Numerical Study on Optimum Designing of the Air Distribution Structure of a New Cyclone Combustor

Abstract

A new type of cyclone combustor is designed based on the traditional pulverized coal liquid slag combustor in this paper. According to the characteristics of swirl combustion and flow, numerical simulation of pulverized coal combustion in a new cyclone combustor has carried out using Realizable k-ε equation model with swirl modified to gas phase and stochastic trajectory model under Lagrange coordinate system to particle phase. Flows and combustion characteristics under different working conditions are mainly studied by changing the angles of primary and secondary air inlets, and then structural characteristics of the combustor are analyzed. Results show that structural characteristics of the primary and secondary air have great influence on internal flow and combustion characteristics of the combustor. When the pitch angle, the rotation angle of the secondary air and the expansion angle of the primary air respectively are 20°, 51° and 60°, the combustion efficiency of the combustor can reach up to 98.1% and it is conducive to high-temperature liquid slagging. It is also helpful to prevented pulverized coal depositing and accumulating near the wall and then plugging the combusting channel during the starting stage in low temperature region.