74 results about "Steady state temperature" patented technology

The invention provides an electrical equipment overheating hidden danger early warning method and system based on unmanned aerial vehicle multi-spectral imaging, and belongs to the technical field of power equipment state monitoring, and the method comprises the steps: firstly obtaining ultraviolet photons and spatial point cloud data collected by an unmanned aerial vehicle; a three-dimensional model is constructed based on the point cloud, and electric field distribution information is obtained through finite element analysis. And the photon data and the electric field information are combined, and the discharge charge quantity and distribution are obtained through space inversion correction. And calculating the discharge current density by using an energy dissipation model, and determining the discharge thermal power loss density in combination with the local electric field. And finally, a steady-state heat conduction equation is solved based on the heat conduction and dissipation parameters, temperature field distribution under heat balance is calculated, and early warning information is generated when the steady-state temperature exceeds a heat-resistant threshold value. According to the invention, early-stage accurate prediction and positioning of the hidden overheating fault of the electrical equipment caused by insulation degradation are realized.

The invention discloses a wire temperature-current-carrying capacity coupling prediction method and system considering environmental factor correction, and belongs to the technical field of power transmission lines, and the method comprises the steps: obtaining the steady-state temperature, current-carrying capacity and environmental parameters of a wire, and carrying out the supplementation of missing values; establishing a current-carrying capacity-temperature polynomial equation based on the data after missing value supplementation; state judgment is carried out on the working condition of the wire according to the environment temperature change rate, and wire temperatures in different states are obtained through calculation; and inputting real-time environment parameters into a parameterized model obtained by fitting according to historical data, and jointly substituting into the current-carrying capacity-temperature polynomial equation in combination with the conductor temperatures in different states to obtain the current-carrying capacity. According to the method, the coefficient generation model can be finely adjusted to ensure that the model can adapt to physical characteristic changes caused by factors such as aging and pollution of the line, and long-term prediction precision is kept.

The invention relates to the technical field of nanofluid enhanced heat transfer simulation, in particular to a molecular dynamics-based mixed nanofluid heat transfer characteristic analysis method, which comprises the following steps of: constructing a molecular model comprising copper, graphene nanoparticles and an ionic liquid / water mixed base solution, and calculating the heat transfer characteristic of the mixed nanofluid through a distribution potential function and a periodic boundary condition; and performing energy minimization and molecular dynamic relaxation to achieve thermodynamic equilibrium. A steady-state temperature gradient is established based on the unbalanced molecular dynamics principle, and the thermal conductivity is calculated according to the Fourier law. Microcosmic parameters such as a radial distribution function, mean square displacement and the number of hydrogen bonds are synchronously analyzed, and a coupling mechanism of interaction and heat transfer performance of the nano-particle-base fluid interface is disclosed. According to the method, the heat transfer characteristic of the mixed nanofluid can be clarified on the molecular scale, and an efficient and reliable analysis means is provided for nanofluid screening and design in application of a solar heat collector, a heat management system and the like.

The invention provides a temperature compensation method for a pressure sensor, and the method comprises the steps: applying a plurality of known pressures to the pressure sensor at a plurality of steady-state temperatures, and collecting the corresponding output voltages of the pressure sensor at the steady-state temperatures and the known pressures; determining a reference parameter of the pressure sensor for temperature compensation according to a mapping relation among the steady-state temperature, the known pressure and the output voltage; in the real-time working process of the pressure sensor, environment temperature data of the pressure sensor are continuously collected at a preset frequency, and a temperature sequence is formed; predicting a temperature change trend in a future time period according to the temperature sequence; based on the output voltage, the temperature change trend and the reference parameters of the pressure sensor at the current moment, the pressure value after dynamic temperature compensation is obtained, the hysteresis of traditional static temperature compensation during dynamic temperature change is effectively overcome, and the measurement precision and the dynamic response capability of the pressure sensor under the complex temperature change working condition are remarkably improved.

