事故状态下超临界循环流化床锅炉炉内非稳态传热过程理论分析与计算

Theoretical Analysis and Calculation of the Unsteady Heat Transfer Process of Supercritical Circulating Fluidized Bed Boiler Furnace under the Emergency Conditions

对于目前的国产型350 MW超临界CFB锅炉,通常不配置紧急补给水系统,在发生紧急事故时,如:给水泵故障突然停运或风机跳闸、全厂停电、汽轮机跳闸等极端恶劣情况下,水冷系统无法正常得到补给水,必须考虑炉膛内的床料蓄热对水冷壁系统受热面的影响,如:多长时间能使管内的工质发生蒸干从而使管子壁温飞升,产生安全性问题等。结合传热学的基本理论,对此极端情况下炉膛内的非稳态传热问题进行了理论分析与计算,可为电厂实际运行人员快速处理此类事故时提供一些定量的参考。

For the current domestic 350 MW supercritical Circulating Fluidized Bed boiler, the emergency feed water system is not usually adopted. In case of an emergency such as the stopping of feed water supply due to feed water pump failure suddenly or tripping of fans, electricity power and turbine, the influence on water wall surface from bed material heat storage must be considered. For example, how long will the water inside tubes dry out？ How about the tube material security issues. And so on. In this paper, the theoretical analysis and calculation of the unsteady heat transfer process will be discussed briefly, which can provide some quantitative reference to the actual operators of the power plant when such emergency happened.