Study On Single Particle Combustion Characteristics Of Peanut Shell Molding Fuel

China’s agricultural and forestry waste is abundant in production and is a clean renewable resource,Compressing it into solid fuel is an ideal alternative fuel for small and medium-sized industrial boilers.At present,in order to achieve efficient and clean utilization of biomass forming fuels,research on its combustion characteristics has gradually received attention.In this thesis,peanut shell particles and peanut shell briquettes were taken as research objects,the combustion and pollutant emission characteristics of single molding fuel was studied by thermogravimetric experiments and tube furnace combustion experiments,which provided reference for the design and optimization of peanut shell molding fuel combustion equipment.The combustion characteristics of Peanut shell powder fuels were studied by thermogravimetric experiments.The results showed that the TG and DTG curves of peanut shell particles and peanut shell briquettes showed similar trends,but the temperature range,weight loss rate and maximum weight loss rate of each stage were different;When the heating rate increases,the TG curve shifts to the high temperature region,and the DTG curve moves down as a whole,The flammability index C and the comprehensive combustion characteristic index S are both increased.The weight loss method was used to study the constant temperature combustion weight loss characteristics of peanut shell particles and peanut shell briquettes at different combustion temperatures.The results showed that the constant temperature combustion weight loss curve of low temperature(300~400℃)is similar to the thermogravimetric curve(TG)of powdered fuel,and the pyrolysis process is slow in stages;The constant temperature combustion weight loss curves at high temperature(600~1000℃)are obviously two-stage,the first stage is the rapid weight loss stage,and the weight loss rate is high,which is the main stage of combustion,the second stage is the slow weight loss phase,with a lower weight loss rate and a longer duration.In addition,as the combustion temperature increases,the weight loss rate and the weight loss rate increase,the maximum weight loss rate time,and the burnout time are continuously advanced.The combustion process of a single peanut shell molding fuel was studied by flue gas analysis,and the effects of combustion temperature,air flow and fuel quality on its combustion characteristics were investigate.The results showed that with the increase of combustion temperature,the increase of air flow and the decrease of fuel quality,the combustion rate increases,the maximum combustion rate time and burnout time are shortened continuously,the combustion temperature has the most significant influence on the combustion process.Comparative study on the combustion process of equal amount of peanut shell particles and peanut shell briquettes under the same conditions.The results showed that the combustion process is similar,but the duration of each stage of combustion is significantly different.When the combustion temperature is 600℃,the volatilization analysis and combustion time of the Peanut shell briquettes is 60s,and the fixed carbon burning time is 180s.but the volatilization analysis and combustion time of the Peanut shell particles is 84s and the fixed carbon burning time is 102s.The effects of combustion temperature,air flow rate and flue gas recirculation rate on NO_X emission characteristics of peanut shell molding fuel were studied.The results showed that the NO_X emission decreases with the increase of combustion temperature,the decrease of air flow rate and the increase of flue gas recirculation rate.