value P0 is calculated according to the following formula: P0 = A*Py.

4. The air conditioner control method according to claim 1, wherein "determining the defrost strategy of the air conditioner according to the relationship between the power factor monitoring value and the power factor correction value" comprises: Each time the power factor monitoring value P is obtained, the attenuation ratio H thereof compared to the corresponding power factor correction value Py is calculated, where H=(P0-P) / P; A defrost strategy for the air conditioner is determined according to the attenuation ratio.

5. The air conditioner control method according to claim 4, wherein "determining the defrost strategy of the air conditioner according to the attenuation ratio" comprises: When the attenuation ratio H is greater than a preset first attenuation ratio and gradually increases, and the coil temperature of the indoor unit is lower than a second preset temperature, the air conditioner is controlled to operate in a defrost mode; Continuously monitoring the attenuation ratio H; When the attenuation ratio H is less than the preset second attenuation ratio and the coil temperature of the indoor unit is greater than a third preset temperature, the air conditioner is controlled to exit the defrost mode and return to the cooling mode.

6. The air conditioner control method according to claim 5, wherein The defrost mode includes: Stop the outdoor unit of the air conditioner and keep the fan of the indoor unit running.

7. The air conditioner control method according to claim 5, wherein The second preset temperature is lower than 0°C, and the third preset temperature is higher than 0°C.

8. The air conditioner control method according to claim 5, wherein "determining the defrost strategy of the air conditioner according to the attenuation ratio" further comprises: Calculate the duration of each defrost mode; If the duration is less than the first preset time, increasing the value of the first attenuation ratio; If the duration is greater than a second preset time, the value of the first attenuation ratio is reduced, and the second preset time is greater than or equal to the first preset time.

9. The air conditioner control method according to claim 8, wherein The value of the first attenuation ratio is set between a lower limit and an upper limit.

10. The air conditioner control method according to claim 8, further comprising: If the duration is greater than or equal to the first preset time and less than or equal to the second preset time, the value of the first attenuation ratio remains unchanged, and the second preset time is greater than the first preset time.

11. The air conditioner control method according to claim 1, wherein before "obtaining at least one set of measured data of the indoor ambient temperature, the fan speed of the indoor unit, and the power factor of the fan, and calculating the power factor fitting value under the indoor ambient temperature and the fan speed according to a pre-stored fitting function", the method further comprises: The coil temperature of the indoor unit is acquired in real time, and it is determined that the coil temperature is less than a first preset temperature.

12. The air conditioner control method according to claim 1, wherein The power factor is the product of the fan power and a preset coefficient.

13. An air conditioner comprising an indoor unit and a controller, wherein the indoor unit has a fan, and the controller comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it is used to implement the control method according to any one of claims 1 to 12. 14 . A computer-readable storage medium storing a computer program, wherein the computer program implements the control method according to claim 1 when executed by a processor.

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