Numerical Simulation Of DC Arc And Trait Research Of Plasma Ignition

It needs to consume a lot of oil during the course of pulverized coal boiler commissioning, cold startup and low load combustion stabilization. Oil is very indigent in our country, and oil price is higher and higher in international market, therefore, saving oil is imperative. Plasma ignition system can ignite pulverized coal and stabilize flame without any oil, which is an important means to save oil used for the boiler ignition, flame stabilization and commissioning. It can be used to effectively reduce the cost of power generation, save oil resource and enhance the energy security for China. Plasma ignition combustor is one of the main equipment of the plasma ignition system, whose structure and ignition characteristics play the key role in the application and popularity of plasma ignition technology. Therefore, this paper studies the ignition characteristics of plasma ignition burner in the round.Firstly, this paper introduces constitutes of plasma ignition system, the basic characteristics of plasma, pulverized coal combustion improved by plasma and quantity of heat analysis of plasma electropult. On this condition, applying knowledge of physical chemistry and thermodynamics, this thesis calculates theoretically plasma temperature of plasma generator outlet.Secondly, the temperature and velocity field of DC arc plasma obtained by ANSYS with MHD model. The result shows that the temperature at center of anode spout is highest and temperature fall gradually from center to brim, which presents parabola. Velocity distribution is like as temperature. Distribution of temperature and velocity is described with equations which are used as the boundary condition of plasma ignition numerical simulation. DC Arc is simulated in different condition. The thesis gains the effect of power of plasma generator, flux of compressed air and flux of cooling water on temperature of electrode.Thirdly, the ignition and combustion process of Plasma ignition combustor is simulated with CFD software FLUNT. k-εmodel is employed to simulate gas turbulent flow. Equilibrium Mixture Fraction/PDF Model is employed to simulate gas turbulent combustion. P1 model is used to simulate radiation heat transfer. Two competing rates model is employed to simulate pulverized coal volatilization. Stochastic tracking model is employed to simulate pulverized coal track. Kinetics/diffusion limited model is employed to simulate coke combustion. Key ignition factors distributions such as the temperature field, velocity field CO2distribution, CO distribution are obtained, which studies the ignition characteristics of plasma ignition burner in the round.Finally, ignition and combustion process of plasma ignition combustor is simulated with CFD software FLUNT in different condition. The thesis gains the effect of primary air velocity, pulverized coal concentration, primary air velocity on the ignition characteristics of plasma, which supply gist with ameliorating and designing plasma combustor.