Flame Structure And Emission Characteristics Of Petal-swirl Combustor

As the energy transforms rapidly,the clean energy is replacing the traditional fossil flue gradually.Electricity serves as the core energy of modern industry.However,expect of the nuclear energy,fossil flue combustion creates the major electricity.As the result,air pollution problem comes.In order to reduce the emission of combustion pollutants,the gas burner is considered as a better way to approach the harmony between nature and industry.In this paper,a combustor consisted of two kinds of petal structures,non-swirl and swirl,and swirler are used to investigate how the different structures of combustor exert efforts on flame construction,stability and emission characteristics.The flame and CH constructions are captured through a digital camera and a 440 nm optical filter.These photos of the flame and CH constructions show that as the central swirl number increases,the flame shorted and optical radiation enhanced.When the central swirl flow has a common direction towards the swirl-petal,the flame shows a wider radial dimension and further mean flame temperature.The conclusions from the experiment of thermal-acoustic oscillation are that the amplitude peek value of combustion increases and combustion stability deteriorates as the equivalence ratio decrease in non-swirl petal and central swirler combustor.On the contrary,in the swirl-petal and central swirler combustor,there is a low level amplitude peek value and a better combustion stability.The NOx emission concentration increases as the equivalence ratio going up,but the CO emission concentration changes in an opposite trend.As the central swirl number increasing,emission of CO decreases but NOx emission raises.CO and NOx emission concentrations are more preferable when the premixed gas staged ratio is 7:0:3.The numerical simulation of combustion shows that the swirl-petal structure can influence the flow stream and species contributions on the cross sections of the combustor downstream.When the central swirl increases,the size of inner recirculation zone grows in radial direction,flame volumes increase as well.