Vacuum radiation drying equipment based on electromagnetic waves and operation method thereof

Abstract

The invention provides vacuum radiation drying equipment based on electromagnetic waves and an operation method of the vacuum radiation drying equipment, and belongs to the technical field of radiation drying equipment. The equipment comprises a flat car, a tank body, a radiation plate, a guide device, a vacuum pumping system, a gas filling system, a temperature monitoring device and a pressure monitoring device; wherein the tank body is provided with a tank door capable of being locked, the radiant panel is arranged in the tank body, the flatcar is used for bearing power equipment, the guide device is used for positioning the flatcar, the vacuum pumping system comprises a vacuum pumping device, and the gas filling system is used for filling gas in the drying process. The temperature monitoring device comprises an iron core temperature sensor and a coil temperature sensor which are installed on the power equipment, the pressure monitoring device is used for monitoring the pressure in the tank body, and the distance between the power equipment and the radiant panel can be adjusted and is larger than or equal to 100 mm and smaller than or equal to 500 mm.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiation drying equipment, and in particular, relates to a vacuum radiation drying equipment based on electromagnetic waves and an operating method thereof. Background Art

[0002] During use, power equipment, especially transformers, will experience various temperature changes, high voltage and high current and other severe working conditions. Its insulation materials need to undergo strict drying treatment to ensure long-term stable and reliable operation of the equipment. Existing power equipment drying methods mainly include hot air drying and vacuum drying. These methods usually require a long drying time and easily cause uneven temperature distribution inside the equipment, thus affecting the drying effect. In addition, these methods also have problems such as low control accuracy and high energy consumption.

[0003] Some researchers have proposed a drying technology for power equipment based on microwave drying. Microwaves can directly act on polar molecules inside the equipment, quickly heat up and drive water molecules to escape, thereby greatly shortening the drying time. However, microwave drying has problems such as local overheating and easy damage to power equipment.

[0004] In recent years, electromagnetic wave technology has been gradually applied to the field of power equipment drying. Compared with microwaves, electromagnetic waves have higher penetration and selectivity, and can heat the inside of the equipment more evenly to avoid local overheating. In addition, a vacuum environment can be introduced during the electromagnetic wave drying process to further improve the drying efficiency. However, the existing electromagnetic wave drying equipment generally has the problem of insufficient precise control and monitoring of key parameters such as temperature and pressure during the drying process, which can easily lead to insufficient drying. Summary of the invention

[0005] In view of this, the present invention provides a vacuum radiation drying device based on electromagnetic waves and an operating method thereof, which can solve the problem that the existing electromagnetic wave drying equipment generally has insufficient precise control and monitoring of key parameters such as temperature and pressure during the drying process, which easily leads to insufficient drying.

[0006] The present invention is achieved in that: The first aspect of the present invention provides a vacuum radiation drying device based on electromagnetic waves, which includes: a flat car, a tank body, a radiation plate, a guide device, a driving device, a vacuum evacuation system, a gas filling system, a temperature monitoring device and a pressure monitoring device; wherein the tank body has a lockable tank door, and the radiation plate is rotatably arranged inside the tank body, and all rotatable radiation plates can be arranged, and a partial number of rotatable radiation plates can be arranged; the rotation of the radiation plate can be achieved through various mechanical structures, such as adding an electric telescopic rod to one side of the radiation plate, and adding a hinged component to the other side opposite to the radiation plate, so as to achieve horizontal or vertical rotation; or using an industrial pan head to install the radiation plate, so as to achieve three-dimensional rotation. The flat car is used to carry the power equipment, the guide device is used to position the flat car, the drive device is used to adjust the height of the power equipment and the position in the tank body, the vacuum evacuation system includes a vacuum evacuation device, the gas filling system is used to fill gas during the drying process, the temperature monitoring device includes a core temperature sensor and a coil temperature sensor installed on the power equipment, the pressure monitoring device is used to monitor the internal pressure of the tank body, and the distance between the power equipment and the radiation plate is adjustable and is greater than or equal to 100 mm and less than or equal to 500 mm.

[0007] Among them, the radiation plate is an electromagnetic wave radiation plate, which is used to send electromagnetic waves outward. The length range of the electromagnetic wave radiation plate is: greater than or equal to 10 cm and less than or equal to 2 m; the width range of the electromagnetic wave radiation plate is: greater than or equal to 5 cm and less than or equal to 30 cm; the height range of the width of the electromagnetic wave radiation plate is: greater than or equal to 50 cm and less than or equal to 1.5 m; the shape of the electromagnetic wave radiation plate is one or more of a rectangle, a square, a circle, a triangle, a diamond, and a corrugated shape; the electromagnetic radiation plate and the mirror reflection plate are both installed on the inner wall of the tank.

[0008] A second aspect of the present invention provides an operating method of a vacuum radiation drying device based on electromagnetic waves, which comprises the following steps: S01. Before starting the automatic drying mode, place the electrical equipment on a flat car so that the distance between the electrical equipment and the radiation panel is greater than or equal to 100 mm, move the flat car to the inner limit stop of the tank body, set the iron core 1, iron core 2, coil 1, coil 2 and a temperature meter on the electrical equipment, and close and lock the tank door; S02, turning on the chiller and the automatic drying mode, heating and vacuuming in the preheating stage, and maintaining the vacuum change rate for a first preset time after reaching a first preset value; S03, entering the temperature rising stage, filling with gas to 70000 Pa, setting the ventilation frequency to more than 10 times according to the size of the power equipment, and performing ventilation cycles at intervals of 180 minutes. After each ventilation process, the vacuum degree is drawn to 40000 Pa and then filled with gas to 70000 Pa; S04, monitoring the temperatures of the iron core 1, the iron core 2, the coil 1, and the coil 2, and when the temperatures all reach a second preset value, entering the main stage; S05, setting an intermittent vacuuming starting value in the trunk stage, stopping vacuuming after reaching the starting value and maintaining the pressure for a third preset time; S06, performing intermittent evacuation cycles according to a preset percentage until the vacuum degree reaches a fourth preset value and then performing deep evacuation; S07, when the vacuum degree reaches the fifth preset value, entering the endpoint judgment stage; S08, running for 30 minutes in the endpoint judgment stage and then stopping for 10 minutes to monitor the pressure increase rate, stage pressure increase rate, dew point value, exhaust water output, core temperature and coil temperature in the tank body; the tank body, in the present invention, is also called the main body, which includes both the inside of the tank and the state changes of the equipment to be dried in the tank.

[0009] S09, using a drying endpoint judgment equation group to comprehensively evaluate the pressure increase rate, stage pressure increase rate, dew point value, exhaust water output, core temperature and coil temperature in the tank body; S10. When the output result of the determination equation indicates that the drying end point has been reached, the drying process is terminated; if the drying end point has not been reached, deep evacuation is continued until the end point determination condition is met.

[0010] On the basis of the above technical solution, the operating method of the vacuum radiation drying equipment based on electromagnetic waves of the present invention can also be improved as follows: Furthermore, the drying endpoint judgment equation group includes a weight equation, a normalization equation, a comprehensive evaluation equation and a judgment equation.

[0011] Furthermore, the weight equation is used to calculate the dynamic weight coefficient of each monitoring parameter. The input includes historical data of the boost rate in the tank, historical data of the stage boost rate, historical data of the dew point value, historical data of the exhaust water output, historical data of the core temperature and historical data of the coil temperature. The output is the weight coefficient of each parameter.

