Transient analysis-based hemispherical total emittance measurement method for large-temperature difference sample

Abstract

The invention discloses a transient analysis-based hemispherical total emittance measurement method for a large-temperature difference sample. The transient analysis-based hemispherical total emittance measurement method comprises the following steps of arranging multiple thermocouples on a sample, applying electric current to the sample in vacuum to heat the sample to a high temperature, naturally cooling the sample, dividing the sample cooling process into multiple temperature sub-stages, representing hemispherical total emittance, heat conductivity coefficient and specific heat capacity respectively by temperature-related mathematical functions, dividing the sample into multiple micro-control units along an axial direction, constructing an energy-balance equation of the micro-control units at a certain time point in sample cooling, and calculating values of hemispherical total emittance, heat conductivity coefficient and specific heat capacity in sample cooling. The transient analysis-based hemispherical total emittance measurement method is suitable for measurement of hemispherical total emittance of a conductor material sample having large temperature gradient distribution and can realize measurement of heat conductivity coefficient and specific heat capacity of the conductor material.

Description

technical field [0001] The invention relates to the field of hemispherical total emissivity measurement of conductive materials, in particular to a method for simultaneously measuring hemispherical total emissivity, thermal conductivity and specific heat capacity of samples with large temperature differences based on transient analysis. Background technique [0002] Hemispherical total emissivity is one of the important thermophysical parameters of materials, which characterizes the surface thermal radiation ability of materials, and is an important basic physical property data for the study of radiation measurement, radiation heat transfer and thermal efficiency analysis. With the wide application of new materials in high-tech fields such as energy power and aerospace, more urgent needs have been put forward for the measurement of hemispherical total emissivity. Compared with other thermal physical parameters, the hemispherical total emissivity measurement method The techni...

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Problems solved by technology

[0010] The purpose of the present invention is to provide a method for measuring the hemispherical full emissivity of samples with large temperature differences based on transient analysis, so as to overcome the inability of the prior art transient calorimetry to conduct hemispherical full emissivity of conductor materials with large temperature gradient distribution. When the thermal conductivity and specific heat capacity of the conductor material are unknown, it is impossible to measure the hemispherical full emissivity of the conductor material, etc.

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