Rotating speed control method and device of inverter compressor, drying equipment and storage medium

Abstract

The invention relates to the technical field of household appliances, particularly provides a rotating speed control method and device of an inverter compressor, drying equipment and a storage medium, and aims at solving the technical problem that an existing heat pump washing and protecting integrated machine is low in drying effect. In order to achieve the purpose, the rotating speed control method of the inverter compressor comprises the steps that the operation duration of the inverter compressor and the mapping relation between the rotating speed and the operation duration of the inverter compressor are obtained; determining a first rotating speed of the inverter compressor based on the operation duration and a rotating speed-operation duration mapping relation; and controlling the inverter compressor to operate according to the first speed. In this way, the drying effect of the drying equipment is improved, and the use experience of a user is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and specifically provides a speed control method and device for a variable frequency compressor, a drying device and a storage medium. Background Art

[0002] At present, the variable frequency compressor of the heat pump washer-dryer will face different ambient temperatures when in use. Low temperature environment will cause refrigerant liquid shock, and high temperature environment will cause system overheating, which may damage the heat exchange system, resulting in poor drying effect and poor user experience.

[0003] Accordingly, the art requires a new speed control solution for a variable frequency compressor to solve the above problems. Summary of the invention

[0004] In order to overcome the above defects, the present invention is proposed to solve or at least partially solve the above technical problems. The present invention provides a speed control method, device, drying equipment and storage medium for a variable frequency compressor.

[0005] In a first aspect, the present invention provides a method for controlling the speed of a variable frequency compressor, which is applied to a drying device, and the method comprises:

[0006] Acquire the operation time of the variable frequency compressor and the mapping relationship between the rotation speed and the operation time of the variable frequency compressor;

[0007] Determine a first speed of the variable frequency compressor based on the operating time and the mapping relationship between the speed and the operating time;

[0008] The variable frequency compressor is controlled to operate at the first speed.

[0009] In one embodiment, the mapping relationship is a quadratic equation;

[0010] The mapping relationship between the speed and the running time of the variable frequency compressor is obtained based on the following steps:

[0011] Establishing a quadratic equation of the speed of the variable frequency compressor with respect to the running time, wherein the equation includes at least a first coefficient;

[0012] fitting a curve of the first coefficient of the quadratic equation;

[0013] Collect the current ambient temperature;

[0014] The first coefficient is determined based on a curve of the ambient temperature and the first coefficient.

[0015] In one embodiment, the mapping relationship between the speed and the running time of the variable frequency compressor is:

[0016] RPM = ax 2 +bx+c

[0017] Wherein, RPM is the rotation speed, a is the second coefficient, b is the first coefficient, c is the initial rotation speed of the variable frequency compressor, and x is the operating time of the variable frequency compressor.

[0018] In one embodiment, the curve fitting the first coefficient of the quadratic equation includes:

[0019] collecting the optimal frequency increase of the variable frequency compressor under different ambient temperatures;

[0020] A least square method is used to fit a curve of the first coefficient based on the optimal up-conversion frequency.

[0021] In a specific embodiment, the drying device further includes a condenser; after the variable frequency compressor runs at the first speed for a preset period of time, the method further includes:

[0022] Obtaining a first outlet air temperature of the condenser;

[0023] Determining whether the first air outlet temperature reaches a first temperature threshold;

[0024] If so, the drying device is controlled to enter a constant temperature stage, and the first speed of the variable frequency compressor is adjusted to a second speed, wherein the second speed is less than the first speed.

[0025] In a specific embodiment, when the drying device is in a constant temperature stage, the method further comprises:

[0026] Obtaining a second air outlet temperature of the condenser;

[0027] determining whether the second air outlet temperature exceeds a second temperature threshold;

[0028] If so, the second speed of the variable frequency compressor is adjusted to a third speed, wherein the third speed is less than the second speed.

[0029] In a specific embodiment, when the drying device is in a constant temperature stage, the method further comprises:

[0030] Detecting the exhaust temperature at the outlet of the variable frequency compressor;

[0031] Determining whether the exhaust temperature at the outlet of the variable frequency compressor exceeds a third temperature threshold;

[0032] If so, the second speed of the variable frequency compressor is adjusted to a fourth speed, wherein the fourth speed is less than the second speed.