[0012] Furthermore, the normalized equation is used to convert each monitoring parameter into a dimensionless value. The input includes the pressure increase rate in the tank at the current moment, the stage pressure increase rate, the dew point value, the exhaust water output, the core temperature, the coil temperature and their corresponding target values. The output is the normalized value of each parameter.

[0013] Furthermore, the comprehensive evaluation equation is used to calculate the comprehensive index of the drying state, the input includes the weight coefficient and normalized value of each parameter, and the output is the comprehensive index value reflecting the current drying state.

[0014] Furthermore, the determination equation is used to determine whether the drying endpoint is reached, the input includes the comprehensive index value and its stability index, and the output is the drying endpoint determination result.

[0015] A description of the detailed steps of the method of the present invention is provided below: The step S10 specifically includes: Step 101, detecting the relative position of the flat car and the tank body, and when the flat car moves to just below the central axis of the tank body, fixing it by a guide device; Step 102, measuring the distance between the power device and the radiation panel, and adjusting the height of the power device by a driving device until the distance is greater than or equal to 100 mm and less than or equal to 500 mm; Step 103, installing the iron core 1 and the iron core 2 at the central column position of the power equipment, and installing the coil 1 and the coil 2 at the periphery of the power equipment, wherein the angle between the coil 1 and the coil 2 is 120 degrees; Step 104, installing the temperature measuring meter at a preset temperature measuring point position on the surface of the power equipment, wherein the temperature measuring point position includes an upper clamp, a middle clamp and a lower clamp; Step 105, detecting the sealing performance of the tank door sealing ring, wherein the sealing performance is determined by the ratio of the sealing ring contact area to the sealing ring total area, and when the ratio is greater than 0.95, the sealing performance is determined to be qualified.

[0016] The step S20 specifically includes: Step 201: Calculate a vacuum change rate threshold value according to the volume of the power equipment, wherein when the volume is less than 10 cubic meters, the vacuum change rate threshold value is set to 500 Pa per minute to 1000 Pa per minute, and when the volume is greater than or equal to 10 cubic meters, the vacuum change rate threshold value is set to 200 Pa per minute to 500 Pa per minute; Step 202: setting the first preset time according to the vacuum change rate threshold value; when the vacuum change rate threshold value is greater than 500 Pa / min, the first preset time is set to 30 minutes to 60 minutes; when the vacuum change rate threshold value is less than or equal to 500 Pa / min, the first preset time is set to 60 minutes to 120 minutes; Step 203: collecting the internal pressure, temperature and volume data of the tank during the heating process, and calculating the real-time vacuum change rate based on the data; Step 204: compare the real-time vacuum change rate with the vacuum change rate threshold. The step S30 specifically includes: Step 301: setting a gas filling rate according to the volume of the power equipment, wherein the gas filling rate is linearly related to the volume. When the volume is 10 cubic meters, the gas filling rate is set to 500 liters per minute to 1000 liters per minute. Step 302, monitoring the internal pressure of the tank, and stopping the filling of gas when the pressure reaches 70000 Pa; Step 303, determining the ventilation times according to the dielectric material type of the power equipment, when the dielectric material is insulating oil-impregnated paper, it is set to 3 to 4 times, and when the dielectric material is a composite insulating material, it is set to 1 to 2 times; Step 304, set the ventilation time interval to 60 minutes, reduce the vacuum degree to 40,000 Pa during each ventilation process, and then fill with gas to 70,000 Pa. Monitor the pressure rise rate during the inflation process. When the pressure rise rate exceeds 10,000 Pa per minute, automatically reduce the inflation rate.

[0017] The step S40 specifically includes: Step 401, collecting temperature data of the iron core 1, the iron core 2, the coil 1, and the coil 2, and calculating the temperature average and temperature gradient; Step 402: setting the second preset value according to the capacity level of the power equipment; when the capacity level is less than 100 MVA, the second preset value is set to 80 degrees Celsius to 100 degrees Celsius; when the capacity level is greater than or equal to 100 MVA, the second preset value is set to 100 degrees Celsius to 120 degrees Celsius; Step 403: monitor the temperature average value and the temperature gradient, and when the temperature average value reaches the second preset value and the temperature gradient is less than 10 degrees Celsius per meter, enter the next stage.

[0018] The step S50 specifically includes: Step 501, setting the intermittent vacuum starting value according to the insulation level of the power equipment, when the insulation level is 35 kV, the intermittent vacuum starting value is set to 40000 Pa to 70000 Pa, when the insulation level is 110 kV, the intermittent vacuum starting value is set to 30000 Pa to 40000 Pa; Step 502: setting the third preset time according to the volume of the power equipment; when the volume is less than 10 cubic meters, the third preset time is set to 120 minutes to 180 minutes; when the volume is greater than or equal to 10 cubic meters, the third preset time is set to 180 minutes to 240 minutes; Step 503: Use a vacuum gauge to monitor the vacuum degree inside the tank body. When the vacuum degree reaches the intermittent vacuum pumping starting value, stop evacuating and maintain the third preset time.

[0019] The step S60 specifically includes: Step 601, setting the preset percentage according to the capacity level of the power equipment, when the capacity level is less than 100 MVA, the preset percentage is set to 70% to 80%, and when the capacity level is greater than or equal to 100 MVA, the preset percentage is set to 80% to 90%; Step 602: setting the fourth preset value according to the insulation level of the power equipment; when the insulation level is 35 kV, the fourth preset value is set to 10,000 Pa to 20,000 Pa; when the insulation level is 110 kV, the fourth preset value is set to 40,000 Pa to 10,000 Pa; Step 603: monitor the vacuum degree change curve during the intermittent evacuation process, calculate the vacuum degree change rate according to the vacuum degree change curve, and start the deep evacuation device when the vacuum degree change rate is less than 100 Pa per minute.

[0020] The step S70 specifically includes: Step 701, setting the fifth preset value according to the type of dielectric material of the power equipment, when the dielectric material is insulating oil-impregnated paper, setting it to 2000 Pa to 3000 Pa, when the dielectric material is a composite insulating material, setting it to 1000 Pa to 2000 Pa; Step 702, monitoring the vacuum degree inside the tank body, when the vacuum degree is less than the fifth preset value and lasts for more than 60 minutes, entering the endpoint judgment stage; Step 703: Collect vacuum degree data and calculate vacuum degree fluctuation rate. When the vacuum degree fluctuation rate is greater than 10%, extend the deep evacuation time.

[0021] The step S80 specifically includes: Step 801, monitoring the pressure increase rate in the tank, the range of which is 100 Pa per 10 minutes to 200 Pa per 10 minutes; Step 802, monitoring the pressure increase rate of the stage, which ranges from 50 Pa per 10 minutes to 100 Pa per 10 minutes; Step 803, monitoring the dew point value, which ranges from -60 degrees Celsius to -40 degrees Celsius; Step 804, monitoring the exhaust water output, the range of which is 0.5 grams per 10 minutes to 1 gram per 10 minutes; Step 805: monitor the core temperature and the coil temperature. When the temperature difference between the two is greater than 20 degrees Celsius, extend the monitoring time to 60 minutes.

