Combustion with lean premixed and low swirl is an effective way of flame organization.It can improve the flame stability and reduce NOX emission.In this kind of combustion,one of the most important issues is fuel/air ...Combustion with lean premixed and low swirl is an effective way of flame organization.It can improve the flame stability and reduce NOX emission.In this kind of combustion,one of the most important issues is fuel/air premixed characteristics.How the structure parameters influence that issue is figured out through numerical simulation.The structure parameters concerned in the study are as follows.They are shape of blades,number of blades,location and shape of gas jet.The influences of them are analysed with comprehensive consideration of many aspects.With the same light shading rate and stagger angle,the axial swirler with curved blades has worse premixed uniformity and lower pressure loss than the one with straight blades.With the same structure of each blade,the decrease of the quantity of blades does influence the pressure loss,while the quantity of gas jets changes correspondingly.But it has little effect on premixed uniformity in a certain range.However,more blades make contribution to better premixed performance.When the total flow area is the same,the axial and circumferential positions of the fuel jets also greatly influence the premixing process.When the fuel jets are upstream the blades and locate at middle of the vanes,the premixing performance is the best.Meanwhile,the jet direction of the fuel jets is a very important influencing factor of the premixing process.When the fuel jet direction is oblique downward at an angle of 30°to the horizontal,the premixing effect is better than the horizontal outflow,which is better than the oblique upward structure.展开更多
基金This study is supported by Shanghai Committee of Science and Technology(Grant No.18DZ1202003).
文摘Combustion with lean premixed and low swirl is an effective way of flame organization.It can improve the flame stability and reduce NOX emission.In this kind of combustion,one of the most important issues is fuel/air premixed characteristics.How the structure parameters influence that issue is figured out through numerical simulation.The structure parameters concerned in the study are as follows.They are shape of blades,number of blades,location and shape of gas jet.The influences of them are analysed with comprehensive consideration of many aspects.With the same light shading rate and stagger angle,the axial swirler with curved blades has worse premixed uniformity and lower pressure loss than the one with straight blades.With the same structure of each blade,the decrease of the quantity of blades does influence the pressure loss,while the quantity of gas jets changes correspondingly.But it has little effect on premixed uniformity in a certain range.However,more blades make contribution to better premixed performance.When the total flow area is the same,the axial and circumferential positions of the fuel jets also greatly influence the premixing process.When the fuel jets are upstream the blades and locate at middle of the vanes,the premixing performance is the best.Meanwhile,the jet direction of the fuel jets is a very important influencing factor of the premixing process.When the fuel jet direction is oblique downward at an angle of 30°to the horizontal,the premixing effect is better than the horizontal outflow,which is better than the oblique upward structure.