[0033] In a second aspect, the present invention provides a speed control device for a variable frequency compressor, the device comprising:

[0034] An acquisition module, the acquisition module is configured to acquire the operation time of the variable frequency compressor and the mapping relationship between the rotation speed and the operation time of the variable frequency compressor;

[0035] a determination module, the determination module being configured to determine the rotation speed of the variable frequency compressor based on the operation duration and the mapping relationship between the rotation speed and the operation duration;

[0036] A control module is configured to control the variable frequency compressor to operate at the rotation speed.

[0037] In a third aspect, a drying device is provided, which includes at least one processor and at least one storage device, wherein the storage device is suitable for storing multiple program codes, and the program codes are suitable for being loaded and run by the processor to execute the speed control method of the variable frequency compressor described in any one of the above.

[0038] In a fourth aspect, a computer-readable storage medium is provided, wherein a plurality of program codes are stored in the computer-readable storage medium, wherein the program codes are suitable for being loaded and run by a processor to execute any of the aforementioned methods for controlling the speed of a variable frequency compressor.

[0039] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0040] The present invention provides a speed control method for a variable frequency compressor, which specifically includes: obtaining the operation time of the variable frequency compressor and the mapping relationship between the speed of the variable frequency compressor and the operation time; determining the first speed of the variable frequency compressor based on the mapping relationship between the operation time and the speed-operation time; and controlling the variable frequency compressor to operate at the first speed. In this way, the speed of the variable frequency compressor can be accurately controlled according to the operation time of the compressor, thereby protecting the heat exchange system, improving the drying effect of the drying equipment, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In addition, similar numbers in the figures are used to represent similar components, among which:

[0042] Figure 1 1 is a flow chart of main steps of a method for controlling the speed of a variable frequency compressor according to an embodiment of the present invention;

[0043] Figure 2It is a schematic diagram of the main structural block diagram of a speed control device for a variable frequency compressor according to an embodiment of the present invention;

[0044] Figure 3 Schematic diagram of the structure of a drying device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] Some embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0046] In the description of the present invention, "module" and "processor" may include hardware, software or a combination of the two. A module may include hardware circuits, various suitable sensors, communication ports, and memories, and may also include software parts, such as program codes, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing functions. The processor may be implemented in software, hardware, or a combination of the two. Non-temporary computer-readable storage media include any suitable medium that can store program codes, such as a magnetic disk, a hard disk, an optical disk, a flash memory, a read-only memory, a random access memory, and the like. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and / or B", and may include only A, only B, or A and B. The singular terms "one" and "the" may also include plural forms.

[0047] At present, the variable frequency compressor of traditional heat pump washer-dryers will face different ambient temperatures when in use. Low temperature environment will cause refrigerant liquid shock, and high temperature environment will cause system overheating, which may damage the heat exchange system, resulting in poor drying effect and poor user experience.

[0048] To this end, the present application provides a speed control method, device, drying equipment and storage medium for a variable frequency compressor, specifically including: obtaining the operating time of the variable frequency compressor and the mapping relationship between the speed of the variable frequency compressor and the operating time; determining the first speed of the variable frequency compressor based on the mapping relationship between the operating time and the speed-operating time; and controlling the variable frequency compressor to operate at the first speed. In this way, the speed of the variable frequency compressor can be accurately controlled according to the operating time of the compressor and the current ambient temperature, thereby protecting the heat exchange system, improving the drying effect of the drying equipment, and improving the user experience.

[0049] The speed control method of the variable frequency compressor of the present application is mainly applied to drying equipment, wherein a heat pump washing and care machine can be used as an example of the drying equipment, but is not limited thereto.

[0050] The existing heat pump washing and care machine includes a heat exchange system, which includes at least a condenser, an evaporator and a heat exchange element, etc. This is common knowledge in the field and will not be elaborated here.

[0051] See attached Figure 1 , Figure 1 1 is a flow chart of main steps of a method for controlling the speed of a variable frequency compressor according to an embodiment of the present invention.

[0052] like Figure 1 As shown, the speed control method of the variable frequency compressor in the embodiment of the present invention mainly includes the following steps S100 to S300.

[0053] Step S100: acquiring the operation time of the variable frequency compressor and the mapping relationship between the rotation speed and the operation time of the variable frequency compressor.

[0054] Step S200: determining a first speed of the variable frequency compressor based on the operation duration and the mapping relationship between the speed and the operation duration.

