灵活性运行的锅炉联箱应力分析及寿命计算

Stress Analysis and Lifetime Calculation of a Boiler Header in Flexible Operation

以某灵活性运行的超临界锅炉末级过热器出口汇集联箱为研究对象,结合锅炉负荷从200 MW到600 MW再到180 MW变化时的实时运行数据,采用Ansys有限元软件进行热应力、机械应力以及两者共同作用的总应力分析,讨论了各种应力在联箱中的分布情况。根据疲劳-蠕变交互作用下的累积损伤计算方法对联箱在灵活调峰运行时的疲劳和蠕变寿命损耗进行了评估。结果表明:灵活性运行时由于交变产生的热应力对联箱疲劳寿命影响较小,蠕变是影响其寿命损耗的主要因素。

Taking the final superheater outlet header of a supercritical boiler in flexible operation as an object of study,an analysis was conducted on the thermal stress,mechanical stress and their combined stress using Ansys finite element software,based on operation data of the unit with the load changing from 200 MW to 600 MW and finally to 180 MW,so as to analyze the distribution of above stresses in the header.The fatigue and creep life expenditure of the header during peaking process under flexible operation were evaluated according to the linear cumulative calculation method of fatigue-creep interaction.Results show that under the action of alternating thermal stress during flexible operation,the fatigue life expenditure is smaller than the creep life expenditure,and the latter one is the main factor determining the lifetime of the header.