Study on Air Preheater Corrosion Problem of CFB Biomass Directed-Fired Boiler in Zhanjiang Biomass Power Plant

Biomass has attracted more and more attention in the world as renewable energy. Biomass direct-fired technology is a relatively mature technology with widely application in China. Due to the high content of alkali metals and chlorine in the biomass fuel, biomass direct-fired power plant suffers from ash-deposition and corrosion problems of low-temperature heating surface in boiler, accordingly impact the security and economy of boiler. Based on the literature survey, on-site detection, as well as EDXRF experimental analysis, reasons which resulted in ash-depostion and corrosion problems of air preheater are analyzed for 2×50MW CFB (Circulating Fluidized Bed) boilers in Zhanjiang Biomass Direct-fired Power Plant by Guangdong Yudean Group. Suggestive measures to prevent ash-depostion and corrosion are also proposed in this paper by the analysis of biomass combustion characteristics, ash-depostion and corrosion formation mechanism.