Exergy transfer characteristics of gas-solid heat transfer through sinter bed layer in vertical tank

Abstract

The examination of exergy transfer characteristics caused by gas-solid heat transfer through sinter bed layer in vertical tank has been presented. Correlations involving relevant variables to predict the mean exergy transfer coefficient, the mean exergy transfer Nusselt number and the non-dimensional exergy flux have been derived by applying the second law of thermodynamics and non-equilibrium thermodynamics theory. The relationships of mean exergy transfer Nusselt number with the heat transfer Nusselt number, Reynolds number, the non-dimensional heat flux and the non-dimensional pressure drop are determined. The experimental results of exergy transfer characteristics in sinter bed layer with different gas superficial velocity, sinter particle diameter and bed layer height are obtained from homemade gas-solid heat transfer setup, and the effects of air outlet temperature, non-dimensional temperature and Reynolds number on the exergy transfer characteristics are analyzed. The research results show that for a given experimental condition, the mean exergy transfer Nusselt number gradually decreases with the increase of Reynolds number and sinter bed layer height. The mean exergy transfer Nusselt number would be less than zero for a lower air outlet temperature, which is pointless for gas-solid heat transfer process in sinter bed layer.