600MW汽轮机轴系调整和基础沉降分析

Shaft System Test and Foundation Settlement in the Overhaul for a 600 MW Steam Turbine

某台600 MW汽轮发电机组存在严重的轴承温度过高和振动不稳定隐患,在机组带负荷过程中,2号轴承金属温度已经达到95℃已影响到机组额定运行的能力。经测量检查存在轴系错位,需要进行揭缸大修、分析原因、消除缺陷、恢复机组的正常运行。通过对汽轮发电机组轴系标高的现场测量和相对标高的分析,得出轴系标高的不正常变化是导致2号轴承金属温度过高的主要原因之一。介绍了汽轮发电机组轴系的基本慨念和设计的主要内容,及轴系标高的现场测量方法,结合标高检测结果,经踪合分析,制定并实施了冷态下轴系标高调整方案,其中1号轴承标高的上抬,采用偏心轴承壳体,可满足轴系标高的调整要求。该机组大修后经运行考核,汽轮机的振动和轴承金属温度均在优良范围内。最后揭示了轴系标高的不正常变化与基础沉降之间一定的牵连关系,并提出在原基础沉降观测失控后的必要检查测量措施。

In a power plant of a 600MW Steam turbine generator unit exists serious excessive bearing temperature and vibration instability risks.In the unit load process, 2# bearing metal temperature, which has reached 95℃, has affected the ability of unit rated operation.Checked by measurement, the existence of shafting dislocation make it essential to open the cylinder overhaul, analyze the reasons, eliminate defects and restore the normal operation of the unit.Through the analysis of the scene on the elevation of Steam turbine generator shaft system measurement and relative elevation, this paper concludes that shafting elevation abnormal change is one of the main causes of 2# bearing metal high temperature.Furthermore, it introduces the main contents of the basic concept and design of Steam turbine generator shaft system, and the field of shafting elevation measurement method, combined with the elevation of the detection result, the tracking and analysis, the formulation and implementation of the shafting ele-vation adjustment scheme of cold, which carried on 1# bearing elevation, using partial spindle bearing shell, can meet the needs of shafting elevation adjustment request.After operation examination, steam turbine vibration and the bearing metal temperature are within relevant range.Finally, the results reveal certain implicated relationship between settling shafting elevation abnormal change and foundation, and puts forward the necessary measures in check after getting out the original foundation settlement observation.