The invention relates to an environment-friendly switch vacuum arc-extinguishing chamber contact temperature monitoring method and system based on surface acoustic wave array sensing and inversion, and belongs to the field of electrical monitoring. In order to solve the problem that in the prior art, non-intrusive and high-reliability monitoring of the contact temperature of the vacuum arc-extinguishing chamber is difficult to realize due to vacuum sealing and metal shielding, the technical scheme of the invention is as follows: an acoustic surface wave sensor array comprising three or more sensing nodes is constructed on the outer wall of the vacuum arc-extinguishing chamber, and the longitudinal temperature gradient distribution of the outer wall is captured in a lossless manner. A narrow-band flat-plate reader antenna is adopted to realize array signal parallel transmission with a high signal-to-noise ratio, and the steady-state temperature of an internal contact is accurately inverted through a pre-trained physical information neural network (PINN) model by utilizing multi-source data fusion and array characteristics. According to the method, a non-intrusive monitoring function from external sensing to internal deduction is realized, the problem that the temperature of the contact cannot be measured in a high-voltage closed environment is solved, and a key technical support is provided for safe operation of environment-friendly switch equipment.

The invention discloses an IGBT temperature field calculation method, system, medium and equipment based on data driving, and the method comprises the steps: building a finite element thermal model based on the geometric structure and material thermal parameters of an IGBT module; simulating steady-state temperature field distribution under each working condition by using a finite element thermal model, and constructing a multi-working-condition training data set comprising input variables and corresponding temperature field output; constructing a main network-branch network neural network model, and training the main network-branch network neural network model by using the multi-working-condition training data set; inputting the power loss value and heat dissipation parameters measured in real time into an IGBT temperature field prediction model to obtain an initial temperature field prediction result; updating the power loss value according to the initial temperature field prediction result, and inputting the updated power loss into the IGBT temperature field prediction model again for a new round of temperature field prediction; and repeatedly executing until the power loss difference value between two adjacent iterations is smaller than a preset convergence threshold value, stopping iteration and outputting a final steady-state temperature field.

The invention discloses a vacuum circuit breaker conductive loop temperature rise simulation optimization method, which comprises the following steps of: obtaining structure parameters of a circuit breaker, identifying a temperature rise sensitive area and constructing a simplified geometric model and a grid model; establishing a multilayer coating equivalent model and a contact resistance analytical model based on the coating parameters and the surface roughness, and determining initial contact parameters; constructing an electro-thermal coupling multi-physical field simulation model, executing bidirectional coupling iteration solution of a current field and a temperature field, and dynamically correcting the resistance value of the contact resistance analysis model according to the current temperature field distribution in the iteration process until a convergence condition is met; and outputting a steady-state temperature field and determining an optimal process scheme. According to the method, the temperature-load coupled contact resistance dynamic evolution model is established, so that the problem of prediction deviation caused by neglecting of contact surface microstructure dynamic change in traditional simulation is solved, and the temperature rise calculation precision is improved.

The invention relates to a hot rod effective power evaluation method based on spatial distribution characteristics of a soil body temperature field, and is suitable for permafrost region engineering. The method comprises the following steps: selecting a hot rod which works stably, arranging temperature measuring holes on a horizontal section of a vertical axis in the middle of an evaporation section according to a near field, a middle field and a far field, and obtaining soil body temperatures T at different radial distances r; based on the steady-state heat conduction theory, regression analysis is carried out on measured data, a mathematical model T = C1 * ln (r) + C2 is constructed, and a coefficient C1 is solved; and combining the heat conductivity coefficient lambda of the soil body with the effective length L of the hot rod, and calculating the effective refrigeration power of the hot rod on the soil body by utilizing a formula Q =-2pi lambda LC1. The method does not need to pre-embed a sensor, does not interfere with the operation of the hot rod, and can include the contact thermal resistance influence between the hot rod and the soil body. The method has the advantages of high measurement precision, low cost and the like, and realizes in-situ and quantitative evaluation of the actual refrigeration efficiency of the existing engineering hot rod.

The invention discloses a temperature prediction method for a motor component, the motor component comprises at least one of a rotor or a stator, and the method comprises the steps that a motor controller obtains the instantaneous temperature and the current value of the motor component at a first moment, and inquires a first calibration table according to the current value and the position of the rotor, the steady-state temperature of the motor component and the time parameter of the motor component are obtained, and the time parameter comprises at least one of the winding time constant of the stator or the permanent magnet time constant of the rotor. And then, according to the instantaneous temperature of the motor component at the first moment, the steady-state temperature of the motor component and the time parameter of the motor component, predicting the instantaneous temperature of the motor component at the second moment. The data required by the method can be accurately obtained through measurement or query under different working conditions of the motor, so that the method has accuracy and universality.