[0022] The step S90 specifically includes: Step 901, obtaining real-time data of the pressure increase rate in the tank, the stage pressure increase rate, the dew point value, the exhaust water output, the core temperature and the coil temperature; Step 902, setting the sixth preset value according to the capacity level of the power equipment, including the pressure increase rate in the tank is less than 150 Pa per 10 minutes, the stage pressure increase rate is less than 75 Pa per 10 minutes, the dew point value is lower than minus 50 degrees Celsius, the exhaust water volume is less than 0.8 grams per 10 minutes, the core temperature does not exceed 90 degrees Celsius, and the coil temperature does not exceed 100 degrees Celsius; Step 903, determining whether the real-time data meets the sixth preset value, if not, starting the deep evacuation device and extending the monitoring time to 120 minutes.

[0023] The calculation or mathematical model involved in the present invention is described in detail below: 1. The calculation of vacuum change rate in S02 requires modeling: The vacuum change rate calculation equation is specifically expressed as follows: ; In the formula, is the vacuum change rate, in Pa / s; is the vacuum degree, the unit is Pa; is time, unit is s; is the current temperature in K; is the reference temperature, in K; is the cavity volume, in m³; is the volume temperature correction coefficient; is the pressure-temperature correction factor.

[0024] 2. The drying endpoint judgment equation group in S09 is specifically described as follows: The drying endpoint judgment equation group contains the rotation angle of the radiation plate; The weight equation is specifically expressed as follows: ; In the formula, For the The weight coefficient of the parameter, the value range is [0,1]; For the The standard deviation of the parameters; For the The difference between the current value and the target value of a parameter; is the total number of parameters, the value is 6; is the radiation sensitivity coefficient, which characterizes the response degree of the parameter to the radiation change and is obtained through experimental calibration; is the partial derivative of the parameter with respect to the angle of the radiation panel; is the partial derivative of the parameter with respect to the distance from the radiation plate; is a random disturbance term, which follows a normal distribution .

[0025] The parameter acquisition method is: Calculated from historical data: ,in is the number of historical data points, For the The value of historical data points, is the average value of historical data; Calculate through real-time measurement: ,in is the current measured value, is the target value; and Compute by numerical difference method: , .

[0026] The normalized equation is specifically expressed as follows: ; In the formula, For the Normalized values ​​of parameters; is the current value of the parameter; is the historical minimum value of the parameter; is the historical maximum value of the parameter; is the change rate weight coefficient, the value range is [0.1,0.3]; is the parameter change rate; is the angle influence coefficient, and its value range is [0.5,1.5]; is the angle attenuation coefficient, and its value range is [0.01,0.1]; is the angle of the radiation panel (radian); is the distance influence coefficient, and its value range is [1,3]; is the distance from the radiation panel to the measuring point (meter); is the measurement error, which follows a uniform distribution .

[0027] The comprehensive evaluation equation is specifically expressed as follows: ; In the formula, is the comprehensive index value; For parameters With parameters The correlation coefficient matrix of is the interaction coefficient, and its value range is [0.2,0.5]; is the systematic error, which follows an exponential distribution .

[0028] Among them, the correlation coefficient matrix The calculation method is: .

[0029] The determination equation is specifically expressed as follows: ; In the formula, for The result of the determination at the time; is the observation window length, the value is 30; for The comprehensive index value at the moment; is the endpoint determination threshold; is the volatility penalty coefficient, the value range is [1.5, 2.0]; In the observation window The average value of is the trend weight coefficient, and its value range is [0.3,0.7]; is the integration time window, the value is 60; is the system noise, which follows the Laplace distribution .

[0030] Explanation of the equation principle: The weight equation adopts a dual weighting mechanism of standard deviation and target distance, and introduces the partial derivative of the radiation panel position, which reflects the sensitivity of the parameters to the radiation characteristics; The normalized equation uses exponential decay and inverse square decay models to describe the influence of the angle and distance of the radiation panel, which conforms to the physical characteristics of radiation; The comprehensive evaluation equation uses a matrix form to express the correlation between parameters, which better describes the integrity and coupling of the system; The determination equation adds an integral term to capture the dynamic change characteristics of the system and improve the reliability of the determination.

[0031] The following is a detailed explanation of the derivation process and parameter sources of each equation: 1. Derivation process of weight equation: Step 1: Construct basic weight calculation formula: ; This step considers the volatility of the parameters ( ) and target gap ( ); Step 2: Introduce the influence of the radiation panel position: ; in The results are obtained by the following experiments: (1) The distance between the radiation panel and the parameter response is measured at different angles; (2) The angle is fixed and the parameter response is measured at different distances; (3) The least squares method is used to fit the obtained value; Step 3: Add random perturbation terms: ; Finally, the complete weight equation is formed.

[0032] 2. The derivation process of the normalization equation: Step 1: Standard normalization processing: ; Step 2: Add dynamic change items: ; in Determine the optimal value through time series analysis; Step 3: Introduce the angle influence function: ; Here, Gaussian function is used to describe the angle effect, where: Determined by radiation intensity measurement experiments; Determined by fitting the radiation distribution; Step 4: Introduce distance influence function: ; The inverse square law is used to describe the distance attenuation, Determined by energy decay experiments; Finally, the complete normalized equation is formed: .

[0033] 3. The derivation process of the comprehensive evaluation equation: Step 1: Construct a linear combination: ; Step 2: Introduce the correlation matrix: ; Step 3: Optimization Value: Use the cross-validation method to determine the optimal : (1) Divide the historical data into a training set and a validation set; (2) Calculate different (3) Verify the accuracy of the evaluation results on the validation set; (4) Select the one with the smallest validation error. value; Finally, a complete comprehensive evaluation equation is formed: .

[0034] 4. Derivation process of the determination equation: Step 1: Construct the basic determination formula: ; Step 2: Add volatility penalty term: ; in Determine the optimal value through Monte Carlo simulation; Step 3: Introduce trend integral term: ; The steps to determine the drying process are as follows: (1) Collect the endpoint data of the historical drying process; (2) Calculate the different (3) Select the one with the highest accuracy value; Finally, the complete determination equation is formed: .

[0035] The effects of these equations are reflected in: 1. The weight equation can dynamically adjust the importance of each parameter to adapt to the characteristics of different drying stages; 2. The normalization equation realizes the unified expression of multi-scale characteristics and improves the comparability of data; 3. The comprehensive evaluation equation captures the complex interactions between parameters and provides a more accurate assessment of the system status; 4. The determination equation comprehensively considers static and dynamic characteristics to improve the reliability of endpoint determination.

[0036] Innovations include: 1. The partial derivative description of the radiation panel position is introduced to achieve accurate characterization of spatial characteristics; 2. A variety of error distribution models are used to better conform to the randomness in actual engineering; 3. Matrix operations are used to process high-dimensional data associations to improve computational efficiency; 4. The time integral term is considered to reflect the historical evolution characteristics of the system.

[0037] Compared with the prior art, the vacuum radiation drying equipment based on electromagnetic waves and the operation method thereof provided by the present invention have the following beneficial effects: 1. Real-time and precise monitoring and control of key parameters such as temperature and pressure. The equipment is equipped with temperature sensors, pressure sensors, etc., which can monitor the temperature and vacuum changes inside the power equipment in real time, and accurately adjust the distance between the power equipment and the radiation plate through the drive device to ensure the uniformity and controllability of heating.

[0038] 2. Adaptive drying strategy. According to the capacity level, medium material type and other characteristics of different power equipment, the number of ventilation times, intermittent vacuum starting value, preset percentage and other parameters in the drying process are automatically adjusted to optimize the drying effect.

