151 results about "Conduction equation" patented technology

The present invention discloses a dynamic secondary cooling control method for slab continuous casting based on a double-cooling mode, which comprises the following steps of: collecting casting process data and indexing target cooling temperatures and ABC parameters of each cooling area; dynamically calculating the heat conduction process of a continuously cast slab in the current period according to a heat conduction equation; calculating the temperature tracking error of each cooling area and calculating the water amount of each cooling area in a second cooling mode by taking the temperature tracking error as a regulation factor; respectively calculating the water amount of each cooling area in a first cooling mode based on the ABC parameters and the current casting speed; determining whether the temperature tracking error exceeds a preset threshold and comparing the water amounts in the two modes to determine the cooling mode and the controlled water amount in the current period; and validating the reasonableness of the controlled water amount, and correcting the controlled water amount to be a preset maximum water amount or minimum water amount if the controlled water amount exceeds the preset maximum water amount or minimum water amount. The invention guarantees the quality stability of the cast blank in secondary cooling process.

The invention discloses a method for determining the position of an erosion line of a hearth of a blast furnace and belongs to the technical field of prolonging service life of the blast furnace. Compared with the prior art, the method for determining the erosion line of the hearth of the blast furnace has the advantages that the calculation amount is small, and accuracy is high. According to the method, a temperature field in a brick line of the hearth is directly calculated based on a steady-state heat conduction equation by a method for stabilizing a grid by using finite elements or finite difference; the heat conductivity coefficient of the brick lining is determined according to the temperature of grid nodes in iterative computation; if the temperature is more than 1,450 DEG C, the temperature field in the brick lining of the hearth is calculated and determined by using the effective heat conductivity coefficient of molten iron; the position of the position of the 1,150-DEG C erosion line is determined according to the temperature field; according to the method for determining the position of the erosion line, the temperature field is only needed to be calculated once; and compared with the conventional method, the method has the advantages that the calculation amount is greatly reduced, the calculation cycle is shortened, various requirements of operation of the blast furnace can be met, the calculation stability is greatly improved, and the division temperature of the molten iron and the brick line is set to be 1,450 DEG C, so that the actual requirement of the blast furnace can be met.

Providing a probe for an electronic clinical thermometer, which can measure a surface temperature and a deep body temperature of a human body securely in short time, the probe includes a cylindrical housing, a bottomed metal pipe fitted into a top end of the cylindrical housing, and a substrate having two thin-film heat-sensitive elements arranged perpendicularly on an inner wall of the bottomed metal pipe so as to fix one side edge of the substrate tightly on the inner wall. By measuring heat flux between the two thin-film heat-sensitive elements, the surface and the deep body temperatures of the human body can be predicted by applying the measured values into a heat conduction equation without waiting the sensor to reach in heat balance.

Analytical solutions to error bounds on the temperature depth distribution have been given in this invention. Solving the one dimensional steady state heat conduction equation for different sets of boundary conditions and radiogenic heat generation and incorporating Gaussian randomness in the thermal conductivity analytical closed form solutions to the mean and variance in the temperature depth distribution have been obtained. These closed form analytical solutions of mean and variance for the temperature field for different conditions have been used to compute and display the plot and results of the temperature depth profiles along with its error bounds. Quantifying the error statistics in the system output due to errors in the system input is very essential for a better evaluation of the system behavior. Earth Scientists involved in understanding the subsurface thermal structure relevant to geodynamical studies will benefit using these findings.

The embodiment of the invention provides a method for calculating a heat transfer ratio based on the eddy current loss of a rotor segmented sheath of a permanent magnet motor. The method comprises thefollowing steps: separately establishing a field circuit coupling calculation model with a segmented sheath and a field circuit coupling calculation model without sheath for the permanent magnet motor based on vector control, and calculating the loss of each component; then, separately establishing a three-dimensional steady state temperature field solution model with a segmented sheath and a three-dimensional steady state temperature field solution model without sheath for the permanent magnet motor, determining a boundary condition based on an assumed condition, and obtaining a rotor steadystate heat conduction equation; separately calculating a heat conductivity coefficient in an air gap and the heat conductivity coefficient of a stator winding, substituting the heat conductivity coefficients in the rotor steady state heat conduction equation, and using the loss as the heat source of a solution domain to obtain a steady state temperature field of the permanent magnet motor; and separately calculating the temperature of each component under the action on basic wave current on the permanent magnet motor in which the rotor has no sheath and the permanent magnet motor in which therotor has the segmented sheath, and calculating the heat transfer ratio of each component according to the temperature of each component. The method provided by the invention provides important theoretical basis for the design of an electromagnetic structure of the permanent magnet motor.