[0055] Step S300: controlling the variable frequency compressor to operate at the first speed.

[0056] Based on the above steps S100 to S300, the method includes: obtaining the operation time of the variable frequency compressor and the mapping relationship between the speed of the variable frequency compressor and the operation time; determining the first speed of the variable frequency compressor based on the mapping relationship between the operation time and the speed-operation time; and controlling the variable frequency compressor to operate at the first speed. In this way, the speed of the variable frequency compressor can be accurately controlled according to the operation time of the compressor and the current ambient temperature, thereby protecting the heat exchange system, improving the drying effect of the drying equipment, and improving the user experience.

[0057] The above steps S100 to S300 are further explained below.

[0058] In a specific implementation, the mapping relationship is a quadratic equation; specifically, the mapping relationship between the speed and the running time of the variable frequency compressor can be obtained through the following steps S101-S104:

[0059] Step S101: establishing a quadratic equation of the rotation speed of the variable frequency compressor with respect to the running time, wherein the equation includes at least a first coefficient.

[0060] A quadratic equation can be used as an example of a mapping relationship, but is not limited thereto.

[0061] Specifically, the mapping relationship between the speed of the variable frequency compressor and the running time is a quadratic equation of the speed of the variable frequency compressor with respect to the running time of the variable frequency compressor.

[0062] In a specific implementation, the mapping relationship between the speed and the running time of the variable frequency compressor is:

[0063] RPM = ax 2 +bx+c

[0064] Wherein, RPM is the rotation speed, a is the second coefficient, b is the first coefficient, c is the initial rotation speed of the variable frequency compressor, and x is the operating time of the variable frequency compressor.

[0065] Specifically, the second coefficient a, the first coefficient b and the coefficient c are all polynomial coefficients of a quadratic equation, wherein the second coefficient a is a constant. In a specific embodiment, the preferred value of a is -1.84. The first coefficient b is a coefficient obtained after fitting, which is a variable related to the current ambient temperature. The polynomial coefficient c is the initial speed or the minimum speed of the variable frequency compressor.

[0066] Step S102: fitting a curve of the first coefficient of the quadratic equation.

[0067] In a specific embodiment, the curve fitting the first coefficient of the quadratic equation includes:

[0068] collecting the optimal frequency increase of the variable frequency compressor under different ambient temperatures;

[0069] A least square method is used to fit a curve of the first coefficient based on the optimal up-conversion frequency.

[0070] The optimum frequency of the frequency increase is the frequency of the compressor when the refrigerant is completely returned to the compressor in the form of gas at each ambient temperature.

[0071] Specifically, the optimal frequency conversion of the variable frequency compressor under different ambient temperatures is collected in advance through experiments, thereby obtaining multiple sets of data on the optimal frequency conversion under different ambient temperatures. Then, the least square method is used to perform curve fitting on the multiple sets of data on the optimal frequency conversion, thereby obtaining a curve of the first coefficient b with respect to the ambient temperature.

[0072] The least squares method, also known as the least square method, finds the best function match for the data by minimizing the sum of squares of the errors. The least squares method can be used to easily obtain unknown data and minimize the sum of squares of the errors between the obtained data and the actual data. The least squares method can also be used for curve fitting, and some other optimization problems can also be expressed by the least squares method by minimizing energy or maximizing entropy. The least squares method is widely used in parameter estimation because of its simple principle, fast convergence speed, and easy understanding and implementation.

[0073] Curve b = dy 2 +ey+f can be used as an example of a curve of the first coefficient b after fitting, where y represents the current ambient temperature, and d, e, and f are all coefficients of the polynomial.

[0074] Step S103: Collect the current ambient temperature.

[0075] Specifically, the current ambient temperature can be collected through a temperature sensor.

[0076] Step S104: determining the first coefficient based on the ambient temperature and the curve of the first coefficient.

[0077] Exemplarily, the ambient temperature is introduced into the curve of the first coefficient b to obtain the value of the first coefficient b.

[0078] In this way, the purpose of establishing a polynomial equation between the speed of the variable frequency compressor and the operating time of the variable frequency compressor and fitting the polynomial coefficients of the equation according to the ambient temperature is achieved, so that the speed of the variable frequency compressor can be accurately controlled according to the current ambient temperature and the operating time of the variable frequency compressor, and the heat exchange system can be protected regardless of high temperature or low temperature environment, while improving the drying effect.

