Exergy Analysis of Auxiliary Boiler for Marine Application

Abstract

Low-pressure auxiliary boiler is used for generating steam for the purpose of fuel oil heating, tank cleaning, lubricating oil purification, operation of cargo pump, power generation and air conditioning in commercial marine vessels. The thermal performance of these auxiliary boilers is very poor. The present study investigates the auxiliary boiler of capacity 400 kg/h at 10.5 kg/cm2 installed in training ship at Tolani Maritime Institute, Pune. The parametric analysis of the auxiliary boiler for first and second law of thermodynamic efficiency calculation, exergy efficiency and numerical analysis on pressure jet burner is carried out. This study is aimed to enhance the energy saving in auxiliary boiler on-board ship. The light diesel oil is used as a fuel in this study. The reverse flame from the jet burner is heating the water tubes, which generates wet steam. The flue gases leaving the boiler will pass through economizer where feed water temperature raises to saturated level. Existing condition of this boiler is assessed by rate of fuel consumption per day at steam pressure 10.5 kg/cm2 and irreversibility at its various parts and proposes various remedial actions to overcome these losses. Computation fluid analysis of combustion reveals that the improper air circulation leads to less heat transfer at water tubes and complete oxidation of hydrocarbon.