AN IDEA OF STAGED AND LARGE VELOCITY DIFFERENTIAL SECONDARY AIR FOR WATERWALL EROSION PROTECTION AND OXYGEN COMPLEMENTARITY
A successful design of circulating fluidized bed (CFB) boiler should have the highest combustion efficiency, economic operation, and optimum availability. There is a coupled phenomenon of an oxygen lean zone existing in the CFB boiler furnace which depresses combustion efficiency and particle (group) falling down faster and faster when it falls along the waterwall, abrading the tube metal effectively. A new secondary air design for the oxygen lean zone and erosion protection is conceived by using staged and large velocity differential secondary air. For example, a part of concentrate supplied secondary air has been divided into two parts: a low velocity part and a high velocity part. The low velocity part is used for rigid gas layer to reduce the particle falling velocity, and the high velocity part is used for oxygen supply. It is believed that 40～60m/s projecting air velocity could send new oxygen to at least half furnace depth in a short projecting lift as shown in calculation. In another view point, operational superficial gas velocity has an obvious effect on waterwall metal erosion, with a lower operation velocity having lower erosion.
circulating fluidized bed (CFB) boiler secondary air combustion
B.Q.Liu X.H.Zhang
Department of Thermal Energy Engineering, University of Science and Technology Beijing,Beijing, 1000 Department of Thermal Energy Engineering, University of Science and Technology Beijing, Beijing, 100
国际会议
第20届国际流化床燃烧会议(20th International Conference on Fluidized Bed Combustion)
西安
英文
1159-1164
2009-05-18（万方平台首次上网日期，不代表论文的发表时间）