Experimental Study on Technical Difficulties of Botswana First Circulating Fluidized Bed Boiler during Loading Process

Abstract

For study of technical difficulties that make Botswana first CFB (Circulating Fluidized Bed) boiler can’t reach full load at beginning of loading process, first experiments were carried out as awful experimental cases to analyze influencing factors; Second experiments were carried out as tentative experimental cases to select useful solutions; Third experiments were carried out as targeted experimental cases to execute chose solutions. Results indicate that one prominent difficulty during CFB boiler reaching full load is that boiler operation bed temperature was too high which was a comprehensive effect with some other influencing factors. CFB boiler bed temperature MFT (Main Fuel Trip) set point slight increasing, grain size changing of both start-up material and feeding coal, limestone injecting, fluidizing air of seal pot and FBHE appropriate controlling and FBHE (Fluid Bed Heat Exchanger) gradually start working are taken simultaneously, all these effective solutions solve the technical difficulties and accelerate the boiler reach full load, but attentions still need to be paid for the boiler stable operation permanently in future.