Investigation of Heat Transfer and Combustion in the Advanced Fluidized Bed Combustor (FBC).

This technical report summarizes the research conducted and progress achieved during the period from April 1, 1997 to June 30, 1997. The exploratory hot model was modified to explore the operational limits, fuel flexibility, and the role of heat transfer in combustion control. Eight air injection nozzles were newly designed to set different angles. Three runs of independently controllable water-cooling tubes were arranged to study the local heat transfer characteristics along the flow direction of the combustor height. The fuel nozzle was carefully designed to improve the fuel atomization quality. The igniter system was designed to safe and dependable ignition. According to the established safety and health guideline, the auxiliary subsystems are inspected carefully. All instruments are checked and calibrated for the system test. The combustion test result was analyzed to understand thermal performance and heat transfer characteristics. The flame enthalpy decreased along the combustor height. The heat is removed by the cooling water at different zones during the combustion test. The axial variation of heat transfer coefficient was predicted. The heat transfer coefficient is generally lower in the top area than in the bottom of the combustor