Physical Basis of Thermal Conduction

This chapter introduces the temperature gradient and Fourier law based on the theory of substance heat conduction. Then, the differential equation of heat conduction is deduced, and the boundary conditions for the definite solution are given. On the basis of understanding the heat conduction, the micro-mechanisms of heat conduction of gases, liquids, and solids are compared, and the relevant formulas for calculating the thermal conductivity of different substances are summarized. Finally, some factors affecting the thermal conductivity of solid materials, including pressure, temperature, and crystal structure, are summarized.