超超临界1000MW机组锅炉汽水分离器冷态启动安全性分析  

Safety analysis on cold state startup of steam separator in an ultra-supercritical 1000MW unit boiler

作　　者：余岳溪[1] 廖宏楷[1] 吴超伟[2] 周懿[2] 钟崴[2] 

机构地区：[1]广东电网公司电力科学研究院,广东广州510000 [2]浙江大学热工与动力系统研究所,浙江杭州310027

出　　处：《热力发电》2015年第2期58-63,共6页Thermal Power Generation

摘　　要：汽水分离器是超超临界机组锅炉中最为重要的厚壁承压元件,定量分析其在各种运行工况下的安全性对于火电机组的安全和优化运行至关重要。对某超超临界1 000 MW机组锅炉汽水分离器在冷态启动过程中的应力场、温度场进行数值模拟计算,在此基础上研究了汽水分离器的热应力、机械应力以及两者矢量叠加的总应力的变化规律,进而使用基于弹性分析的疲劳-蠕变交互作用下的寿命评估计算方法,对冷态启动过程中汽水分离器的寿命损耗进行了计算。结果表明,汽水分离器在冷态启动中,热应力值总体变化趋势是先增后减,机械应力是逐渐增大,且机械应力最终取代热应力成为影响总应力值的主要因素。该汽水分离器的引入管与筒体相贯线区域存在较大的应力集中,在冷态启动过程中具有较大的安全裕度。Steam separator is the most important thick-wall pressure element in ultra-supercritical utility boilers.Quantitative analysis on steam separators in various operating conditions has great significance in safe and optimized operation of thermal power units.Numerical simulation on stress field and temperature field of the steam separator of a 1 000 MW ultra-supercritical boiler during cold state start was performed.On this basis,the law of thermal stress,mechanical stress and the total stress was investigated.Then,the elastic analysis based creep-fatigue evaluation algorithm was adopted to calculate the service life damage of the separator during coal state start.The results show that,during cold state startup,thermal stress of the separator increases first and then decreases,while the mechanical stress increases gradually and eventually replaces the thermal stress as the major factor affecting the value of the total stress.The stress concentrated largely in intersection line zone of the induced tube and cylinder of the separator,indicating this separator has large safety margin.

关 键 词：超超临界机组 燃煤锅炉 汽水分离器 冷态启动 机械应力 热应力 疲劳-蠕变 寿命预测 

分 类 号：TK222[动力工程及工程热物理—动力机械及工程]