A new swirl combustion device was designed and enhaneed,which realized the utilization of steel slag,achieved highly efficient and clean coal combustion,and simultaneously realized a fully elemental utilization of coa...A new swirl combustion device was designed and enhaneed,which realized the utilization of steel slag,achieved highly efficient and clean coal combustion,and simultaneously realized a fully elemental utilization of coal.The distribution laws of different sized particulate matter(PM)emission and the enrichment laws of elements in particles under diverse conditions(such as various excess air coefficients and different coal ratios)were systematically studied.The enrichments of PM under both non-staged and fuel-staged conditions were also investigated.The results indicated that fuel-staged combustion is more helpful in reducing PM emissions than non-staged combustion,and a suitable coal ratio is also beneficial for reducing PM emissions.The melted liquid steel slag drop captured the fly ash produced from pulverized combustion,thus reducing PM emission.The alkali metal elements(K,Na,and Mg),the trace elements(As and Ti).and S have an obvious enrichment tendency in PM]and PM2.5,A different coal ratio under fuel-staged combustion has a significant influence on the enrichment of Al,Si,Ca,and Fe in PM),whereas in PM2.5.PM4,and PM10,the effect of different coal ratios on the enrichment of each element is slight.展开更多
Experimental and numerical investigations have been carried out on the effects of multi-swirl interaction patterns on self-excited unstable combustion characteristics based on a five-nozzle can combustor.The multi-swi...Experimental and numerical investigations have been carried out on the effects of multi-swirl interaction patterns on self-excited unstable combustion characteristics based on a five-nozzle can combustor.The multi-swirl interaction patterns include equal swirl intensity interaction and strong-weak swirl interaction.The thermo-acoustic instability characteristics indicate that increasing the central nozzle swirl intensity transforms the interaction pattern from equal swirl intensity interaction to strong-weak swirl interaction,which can significantly weaken the thermo-acoustic coupling effect under low equivalence ratio conditions,and substantially reduce the dynamic pressure amplitude during unstable combustion.The instantaneous flame structures show that the multi-swirl flames exhibit chaotic oscillations under low equivalence ratio conditions.With equivalence ratios greater than 0.71,a clear flame interaction boundary appears,and the flames can exhibit periodic oscillations in a regular structure.However,different interaction patterns result in the completely different phase oscillations in the central and outer flames.The time-averaged flame structures also indicate that strong-weak swirl interaction leads to an increase in the flame angle and a decrease in the flame length for both the central and outer flames,and the variations in the flame angle and length have great impacts on the thermo-acoustic instability mode.The fuel-staging combustion characteristics demonstrate that the instability combustion conditions with a dominant frequency of 100 Hz are greatly broadened by the strong-weak swirl interaction pattern,and the overlapping operating conditions between this mode and other modes are greatly increased.This implies that it is more flexible to adjust the thermo-acoustic unstable mode,which is conducive to the passive suppression of thermo-acoustic instability.展开更多
文摘A new swirl combustion device was designed and enhaneed,which realized the utilization of steel slag,achieved highly efficient and clean coal combustion,and simultaneously realized a fully elemental utilization of coal.The distribution laws of different sized particulate matter(PM)emission and the enrichment laws of elements in particles under diverse conditions(such as various excess air coefficients and different coal ratios)were systematically studied.The enrichments of PM under both non-staged and fuel-staged conditions were also investigated.The results indicated that fuel-staged combustion is more helpful in reducing PM emissions than non-staged combustion,and a suitable coal ratio is also beneficial for reducing PM emissions.The melted liquid steel slag drop captured the fly ash produced from pulverized combustion,thus reducing PM emission.The alkali metal elements(K,Na,and Mg),the trace elements(As and Ti).and S have an obvious enrichment tendency in PM]and PM2.5,A different coal ratio under fuel-staged combustion has a significant influence on the enrichment of Al,Si,Ca,and Fe in PM),whereas in PM2.5.PM4,and PM10,the effect of different coal ratios on the enrichment of each element is slight.
基金the National Science and Technology Major Project(HT-J2019-II-0018-0039)of China for financial support。
文摘Experimental and numerical investigations have been carried out on the effects of multi-swirl interaction patterns on self-excited unstable combustion characteristics based on a five-nozzle can combustor.The multi-swirl interaction patterns include equal swirl intensity interaction and strong-weak swirl interaction.The thermo-acoustic instability characteristics indicate that increasing the central nozzle swirl intensity transforms the interaction pattern from equal swirl intensity interaction to strong-weak swirl interaction,which can significantly weaken the thermo-acoustic coupling effect under low equivalence ratio conditions,and substantially reduce the dynamic pressure amplitude during unstable combustion.The instantaneous flame structures show that the multi-swirl flames exhibit chaotic oscillations under low equivalence ratio conditions.With equivalence ratios greater than 0.71,a clear flame interaction boundary appears,and the flames can exhibit periodic oscillations in a regular structure.However,different interaction patterns result in the completely different phase oscillations in the central and outer flames.The time-averaged flame structures also indicate that strong-weak swirl interaction leads to an increase in the flame angle and a decrease in the flame length for both the central and outer flames,and the variations in the flame angle and length have great impacts on the thermo-acoustic instability mode.The fuel-staging combustion characteristics demonstrate that the instability combustion conditions with a dominant frequency of 100 Hz are greatly broadened by the strong-weak swirl interaction pattern,and the overlapping operating conditions between this mode and other modes are greatly increased.This implies that it is more flexible to adjust the thermo-acoustic unstable mode,which is conducive to the passive suppression of thermo-acoustic instability.