[0079] The above is a further description of step S100 , and the following is a further description of step S200 .

[0080] With respect to step S200, the current operating time of the variable frequency compressor is brought into the mapping relationship between the speed and the operating time of the variable frequency compressor, so as to obtain the first speed of the variable frequency compressor.

[0081] In step S300, the variable frequency compressor is controlled to operate at the first speed.

[0082] In this way, the purpose of accurately controlling the speed of the variable frequency compressor according to the current ambient temperature and the operating time of the variable frequency compressor is achieved, and the heat exchange system can be protected regardless of high temperature or low temperature environment, while improving the drying effect.

[0083] In a specific embodiment, the drying device further includes a condenser; after the variable frequency compressor runs at the first speed for a preset period of time, the method further includes:

[0084] Obtaining a first outlet air temperature of the condenser;

[0085] Determining whether the first air outlet temperature reaches a first temperature threshold;

[0086] If so, the drying device is controlled to enter a constant temperature stage, and the first speed of the variable frequency compressor is adjusted to a second speed, wherein the second speed is less than the first speed.

[0087] The preset duration is the time pre-set in the program of the drying device, which may be 3 minutes, 10 minutes, etc.

[0088] The first temperature threshold is a preset temperature value obtained in advance through experiments.

[0089] A temperature sensor is provided on the air duct between the condenser and the drum inlet to collect the first outlet air temperature of the condenser.

[0090] The first air outlet temperature of the condenser collected by the temperature sensor is obtained, and the first air outlet temperature is further compared with the first temperature threshold. When the first air outlet temperature reaches the first temperature threshold, it means that the current temperature in the drum can meet the temperature conditions required for drying. The drying equipment is controlled to enter the constant temperature stage, and the first speed of the variable frequency compressor is reduced to the second speed.

[0091] In this way, the speed of the variable frequency compressor can be further corrected according to the air outlet temperature of the condenser, so as to achieve precise control of the compressor speed and thus improve the drying efficiency.

[0092] In a specific embodiment, when the drying device is in a constant temperature stage, the method further comprises:

[0093] Obtaining a second air outlet temperature of the condenser;

[0094] determining whether the second air outlet temperature exceeds a second temperature threshold;

[0095] If so, the second speed of the variable frequency compressor is adjusted to a third speed, wherein the third speed is less than the second speed.

[0096] The second temperature threshold is a preset temperature value obtained in advance through experiments. In one embodiment, the second temperature threshold may be equal to the first temperature threshold.

[0097] Specifically, when the drying equipment is in the constant temperature stage and the outlet temperature of the condenser is greater than the second temperature threshold, it means that the current temperature in the drum can meet the temperature conditions required for drying under the constant temperature state, and the second speed of the variable frequency compressor is reduced to the third speed.

[0098] In this way, the speed of the variable frequency compressor can be further corrected according to the air outlet temperature of the condenser, so as to achieve precise control of the compressor speed and thus improve the drying efficiency.

[0099] In a specific embodiment, when the drying device is in a constant temperature stage, the method further comprises:

[0100] Detecting the exhaust temperature at the outlet of the variable frequency compressor;

[0101] Determining whether the exhaust temperature at the outlet of the variable frequency compressor exceeds a third temperature threshold;

[0102] If so, the second speed of the variable frequency compressor is adjusted to a fourth speed, wherein the fourth speed is less than the third speed.

[0103] The third temperature threshold is a preset temperature value obtained in advance through experiments.

[0104] A temperature sensor is provided on the pipeline between the variable frequency compressor and the condenser, which can collect the exhaust temperature at the outlet of the variable frequency compressor.

[0105] Specifically, when the drying equipment is in a constant temperature stage and the exhaust temperature at the outlet of the variable frequency compressor is greater than a third temperature threshold, the second speed of the variable frequency compressor is reduced to a fourth speed.

[0106] In one embodiment, the fourth rotational speed may be less than the third rotational speed.

[0107] In this way, the speed of the variable frequency compressor is adjusted according to the comparison between the exhaust temperature at the outlet of the variable frequency compressor and the preset threshold value, so as to achieve precise control of the compressor speed, thereby improving the drying efficiency.