[0039] 3. Scientific drying endpoint judgment mechanism. The present invention adopts a drying endpoint judgment equation group including weight equation, normalization equation, comprehensive evaluation equation and judgment equation, combined with multiple parameters such as the boost rate, stage boost rate, dew point value, exhaust water output, temperature, etc. in the tank of the power equipment, to realize the intelligent judgment of the drying endpoint and greatly improve the stability of the drying quality.

[0040] 4. Significantly shorten the drying time. Compared with traditional hot air drying and vacuum drying, the present invention adopts electromagnetic wave radiation heating and deep vacuum evacuation, which shortens the drying time by 30%-50% and can ensure uniform temperature distribution inside the power equipment.

[0041] 5. Improve energy efficiency and reduce costs. Since the drying time is greatly shortened, the energy consumption and operating costs of the equipment are also reduced accordingly.

[0042] In summary, the electromagnetic wave vacuum radiation drying power equipment of the present invention, through precise temperature and pressure monitoring, adaptive drying strategy and scientific endpoint judgment mechanism, greatly shortens the drying time and improves energy efficiency, while also significantly improving the stability and reliability of drying quality, and solves the problem that the existing electromagnetic wave drying equipment generally has insufficient precise control and monitoring of key parameters such as temperature and pressure during the drying process, which easily leads to insufficient drying. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flow chart of the apparatus provided by the present invention; Figure 2 A flow chart of the method of operating the device provided by the present invention; Figures 3 to 7 A schematic diagram of the structure of electromagnetic wave radiation plates of different shapes in the vacuum radiation transformer drying method provided in Example 1 of the present invention; wherein, Figure 3 It is a rectangular electromagnetic wave radiation plate. Figure 4 It is a circular electromagnetic wave radiation plate. Figure 5 It is a triangular electromagnetic wave radiation plate. Figure 6 It is a diamond-shaped electromagnetic wave radiation plate. Figure 7 It is a corrugated electromagnetic wave radiation plate; Figure 8 It is a three-dimensional schematic diagram of the tank body in Example 1; Fig. 9 This is a physical picture of the tank in Example 1; Fig.10 This is a physical picture of the vacuum radiation drying equipment in Example 1. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0045] like Figure 1 The figure shows a schematic diagram of a vacuum radiation drying device based on electromagnetic waves provided by the present invention, which includes a flat car, a tank body, a radiation plate, a guide device, a drive device, a vacuum evacuation system, a gas filling system, a temperature monitoring device and a pressure monitoring device. The tank body has a lockable tank door, and the radiation plate is rotatably arranged inside the tank body. The flat car is used to carry the power equipment, and further includes a guide device for positioning the flat car, and also includes a drive device for adjusting the height of the power equipment and the position in the tank body.

[0046] The vacuum evacuation system includes a vacuum pump, which can be a vacuum pump; a vacuum pump with higher power and greater vacuum pressure can be used for deep vacuuming. The gas filling system is used to fill gas during the drying process, which can be implemented by a gas filling pump, or it can be connected to other gas tanks to fill the gas in the gas tank during the drying process. The temperature monitoring device includes an iron core temperature sensor and a coil temperature sensor installed on the power equipment to monitor the temperature. The pressure monitoring device is used to monitor the internal pressure of the tank. The distance between the power equipment and the radiation plate is adjustable, and is greater than or equal to 100 mm and less than or equal to 500 mm. The specific distance adjustment can also be achieved by fixing bolts of different lengths for fixing the radiation plate, or by installing brackets of different sizes, installing electric telescopic rods or pan-tilts on the brackets, fixing the radiation plate, and realizing the angle rotation of the radiation plate. The rotation of the angle can be precisely controlled by a single-chip microcomputer, and the power equipment can be a device containing coils and iron cores, such as a transformer, a reactor, etc.

[0047] The guide device includes a positioning pin, a guide rail and a guide wheel. The positioning pin is aligned with the central axis of the tank body, and the guide rail is installed at the bottom of the tank body. The flat car cooperates with the guide rail through the guide wheel to achieve accurate positioning and movement of the flat car. There are corresponding positioning holes on the flat car and the bottom of the tank body. The flat car can be fixed with the positioning pin by manual plugging or elastic positioning pins. The guide wheel can be installed on the flat car to cooperate with the guide rail, such as the guide rail cross section is concave to carry the guide wheel; or the guide wheel can be installed in the guide rail, and the outer circumference protrudes from the guide rail. The bottom of the flat car has a slide groove to adapt to the guide rail. When the flat car moves, the guide wheel plays a role of assisting.

[0048] The vacuum evacuation system also includes a vacuum gauge and a pressure regulating valve. The vacuum gauge is used to monitor the vacuum degree inside the tank and to control the pressure regulation of the vacuum evacuation system and the gas filling system. The gas filling system uses nitrogen or similar inert gas.

[0049] The temperature monitoring device also includes a temperature measuring meter, which is installed at the upper clamp, middle clamp and lower clamp of the power equipment and is used to comprehensively monitor the temperature changes of different parts of the power equipment.

[0050] like Figure 2 As shown, the following are the specific implementation steps of the operation method of the vacuum radiation drying equipment based on electromagnetic waves: Step S01: Before starting the automatic drying mode, place the power equipment on a flat car so that the distance between the power equipment and the radiation panel is greater than or equal to 100 mm, and move the flat car to the inner limit stop of the tank. Set the iron core 1, iron core 2, coil 1, coil 2 and temperature meter on the power equipment, and close and lock the tank door.

[0051] Step S02: Turn on the chiller and the automatic drying mode, and heat and vacuumize in the preheating stage until the vacuum change rate reaches the first preset value and then maintains the first preset time. Specifically, the vacuum change rate threshold is calculated according to the volume of the power equipment. When the volume is less than 10 cubic meters, the vacuum change rate threshold is set to 500 Pa per minute to 1000 Pa per minute. When the volume is greater than or equal to 10 cubic meters, the vacuum change rate threshold is set to 200 Pa per minute to 500 Pa per minute. The first preset time is set according to the vacuum change rate threshold. When the threshold is greater than 500 Pa per minute, the first preset time is set to 30 minutes to 60 minutes. When the threshold is less than or equal to 500 Pa per minute, the first preset time is set to 60 minutes to 120 minutes. During the heating process, the internal pressure, temperature and volume data of the tank body are collected, and the real-time vacuum change rate is calculated based on these data, and the real-time vacuum change rate is compared with the vacuum change rate threshold. When the real-time vacuum change rate is less than the threshold and the duration reaches the first preset time, the preheating stage is completed.

[0052] Step S03: Enter the temperature rise stage and fill the gas to 70,000 Pa. Set the gas filling rate according to the volume of the power equipment. When the volume is 10 cubic meters, the filling rate is set to 500 liters per minute to 1,000 liters per minute. Monitor the internal pressure of the tank and stop filling the gas when the pressure reaches 70,000 Pa. Determine the number of ventilation times according to the type of dielectric material of the power equipment. When the dielectric material is insulating oil-impregnated paper, it is set to 3 to 4 times, and when the dielectric material is a composite insulating material, it is set to 1 to 2 times. Set the ventilation time interval to 60 minutes. During each ventilation process, reduce the vacuum degree to 40,000 Pa and then fill the gas to 70,000 Pa. Monitor the pressure rise rate during the inflation process. When the pressure rise rate exceeds 10,000 Pa per minute, automatically reduce the inflation rate.

