450t/h循环流化床锅炉床温运行特性分析

针对目前循环流化床锅炉床温控制水平较低．难以投入自动控制的问题，基于某电厂450t/h循环流化床锅炉的运行数据和运行实例，较全面地分析了给煤、一次风、氧量、床层高度、负荷等主要因素对床温的影响。分析发现：给煤调节床温具有滞后性，煤质和煤粒径对床温也有一定影响；不同运行工况下一次风对床温可能有不同影响；氧气浓度变化可反映炉内的燃烧工况；密相区料层厚度变化会带来床温变化；床温只是影响负荷的主要因素之一，所得结论可对循环流化床锅炉运行、床温控制系统的设计和了解床温调节规律提供参考。

Analysis on bed temperature operational characteristics of 450 t/h CFB boiler

Presently the control level of bed temperature of circulating fluidized bed (CFB) boiler is comparatively low, it is difficult to put automatic control into operation. On the basis of the operating data of a commercial 450 t/h CFB boiler, the authors systematically analyze the main factors which influence the change of bed temperature. The record of the operation data shows that the lag of the bed temperature is a common phenomenon while fuel supply is changed; coal quality and its grain diameter spectrum also have notable influence on bed temperature; primary air rate has different influences on bed temperature in different operating conditions; the change of oxygen concentration can reflect combustion conditions in the furnace; the change of dense zone height will result in the change of bed temperature; bed temperature is one of the main factors which lead to load variation. The conclusions can provide references for the design of control system and safe operation of CFB boiler.