Measurement Method Of High Temperature Molten Salt Emissivity And Inversion Calculation Of Absorption Coefficient

With the development of society,the growth of global energy use and unscientific use,fossil fuels and other non renewable energy will become increasingly exhausted which have a serious impact on the environment.In order to maintain the sustainable development of the society,it requires people to develop a series of new energy such as solar energy and nuclear energy.But the physical parameters of molten salt are scarce and mostly older than the older and the physical parameters and measurement of molten salt get in a lot of experiments only consider the convection and conduction and ignore the radiation part.First of all,a high temperature furnace was designed for the physical properties of molten salts and a high temperature emissivity measurement system was designed to measure the normal spectral emissivity of the sample.In this paper we have analysis the relationship between energy transmission characteristics of the sample radiation in the heating chamber and the internal spectrometer detector.we also established the theoretical relationship between the parameters of the sample.A formula for measuring the emissivity of the sample is derived and a formula for calculating the spectral absorption coefficient is derived from normal spectral emissivity.The interaction between pulse energy and semitransparent medium is studied.The positive problem and the inverse problem are studied in this paper.The positive studies the pulse intense laser irradiation in semi transparent media coupling transient radiation and conduction heat transfer.The inverse problem is using particle swarm algorithm to calculate the inversion of absorption coefficient and thermal conductivity in semitransparent medium which laid the foundation for the subsequent inversion of molten salt.In order to verify the validity and accuracy of the experimental system,some typical solid materials are selected to calibrate the experimental system.Then the spectral emissivity of 304 steel and silicon carbide materials at 400℃,500℃,600℃,700℃and 800℃temperatures was measured we analysis the effect of the detector in the measurement of the response function,background function,signal sample,the sample surface temperature and the surrounding environment and other factors on the uncertainty of the measurement system and calculate the total relative uncertainty.