典型贵州煤的燃烧与结渣特性试验研究OA

This study focuses on Guizhou thermal coal,and five typical coal samples(Gui A,Gui B,Gui C,Gui D,and Gui E)are sampled to investigate their combustion and slagging characteristics.The research pro-vides theoretical support for the safe utilization of Guizhou thermal coal in boilers.Kinetic experiments are con-ducted using Discovery TGA 55 thermogravimetric analyzer under an air atmosphere with heating rates ranging from 5 K/min to 30 K/min.The combustion characteristic parameters are analyzed,and the combustion activa-tion energy is calculated using the Flynn-Wall-Ozawa(FWO)and Kissinger-Akahira-Sunose(KAS)meth-ods.Furthermore,the ash chemical compositions are determined via X-ray fluorescence(XRF)spectroscopy,and the ash fusion temperatures are measured using the angle pyramid method.Five indices,including the acid-base ratio and silica ratio,are employed to evaluate the slagging characteristics.An increase in the heating rate significantly elevate the ignition temperature,burn-out temperature,and the temperature corresponding to the maximum weight loss rate for all coal samples,while decreasing the maximum weight loss rate DDTG,max.The combustion activation energy of all samples initially increased and then decreased with the conversion rate.Dis-crimination based on the acid-base ratio or silica ratio indicates that all coal samples exhibites medium slagging tendency.According to the silica-alumina ratio,only Gui E exhibits slight slagging tendency,whereas the oth-ers exhibit medium slagging tendency.However,analysis of the fusion characteristics reveales that the soften-ing temperatures of the five coal ashes are concentrated in the range of 1 200℃～1 300℃,suggesting relatively severe slagging tendency.Inadequate internal heat transfer of coal samples at high heating rates increases the dif-ficulty of initiating combustion reactions and retards the reaction process.In the initial stage of coal combustion,a relatively high energy barrier must be overcome;after entering the rapid combustion stage,the activation ener-gy decreases significantly,facilitating the reaction.Overall,the Guizhou coal samples selected in this experi-ment exhibit a medium-to-severe slagging tendency.This study provides a reference for the optimized combus-tion and slagging prevention of Guizhou coal in utility boilers.