[0053] Step S04: Monitor the temperature of the iron core 1, iron core 2, coil 1, and coil 2 in the power equipment to be dried. When the temperature reaches the second preset value, enter the trunk stage. Specifically, collect these temperature data and calculate the temperature average and temperature gradient. Set the second preset value according to the capacity level of the power equipment. When the capacity level is less than 100 megavolt-amperes, the second preset value is set to 80 degrees Celsius to 100 degrees Celsius. When the capacity level is greater than or equal to 100 megavolt-amperes, the second preset value is set to 100 degrees Celsius to 120 degrees Celsius. Monitor the temperature average and temperature gradient. When the temperature average reaches the second preset value and the temperature gradient is less than 10 degrees Celsius per meter, enter the next stage.

[0054] Step S05: Set the intermittent vacuum starting value in the trunk stage, stop vacuuming and maintain the pressure for the third preset time after reaching the starting value. Specifically, the intermittent vacuum starting value is set according to the insulation level of the power equipment. When the insulation level is 35 kV, the starting value is set to 40,000 Pa to 70,000 Pa, and when the insulation level is 110 kV, the starting value is set to 30,000 Pa to 40,000 Pa. Set the third preset time according to the volume of the power equipment. When the volume is less than 10 cubic meters, the third preset time is set to 120 minutes to 180 minutes, and when the volume is greater than or equal to 10 cubic meters, the third preset time is set to 180 minutes to 240 minutes. Use a vacuum gauge to monitor the vacuum degree inside the tank. When the vacuum degree reaches the intermittent vacuum starting value, stop vacuuming and maintain the third preset time.

[0055] Step S06: Perform intermittent evacuation cycles according to a preset percentage until the vacuum reaches a fourth preset value and then perform deep evacuation. Specifically, the preset percentage is set according to the capacity level of the power equipment. When the capacity level is less than 100 MVA, the preset percentage is set to 70% to 80%. When the capacity level is greater than or equal to 100 MVA, the preset percentage is set to 80% to 90%. The fourth preset value is set according to the insulation level of the power equipment. When the insulation level is 35 kV, the fourth preset value is set to 10,000 Pa to 20,000 Pa. When the insulation level is 110 kV, the fourth preset value is set to 40,000 Pa to 10,000 Pa. During the intermittent evacuation process, the vacuum change curve is monitored. According to the vacuum change rate, when the change rate is less than 100 Pa per minute, the deep evacuation device is started.

[0056] Step S07: When the vacuum degree reaches the fifth preset value, enter the endpoint judgment stage. Specifically, the fifth preset value is set according to the dielectric material type of the power equipment. When the dielectric material is insulating oil-impregnated paper, it is set to 2000 Pa to 3000 Pa, and when the dielectric material is a composite insulating material, it is set to 1000 Pa to 2000 Pa. Monitor the vacuum degree inside the tank. When the vacuum degree is less than the fifth preset value and the duration exceeds 60 minutes, enter the endpoint judgment stage. At the same time, collect vacuum degree data and calculate the vacuum degree fluctuation rate. When the fluctuation rate is greater than 10%, extend the deep evacuation time.

[0057] Step S08: After running for 30 minutes in the end judgment stage, stop for 10 minutes to monitor the boost rate, stage boost rate, dew point value, exhaust water output, iron core temperature and coil temperature in the tank. Specifically, it includes: monitoring the boost rate in the tank, which ranges from 100 Pa per 10 minutes to 200 Pa per 10 minutes; monitoring the stage boost rate, which ranges from 50 Pa per 10 minutes to 100 Pa per 10 minutes; monitoring the dew point value, which ranges from minus 60 degrees Celsius to minus 40 degrees Celsius; monitoring the exhaust water output, which ranges from 0.5 grams per 10 minutes to 1 gram per 10 minutes; monitoring the iron core temperature and coil temperature, and when the temperature difference between the two is greater than 20 degrees Celsius, the monitoring time is extended to 60 minutes.

[0058] Step S09: Use the drying endpoint judgment equation group to comprehensively evaluate the boost rate, stage boost rate, dew point value, exhaust water output, core temperature and coil temperature in the tank. Specifically, it includes: obtaining real-time data of these parameters, setting the sixth preset value according to the capacity level of the power equipment, including the boost rate in the tank is less than 150 Pa per 10 minutes, the stage boost rate is less than 75 Pa per 10 minutes, the dew point value is lower than minus 50 degrees Celsius, the exhaust water output is less than 0.8 grams per 10 minutes, the core temperature does not exceed 90 degrees Celsius, and the coil temperature does not exceed 100 degrees Celsius. Determine whether the real-time data meets the sixth preset value. If it does not meet the sixth preset value, start the deep evacuation device and extend the monitoring time to 120 minutes.

[0059] The drying endpoint judgment equation group includes weight equation, normalization equation, comprehensive evaluation equation and determination equation. The weight equation is used to calculate the dynamic weight coefficient of each monitoring parameter, taking into account the volatility of the parameter and the degree of proximity to the target. The normalization equation is used to convert each parameter into a dimensionless value, taking into account the absolute value and change trend of the parameter. The comprehensive evaluation equation calculates the comprehensive index of the drying state, taking into account the interaction between parameters. The determination equation determines whether the drying endpoint is reached, and adopts the sliding window average and fluctuation penalty mechanism to improve the stability and reliability of the determination.

[0060] Step S10: When the output result of the drying endpoint determination equation indicates that the drying endpoint has been reached, the drying process is terminated; if the drying endpoint has not been reached, the vacuum is continued until the endpoint determination condition is met. Specifically, it includes: detecting the relative position of the flat car and the tank body, and when the flat car moves to the bottom of the central axis of the tank body, the flat car is fixed by a guide device; measuring the distance between the power equipment and the radiation plate on the top of the tank body, and driving the power equipment to be dried on the flat car to rise and fall through a driving device placed on the flat car, such as a hydraulic lifting platform, and adjusting the height of the power equipment until the distance to the radiation plate on the top is greater than or equal to 100 mm and less than or equal to 500 mm; horizontal movement can be achieved by moving the guide rail / screw of the X-axis or Y-axis to realize the movement of the power equipment to be dried on the workbench surface, and keep it in the center of the tank body to avoid manual placement and adjustment of the position by the user. Install the iron core 1 and the iron core 2 at the central column position of the power equipment, and install the coil 1 and the coil 2 on the periphery with an angle of 120 degrees; install a temperature meter at a preset temperature measuring point position on the surface of the power equipment, including an upper clamp, a middle clamp and a lower clamp; detect the sealing performance of the tank door sealing ring, and judge that the sealing performance is qualified when the ratio of the sealing ring contact area to the total area is greater than 0.95.

[0061] Specifically, the principle of the present invention is: the core of the technical solution of the electromagnetic wave vacuum radiation drying power equipment of the present invention is to effectively solve the problems existing in the existing drying technology through precise monitoring and adaptive control combined with a scientific drying endpoint judgment mechanism.

[0062] First, the equipment uses a radiation plate as a heating source, and uses electromagnetic waves to directly act on the inside of the power equipment, which can achieve rapid and uniform heating. At the same time, the vacuum environment inside the equipment can not only improve the heating efficiency, but also reduce the aging of the insulating material by oxygen. The real-time monitoring of the temperature sensor and the pressure sensor, combined with the precise adjustment of the height of the power equipment by the drive device, ensures the controllability and uniformity of the heating, and avoids problems such as local overheating.

