A temperature control monitoring system for new energy wind turbine generator sets

Abstract

The present invention discloses a temperature control and supervision system for a new energy wind turbine generator set, and belongs to the technical field of temperature control and supervision of new energy equipment. The present invention obtains an infrared detection image of a detection object shell through an image detection module, and uses the obtained color change number as a determination factor for whether to mark the detection object as a suspected heating part, finds out the suspected heating part, narrows the detection range of a traditional temperature sensor, obtains the color change floating value of the suspected heating part, generates a surface temperature warning signal through color change floating value analysis, and then uses an internal temperature detection module to perform multi-point detection on the internal operating temperature of the suspected heating part, obtains the temperature change floating value of the suspected heating part, and then uses the temperature change floating value as a determination factor for whether to mark the suspected heating part as a confirmed heating part, and adopts the detection methods of "from surface to inside", "from wide to narrow", and "combination of inside and outside" to achieve rapid and accurate positioning of the heating part, and perform cooling control on the heating part.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature control and supervision of new energy equipment, and more specifically, to a temperature control and supervision system for a new energy wind turbine generator set. Background Art

[0002] New energy wind turbines are systems that convert wind kinetic energy into electrical energy. Wind turbines include structures such as wind rotors, generators, and gearboxes. Wind turbines are prone to heating failures during long-term operation. When a wind turbine has a continuous heating failure, it affects its normal operation and even reduces the service life of the equipment. Therefore, heating failure detection and temperature control are important tasks in wind turbine inspections.

[0003] Currently, the commonly used temperature detection method is to install temperature sensors inside the equipment. However, for heating parts with complex structure, large temperature measurement area and uneven temperature distribution, ordinary temperature measurement methods cannot quickly and accurately locate the heating parts, which is not conducive to technicians to accurately determine the heating parts and make targeted temperature control improvement measures. Therefore, it is difficult to ensure the safe, stable and efficient operation of wind turbines.

[0004] To this end, we propose a temperature control monitoring system for new energy wind turbines to address the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the existing practical problems. Compared with the existing technology, a temperature control and monitoring system for new energy wind turbine generator sets is provided. The infrared detection image of the shell of the detection object is obtained through an image detection module, and the obtained color change number is used as a judgment factor for whether to mark the detection object as a suspected hot spot, find out the suspected hot spot, narrow the detection range of the traditional temperature sensor, obtain the color change floating value of the suspected hot spot, and generate a surface temperature warning signal through the color change floating value analysis. Then, the internal operating temperature of the suspected hot spot is detected at multiple points through the internal temperature detection module, and the temperature change floating value of the suspected hot spot is obtained. The temperature change floating value is used as a judgment factor for whether to mark the suspected hot spot as a confirmed hot spot. The detection methods of "from the surface to the inside", "from the wide to the narrow", and "combination of inside and outside" are adopted to realize rapid and accurate positioning of the hot spot, and to perform cooling control on the hot spot.

[0006] The object of the present invention can be achieved by the following technical solutions: A temperature control monitoring system for a new energy wind turbine generator set, comprising a monitoring platform, wherein the monitoring platform is communicatively connected with an image detection module, an internal temperature detection module, an evaluation and analysis module, and a refrigeration control module; during the operation of the wind turbine generator set, the monitoring platform marks multiple temperature detection locations of the wind turbine generator set as detection objects;

[0007] The image detection module is used to capture images of each detection object to obtain an infrared detection image, obtain a color change number based on the infrared detection image analysis, mark the detection object whose color change number is greater than the color change number threshold as a suspected fever site, obtain the color change floating value SFZ of the suspected fever site, generate a surface temperature warning signal through the color change floating value analysis, and send the surface temperature warning signal to the internal temperature monitoring module and the evaluation and analysis module via the supervision platform;

[0008] After receiving the surface temperature warning signal, the internal temperature detection module performs multi-point detection on the internal operating temperature of the suspected heating part, obtains the temperature change floating value WFZ of the suspected heating part, generates an internal temperature warning signal and an internal temperature normal signal through the temperature change floating value, marks the suspected heating part corresponding to the internal temperature warning signal as a confirmed heating part, and sends the internal temperature warning signal and the internal temperature normal signal to the evaluation and analysis module and the environment detection module respectively;