The invention relates to a method and a system for insulator temperature rise diagnosis. The method comprises the following steps: according to a heat conduction equation of an insulator and a boundary condition corresponding to the insulator, establishing a radial temperature calculation model of the insulator, wherein the radial direction is the direction vertical to a center axis of the insulator; obtaining outer surface temperature of the insulator, insulator parameters, and environment parameters corresponding to the environment where the insulator is in; according to the outer surface temperature, the insulator parameters, the environment parameters, and the radial temperature calculation model, obtaining internal heat source temperature of the insulator; according to the internal heat source temperature, diagnosing temperature rise degree of the insulator. The insulator temperature rise diagnosis method can improve accuracy of insulator temperature rise diagnosis.

The invention discloses a thermal diffusivity measurement method for a two-dimensional anisotropy nanometer material. The method comprises the following steps that: using continuous heating laser to heat the surface of a sample, using continuous detection laser of which the light spot center position is adjustable to detect the steady state plane temperature distribution of the surface of the sample, and obtaining two characteristic directions of the thermal diffusivity of the sample; using heating pulse laser to heat the surface temperature of the sample, enabling the temperature to periodically change, and using detection pulse laser of which the light spot center position is adjustable to obtain the temperature rise and reduction curves of different position points in two characteristicdirections; and according to the temperature rise and reduction curves of different position points, establishing a non-steady-state heat conduction equation set to fit, or utilizing a phase lock principle to carry out data processing to obtain the thermal diffusivity of the sample. The method is a non-contact nondestructive measurement method, the thermal diffusivities of two characteristic directions can be simultaneously obtained, and the direct measurement of the thermal diffusivities of nonmetal two-dimensional anisotropy nanometer materials of which the thickness is from a single atom to hundreds of nm is realized.

The invention discloses a thin-wall local heat transfer coefficient measuring method based on thermal fluctuation coupling infrared imaging, and the method obtains a steady local heat transfer coefficient of the other side (a to-be-measured side) of a thin wall through an analytic solution of a one-dimensional unsteady state heat conduction equation under the condition that one side (a reference side with a known heat transfer coefficient) is under the periodic heat flow boundary condition, wherein the other side is in univalent function relation with a phase different between the reference side wall temperature and an applied heat flow fluctuation signal. According to the invention, the method is not affected by the temperature measurement precision of an infrared imager, and can achieve the non-contact quick measurement of the surface local heat transfer coefficient of the features of the thin wall through the collection of the thermal fluctuation of the reference side and a surface temperature signal of the thin wall based on infrared imaging.

The invention discloses a silicon melt temperature field reconstruction method based on a free liquid level temperature measurement value and a feature function interpolation. The feature value problem of a heat conduction equation is used for analyzing the silicon melt model of the equal-diameter stage of the two-dimensional axial symmetry crystal growth process of a single crystal furnace, and a feature value and a corresponding feature function are obtained by calculation; a threshold scalar function is used for calculating the function of each feature function for an area to be reduced; a scalar value is set as a measuring standard for selecting the feature function; on the basis of a multi-population genetic algorithm, the arrangement position of a temperature sensor measuring point is optimized; finally, the group of temperature measurement values combined on an optimization position and the selected feature function are used for carrying out calculation to obtain a weight factor which reflects he characteristics of a silicon melt area; and an inner product operation is carried out with the feature function of each point in the silicon melt to obtain the temperature distribution of the silicon melt. By use of the method, the influence of a complex structure for an arrangement temperature sensor is reduced, the method is free from a heat conduction physical problem, and expansibility is good.