[0063] Secondly, the various parameter settings in the drying process, such as the number of ventilation times, the intermittent vacuum starting value, the preset percentage, etc., are adaptively adjusted according to the capacity level of different power equipment, the type of dielectric material, etc. This adaptive strategy enables the drying process to be optimized according to the characteristics of different equipment, thus improving the drying effect.

[0064] Finally, the present invention adopts a set of drying endpoint judgment equations including weight equations, normalization equations, comprehensive evaluation equations and judgment equations. This set of equations comprehensively considers multiple parameters such as the pressure increase rate in the tank, the stage pressure increase rate, the dew point value, the exhaust water output, and the temperature. It can not only evaluate the current drying state in real time, but also predict the drying trend, providing a scientific basis for determining the optimal drying endpoint. Compared with the traditional endpoint judgment method that relies on experience, this set of equations greatly improves the repeatability and stability of the drying quality.

[0065] In order to better understand and implement the present invention, the following provides Example 1 of the first specific application scenario of the present invention: A power equipment manufacturing company is producing a 110kV large transformer, which uses a composite insulation material as a power medium. In order to ensure the insulation stability of the transformer during long-term operation, the company decides to use the vacuum radiation drying technology based on electromagnetic waves proposed in the present invention to dry the transformer.

[0066] The main parameters of the transformer are shown in Table 1:

[0067] According to the specific parameters of the transformer, the company has formulated the following implementation plan: 1. Installation and debugging of the device: First, place the transformer on the flat car of the equipment, and adjust the distance between the transformer and the radiation plate to 400 mm through the driving device. The core temperature sensor and the coil temperature sensor are installed on the central column and the periphery of the transformer respectively, and the temperature measurement points include the upper, middle and lower clamps. After testing, the contact area of ​​the tank door sealing ring accounts for 98% of the total area, and it can be determined that the sealing is good. The radiation plate provided in this embodiment 1 can be divided into 5 shapes, among which, Figure 3 It is a rectangular electromagnetic wave radiation plate, mainly used in some conventional transformer vacuum drying technologies. Figure 4 It is a circular electromagnetic wave radiation plate. Each of the radiation plates is small in size and arranged side by side. It is mainly used in small-capacity transformers. Figure 5 and Figure 6 They are respectively a triangular electromagnetic wave radiation plate and a diamond electromagnetic wave radiation plate. The radiation plate is mainly used for air-cooled dry-type transformers. Figure 7 It is a corrugated electromagnetic wave radiation plate, which is mainly used in large transformers. Selecting a suitable electromagnetic wave radiation plate according to the type of transformer to be dried can reduce the power loss during system operation and increase the drying efficiency. Fig. 9 , 10 shown.

[0068] Furthermore, after a large number of tests, the tank (such as Figure 8 , 9The method for arranging the size, shape and number of the electromagnetic wave radiation plates in the vacuum radiation transformer drying method specifically includes: when the vacuum radiation transformer drying method is used to vacuum dry a small-capacity transformer, a circular electromagnetic wave radiation plate is selected, and multiple circular electromagnetic wave radiation plates are arranged side by side; when the vacuum radiation transformer drying method is used to vacuum dry an air-cooled dry-type transformer, a rectangular electromagnetic wave radiation plate, a triangular electromagnetic wave radiation plate or a diamond electromagnetic wave radiation plate is selected; when the vacuum radiation transformer drying method is used to vacuum dry a large transformer, a rectangular electromagnetic wave radiation plate, a triangular electromagnetic wave radiation plate, a diamond electromagnetic wave radiation plate or a corrugated electromagnetic wave radiation plate is selected. Among them: (1) A circular electromagnetic wave radiation plate is used, each furnace consumes 1000 degrees of electricity, each furnace takes 14.8 hours, and the trace water content is controlled within 20ppm.

[0069] (2) A rectangular electromagnetic wave radiation plate is used, each furnace consumes 1000 degrees of electricity, each furnace takes 15 hours, and the trace water content is controlled within 20ppm-35ppm.

[0070] (3) Using triangular electromagnetic wave radiation plates, each furnace consumes 1000 degrees of electricity, each furnace takes 15 hours, and the trace water content is controlled within 20ppm.

[0071] (4) Using diamond-shaped electromagnetic wave radiation plates, each furnace consumes 1000 degrees of electricity, each furnace takes 15 hours, and the trace water content is controlled within 20ppm.

[0072] (5) Using corrugated electromagnetic wave radiation plate, each furnace consumes 1000 degrees of electricity, each furnace takes 15 hours, and the trace water content is controlled within 20ppm-35ppm.

[0073] 2. Preheating stage: After turning on the automatic drying mode, the preheating stage is entered first. According to the transformer volume of 13 m³, the vacuum change rate threshold is calculated to be 300 Pa / min to 500 Pa / min, and the first preset time is set to 90 minutes. During the heating and vacuuming process, the real-time vacuum change rate is calculated by real-time monitoring of the pressure, temperature and volume changes inside the tank. When the real-time vacuum change rate is less than 300 Pa / min and the duration reaches 90 minutes, the preheating stage is completed.

[0074] 3. Heating stage: After entering the heating stage, start filling the tank with gas. According to the volume of the transformer of 13 m³, set the gas filling rate to 800 L / min. Monitor the pressure in the tank and stop filling when it reaches 70,000 Pa. Considering that the transformer uses composite insulation materials, set the number of ventilation times to 2 times, with an interval of 180 minutes each time. During each ventilation process, first reduce the vacuum degree to 40,000 Pa, and then fill the gas to 70,000 Pa. During the inflation process, closely monitor the pressure rise rate, and automatically reduce the inflation rate when it exceeds 10,000 Pa / min.

[0075] 4. Main stage: When the core temperature and coil temperature both reach 110 degrees Celsius, enter the main stage. First, according to the insulation level of the transformer 110kV, set the intermittent vacuum starting value to 40000 Pa, and combined with the volume of the transformer 13 m³, set the third preset time to 210 minutes. During the intermittent vacuuming process, a vacuum gauge is used to monitor the vacuum degree in the tank in real time. Once it reaches 40000 Pa, stop vacuuming and keep it for 210 minutes. Preferably, 50000Pa can also be selected.

[0076] 5. Deep evacuation: According to the capacity level of the transformer 200MVA, the preset percentage is set to 85%, that is, the vacuum degree is maintained between 40000 Pa and 80000 Pa each time the evacuation is performed. At the same time, according to the 110kV insulation level, the fourth preset value is set to 8000 Pa. During the intermittent evacuation process, the vacuum degree change rate is monitored in real time. Once it is less than 100 Pa / min, the deep evacuation device is started until the vacuum degree is less than 2000 Pa.

[0077] 6. End point judgment: When the vacuum degree is less than 2000 Pa and the duration exceeds 60 minutes, the end point judgment stage is entered. In this stage, the system first runs for 30 minutes and then stops for 10 minutes to measure the pressure increase rate, stage pressure increase rate, dew point value, exhaust water output, core temperature, coil temperature and other parameters in the tank.

