Numerical Simulation On Combustion Characteristics Of A0.5MW Central Fuel Rich Swirl Burner

The Central fuel rich (CFR) swirl burner is a new high combustion efficiencyand low NOxburner.To make further study on CFR swirl burner, a0.5MW hot-statetest bed using the CFR swirl burner was built up in Combustion EngineeringResearch Institute, Harbin Institute of Technology. Firstly, numerical simulation ongas/particle flow field of the CFR swirl burner used on0.5MW hot-state test bedwas carried out. Secondly, numerical simulation on combustion characteristics ofthe hot-state test bed under different primary particle concentration and differentoperate parameters was carried out. The followings are research results:The results of numerical simulation on gas/particle flow field show that withthe increase of primary particle concentration of swirl burner, the velocity of coalparticle diffusion at the nozzle region of burner increases. By comparing thenumerical simulation results and obtained PDA test data, the distribution of axialvelocity, radial velocity and tangential velocity at the nozzle region of burner arenearly same and in good agreement. Thus the correctness of the mesh on swirlburner and selected mathematic model to simulate gas/particle flow field wasverified.The results of numerical simulation on combustion characteristics show thatwith the increase of primary particle concentration, the combustion rate slows down,the gas temperature decreases, the NO concentration decreases. With the increase ofexcess air coefficient, the penetration depth of primary air decreases, thecombustion rate speeds up, the gas temperature increases, the NO concentrationincreases. With the increase of inner secondary air ratio, the penetration depth ofprimary air decreases, the combustion rate speeds up, the gas temperature increases,the NO concentration increases. By comparing the numerical simulation results andobtained temperature, gas concentration data in hot-state experiment, it was foundthat they are in good agreement. Thus the correctness of the mesh on swirl burnerand furnace and selected mathematic model to simulate combustion characteristicswas verified.