| The co-combustion of biomass and coal in CFB boiler is a simple and efficient way to utilize biomass.Based on the thermodynamic law,the co-combustion system of biomass and coal in 369 t/h high temperature and high pressure circulating fluidized bed boiler is analyzed.The effects of biomass ratio,moisture content and biomass types on the flue gas temperature,thermal efficiency and efficiency of the boiler are studied.The main conclusions are as follows:(1)The influence of blending proportion and moisture on the flue gas temperature and thermal efficiency of boilers: blending 0%,10%,20% and 30% corn stalk with different proportion,the flue gas temperature rises from 135 ℃ to 138 ℃,the thermal efficiency of boilers decreases from 89.62% to 89.3%;blending 30% corn stalk with moisture content of 10%,15%,20%,25%,30% respectively,and the flue gas temperature rises from 138 ℃ to 141 ℃,and the thermal efficiency of boilers decreases from 89.28% to 88.97%;(2)The influence law of mixing proportion and moisture on the boiler’s scraper efficiency: mixing 0% to 30% corn stalk,the boiler’s efficiency drops from 46.11% to 45.35%;mixing 30% corn stalk,its moisture changes from 10% to 30%,and the boiler’s efficiency drops from 45.34% to 45.27%;(3)The influence of blending proportion and moisture on heat transfer efficiency and scratch loss of heating surface and other heating surface in furnace: blending 0% to 30% corn stalk,the heat transfer efficiency of heating surface in furnace decreases from 38.15% to 37.28%.Among all scratch losses in furnace,the combustion loss can not be increased from 63.9% to 66.39%.When blending 30% corn stalk,the moisture content changes from 10% to 30%.The heat transfer efficiency of the heating surface in the furnace decreases from 37.28% to 37.22%,and the non-recursive burning loss increases from 66.38% to 67.16%.(4)The effects of biomass types on boiler thermal efficiency and scraper efficiency are as follows: burning 20% different biomass at low load,boiler thermal efficiency changes from 89.73% to 90%,scraper efficiency changes from 45.62% to 45.75%. |
