某大型水电站异常振动和出力不足问题研究

Study on abnormal vibration and insufficient output of turbine generator unit of a large hydropower station

以我国自主研发的600 MW级混流式水轮发电机组投运后的运行状态为例展开研究分析。针对该大型水电站高负荷区出现的异常振动和最大出力不达标的严重问题,从问题的产生机理分析和故障诊断入手,先对引起异常振动的原因展开分析,然后通过对现场稳定性和出力测试结果进行评估,提出了对机组实施改进的方案,即沿着水轮发电机组转轮叶片的出水边进行切割修型,并同时对泄水锥进行改进,再结合数值和同步模型试验的模拟结果进行比较分析,成功地解决了该水电站的高负荷区域异常振动和出力不足问题,并由此提炼出一套较为完整的针对这一类型问题的分析和处理通用方法。

Taking the 600 MW Francis turbine generator unit that is independently researched and developed by domestic insti-tutes and then put into operation in a large hydropower station as a study object, the abnormal vibration and insufficient maximum output of the unit in high-load operation are studied through problem genesis mechanism analysis and failure diagnosis. The cau-ses of the abnormal vibration are first analyzed, and the improvement scheme is proposed according to the field test results of unit stability and output. By trimming the outlet edge of the runner blade and modifying the runner cone, in combination with compari-son and analysis of numerical simulation and simultaneous model test results, the problems of abnormal vibration and insufficient maximum output of the unit in high-load operation are successfully solved, on the basis of which, a general and relatively com-plete problem analysis and solution formula is summarized.