The invention discloses a method and a device for measuring contact thermal resistance under a vacuum condition by taking an electron beam as a heat source, and relates to the technical field of thermotechnical measurement. The device comprises a vacuum cavity, an upper pressing plate with a through hole, an electron beam heating unit, a tungsten ingot, a sample piece stacking body formed by coaxially stacking a sample piece A and a sample piece B, a water cooling module, a heat insulation unit, a pressure applying unit, a temperature measuring unit and a control unit. The method comprises the following steps: heating a tungsten ingot by electron beams in vacuum, and establishing a steady-state temperature field through water cooling; acquiring steady-state temperature data under two different heating powers; a group of data is used as a reference, the interface temperature difference and the heat flux density are accurately solved by adopting a reference method in combination with the heat conductivity of the sample, and finally the contact thermal resistance is calculated. According to the method, the problems of air heat conduction interference, insufficient heat source power and large lateral heat loss in a traditional method are solved, and high-precision direct measurement of the contact thermal resistance of the solid interface under the vacuum, high-temperature and high-heat-flow conditions is realized.

This application provides a method and system for early warning of overheating hazards in electrical equipment based on UAV multispectral imaging, belonging to the field of power equipment condition monitoring technology. This application first acquires ultraviolet photon and spatial point cloud data collected by a UAV. A three-dimensional model is constructed based on the point cloud, and electric field distribution information is obtained through finite element analysis. Combining photon data and electric field information, the discharge charge quantity and distribution are obtained through spatial inversion correction. Then, the discharge current density is calculated using an energy dissipation model, and the discharge heat power loss density is determined by combining the local electric field. Finally, the steady-state heat conduction equation is solved based on heat conduction parameters to calculate the temperature field distribution under thermal equilibrium. When the steady-state temperature exceeds the heat resistance threshold, an early warning message is generated. This application achieves early and accurate prediction and location of hidden overheating faults in electrical equipment caused by insulation degradation.

The invention discloses a sag calculation method fusing a single / double-node thermal model and a wind-induced bidirectional effect, and belongs to the technical field of power transmission lines of power systems. The method comprises the steps that firstly, a wire heat-force-wind coupling basic model is built, a wire temperature field is calculated through a single-node or double-node heat model, and equivalent mechanical parameters are calculated based on the layering characteristics of the composite wire; further quantifying the bidirectional coupling relationship of the wind-induced effect, including wind-induced load and convective heat transfer; then establishing a length compatible residual equation, and iteratively solving the horizontal tension and the steady-state temperature by adopting a Newton-Raphson method; and finally, calculating a midspan composite sag and a component thereof based on a catenary theory. According to the method, unified coupling modeling of the temperature effect and the wind-induced effect is achieved, the problems of thermal-force separation and inaccurate parameter description of a traditional method are solved, the sag calculation precision and efficiency are remarkably improved, and an accurate basis can be provided for line safety evaluation under dynamic capacity increasing.

The invention discloses a hybrid thermal network modeling method and system for a journal sticking type synchronous generator, and belongs to the technical field of electrical excitation synchronous generator thermal network modeling analysis, and the method comprises the steps: dividing the journal sticking type synchronous generator into a solid heat transfer domain and a fluid heat transfer domain, and carrying out the node discretization of each region; establishing thermal resistance connection among the discrete nodes, and constructing a thermal network model comprising conduction thermal resistance, contact thermal resistance and initial convection heat transfer thermal resistance; setting a characteristic fluid heat transfer subdomain physical boundary condition, carrying out local three-dimensional steady-state fluid dynamic simulation, carrying out inversion calculation to extract a convective heat transfer coefficient, and correcting convective heat resistance of a corresponding node in the heat network model; and on the basis of the corrected thermal network model and the physical attributes of the nodes, establishing a global thermal balance differential equation set, and solving the global thermal balance differential equation set by adopting a temperature-loss coupling iteration method to obtain global steady-state temperature field data. The thermal management design precision and efficiency of the generator can be improved.