[0078] According to the transformer's capacity rating of 200MVA, the target value of the voltage boost rate inside the tank is less than 150 Pa / 10min, the target value of the stage voltage boost rate is less than 75 Pa / 10min, the target dew point value is below minus 50 degrees Celsius, the target exhaust water output is less than 0.8g / 10min, the core temperature does not exceed 90 degrees Celsius, and the coil temperature does not exceed 100 degrees Celsius.

[0079] The measured data generated during the above drying process is brought into the drying endpoint judgment equation group for comprehensive evaluation. If the judgment result shows that the drying endpoint has been reached, the drying process is terminated; if it does not meet the standard, deep evacuation is continued until the endpoint judgment conditions are met.

[0080] Through precise control and adaptive adjustment of the above six steps, the 110kV transformer finally completed the drying process, and all performance indicators met the requirements, laying the foundation for subsequent long-term stable operation.

[0081] Embodiment 2: A power company is planning to carry out routine maintenance on a 35kV distribution transformer, which includes drying the insulation material (insulating oil-impregnated paper) inside the transformer. The company decides to use the vacuum radiation drying technology based on electromagnetic waves proposed in the present invention to dry the transformer.

[0082] The main parameters of the 35kV distribution transformer are shown in Table 2:

[0083] According to the specific parameters of the transformer, the company took the following steps: Step 01: First, place the 35kV distribution transformer on the flat car of the equipment, and adjust the distance between the transformer and the radiation plate to 350 mm through the drive device on the flat car. Install the core 1 and core 2 sensors at the center column of the transformer, install the coil 1 and coil 2 sensors on the periphery, and install the temperature gauges at the upper, middle and lower clamps on the surface of the transformer. After testing, the contact area of ​​the tank door sealing ring of the transformer accounts for 97% of the total area, which can be judged to be in good sealing condition. After completing the above preparations, close and lock the tank door.

[0084] Step 02: After turning on the automatic drying mode, enter the preheating stage. According to the transformer volume of 8 m³, the vacuum change rate threshold is calculated to be 400 Pa / min to 700 Pa / min, and the first preset time is set to 75 minutes. During the heating and vacuuming process, the real-time vacuum change rate is calculated by real-time monitoring of the pressure, temperature and volume changes inside the tank. When the real-time vacuum change rate is less than 400 Pa / min and the duration reaches 75 minutes, the preheating stage is completed.

[0085] Step 03: After entering the temperature rise stage, start filling the tank with gas. According to the volume of the transformer of 8 m³, set the gas filling rate to 600 L / min. Monitor the pressure in the tank and stop filling when it reaches 70000 Pa. Considering that the transformer uses insulating oil-impregnated paper, set the number of ventilation times to 3 times, with an interval of 180 minutes each time. During each ventilation process, first reduce the vacuum degree to 40000 Pa, and then fill the gas to 70000 Pa. During the inflation process, closely monitor the pressure rise rate, and automatically reduce the inflation rate when it exceeds 10000 Pa / min.

[0086] Step 04: When the temperature of core 1, core 2, coil 1, and coil 2 all reach 90 degrees Celsius, enter the main stage. According to the insulation level of the 35kV transformer, the intermittent vacuum starting value is set to 60000 Pa, and combined with the volume of the transformer of 8 m³, the third preset time is set to 150 minutes. During the intermittent vacuuming process, a vacuum gauge is used to monitor the vacuum degree in the tank in real time. Once it reaches 60000 Pa, the vacuuming is stopped and maintained for 150 minutes.

[0087] Step 05: According to the 35kV transformer with a capacity of 50MVA, the preset percentage is set to 75%, that is, the vacuum degree is maintained between 60000 Pa and 80000 Pa each time the vacuum is evacuated. At the same time, according to the 35kV insulation level, the fourth preset value is set to 140000 Pa. During the intermittent evacuation process, the vacuum degree change rate is monitored in real time. Once it is less than 100 Pa / min, the deep evacuation device is started until the vacuum degree is less than 2500 Pa.

[0088] Step 06: When the vacuum degree is less than 2500 Pa and lasts for more than 60 minutes, enter the endpoint judgment stage. In this stage, run for 30 minutes and then stop for 10 minutes to measure the pressure increase rate, stage pressure increase rate, dew point value, exhaust water output, core temperature and coil temperature in the tank.

[0089] According to the capacity of the 0MVA transformer, the target value of the voltage boost rate inside the tank is less than 150 Pa / 10min, the target value of the stage voltage boost rate is less than 75 Pa / 10min, the target dew point value is below minus 50 degrees Celsius, the target exhaust water output is less than 0.8 g / 10min, the core temperature does not exceed 90 degrees Celsius, and the coil temperature does not exceed 100 degrees Celsius.

[0090] The measured data is brought into the drying endpoint judgment equation group for comprehensive evaluation. If the judgment result shows that the drying endpoint has been reached, the drying process is terminated; if it does not meet the standard, deep evacuation is continued until the endpoint judgment conditions are met.

[0091] Specifically, the specific calculation process of comprehensive evaluation using the drying endpoint judgment equation group is described in detail as follows: (1) Transformer weight calculation process: ; ; ; ; Substituting into the weight equation: ; Since the weights change over time, after calculation, the following table 3 shows the weight changes over time: Table 3 Weight changes over time

[0092] (2) Calculate the normalized value ; The normalized values ​​at different stages are calculated and shown in Table 4 below.

[0093] Table 4 Normalized value calculation table

[0094] (3) Calculate the correlation coefficient matrix R: ; Substitute into the comprehensive evaluation equation: ; (4) Based on the data of the 30-minute observation window, calculate the decision function: ; The determination results at different time points are shown in Table 5 below: Table 5 Judgment results table

[0095] In addition, in the process of this embodiment, the judgment was also made according to the traditional manual judgment method and the threshold judgment method, and the judgment accuracy was judged according to the actual results after drying. The accuracy formula is the dryness at the end point of the judgment / the final dryness, where the final dryness refers to the dryness obtained by the complete drying experiment without considering the loss caused by over-drying of the drying equipment. As shown in Table 6, it is an evaluation comparison table of the three methods.

[0096] Table 6 Evaluation comparison of three methods

[0097] Step 07: According to the end point judgment result, if the drying end point has not been reached, continue to deep evacuate. Specifically include: detecting the relative position of the flat car and the tank body, opening the guide device when the flat car moves to the bottom of the central axis of the tank body; measuring the distance between the transformer and the radiation plate, adjusting it to 350 mm to 500 mm through the drive device; installing the core 1, core 2 and coil 1, coil 2 sensors on the central column and periphery of the transformer respectively, and installing a temperature gauge at the preset temperature measurement point on the surface; detecting the sealing of the tank door sealing ring, and judging it as qualified when the ratio of the contact area to the total area is greater than 0.95.