[0108] It should be pointed out that although the various steps in the above embodiments are described in a specific order, those skilled in the art can understand that in order to achieve the effects of the present invention, different steps do not have to be performed in such an order. They can be performed simultaneously (in parallel) or in other orders. These changes are within the scope of protection of the present invention.

[0109] Furthermore, the present invention also provides a speed control device for a variable frequency compressor.

[0110] See attached Figure 2 , Figure 2It is a main structural block diagram of a speed control device for a variable frequency compressor according to an embodiment of the present invention.

[0111] like Figure 2 As shown, the speed control device of the variable frequency compressor in the embodiment of the present invention mainly includes an acquisition module 11, a determination module 12 and a control module 13. In some embodiments, one or more of the acquisition module 11, the determination module 12 and the control module 13 can be combined into one module.

[0112] In some embodiments, the acquisition module 11 may be configured to acquire the operating time of the variable frequency compressor and the mapping relationship between the rotation speed and the operating time of the variable frequency compressor.

[0113] The determination module 12 may be configured to determine the rotation speed of the variable frequency compressor based on the operation duration and the mapping relationship between the rotation speed and the operation duration.

[0114] The control module 13 may be configured to control the variable frequency compressor to operate at the rotation speed.

[0115] In one implementation, the description of the specific implementation functions can refer to steps S100-S300.

[0116] The present application provides a speed control device for a variable frequency compressor, specifically, an acquisition module acquires the operation time of the variable frequency compressor and the mapping relationship between the speed of the variable frequency compressor and the operation time; a determination module determines the speed of the variable frequency compressor based on the mapping relationship between the operation time and the speed-operation time; and a control module controls the variable frequency compressor to operate at a given speed. In this way, the speed of the variable frequency compressor can be accurately controlled according to the operation time of the compressor and the current ambient temperature, thereby protecting the heat exchange system, improving the drying effect of the drying equipment, and improving the user experience.

[0117] The speed control device of the variable frequency compressor is used to execute Figure 1 The embodiment of the speed control method of the variable frequency compressor shown in the figure has similar technical principles, technical problems solved and technical effects produced. Technicians in this technical field can clearly understand that for the convenience and conciseness of description, the specific working process and related instructions of the speed control device of the variable frequency compressor can refer to the contents described in the embodiment of the speed control method of the variable frequency compressor, which will not be repeated here.

[0118] It is understood by those skilled in the art that the present invention implements all or part of the processes in the method of the above embodiment, and can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable storage medium may include: any entity or device, medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory, random access memory, electric carrier signal, telecommunication signal and software distribution medium that can carry the computer program code. It should be noted that the content contained in the computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media do not include electric carrier signals and telecommunication signals.

[0119] Furthermore, the present invention also provides a drying device. In an embodiment of the drying device according to the present invention, Figure 3 As shown, the drying device includes at least one processor 31 and at least one storage device 32, the storage device 32 can be configured to store a program for executing the speed control method of the variable frequency compressor of the above method embodiment, and the processor 31 can be configured to execute the program in the storage device, which includes but is not limited to the program for executing the speed control method of the variable frequency compressor of the above method embodiment. For ease of explanation, only the part related to the embodiment of the present invention is shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present invention.

[0120] In the embodiment of the present invention, the drying device may be a control device device formed by various devices. In some possible implementations, the drying device may include multiple storage devices and multiple processors. The program for executing the speed control method of the variable frequency compressor of the above method embodiment can be divided into multiple subprograms, and each subprogram can be loaded and run by the processor to execute different steps of the speed control method of the variable frequency compressor of the above method embodiment. Specifically, each subprogram can be stored in different storage devices, and each processor can be configured to execute the programs in one or more storage devices to jointly implement the speed control method of the variable frequency compressor of the above method embodiment, that is, each processor executes different steps of the speed control method of the variable frequency compressor of the above method embodiment, to jointly implement the speed control method of the variable frequency compressor of the above method embodiment.

[0121] Furthermore, the present invention also provides a computer-readable storage medium. In a computer-readable storage medium embodiment according to the present invention, the computer-readable storage medium can be configured to store a program for executing the speed control method of the variable frequency compressor of the above method embodiment, and the program can be loaded and run by the processor to implement the speed control method of the variable frequency compressor. For ease of explanation, only the parts related to the embodiment of the present invention are shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present invention. The computer-readable storage medium can be a storage device formed by various electronic devices. Optionally, the computer-readable storage medium in the embodiment of the present invention is a non-temporary computer-readable storage medium.