The application discloses an online roll temperature and thermal crown prediction method based on finite difference and polynomial regression, aiming at the technical pain point that the accuracy of the traditional analytical model is insufficient and numerical simulation cannot meet the online real-time calculation demand, a plurality of groups of working conditions are designed through an orthogonal experiment method, and a finite difference method is used to calculate roll steady-state temperature field data to construct a training data set, based on the data set, a polynomial regression algorithm with elastic network regularization is used to fit an axial temperature distribution general model with the roll temperature field as an input variable, after obtaining the online surface axial temperature distribution of the roll, the general model is substituted into the internal temperature field to restore the internal temperature field and calculate the radial thermal expansion amount at each position, so that compensation information is provided for a shape control system of a rolling mill. The application simplifies complex physical field simulation into lightweight algebraic formula operation, retains the high analytical accuracy of the finite difference method, realizes real-time prediction, and can significantly improve the rolling quality of silicon steel products.

The invention discloses a subsequent process interconnection heat effect evaluation method and device and electronic equipment. And based on the basic information of each through hole / metal wire, constructing an equivalent three-dimensional thermal resistance network of the subsequent process interconnection BEOL, and obtaining a BEOL equivalent thermal resistance netlist output by the network. On the basis of reserving the space structure information of the BEOL, complex physical field simulation and high-precision simulation with high cost do not need to be carried out, the simulation efficiency is improved, the simulation cost is reduced, and meanwhile the simulation precision and the space resolution are guaranteed. And then circuit simulation is carried out based on the circuit netlist and the BEOL equivalent thermal resistance netlist to obtain a steady-state temperature value of each node. A static equivalent thermal resistance modeling process is converted into a dynamic process cooperating with simulation, and the accuracy of a circuit-level simulation result is improved. Thermal effect evaluation is carried out based on the steady-state temperature value, the BEOL equivalent thermal resistance net list and the through hole density of each metal layer, and data support is conveniently provided for device performance evaluation and circuit layout optimization.

The application discloses a kind of high-precision stable control methods for industrial metal gallium electrolytic deposition process temperature, comprising: the dynamic mechanism model of metal gallium electrolytic process temperature is established, and the steady-state temperature of electrolytic process is solved;Collect metal gallium electrolytic process temperature control input and temperature output data, and construct input-output data set;According to the preset mechanism enhancement proportion, replace several data points of original output data set with steady-state temperature value, and obtain mechanism-enhanced output data set;Using mechanism-enhanced output data set and original input data set, a subspace identification method is used to obtain a temperature prediction model;According to Lyapunov theorem, the stable solution of control quantity is solved, and the objective function of asymptotically stable model predictive control is constructed using the temperature prediction model;And under the premise of meeting the system constraint condition, the optimal control quantity sequence of temperature is solved by rolling optimization.The application can efficiently and stably control the temperature of metal gallium electrolytic deposition process.

The invention provides a method and a system for testing each heat conduction coefficient of a square laminated battery, and belongs to the field of electric vehicle heat management. The method comprises the following steps: arranging a first heating film on an x-direction middle section of a roll core in the battery, insulating xy and xz surfaces, constructing a one-dimensional heat exchange condition of a yz surface, and calculating an x-direction heat conduction coefficient after measuring a steady-state temperature; a second heating film is arranged in the middle of a roll core in the battery in the y direction, xy and yz surfaces are subjected to heat insulation, and the one-dimensional heat exchange condition of the xz surface is constructed; measuring the steady-state temperature and then calculating a y-direction heat conduction coefficient; a third heating film is arranged in the center of the z-direction top of a roll core in the battery, xz and yz surfaces are subjected to heat insulation, and the xy surface one-dimensional heat exchange condition is constructed; and recording temperature data in the heating process, and determining a z-direction heat conduction coefficient through iterative optimization in combination with the x-direction heat conduction coefficient and the y-direction heat conduction coefficient. The method can accurately reflect the real heat conduction behavior in the battery, and solves the problem of test deviation caused by the heat conduction influence of a metal shell in a traditional external heating method.

