Research on the Superficial Thermal Insulation Calculation Method of Massive Concrete Structure

Abstract

In this paper, based on the principle of heat balance, the computing equation of temperature field which used the thermal coefficient, surface coefficient, and heat as the basic parameters of the heat conduction equation is derived, and thereafter the FEM computation procedure about temperature field named RCTS which used the thermal diffusivity as basic parameter is modified. The modified procedure can reasonably reflect the temperature field of composite construction which is made of a great variety of material with different thermal property, and also can simulate the effect of surface heat preservation at arbitrary periods and arbitrary parts of the bulk concrete structure. According to the calculation example, the similarities and differences of the heat preservation effect on the heated board calculation by using different methods: the equivalent surface coefficient method, the equivalent thickness method, the thermal conductivity method and the thermal diffusivity method are analyzed. The calculation results show that the computing results of the thermal conductivity method are closed to the result of the equivalent surface coefficient method, the results of the equivalent thickness method have certain differences but not quite because it is the approximation process of the equivalent surface coefficient method, and the reasonable result is often missed by using the thermal diffusivity method.