[0098] By adopting the drying endpoint judgment equation group of the present invention, compared with the traditional manual experience judgment and simple parameter threshold judgment method, it has the following significant advantages: First, in terms of accuracy, the traditional manual experience judgment mainly relies on the subjective judgment of the operator, which is easily affected by personal experience and working status, and the judgment result has large fluctuations. Although the simple parameter threshold judgment has established a fixed standard, it cannot adapt to the specific conditions under different working conditions. The equation group of the present invention realizes the dynamic adjustment of parameter importance through the weight equation, the normalization equation ensures the comparability of different parameters, the comprehensive evaluation equation captures the interaction between parameters, and the judgment equation considers the dynamic characteristics of the system, making the endpoint judgment more objective and accurate. Actual application data show that the judgment accuracy of the method of the present invention is 25% higher than that of the traditional method and 15% higher than that of the simple threshold judgment. Secondly, in terms of adaptability, the traditional judgment method is difficult to cope with complex and changeable drying conditions. When encountering transformers of different specifications and different insulation structures, it is necessary to re-formulate the judgment standard. The equation group of the present invention realizes adaptive adjustment to different working conditions by considering the influence of the radiation plate position, introducing a variety of error distribution models, and using matrix operations to process high-dimensional data associations and other innovative designs. Test data show that the adaptability of the method of the present invention to different types of transformers reaches more than 90%, which is much higher than the 65% of the traditional method and the 75% of the simple threshold judgment. In terms of efficiency, traditional manual judgment often adopts a conservative strategy, resulting in extended drying time. Although simple threshold judgment can shorten the time, under-drying or over-drying may occur. The equation group of the present invention realizes precise control of the drying process by real-time calculation of the weights of each parameter and dynamic evaluation of the system state. Statistical data show that the method of the present invention can shorten the drying time by 20% to 30%, while ensuring that the drying quality meets the standard. In terms of reliability, traditional methods are difficult to deal with abnormal situations. Once sensor failure or process fluctuation occurs, it is easy to cause judgment errors. The equation group of the present invention establishes a reliable judgment mechanism through multi-sensor data fusion, parameter interaction analysis, system dynamic feature extraction and other means. Practice has proved that even in the case of partial sensor failure, the method of the present invention can still maintain a judgment accuracy of more than 85%. In terms of economy, traditional judgment methods often cause energy waste and require experienced operators to be on duty for a long time. The equation group of the present invention reduces labor costs and energy consumption through intelligent judgment, and avoids equipment damage caused by overdrying. According to statistics, the method of the present invention can save 15% to 20% of the operating cost, and the energy-saving effect is remarkable.

[0099] It should be noted that the variables involved in the description of the present invention are explained in detail as shown in Table 7 below.

[0100] Table 7 Variable explanation table

[0101] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vacuum radiation drying device based on electromagnetic waves, characterized in that: include: A flat car, a tank body, a radiation plate, a vacuum evacuation system, a gas filling system, a temperature monitoring device and a pressure monitoring device; wherein the tank body has a lockable tank door, the radiation plate is rotatably arranged inside the tank body, the flat car is used to carry electrical equipment, the vacuum evacuation system includes a vacuum pumping device, the gas filling system is used to fill gas during the drying process, the temperature monitoring device includes: a core temperature sensor and a coil temperature sensor installed on the electrical equipment to be dried, the pressure monitoring device is used to monitor the internal pressure of the tank body, and the distance between the electrical equipment and the radiation plate is adjustable and is not less than 100 mm and not more than 500 mm.

2. The vacuum radiation drying equipment based on electromagnetic waves according to claim 1, characterized in that: Also includes: The guide device includes a positioning pin, a guide rail and a guide wheel. The positioning pin is aligned with the central axis of the tank body. The guide rail is installed at the bottom of the tank body. The flat car cooperates with the guide rail through the guide wheel to achieve positioning and movement of the flat car.

3. The vacuum radiation drying equipment based on electromagnetic waves according to claim 2, characterized in that: The vacuum evacuation system also includes a vacuum gauge and a pressure regulating valve. The vacuum gauge is used to monitor the vacuum degree inside the tank body. The pressure regulating valve is used to control the pressure regulation of the vacuum evacuation system and the gas filling system. The gas filling system uses nitrogen.

4. The vacuum radiation drying equipment based on electromagnetic waves according to claim 3, characterized in that: The temperature monitoring device also includes a temperature measuring meter, which is installed at the upper clamp, middle clamp and lower clamp of the power equipment and is used to comprehensively monitor the temperature changes of different parts of the power equipment.

5. An operating method of a vacuum radiation drying device based on electromagnetic waves using the vacuum radiation drying device according to claim 1, characterized in that: The following steps are involved: S01. Before starting the automatic drying mode, place the electrical equipment on a flat cart, move the flat cart to the inner limit stop of the tank body, make the distance between the electrical equipment and the radiation plate not less than 100 mm, arrange an iron core (1), an iron core (2), a coil (1), a coil (2) and a temperature gauge on the electrical equipment, and close and lock the tank door; S02, turning on the chiller and the automatic drying mode, heating and vacuuming in the preheating stage, and maintaining the vacuum change rate for a first preset time after reaching a first preset value; S03, entering the temperature rising stage, filling with gas to 70000 Pa, setting the ventilation frequency to more than 10 times according to the size of the power equipment, and performing ventilation cycles at any interval of 30 to 90 minutes. After each ventilation process, the vacuum degree is drawn to 40000 Pa and then filled with gas to 70000 Pa; S04, monitoring the temperatures of the iron core (1), the iron core (2), the coil (1), and the coil (2), and when the temperatures all reach a second preset value, entering the main stage; S05, setting an intermittent vacuuming starting value in the trunk stage, stopping vacuuming after reaching the starting value and maintaining the pressure for a third preset time; S06, performing intermittent evacuation cycles according to a preset percentage until the vacuum degree reaches a fourth preset value and then performing deep evacuation; S07, when the vacuum degree reaches the fifth preset value, entering the endpoint judgment stage; S08, after running for 30 minutes in the endpoint judgment stage, stop for 10 minutes to monitor the pressure increase rate, stage pressure increase rate, dew point value, exhaust water output, core temperature and coil temperature in the tank; S09, using a drying endpoint judgment equation group to comprehensively evaluate the pressure increase rate, stage pressure increase rate, dew point value, exhaust water output, core temperature and coil temperature in the tank; the drying endpoint judgment equation group includes the rotation angle of the radiation plate; S10. When the output result of the determination equation indicates that the drying end point has been reached, the drying process is terminated; if the drying end point has not been reached, deep evacuation is continued until the end point determination condition is met.

6. The vacuum radiation drying equipment based on electromagnetic waves according to claim 5, characterized in that: The drying endpoint judgment equation group includes a weight equation, a normalization equation, a comprehensive evaluation equation and a judgment equation.

7. The vacuum radiation drying equipment based on electromagnetic waves according to claim 6, characterized in that: The weight equation is used to calculate the dynamic weight coefficient of each monitoring parameter. The input includes the historical data of the boost rate in the tank, the historical data of the stage boost rate, the historical data of the dew point value, the historical data of the exhaust water output, the historical data of the core temperature and the historical data of the coil temperature. The output is the weight coefficient of each parameter.

8. The vacuum radiation drying equipment based on electromagnetic waves according to claim 7, characterized in that: The normalization equation is used to convert each monitoring parameter into a dimensionless value. The input includes the pressure increase rate in the tank at the current moment, the stage pressure increase rate, the dew point value, the exhaust water output, the core temperature, the coil temperature and their corresponding target values. The output is the normalized value of each parameter.

9. The vacuum radiation drying device based on electromagnetic waves according to claim 8, characterized in that: The comprehensive evaluation equation is used to calculate the comprehensive index of the drying state, the input includes the weight coefficient and normalized value of each parameter, and the output is the comprehensive index value reflecting the current drying state.

10. The vacuum radiation drying device based on electromagnetic waves according to claim 9, characterized in that: The determination equation is used to determine whether the drying endpoint is reached, the input includes the comprehensive index value and its stability index, and the output is the drying endpoint determination result.

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