The present invention relates to a method for predicting the steady-state temperature of a three-phase multi-circuit tunnel cable core, and an electronic device. The method comprises: establishing a single-phase single-circuit tunnel cable steady-state thermal circuit model, and using the constructed single-phase single-circuit tunnel cable steady-state thermal circuit model to obtain the steady-state temperature of a core of a single-phase single-circuit cable; using a correction method to obtain the steady-state temperature of a cable core arranged in a three-phase single circuit; for a single-phase four-circuit arrangement situation, incorporating the influence of a mutual thermal effect between circuit cables on the temperature of the cable core into equivalent mutual-heating thermal resistance, and introducing the equivalent mutual-heating thermal resistance into the single-phase single-circuit tunnel cable steady-state thermal circuit model, so as to form an improved thermal circuit model to predict the steady-state temperature of a cable core of a single-phase multi-circuit cable; and using a three-phase multi-circuit cable as the combination of single-phase single-circuit, three-phase single-circuit and single-phase multi-circuit, and predicting the temperature of a cable core of the three-phase multi-circuit cable. Compared with the prior art, the present invention has advantages such as quickly and accurately predicting the steady-state temperature of a three-phase multi-circuit tunnel cable core.

The invention discloses a method, device and equipment for quantitatively characterizing a formation heat convection effect and a storage medium, and the method comprises the following steps: determining a layered interface of an upper formation and a lower formation according to an obtained ground temperature gradient; determining the actually measured surface heat flow of the upper stratum according to the average ground temperature gradient of the upper stratum and the harmonic heat conductivity of the upper stratum; pure heat conduction surface heat flow is determined according to the average ground temperature gradient of the lower stratum, the blending heat conductivity of the lower stratum and radioactive element heat production of the upper stratum; and determining a heat convection value of the stratum according to the actually measured surface heat flow of the upper stratum and the pure heat conduction surface heat flow. The method aims at solving the problems that in an existing method, complexity of a stratum structure is not considered, and accurate quantitative analysis is lacked, the stratum heat convection effect is quantitatively represented through steady-state temperature data and accurate stratum in-situ thermophysical properties, and the more accurate and comprehensive quantitative analysis effect is achieved.

A method for non-destructive in-situ determination of the R-value of a material at a mean temperature comprises maintaining three or more steady-state temperatures, each for a respective measurement period, measuring temperature and heat flow through the material, calculating R-values at each steady-state temperature and determining the R-value of the material at the mean temperature from the calculated R-values. A system for non-destructive in-situ determination of the R-value of a material at a mean temperature comprises a housing defining a chamber, a temperature control system for heating and cooling the chamber between three or more steady-state temperatures, heat flux transducers, temperature sensors and a computing device from controlling the temperature control system and comprising a data acquisition system for recording measurements from the heat flux transducers and the temperature sensors.

The application discloses a flexible screen high-frequency bending test failure screening system and method, which utilizes a high-frequency bending machine to test the flexible screen, measures the temperature of the bending area, and determines thermal failure if the surface temperature distribution, temperature rise rate or steady-state temperature exceeds a threshold value; if the temperature detection is qualified, the crack density and thermal stress of the bending area are detected after the temperature field is stabilized, and mechanical failure is determined if the threshold value is exceeded; if the mechanical detection is qualified, the resistance change rate and breakdown voltage of the bending area are detected after the temperature and stress fields are both stabilized, and electrical failure is determined if the threshold value is exceeded, otherwise, the product is qualified. The system comprises a system control module, a mechanical loading module, a temperature detection module, a crack detection module, a thermal stress detection module, an electrical signal detection module and a data processing module, the modules are linked, multi-stage detection is adopted, the reliability of the flexible screen under high-frequency bending conditions can be comprehensively evaluated, and unqualified products can be effectively screened out.

