A Numerical Calculation for the Optimum Operation of Cyclone-based Combustion System

This research carried out a 3-dimensional simulation using computerized fluid dynamics (CFD) for the flow characteristics, temperature distribution, velocity distribution and residence time, etc. in a reactor in order to derive the optimal combustion conditions of an innovative combustion system. The area-weighted average temperature of the outlet of a furnace during combustion at a condition of fuel input rate 1.5 ton/hr, residence time 1.25 sec and air/fuel ratio 2.1 was 1,077℃, which is a suitable temperature for energy recovery and treatment of air pollutants. Exhaust gas is discharged through a duct at a 40∼50 m/s maximum speed along strong vortexes at the center of a combustion chamber, so strong turbulence is created at the center of a combustion chamber to enhance the combustion speed and combustion efficiency. In this system, the optimum operation conditions to prevent incomplete combustion and suppress the formation of thermal NOx were air/fuel ratio 1.9∼2.1 and fuel input rate 1.25∼1.5 ton/hr.Key Words : CFD, Cyclone, Combustion, Temperature distribution, Velocity distribution