Evaluation of Indoor Radiative Heat Transfer Coefficient Based on Experiments and CFD Simulations

Abstract

The radiative heat transfer coefficient is used to calculate radiative heat flux in the heat load calculation conveniently. The radiative heat transfer coefficient is treated as a constant value [4.7W/(m^2・K)] in most practical situations. However the constant radiative heat transfer coefficient is not always applicable to various conditions and may invite the inadequate heat load calculation results. In this paper, evaluation method of radiative heat transfer coefficient based on experiments and simulations was shown. The experiments were carried out in simple shaped laboratory and radiative heat transfer coefficient was evaluated. The results of the radiative heat transfer coefficients were 4.4W/(m^2・K) and 5.7W/(m^2・K) under heating condition and cooling condition respectively. Then the CFD simulations were carried out and radiative heat transfer coefficients were evaluated in the same conditions as the experiments. The evaluated values based on CFD showed good agreement with the experimental values. Therefore this paper concluded that the radiative heat transfer coefficient should not be used as a constant and should be treated appropriately in various conditions.