Numerical Simulations Of Ignition And Combustion Of Pulverized Coal-enriched Oxygen In Swirl Burner

Along with the global econommics fast development, energy and environmentproblems are increasiongly serious. Especially, the Middle East oil is very rich,while the United States and the European Union is economic and trade center allover the world. That is the reason which the relationship is very intense between theUSA and the Middle East. Energy conservation is imperative, the only thing that wecould do is reduced energy consumption. In order to achieve the successful ignitionof electric boilers, a lot of diesel fuel will be used to ignate in operation of boilersduring start-up. This paper combines with the characteristics of oxygen-enrichedcombustion and the ignition of pulverized coal boiler, trying to reduce the diesel oilconsumption in ignition process of pulveraized coal boilers.Recently, oxygen-enriched ignition is paid more attention as the emergingtechnology of ignition. This technology is still in experimental and numericalsimulation investigations. In order to achieve the greatest degree of savings, we alsoneed to do more research studies. The most important factor is whether the ignitionis successful or unsuccessful during start-up, which influence the stability ofpulverized coal combustion. The ignition of pulverized coal and oxygen-enriched airis a kind of the unsteady combustion and forced ignition, but it is very difficult tofind the apprppriate volume fraction of oxygen in the air also. Increasing the oxygenvolume fraction of primary air, the primary combustion （gas-volatile combustionand the surface combustion of carbon residue and oxygen） of pulverized coal withmore fully-oxidants, the temperature levels are increased, the coal-particle burningrate is improved as well. In addition, more CO is oxidized to CO₂in theoxygen-enriched air stream, reducing the amount of CO in the flue gas. Obviously,oxygen-enriched ignition not only is an energy-saving technology, but also isenvironmental protection technology.In this paper, it is based on FLUENT software, focusing on pulverized coalignition in the swirl burner. The single-phase flow, gas-solid two-phase flow andgas-particle combustion are simulated in the swirl burner. The eddy dissipationmodel is selected as turbulent combustion calculation. The effect of pulverized coalparticle size, temperature, pressure, velocity, mass fraction of coal-particle onignation and combustion is anylyzed. The operations on NOx emision are alsopredicted. Present research aims to analyze acceptable operating conditions foroxygen-enriched combustion of puveriaed coal combusors.