Numerical Analysis of Entropy Production during Hydrogen-Air Burner Combustion Process

Abstract: Entropy production during hydrogen-air diffusion in the combustion chamber (СС) was studied. A two-dimensional axisymmetric combustion chamber is considered in this paper. The numerical simulation of combustion has been done by Fluent software. The entropy production per unit volume for heat conduction and convection, mass diffusion, viscous dissipation, and the chemical reaction was calculated by user-defined function (UDF) post-processing, while the entropy production for heat transfer radiation was determined by post-processing with the help of calculated data of temperature. The results reveal that the radiation entropy production cannot be omitted when second law analysis of thermodynamic is adopted in high-temperature conditions such as boilers, heat exchangers, furnaces, etc; in these devices, thermal radiation is the basic mode of heat transfer. The effects of parameters such as Boltzmann number and Reynolds number on entropy production and entropy production number are analyzed. It is shown that the total entropy production number first decreases with the increase Reynolds and Boltzmann numbers; and then gradually increases. The results provide a theoretical reference for the improvement of thermodynamic efficiency for heat transfer and energy utilization.