300MW循环流化床锅炉机组压火的特性分析

Characteristic analysis of banked fire for 300 MW CFB boilers

利用循环流化床(CFB)锅炉蓄热量大的特点,处理锅炉重大缺陷时采用压火(停炉不停机)的处理方法,达到了紧急处理锅炉本体缺陷时机组不解列,减少机组非计划停机的目的。为了考核300 MWCFB锅炉机组运行中发生停炉抢修时机组不解列对汽轮机的影响,对降负荷速度、最低负荷限值、汽缸各段抽汽的影响、升负荷速度、蒸汽升温升压的控制等问题,采用对比分析的方法,分析了压火与机组解列对汽轮机安全性的影响、对CFB锅炉受热面保护的影响、对发电机变压器组和电网安全的影响及2种情况下的经济效益的对比,认为压火更有利于汽轮机的安全运行,并以实践经验阐述了压火的技术措施。

Considering the large heat storage of CFB boilers, the banked fire method was used for the major defeet treatment. The emergency treatment for major defects of boiler proper was accomplished without any power unit separation, and the unplanned outage of power units was reduced significantly. The comparative analysis method was introduced to evaluate the effects on the operation of 300 MW CFB boilers, including the speed of load drop, the limit of the lowest load, the extracting steam of each section, the speed of load rise, the control of steam temperature and pressure etc, The impacts and economic henefits of banked fire and unit separation were compared on the safety of steam turbine, the heating surface of CFB boiler, the generator-transformer unit and the safety of power grid. The result shows that the banked fire is favorable for the safe operation of steam turbine, based on which the technical measures of banked fire were illustrated.