5 MW pilot test study of rapid peaking burner based on pre-gasification strong stable combustion of pulverized coal
The strong stable combustion technology of pulverized coal pre-gasification can balance stable combustion and NOx emis-sion control.Based on this principle,a rapid peaking burner for flexible peaking of power plant boilers had been developed,and the oper-ation performance under different loads,the minimum stable combustion load and rapid load variation capacity of the burner were studied on a 5 MW combustion test rig.The results showed that,after entering the small pre-gasification chamber attached to the burner,the pul-verized coal would undergo gasification reaction and transform into preheated fuel composed of high temperature gas and hot carbon parti-cles.Under low load,the preheated fuel would burn rapidly after entering the furnace,forming a high temperature zone at the root to en-sure the steady combustion of the furnace.With the increase of load,the gasification reaction in the pre-gasification chamber was more complete,and reducing atmosphere was formed with the return flue gas to achieve effective nitrogen reduction.The NOx emission at full load was 159 mg/m3(6％O2)without any auxiliary means,and the carbon content of fly ash was 3.4％,meaning combustion efficien-cy was 99.71％.The rapid peaking burner could still maintain the stable combustion of the furnace under the ultra-low load of 9％,and the outlet oxygen remains stable during the long-term continuous operation of more than one hour.In the range of 15％to 100％load,the rapid load reduction and load rise processes were completed in 8 min and 9 min,and the load ramp rates reached 10.63％/min and 9.44％/min respectively.During the process of load change,the combustion in the furnace remained stable,and the temperature distribu-tion had a fast response to the load change,which verified the excellent performance of the burner in the process of rapid peak regulating.
万方数据
维普