[0009] The environmental detection module is used to obtain environmental information about the environment around the suspected hot part, and obtain an environmental interference value based on the environmental information, and determine whether the surrounding environment has an impact on the color change of the surface of the detection object based on the environmental interference value, and send the determination result to the supervision platform and the refrigeration control module;

[0010] After receiving the surface temperature warning signal and the internal temperature warning signal, the evaluation and analysis module calculates the color change floating value SFZ and the temperature change floating value WFZ to obtain the temperature rise coefficient WX, performs temperature abnormality warning analysis on the confirmed heating parts according to the temperature rise coefficient WX, and sends the warning analysis results to the refrigeration control module.

[0011] As a preferred embodiment of the present invention, the process of the image detection module obtaining the color change number and the suspected fever site according to the infrared detection image analysis includes: using an infrared camera device to take an infrared image of the detection object during the monitoring period, amplifying the infrared image into a pixel grid image and performing grayscale transformation, comparing the grayscale value with the grayscale threshold pre-stored in the supervision platform, and marking the pixel grid with a grayscale value greater than or equal to the grayscale threshold as a color change grid, and obtaining the total number of color change grids as the color change number;

[0012] The color change number is compared with the color change number threshold pre-stored in the supervision platform. When the color change number is greater than the color change number threshold, the detected object is marked as a suspected fever site.

[0013] As a preferred embodiment of the present invention, the process of the image detection module obtaining the color change floating value of the suspected fever site includes: marking the ratio between the total value of all gray values ​​of the suspected fever site greater than the gray value threshold and the color change number as the color change floating value SFZ;

[0014] The color change floating value is compared with the preset color change floating threshold. When the color change floating value is greater than or equal to the preset color change floating threshold, a surface temperature warning signal is generated, otherwise a surface temperature normal signal is generated.

[0015] As a preferred embodiment of the present invention, the process of the internal temperature detection module obtaining the temperature variation floating value of the suspected fever part includes: collecting the real-time operating temperature of multiple detection points during the monitoring period by using multiple temperature sensors evenly arranged in the suspected fever part, marking them as internal temperature values, comparing the internal temperature values ​​with the internal temperature threshold values ​​pre-stored in the supervision platform, and marking the detection points whose internal temperature values ​​are greater than or equal to the internal temperature threshold values ​​as temperature outliers, and obtaining the total number of temperature outliers and marking them as temperature variation number;

[0016] The ratio of the sum of the internal temperature values ​​corresponding to all temperature differences to the temperature variation number is marked as the temperature variation floating value WFZ. The temperature variation floating value is compared with the preset temperature variation floating threshold. When the temperature variation floating value is greater than or equal to the preset temperature variation floating threshold, an internal temperature warning signal is generated, and the suspected fever area is marked as a confirmed fever area. Otherwise, a normal internal temperature signal is generated.

[0017] As a preferred embodiment of the present invention, the process of determining whether the surrounding environment affects the color change of the surface of the detection object is as follows: the environment detection module obtains environmental information, the environmental information includes the temperature and humidity of the surrounding environment, and numerically calculates the temperature and humidity to obtain the environmental interference value;

[0018] The environmental interference value is compared with the preset environmental interference threshold. When the environmental interference value is less than the preset environmental interference threshold, it is determined that the surrounding environment has no effect on the color change of the surface of the detection object. The supervision platform instructs the image detection module to re-take images of each suspected fever site and obtain a new color change floating value for verification;

[0019] When the environmental interference value is greater than or equal to the preset environmental interference threshold, it is determined that the surrounding environment has an impact on the color change of the surface of the detection object, and an environmental warning signal is generated and sent to the refrigeration control module. The refrigeration control module cools down the area around the suspected hot part until a new color change floating value is obtained that is less than the color change floating threshold.

[0020] As a preferred embodiment of the present invention, the process of obtaining the temperature rise coefficient WX by the evaluation and analysis module includes: generating the temperature rise coefficient WX by a formula, , where a1 and a2 represent the proportional coefficients of the color change floating value SFZ and the temperature change floating value WFZ respectively, and α1>α2>1.