The application discloses an aero-engine key part dangerous position temperature rapid evaluation method and device, electronic equipment and storage medium, the method comprises the steps that S1, the temperature value, pressure value and rotating speed value in the flow channel are calculated by using the proportional conversion method, the steady-state temperature of the key part dangerous position is calculated, the transition state temperature calculation reduction model is established, and the model parameters are obtained; S2, the material parameters of the aero-engine key part, the temperature value, pressure value and rotating speed value corresponding to the main flow channel at the life calculation point are substituted into the transition state temperature calculation reduction model to rapidly calculate the transient temperature of the aero-engine key part dangerous position under any state. The application directly calculates the rapid temperature of the key part dangerous position by substituting the mathematical theoretical model established by the flight parameters, avoids the consumption of hardware resources and solving time caused by large-scale simulation solving, improves the calculation speed to the order of millisecond, shortens the design cycle, and reduces the calculation cost.

The invention relates to the technical field of GIS, in particular to a GIS heat tracing module arrangement optimization method and device based on finite element simulation, and the method comprises the steps: constructing a three-dimensional geometric model of a GIS structure, and carrying out the setting of a physical field; establishing a GIS temperature field simulation model based on the three-dimensional geometric model of the GIS structure and physical field setting; a heat tracing module parameter scheme is set, and the heat tracing module parameter scheme meeting the parameter evaluation standard is determined based on the GIS temperature field simulation model; and whether the heating area and the heating power corresponding to the heat tracing module parameter scheme are optimal or not is judged. According to the method, the GIS temperature field simulation model is used for conducting steady-state temperature field simulation on any heat tracing module parameter scheme, the temperature distribution in the GIS after the heat tracing module is arranged is determined in advance, data support is provided for adjusting the heat tracing module parameter scheme, the problem that a dangerous cold spot area is generated after the heat tracing module is arranged is avoided, and the heat tracing efficiency is improved. And faults caused by SF6 liquefaction are effectively prevented.

Device and method for estimating a future temperature (212) of an engine, in particular for intervening in the operation of the engine, wherein a starting value of the engine temperature is measured or specified, wherein at least one operating parameter of the engine influencing the engine temperature, for example a rotational speed, a torque, a coolant temperature, a coolant flow rate, is detected or specified, wherein a steady-state temperature (204) of the engine is estimated with a first data-based model (202) depending on the starting value and the at least one operating parameter, wherein a rate of change (206) of the engine temperature is estimated with a second data-based model (206) depending on the starting value and the at least one operating parameter, and wherein the future temperature (212) of the engine is estimated with a physical model (210) for the engine temperature depending on the starting value, depending on the estimated steady-state temperature (204),and is estimated depending on the estimated rate of change (208).

According to the meibomian gland dysfunction treatment system and the control method, the equipment environment temperature and the host water outlet temperature are collected, a model is established in combination with the equipment heat exchange total thermal resistance, the actual temperature of the eye cup is accurately calculated, then the human body temperature and the man-machine heat exchange total thermal resistance are fused, and finally the steady-state temperature of the contact face of the eye cup and the human eyes is locked. Moreover, PID closed-loop control is adopted, temperature deviation in the heat exchange process of the equipment and the man-machine heat exchange process can be corrected in real time, a proportional link quickly responds to sudden fluctuation of the water flow temperature and the environment temperature, an integral link eliminates accumulated deviation such as continuous heat dissipation of a pipeline, a differential link prejudges the temperature change trend to avoid overshoot, and the heat exchange efficiency is improved. The temperature of the contact surface is always stabilized in a target range, the hot compress temperature is stabilized in a clinical effective interval, and the core target of treatment of lipid softening and gland opening expansion is realized.

The invention discloses a method and a device for detecting heat transfer capacity by using a temperature measuring element, and belongs to the technical field of low-temperature heat transfer test.The method comprises the following steps: detecting steady-state temperature distribution in a to-be-detected state by using the temperature measuring element for a to-be-detected object; a cold source and a controllable heating element are utilized to act on the two ends of an object to be detected respectively, so that the steady-state temperature distribution of the object to be detected is consistent with the steady-state temperature distribution in a to-be-detected state, and the input power of the controllable heating element at the moment is read, namely the steady-state heat transfer amount of the object to be detected in the to-be-detected state. The use of dangerous media such as liquid hydrogen or liquid oxygen can be avoided, and the safety risk of low-temperature testing is solved; the heat transfer amount is directly obtained through an isothermal compensation mechanism, and the error of a heat transfer amount result fitted through temperature difference is eliminated; and multi-temperature-zone test can be realized, and full-temperature-zone measurement at low temperature is supported. The device can be widely applied to accurate testing of thermal performance of low-temperature systems in the fields of superconduction, spaceflight and the like.

