二次再热机组高效烟气再循环系统研究与应用

Research and Application of High-Efficiency Flue Gas Recirculation System for Double-Reheat Unit

为解决烟气再循环系统炉烟循环风机过流件磨损严重、系统故障率高问题,深入分析了炉烟风机磨损导致故障率高及烟气再循环系统运行效率低的原因,提出了系统性解决炉烟风机磨损严重的措施,通过多种炉烟循环方案的对比,提出了降低系统能耗的合理方案,并在某工程项目660 MW超超临界二次再热锅炉多年运行验证,取得了较好效果,已在多个工程上推广使用。经过实践证明,提出的技术方案是有效可行的,可为超超临界二次再热机组烟气再循环再热器调温系统的进一步优化设计提供借鉴。

In order to solve the problem of severe wear of the overflow parts of the flue gas recirculation fan of the flue gas recirculation system and high system failure rate,this paper deeply analyzes the causes of high failure rate and low operation efficiency of flue gas recirculation system caused by the wear of flue gas fan,and puts forward systematic measures to solve the serious wear of flue gas fan from the aspects of flue gas duct and equipment selection,and clarifies the direction of reducing system energy consumption through the comparison of various flue gas recirculation schemes.The technical scheme proposed in this paper has been verified in a 660 MW ultra-supercritical double-reheat boiler of a project for many years,and has achieved good results,and has been widely used in many projects.The practice has proved that the proposed technical scheme is effective and feasible,and can provide a reference for the further optimization design of the flue gas recirculation reheater temperature control system of the ultra-supercritical double-reheat unit.