Numerical Simulation of Combustion in 35 t/h Industrial Pulverized Coal Furnace with Burners Arranged on Front Wall

Abstract

Coal-fired industrial boilers should operate across a wide range of loads and with a higher reduction of pollutant emission in China. In order to achieve these tasks, a physical model including two swirling burners on the front wall and boiler furnace was established for a 35 t/h pulverized coal-fired boiler. Based on Computational Fluid Dynamics (CFD) theory and the commercial software ANSYS Fluent, mathematical modeling was used to simulate the flow and combustion processes under 75% and 60% load operating conditions. The combustion characteristics in the furnace were obtained. The flue gas temperature simulation results were in good agreement with experimental data. The simulation results showed that there was a critical distance L along the direction of the furnace depth (x) and Hc along the direction of the furnace height (y) on the burner axis. When x < L, the concentration of NO decreased sharply as the height increased. When y < Hc, the NO concentration decreased sharply with an increase in the y coordinate, while increasing dramatically with an area-weighted average gas temperature increase in the swirl combustion zone. This study provides a basis for optimizing the operation of nitrogen-reducing combustion and the improvement of burner structures.

Influence of Central Air on Flow and Combustion Characteristics and Low-Load Stabilization Performance of a Babcock Burner

“…For a certain equivalence ratio, Huang et al [16] showed that the inclusion of central air could improve the flame stability and optimize the flame shape. In addition, several studies had demonstrated that increasing the central air in a swirl burner could effectively decrease the emissions of NO x [17][18][19]. For example, Xie et al [20] investigated the effect of secondary air flaring angle and central air ratio on NO x emissions of HT-NR3 burner, using a thermal test stand.…”

Special Issue “CFD Modeling of Complex Chemical Processes: Multiscale and Multiphysics Challenges”

“…Effects of impeller configuration and speed were reported. Han et al [4] studied the combustion performance in a pulverized coal furnace with burners installed on the front wall by coupling the momentum balance (with turbulence model), species transport, and energy balance equations. The goal was to optimize the process for reduced nitrogen emission and air pollution.…”