The two-dimensional and three-dimensional coupling finite element analysis method comprises the following steps that a cross section of a simulation structure is determined, and the cross section is an interface of a two-dimensional structure and a three-dimensional structure; establishing a simulation model, and assigning a two-dimensional structure and a three-dimensional structure; calculating an initial temperature field of the simulation model, and calculating an average temperature at a two-dimensional and three-dimensional coupling interface; and assigning the average temperature to the two-dimensional structure and the three-dimensional structure at the interface, and carrying out temperature field iteration until a steady-state temperature field is obtained. According to the method, the temperature calculation of the three-dimensional grid model and the temperature calculation of the two-dimensional grid model can be accurately coupled together, and meanwhile, the continuity of the temperature and the heat flow at the interface is ensured.

The invention provides an air-cooled motor winding temperature prediction method and device, relates to the technical field of electric driving, and is used for predicting the temperature of an air-cooled motor winding in scenes such as electric aircrafts and electric automobiles. The method mainly comprises the following steps: modeling a motor winding temperature of each rotating speed stable section by using an index approaching model, and solving undetermined parameters of the index approaching model; based on a convective heat transfer formula, the heat dissipation coefficient of each rotating speed stable section is calculated through the motor heat loss, the environment temperature and the steady-state temperature; fitting the steady-state temperature, the time constant and the heat dissipation coefficient under different powers by using a polynomial fitting function to obtain the steady-state temperature, the time constant and the heat dissipation coefficient under a given power; and correcting the steady-state temperature of the given power according to the new environment temperature, and predicting the motor winding temperature under the given power through the corrected steady-state temperature of the given power by using an exponential approaching model.

The invention discloses an anti-dry-burning control method, device and system for dynamically adjusting the temperature of a protection point, and belongs to the field of kitchen appliances. The dry burning prevention control method for dynamically adjusting the temperature of the protection point is applied to the kitchen range. The cooker comprises a temperature detection module, and the temperature detection module is used for detecting the current pot bottom temperature of a pot placed on the cooker. The dry burning prevention control method comprises the steps that multiple continuous current pot bottom temperatures detected by a temperature detection module within a preset time period before the current moment are obtained; based on the multiple current pot bottom temperatures, the steady-state temperature corresponding to the current pot bottom temperature at the current moment is determined; dynamically adjusting a variable anti-dry-burning temperature threshold value corresponding to the current pot bottom temperature at the current moment based on the steady-state temperature; and based on the current pot bottom temperature at the current moment and the variable anti-dry-burning temperature threshold value, the cooker is controlled to carry out anti-dry-burning protection. In this way, the cooker can be intelligently controlled to carry out anti-dry-burning protection, and the accuracy and reliability of the anti-dry-burning protection are improved.

The invention discloses a flexible screen high-frequency bending test failure screening system and method.The method comprises the steps that a high-frequency bending machine is used for testing a flexible screen, the temperature of a bending area is measured, and if the surface temperature distribution or the temperature rise rate or the steady-state temperature exceeds a threshold value, it is judged that thermal failure occurs; if the temperature detection is qualified, after the temperature field is stable, detecting the crack density and the thermal stress of the bending area, and if the crack density and the thermal stress exceed a threshold value, judging that mechanical failure occurs; and if the mechanical detection is qualified and the temperature and the stress field are stable, detecting the resistance change rate and the breakdown voltage of the bending area, if the resistance change rate and the breakdown voltage exceed a threshold value, judging that electrical failure occurs, otherwise, judging that the product is qualified. The system comprises a system control module, a mechanical loading module, a temperature detection module, a crack detection module, a thermal stress detection module, an electric signal detection module and a data processing module, all the modules are linked, multi-stage detection is adopted, the reliability of the flexible screen under the high-frequency bending condition can be comprehensively evaluated, and unqualified products can be effectively screened out.