[0122] Further, it should be understood that since the setting of each module is only for illustrating the functional units of the device of the present invention, the physical devices corresponding to these modules may be the processor itself, or a part of the software in the processor, a part of the hardware, or a part of the combination of software and hardware. Therefore, the number of each module in the figure is only schematic.

[0123] Those skilled in the art will appreciate that the modules in the device can be adaptively split or merged. Such splitting or merging of specific modules will not cause the technical solution to deviate from the principle of the present invention, and therefore, the technical solutions after splitting or merging will fall within the protection scope of the present invention.

[0124] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A speed control method for a variable frequency compressor, applied to drying equipment, characterized in that: The method comprises: Acquire the operation time of the variable frequency compressor and the mapping relationship between the rotation speed and the operation time of the variable frequency compressor; Determine a first speed of the variable frequency compressor based on the operating time and the mapping relationship between the speed and the operating time; The variable frequency compressor is controlled to operate at the first speed.

2. The speed control method of the variable frequency compressor according to claim 1, characterized in that: The mapping relationship is a quadratic equation; The mapping relationship between the speed and the running time of the variable frequency compressor is obtained based on the following steps: Establishing a quadratic equation of the speed of the variable frequency compressor with respect to the running time, wherein the equation includes at least a first coefficient; fitting a curve of the first coefficient of the quadratic equation; Collect the current ambient temperature; The first coefficient is determined based on a curve of the ambient temperature and the first coefficient.

3. The speed control method of the variable frequency compressor according to claim 2, characterized in that: The mapping relationship between the speed and the running time of the variable frequency compressor is: RPM=ax 2 +bx+c Wherein, RPM is the rotation speed, a is the second coefficient, b is the first coefficient, c is the initial rotation speed of the variable frequency compressor, and x is the operating time of the variable frequency compressor.

4. The speed control method of the variable frequency compressor according to claim 3, characterized in that: The curve fitting the first coefficient of the quadratic equation includes: collecting the optimal frequency increase of the variable frequency compressor under different ambient temperatures; A least square method is used to fit a curve of the first coefficient based on the optimal up-conversion frequency.

5. The speed control method of the variable frequency compressor according to claim 1, characterized in that: The drying device further includes a condenser; after the variable frequency compressor runs at the first speed for a preset time, the method further includes: Obtaining a first outlet air temperature of the condenser; Determining whether the first air outlet temperature reaches a first temperature threshold; If so, the drying device is controlled to enter a constant temperature stage, and the first speed of the variable frequency compressor is adjusted to a second speed, wherein the second speed is less than the first speed.

6. The speed control method of the variable frequency compressor according to claim 5, characterized in that: When the drying device is in a constant temperature stage, the method further comprises: Obtaining a second air outlet temperature of the condenser; determining whether the second air outlet temperature exceeds a second temperature threshold; If so, the second speed of the variable frequency compressor is adjusted to a third speed, wherein the third speed is less than the second speed.

7. The speed control method of the variable frequency compressor according to claim 5, characterized in that: When the drying device is in a constant temperature stage, the method further comprises: Detecting the exhaust temperature at the outlet of the variable frequency compressor; Determining whether the exhaust temperature at the outlet of the variable frequency compressor exceeds a third temperature threshold; If so, the second speed of the variable frequency compressor is adjusted to a fourth speed, wherein the fourth speed is less than the second speed.

8. A speed control device for a variable frequency compressor, characterized in that: The device comprises: An acquisition module, the acquisition module is configured to acquire the operation time of the variable frequency compressor and the mapping relationship between the rotation speed and the operation time of the variable frequency compressor; a determination module, the determination module being configured to determine the rotation speed of the variable frequency compressor based on the operation duration and the mapping relationship between the rotation speed and the operation duration; A control module is configured to control the variable frequency compressor to operate at the rotation speed.

9. A drying device, comprising at least one processor and at least one storage device, wherein the storage device is suitable for storing a plurality of program codes, characterized in that: The program code is suitable for being loaded and run by the processor to execute the speed control method for the variable frequency compressor according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a plurality of program codes, characterized in that: The program code is suitable for being loaded and run by a processor to execute the speed control method for a variable frequency compressor according to any one of claims 1 to 7.

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