The effectiveness of perforated liner with bias flow on the control of combustion instability is investigated. Combustion instabilities result from the coupling between acoustic waves and unsteady combustion heat rele...The effectiveness of perforated liner with bias flow on the control of combustion instability is investigated. Combustion instabilities result from the coupling between acoustic waves and unsteady combustion heat release. Sometimes the phenomenon happens in afterburners of aeroengine and rocket engine, and it always causes damage to flame holders, liner seetions and other engine components. Passive methods, such as perforated liner, are often used to suppress such instabilities in application. In this article, first, a burner testbed is built in order to study the characteristic of this phenomenon. The unstable frequencies and unsta- ble area are investigated experimentally. Then an analytical model, based on "transfer element method", is developed and the numerical results are compared with those from experiments. At last the perforated liner is applied to the burner to suppress the instabilities. The results show that the sound pressure can be greatly reduced by the perforated liner.展开更多
The present paper has compared a group of furnace aerodynamic fields at different velocities of side secondary air （SSA） in a test model of 420t/h utility boiler, applying Horizontal Bias Combustion Pulverized Coal ...The present paper has compared a group of furnace aerodynamic fields at different velocities of side secondary air （SSA） in a test model of 420t/h utility boiler, applying Horizontal Bias Combustion Pulverized Coal Burner with Side Secondary Air （HBC-SSA Burner）. Experimental results show that, when the ram pressure ratio of side secondary air （SSA） to primary air （PA） （p2s..v2s2./p1v12） is between 1.0-2.4, the furnace aerodynamic field only varies slightly. The relative rotational diameters （φ/L） in the burner domain are moderate and the furnace is in good fullness. When p2sv2s2/p1v12 is beyond 4, φ/L is so large that the stream sweeps water-cooled wall and rotates strongly in the furnace. Therefore, slagging and high temperature corrosion of tube metal will be formed on the water-cooled wall in actual operation. This investigation provides the basis for the application of this new type burner. In addition, numerical simulations are conducted, and some defects in the numerical simulation are also pointed out and analyzed in this paper.展开更多
基金National Natural Science Foundation of China (50890181)Aeronautical Science Foundation of China (2009ZB51)
文摘The effectiveness of perforated liner with bias flow on the control of combustion instability is investigated. Combustion instabilities result from the coupling between acoustic waves and unsteady combustion heat release. Sometimes the phenomenon happens in afterburners of aeroengine and rocket engine, and it always causes damage to flame holders, liner seetions and other engine components. Passive methods, such as perforated liner, are often used to suppress such instabilities in application. In this article, first, a burner testbed is built in order to study the characteristic of this phenomenon. The unstable frequencies and unsta- ble area are investigated experimentally. Then an analytical model, based on "transfer element method", is developed and the numerical results are compared with those from experiments. At last the perforated liner is applied to the burner to suppress the instabilities. The results show that the sound pressure can be greatly reduced by the perforated liner.
文摘The present paper has compared a group of furnace aerodynamic fields at different velocities of side secondary air （SSA） in a test model of 420t/h utility boiler, applying Horizontal Bias Combustion Pulverized Coal Burner with Side Secondary Air （HBC-SSA Burner）. Experimental results show that, when the ram pressure ratio of side secondary air （SSA） to primary air （PA） （p2s..v2s2./p1v12） is between 1.0-2.4, the furnace aerodynamic field only varies slightly. The relative rotational diameters （φ/L） in the burner domain are moderate and the furnace is in good fullness. When p2sv2s2/p1v12 is beyond 4, φ/L is so large that the stream sweeps water-cooled wall and rotates strongly in the furnace. Therefore, slagging and high temperature corrosion of tube metal will be formed on the water-cooled wall in actual operation. This investigation provides the basis for the application of this new type burner. In addition, numerical simulations are conducted, and some defects in the numerical simulation are also pointed out and analyzed in this paper.
