循环流化床锅炉翼形墙受热面壁温特性分析

Analysis of the Heating-surface Wall Temperature Characteristics of a CFB(Circulating Fluidized Bed) Boiler Wing Wall

以循环流化床锅炉中翼形墙3种典型结构Φ51×5mm、Φ42×5mm和Φ38×5mm为例,分析了工质质量流率和参数对壁温的影响。结果表明,质量流率是保证受热面安全运行的主控因素,壁面与工质的温差随质量流率的增加而减小;管件结构与工质出口温度对壁面与工质温差的影响不明显,但管件结构对鳍片温度的影响较为明显;压力仅在一定程度上对壁温有影响。为兼顾考虑低负荷下锅炉的安全与经济运行,推荐翼形墙受热面内工质设计质量流率选取不宜低于750kg/(m2·s)。本研究为翼形墙受热面的安全运行提供参考。

With the three wing wall typical structures of a circulating fluidized bed boiler serving as an example,namely,51×5mm,42×5mm and 38×5mm,analyzed was the influence of mass flow rate and parameters of the working medium on the wall temperature.It has been found that the mass flow rate is a dominant factor for securing a safe operation of the heating surfaces.The temperature difference between the wall surface and working medium decreases with an increase of the mass flow rate.The influence of the tubing structure and the outlet temperature of the working medium on the temperature difference between the wall surface and working medium is not evident,the influence of the tubing structure on the fin temperature,however,is relatively obvious.The pressure only affects the wall temperature to a certain extent.To consider both the safe and economic operation of a boiler at low loads,it is recommended that the design mass flow rate inside the wing wall heating surface should be chosen at a value not lower than 750 kg/m2·s.The research results can well provide reference for the safe operation of wing wall heating surfaces.