[0021] As a preferred embodiment of the present invention, the process of performing temperature abnormality warning analysis on the confirmed heat-generating parts includes: comparing the temperature rise coefficient WX with the preset temperature rise coefficient threshold value, when the temperature rise coefficient is greater than the maximum value of the preset temperature rise coefficient threshold interval, generating a first-level refrigeration control signal, when the temperature rise coefficient is within the preset temperature rise coefficient threshold interval, generating a second-level refrigeration control signal, when the temperature rise coefficient is less than the minimum value of the preset temperature rise coefficient threshold interval, generating a third-level refrigeration control signal.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] This scheme is to obtain an infrared detection image of the shell of the detection object through an image detection module, and use the obtained color change number as a judgment factor for whether to mark the detection object as a suspected hot spot. It can quickly obtain the temperature information of the shell of the detection object with a complex structure and a large temperature measurement area, find out the suspected hot spot, and narrow the detection range of the traditional temperature sensor. After the suspected hot spot is determined, its color change floating value is obtained, and a surface temperature warning signal is generated through color change floating value analysis. Then, the internal operating temperature of the suspected hot spot is detected at multiple points through the internal temperature detection module to obtain the temperature change floating value of the suspected hot spot. The temperature change floating value is used as a judgment factor for whether to mark the suspected hot spot as a confirmed hot spot. The detection methods of "from surface to inside", "from wide to narrow", and "combination of inside and outside" are adopted to achieve rapid and accurate positioning of the hot spot and perform cooling control on the hot spot.

[0024] When this scheme analyzes the temperature change floating value of the suspected fever area, when a normal internal temperature signal is obtained, it means that the surrounding environmental factors have affected the determination of marking the detection object as a suspected fever area, and the environmental interference value is obtained through environmental information. When the environmental interference value is less than the preset environmental interference threshold, it is determined that the surrounding environment has no effect on the surface color change of the detection object. The supervision platform instructs the image detection module to re-image the suspected fever area and obtain a new color change floating value for verification. When the environmental interference value is greater than or equal to the preset environmental interference threshold, it is determined that the surrounding environment has affected the surface color change of the detection object, and an environmental warning signal is generated, and the surrounding area of ​​the suspected fever area is cooled. Such multiple verifications can effectively improve the accuracy of the determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the overall principle block diagram of the present invention;

[0026] Figure 2 This is a principle block diagram of Embodiment 1 of the present invention;

[0027] Figure 3 This is a principle block diagram of Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0028] The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0029] Example 1: The present invention discloses a temperature control monitoring system for a new energy wind turbine generator set. Figure 1-Figure 2 , including a supervision platform, which is communicatively connected to an image detection module, an internal temperature detection module, an evaluation and analysis module, and a refrigeration control module. During the operation of the wind turbine generator set, the supervision platform marks multiple temperature detection locations of the wind turbine generator set as detection objects.

[0030] The image detection module is used to capture images of each detection object to obtain an infrared detection image, obtain a color change number based on the infrared detection image analysis, and mark the detection object with a color change number greater than the color change number threshold as a suspected hot part. The obtained color change number is used as a determination factor for whether to mark the detection object as a suspected hot part. By using infrared detection, the external shell temperature of the detection object with a complex structure and a large temperature measurement area can be quickly obtained. By mapping the internal temperature of the detection object through the shell temperature, the suspected hot part is found, and the detection range of the traditional temperature sensor is narrowed;

[0031] The specific process is as follows: during the monitoring period, an infrared camera is used to capture an infrared image of the detection object, the infrared image is enlarged into a pixel grid image and grayscale transformation is performed, the grayscale value is compared with the grayscale threshold pre-stored in the supervision platform, and the pixel grids with grayscale values ​​greater than or equal to the grayscale threshold are marked as color-changed grids, and the total number of color-changed grids is marked as the color-changed number;

[0032] The color change number is compared with the color change number threshold value pre-stored in the supervision platform. When the color change number is greater than the color change number threshold value, the detection object is marked as a suspected fever site, and the subsequent internal temperature detection process of the detection object not marked as a suspected fever site is removed;

[0033] The ratio between the total value of all gray values ​​of suspected fever parts greater than the gray value threshold and the color change number is marked as the color change floating value SFZ, and the color change floating value is compared with the preset color change floating threshold. When the color change floating value is greater than or equal to the preset color change floating threshold, a surface temperature warning signal is generated, otherwise a surface temperature normal signal is generated;

[0034] The image detection module sends the surface temperature warning signal to the internal temperature detection module and the evaluation and analysis module through the supervision platform.

