Numerical Study of Optimal Combustion in Tangentially Fired Coal Boiler 625 MW by Considering Rear Pass Temperature

Tangentially fired boilers have a burner system within a single actuator group and a SOFA system that controls the fuel and air distribution to generate boiler combustion in the furnace. The goal of this study was to determine optimal combustion by statistically examining the effect of changes in the burner and SOFA angles on the response of rear pass boiler temperature and NOx concentration in tangentially burned boilers. (1) Tilting burner angles of +30⁰, +15⁰, 0⁰, –15⁰, and –30⁰, and (2) SOFA tilting and yawing angles of –15⁰, –8⁰, 0⁰, +8⁰, +15⁰ were used in this study. The GA (Genetic Algorithm) approach and CFD software were utilized to optimize the rear pass temperature and NOx content response. The simulation results data were then examined using ANOVA, and it was discovered that tilting burner and tilting SOFA have a substantial effect on response, however, yaw SOFA does not. In this scenario, the resulting angle variations for tilting burner, SOFA-tilt, and SOFA-yaw are +11⁰, –15⁰, and 2⁰, respectively. The optimal angle adjustments result in rear pass temperatures of 821.33 ⁰K and 816.27 ⁰K, with a slight fluctuation of 5.06 ⁰K. This was in contrast to the preceding conditions, when the rear pass temperatures of sides A and B were 781.32 ⁰K and 767.83 ⁰K, respectively, resulting in a 13.49 ⁰K difference. Keywords: tilting burner, tilting and yawing SOFA, rear pass temperature, NOx, GA and CFD method