Numerical Simulation Of Gas-Particle Two-Phase Free Jet Coal Combustion

With the advance of modern society, the non-regeneration energy resource such as coal,petroleum and natural gas is increasly decreased. Energy resource has become an issue of continuous development. One is how to improve the energy`s utilizing effiency, the other is how to reduce the pollution while utilizing the energy. Most energy are utilized by combustion,that is ,through combustion,chemical energy turned into thermal energy, thermal energy turned into mechanical energy. So the research of combustion is a critical issue about the national economy and the people's livelihood. In our country`s energy structure, power plant energy make up most of the energy,amount to 75%. Coal is the main fuel in most of the power plant, so coal combustion research has direct realisitic significance.Coal combustion is a complex process involving physics mechanism and chemical reaction.So far,most of the combustion models are base on the experimental data.They are approximate, coarse models. During last decades,with the emergence of computer,applying computer to simulate complex flow area has become an important experimental measure.Gas-partical two phase free jet combustion numerical simulation,including volatilization discharging, coal combustion, radiation heat transfer, partical movement , gas-phase flow and turbulent combustion, involving subjects like multi-phase flow,heat-transfer and combustion. For each step, according to the choose of model, different simulation ways are developed. Model choosing are focus on gas-partical model and turbulent model.In this partical,for gas-partical turbulent model, k-ε-εp model was chosen;for combustion model,we choose EBU-Arrenhunis model;for volatilization discharging model,we choose two-step model. Coal free jet combustion process is simulated; Two-phase free jet volicity field and temperature field are obtained;A comparision between cold and hot turbulent are conducted. The concludsion is that inlet volicity is the main factor of affecting the volicity field and tempeture field.