[0035] After receiving the surface temperature warning signal, the internal temperature detection module performs multi-point detection on the internal operating temperature of the suspected hot part to obtain the temperature change floating value WFZ of the suspected hot part. The process includes: during the monitoring period, multiple temperature sensors are evenly arranged in the suspected hot part to collect the real-time operating temperature of multiple detection points, marking them as internal temperature values, comparing the internal temperature values ​​with the internal temperature thresholds pre-stored in the supervision platform, and marking the detection points with internal temperature values ​​greater than or equal to the internal temperature thresholds as temperature outliers, and the total number of temperature outliers is marked as temperature variation;

[0036] The ratio of the sum of the internal temperature values ​​corresponding to all temperature outliers and the temperature variation is marked as the temperature variation floating value WFZ, and the temperature variation floating value is compared with the preset temperature variation floating threshold. When the temperature variation floating value is greater than or equal to the preset temperature variation floating threshold, an internal temperature warning signal is generated, and the suspected fever site is marked as a confirmed fever site, otherwise a normal internal temperature signal is generated;

[0037] The suspected fever area corresponding to the internal temperature warning signal is marked as a confirmed fever area, and the internal temperature warning signal is sent to the evaluation and analysis module. The detection methods of "from the outside to the inside", "from the wide to the narrow", and "combination of inside and outside" are adopted to achieve rapid and accurate positioning of the fever area.

[0038] After receiving the surface temperature warning signal and the internal temperature warning signal, the evaluation and analysis module calculates the color change floating value SFZ and the temperature change floating value WFZ to obtain the temperature rise coefficient WX. The process includes: generating the temperature rise coefficient WX through the formula, , where a1 and a2 represent the proportional coefficients of the color change floating value SFZ and the temperature change floating value WFZ respectively, and α1>α2>1;

[0039] The temperature rise coefficient WX is compared with the preset temperature rise coefficient threshold. When the temperature rise coefficient is greater than the maximum value of the preset temperature rise coefficient threshold interval, a first-level refrigeration control signal is generated. When the temperature rise coefficient is within the preset temperature rise coefficient threshold interval, a second-level refrigeration control signal is generated. When the temperature rise coefficient is less than the minimum value of the preset temperature rise coefficient threshold interval, a third-level refrigeration control signal is generated.

[0040] According to the temperature rise coefficient WX, an abnormal temperature warning analysis is performed on the confirmed heating parts, and a first-level refrigeration control signal, a second-level refrigeration control signal, and a third-level refrigeration control signal are generated respectively. The first-level refrigeration control signal, the second-level refrigeration control signal, and the third-level refrigeration control signal are sent to the refrigeration control module. The refrigeration control module performs targeted refrigeration control processing on the confirmed heating parts according to different levels of refrigeration control signals.

[0041] Example 2: Please refer to Figure 2When the internal temperature detection module generates a normal internal temperature signal through the temperature change floating value, it indicates that when the surface temperature warning signal is received, the internal temperature of the suspected hot part is within the normal range. Therefore, the abnormal high temperature of the outer shell of the suspected hot part is not caused by the conduction from the inside to the outside. It is speculated that the abnormal high temperature of the outer shell of the suspected hot part is affected by the surrounding environment, and the normal internal temperature signal is sent to the environment detection module;

[0042] The environmental detection module is used to obtain environmental information about the environment around the suspected hot part, and obtain the environmental interference value based on the environmental information, and determine whether the surrounding environment has an impact on the color change of the surface of the detection object through the environmental interference value, and send the determination result to the supervision platform and the refrigeration control module;

[0043] The process includes: obtaining environmental information, which includes the temperature and humidity of the surrounding environment, and marking them as WZ and SZ respectively, and generating the environmental interference value HZ according to the formula. , where b1 and b2 are the proportional coefficients of temperature and humidity respectively;

[0044] The environmental interference value is compared with the preset environmental interference threshold. When the environmental interference value is less than the preset environmental interference threshold, it is determined that the surrounding environment has no effect on the color change of the surface of the detection object. The supervision platform instructs the image detection module to re-take images of each suspected fever site and obtain a new color change floating value for verification;

[0045] When the environmental interference value is greater than or equal to the preset environmental interference threshold, it is determined that the surrounding environment has an impact on the color change of the surface of the detection object, and an environmental warning signal is generated and sent to the refrigeration control module. The refrigeration control module cools down the area around the suspected hot part until a new color change floating value is obtained that is less than the color change floating threshold.

