A Method for Measuring Thermal Properties of Columnar Thermal Insulation Materials

Abstract

The invention provides a method for measuring the thermophysical properties of a columnar heat insulation material, which is used to determine the radial thermal conductivity and axial thermal conductivity of a columnar orthotropic heat insulation material by measuring the temperature change of a point in the measured sample. method of rate and volumetric heat capacity. The method includes: establishing a two-dimensional cylindrical coordinate heat transfer model under the action of a specific form of thermal interference in cylindrical coordinates; using Laplace transformation, Hankel transformation and Laplace inverse transformation methods to obtain the temperature change in orthotropic heat insulation materials Analytical solutions in the time domain; through sensitivity calculations, analyze the correlation of the sensitivity coefficients of radial thermal conductivity, axial thermal conductivity and volumetric heat capacity and the influence of parameters on temperature changes; establish a corresponding measurement system and collect data in real time Transient response data of temperature; using the L-M parameter estimation method, simultaneously determine the radial thermal conductivity, axial thermal conductivity and volumetric heat capacity of the tested orthotropic insulation material. The invention has the advantages of providing a measuring method with convenient implementation and simple steps, which can simultaneously measure the radial thermal conductivity, axial thermal conductivity and volumetric heat capacity of the columnar heat insulating material.

Description

technical field [0001] The invention belongs to the technical field of thermal physical property measurement of materials, in particular, it provides a new measurement method which can simultaneously obtain multiple thermal physical property parameters through one measurement, and determines the orthotropic anisotropy by measuring the temperature change of a point in the measured sample Methods for radial thermal conductivity, axial thermal conductivity, and volumetric heat capacity of insulating materials. Background technique [0002] The thermophysical parameters of materials are one of the most basic physical parameters to understand, understand and evaluate the heat transfer performance of materials, and are the key parameters for basic research, analysis calculation and engineering design of specific heat transfer processes. Accurate measurement of thermophysical parameters is of great significance to the development of many fields such as energy utilization, building ...

AI Technical Summary

Problems solved by technology

However, the existing mature thermal conductivity measurement methods such as hot-line method, hot-wire method, hot-disk, etc., are all based on the principle model of isotropic materials, which are not suitable for the measurement of thermal conductivity of fiber materials.

However, the protected hot plate method and the planar heat source method need to change the measurement direction many times to determine the thermal conductivity of the material in different directions, which increases the complexity and error of the experiment.

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