Exergy Analysis and Irreversibility of Combustion Process of an Auxiliary Boiler for Marine Application

Auxiliary boiler is used on board vessels for the purpose of steam generation. In marine vessels where boiler is running on liquid fuel for the combustion purpose, the irreversibility leads to exergy loss and high operating cost. This exergy analysis of auxiliary boiler (10.5 bar capacity) constitutes a good working tool to access the thermodynamic quality of a system. This study reveals the thermodynamic condition of the system by following a chain of events like irreversibility, degradation of the energy, and loss occur. Numerical analysis of burner for the mass fraction and temperature gradient is carried out for viscous dissipation, heat conduction, mass diffusion, and chemical reaction. It suggests 15% better optimization of the systems and rational operation of the installation than the existing system by exergy addition, exergy losses, and exergy consumption on the measured operating data and the thermodynamic state of the plant components. It reveals that the rate of exergy destruction by chemical reaction can be reduced when the flame temperature is high. This analysis of the auxiliary boiler will contribute to an exergy analysis of combustion process, identification of irreversibility leading to highly energy efficient boiler operation and design modification.