[0046] In summary: the present invention obtains an infrared detection image of the shell of the detection object through an image detection module, and uses the obtained color change number as a judgment factor for whether to mark the detection object as a suspected hot spot. It can quickly obtain the shell temperature of the detection object with a complex structure and a large temperature measurement area, find out the suspected hot spot, and narrow the detection range of the traditional temperature sensor. After the suspected hot spot is determined, its color change floating value is obtained, and a surface temperature warning signal is generated through color change floating value analysis. Then, the internal operating temperature of the suspected hot spot is detected at multiple points through the internal temperature detection module to obtain the temperature change floating value of the suspected hot spot. The temperature change floating value is used as a judgment for whether to mark the suspected hot spot as a confirmed hot spot. The detection methods of "from the surface to the inside", "from the wide to the narrow", and "combination of inside and outside" are adopted to realize rapid and accurate positioning of the hot spot, and to perform cooling control on the hot spot.

[0047] When a normal surface temperature signal is generated through the color change floating value analysis, it means that the surrounding environmental factors have affected the determination of marking the detection object as a suspected hot part. The environmental interference value is obtained through the environmental detection module. When the environmental interference value is less than the preset environmental interference threshold, it is determined that the surrounding environment has no effect on the surface color change of the detection object. The supervision platform instructs the image detection module to re-image the suspected hot part and obtain a new color change floating value for verification. When the environmental interference value is greater than or equal to the preset environmental interference threshold, it is determined that the surrounding environment has affected the surface color change of the detection object, and an environmental warning signal is generated. The surrounding area of ​​the suspected hot part is cooled. Such multiple verifications can effectively improve the accuracy of the determination.

[0048] The above are only preferred specific implementation modes of the present invention; however, the protection scope of the present invention is not limited thereto; any technician familiar with the technical field within the technical scope disclosed by the present invention; any equivalent replacement or change based on the technical solution and improved concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A temperature control monitoring system for a new energy wind turbine generator set, characterized in that: The monitoring platform includes an image detection module, an internal temperature detection module, an evaluation and analysis module, and a refrigeration control module. During the operation of the wind turbine generator set, the monitoring platform marks multiple temperature detection locations of the wind turbine generator set as detection objects. The image detection module is used to capture images of each detection object to obtain an infrared detection image, obtain a color change number based on the infrared detection image analysis, mark the detection object whose color change number is greater than the color change number threshold as a suspected fever site, obtain the color change floating value SFZ of the suspected fever site, generate a surface temperature warning signal through the color change floating value analysis, and send the surface temperature warning signal to the internal temperature detection module and the evaluation and analysis module via the supervision platform; After receiving the surface temperature warning signal, the internal temperature detection module performs multi-point detection on the internal operating temperature of the suspected heating part, obtains the temperature change floating value WFZ of the suspected heating part, generates an internal temperature warning signal and an internal temperature normal signal through the temperature change floating value, marks the suspected heating part corresponding to the internal temperature warning signal as a confirmed heating part, and sends the internal temperature warning signal and the internal temperature normal signal to the evaluation and analysis module and the environment detection module respectively; The environmental detection module is used to obtain environmental information about the environment around the suspected hot part, and obtain an environmental interference value based on the environmental information, and determine whether the surrounding environment has an impact on the color change of the surface of the detection object based on the environmental interference value, and send the determination result to the supervision platform and the refrigeration control module; After receiving the surface temperature warning signal and the internal temperature warning signal, the evaluation and analysis module calculates the color change floating value SFZ and the temperature change floating value WFZ to obtain the temperature rise coefficient WX, performs temperature abnormality warning analysis on the confirmed heating parts according to the temperature rise coefficient WX, and sends the warning analysis results to the refrigeration control module.

