Development And Investigation Of Oil Burner For Chinese Small Cooking Range

To solve the problem that the flame length of imported light oil burner dismatchingchinese small cooking range and high NOXemission, a short flame and low NOXoil burner isdeveloped for the energy conservation and emission reduction in small cooking range.The burner outlet aerodynamic field was studied firstly. The results show that there existsa recirculation zone which consists of two opposite direction vortexs above the radial slot offlame holder, this zone is resulted by the composition of coaxial jet and the rotating jet. Radialvelocity and tangential velocity shows a ‘W’ and ‘U’ type distribution. According the rule ofoutlet flow field and spray combustion theory, a short-flame and low-NOXoil burner withdouble swirl flame holder and exhaust gas recirculation structure was designed preliminarily.CFD method was employed to investigate the spray combustion process, adoptingstandard k turbulence model, Discrete Random Walk model, PDF model, DiscreteOrdinates radiation model and NOXformation model. Simulation results show that the sprayflame consists of two flame-fronts which meet again at the secondary reaction zone. NOXformation concentrates in the high temperature zone of axial flame end. The result agreed wellwith the experiments, that verified the feasibility of the model.Fluent was applied to simulate the combustion performances of the burner with differentspray cone angle and structure size. The results indicate that the flame length is mainlydetermined by the matching degree of the distribution of oil mist concentration and the gasflow. When the spray cone angle is70°and inner swirl intensity was0.736, mixing effect wasbest and the flame length is decreased by16.5%. NO emission can be reduced a lot when theexhaust gas circulation rate is controlled in a suitable range. When the exhaust gas circulationrate was4.1%, the NO emission is decreased by56.1%.