Effect on Combustion Efficiency in CFB Boilers and Measures to Improve Efficiency
SHEN Li 1, LIU De chang 1, ZHANG Shi hong 1, GUO Qiang 2 (1. National Laboratory of Coal Combustion, Huazhong Univ. of Science and Technology, Wuhan 430074, China; 2. Dept. of Thermal Dynmaics, Wuhan Univ., Wuhan 430072, China)
Circulating Fluidized Bed (CFB) technology has many advantages, such as high efficiency, low pollutant emission and excellent fuel flexibility. So it has been developing quickly. However there are some common problems in CFB boilers, for example, the carbon content of fly ash is very high and the combustion efficiency is lower than the design value. This paper analyses the effect on combustion efficiency and the carbon content of fly ash in CFB boilers, including the distribution of particle size and the heating value change of coal, the fractional cold of combustion chamber, and the operation conditions of fly ash circulating combustion system. According to the reasons mentioned above, authors put forward some measures how to maintain the stable combustion, to reduce the carbon content of fly ash as well as to increase the combustion efficiency. These measures have been proved effective in the practical experience in a CFB boiler. Figs 3, tables 2 and refs 5.