Numerical Simulation Of The Influences Of Swirl Intensity On Spray Combustion

Nowadays, energy and environment are two subjects development of society, more and more countries pay their attention to them. The faster development our country economy, the bigger consume energy, and the environmental pollution is becoming worse and worse. It is very important for us to improve combustion efficiency,decrease emission combustion. The spray combustion on different of swirl intensity has been described in this paper.In this paper, a physical model was founded from the combustion device in the laboratory. Then, the process of spray and combustion of the swirl combustor was simulated by FLUENT6.2 software and analyzed the influences of different swirl intensity on spray and combustion.Firstly, numerical simulation was conduced to predict the single gas phase flow in cylindrical combustor and obtained the distribution of single gas phase flow in different swirl intensity, then the air velocity fields on different swirl intensity was analyzed. Results show as the swirl number increases, the central recirculation zone moves upstream then downstream, and the corner recirculation zone becomes diminished.Secondly, numerical simulation was conduced to predict the spray progress in cylindrical combustor and obtained the distribution of velocity vectorgraph, particle tracks and DPM concentration in different swirl intensity, which show that with increasing of the swirl number, the central recirculation zone moves downstream then upstream, the spray angle enlarged firstly then reduced, and the DPM concentration is reduced.Finally, the spray combustion in the combustor was simulated, and obtained the distribution of velocity, flame temperature and contamination. The result show: as the swirl number increased, the high temperature zone of combustor move upstream, the length of flame was shortened and then increased, the diameter of flame was augmented. When the swirl number increases and exceeds a critical value, the high temperature zone moves backward, and the stability of flames increased; as the swirl number increased, the quantity of CO2 increased, and the quantity of CO and NO increased firstly and then decreased.