2. The temperature control monitoring system for a new energy wind turbine generator set according to claim 1 is characterized in that: The process of the image detection module obtaining the color change number and the suspected fever site according to the infrared detection image analysis includes: using an infrared camera device to take an infrared image of the detection object during the monitoring period, amplifying the infrared image into a pixel grid image and performing grayscale transformation, comparing the grayscale value with the grayscale threshold pre-stored in the supervision platform, and marking the pixel grid with a grayscale value greater than or equal to the grayscale threshold as a color change grid, and obtaining the total number of color change grids and marking them as the color change number; The color change number is compared with the color change number threshold pre-stored in the supervision platform. When the color change number is greater than the color change number threshold, the detected object is marked as a suspected fever site.

3. A temperature control monitoring system for a new energy wind turbine generator set according to claim 2, characterized in that: The process of the image detection module obtaining the color change floating value of the suspected hot part includes: marking the ratio between the total value of all gray values ​​of the suspected hot part greater than the gray value threshold and the color change number as the color change floating value SFZ; The color change floating value is compared with the preset color change floating threshold. When the color change floating value is greater than or equal to the preset color change floating threshold, a surface temperature warning signal is generated, otherwise a surface temperature normal signal is generated.

4. The temperature control monitoring system for a new energy wind turbine generator set according to claim 3 is characterized in that: The process of the internal temperature detection module obtaining the temperature variation floating value of the suspected fever part includes: collecting the real-time operating temperature of multiple detection points during the monitoring period by using multiple temperature sensors evenly arranged in the suspected fever part, marking them as internal temperature values, comparing the internal temperature values ​​with the internal temperature thresholds pre-stored in the supervision platform, and marking the detection points whose internal temperature values ​​are greater than or equal to the internal temperature thresholds as temperature outliers, and obtaining the total number of temperature outliers and marking them as temperature variation number; The ratio of the sum of the internal temperature values ​​corresponding to all temperature differences to the temperature variation number is marked as the temperature variation floating value WFZ. The temperature variation floating value is compared with the preset temperature variation floating threshold. When the temperature variation floating value is greater than or equal to the preset temperature variation floating threshold, an internal temperature warning signal is generated, and the suspected fever area is marked as a confirmed fever area. Otherwise, a normal internal temperature signal is generated.

5. A temperature control monitoring system for a new energy wind turbine generator set according to claim 4, characterized in that: The process of determining whether the surrounding environment affects the color change of the surface of the detection object is as follows: the environment detection module obtains environmental information, the environmental information includes the temperature and humidity of the surrounding environment, and numerically calculates the temperature and humidity to obtain the environmental interference value; The environmental interference value is compared with the preset environmental interference threshold. When the environmental interference value is less than the preset environmental interference threshold, it is determined that the surrounding environment has no effect on the color change of the surface of the detection object. The supervision platform instructs the image detection module to re-take images of each suspected fever site and obtain a new color change floating value for verification; When the environmental interference value is greater than or equal to the preset environmental interference threshold, it is determined that the surrounding environment has an impact on the color change of the surface of the detection object, and an environmental warning signal is generated and sent to the refrigeration control module. The refrigeration control module cools down the area around the suspected hot part until a new color change floating value is obtained that is less than the color change floating threshold.

6. The temperature control monitoring system for a new energy wind turbine generator set according to claim 1 is characterized in that: The process of obtaining the temperature rise coefficient WX by the evaluation and analysis module includes: generating the temperature rise coefficient WX through a formula, , where a1 and a2 represent the proportional coefficients of the color change floating value SFZ and the temperature change floating value WFZ respectively, and α1>α2>1.

7. A temperature control monitoring system for a new energy wind turbine generator set according to claim 6, characterized in that: The process of performing temperature abnormality warning analysis on confirmed heating parts includes: comparing the temperature rise coefficient WX with the preset temperature rise coefficient threshold value, when the temperature rise coefficient is greater than the maximum value of the preset temperature rise coefficient threshold range, generating a first-level refrigeration control signal, when the temperature rise coefficient is within the preset temperature rise coefficient threshold range, generating a second-level refrigeration control signal, when the temperature rise coefficient is less than the minimum value of the preset temperature rise coefficient threshold range, generating a third-level refrigeration control signal.

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