Construction Of High Temperature Specific Heat Measurement Calorimeter For Solid Materials

With the continuous development of industrial production and science and technology,the research on thermodynamic properties of solid materials has become more and more intensive.Especially in recent years,with the rise of aerospace technology,calorimetric technology has developed rapidly in the 21st century.Therefore,an accurate and reliable calorimetric method is needed to evaluate the enthalpy and specific heat of solid materials at high temperatures.The nature of learning.The research and development of calorimeter started late in China.In recent years,some domestic laboratories have established relatively mature calorimeters with temperature ranges of 80-400K and 400-600K.Some thermodynamic research work has been carried out.However,the measuring methods and structures of these calorimeters limit the working temperature of the instrument,so that the temperature of the material can reach the upper limit.It is difficult to get the thermodynamic value of the material above 600K.The nature of science limits the research of high temperature materials by domestic researchers.Therefore,the development of high temperature calorimeter in our country is more and more important.However,in China,the number of laboratories developing high temperature calorimeter is very small,which is far from that of developed countries.According to the current situation and trend of calorimeter research and development in China,the development of high temperature calorimeter will provide strong data support for promoting the research of material thermodynamics theory in China.To solve the above problems,a calorimeter for measuring specific heat of solid materials at high temperature is developed in this paper.The structure,control circuit and measurement method of the calorimeter are described,and the experimental data measured by the instrument are analyzed.The instrument adopts the drop-in automatic adiabatic mixing calorimetry to measure solid materials at high temperature.The enthalpy and specific heat of calorimetric reference material a-A1203 were measured at 400-1100K high temperature.The experimental data were fitted to obtain the empirical formula of specific heat.The measured values were compared with the standard values provided by the National Bureau of Standards.The results show that the accuracy of the device is 1%,and the accuracy is(+1.5%).The specific heat and enthalpy of other solid materials(304 stainless steel,In625 nickel base alloy,binary molten salt of heat storage material)were measured by the developed high temperature calorimeter.The enthalpy and specific heat data of the three materials at 470-1100K are obtained by fitting formula,which can provide reference for future experiments and scientific research.