A Simultaniously Analysis of Computational Fluid Dynamics and Exergy of the Fire Tube Boiler

In this study, Exergy analysis and computational fluid dynamics simulation of one of the Iranian Offshore Oil Company boilers at Kharg Island, Dorood 3 (boiler unit) has been carried out simultaneously. A type of fire tube boiler with length of 5980 mm and a diameter of 1360 and three pass tubes is investigated. Desired geometry is drawn using SolidWork software, and the equations are solved using Fluent software. In addition to the momentum equations, the energy and combustion equations were also used to the model. Computational space, including burners, furnaces, hot gas chamber at the end of furnaces, the second pass of the tubes, hot gas chamber from the super heater passes into the third tube pass and finally the stack. Temperature, pressure, velocity and concentration distribution in the boiler has been obtained. The simulation results show good agreement with the experimental data. The results show that the area of maximum mass fraction of NO is made in accordance with the area of maximum temperature in the furnace. NO contaminant is maximum in the flame area. NO contaminant is reduced when the gas temperature in the furnace is reduced;moreover, Exergy analysis is discussed to determine the feasibility of optimize boiler. The results of exergy analysis of operations for the produced heat flux values by fuel gas are obtained and percent error is calculated. The results show that with increasing temperature to °160C fuel, the furnace radiant heat transfer rate increased and the flame temperature and consequently also reduce NO contaminant.