一起汽轮机轴瓦振动大跳机原因分析及处理

Cause Analysis and Treatment of a Turbine Bushing Vibration Jumping

某公司发电厂3号机组投运后,在大负荷试运时因1X、2X振动大机组跳闸,主要原因为围带汽封、隔板汽封、轴端汽封间隙比较小或不均匀,当机组负荷增加、主蒸汽流量增大时会产生汽流激振,主蒸汽调门分别在单阀、顺序阀方式下机组带365MW负荷运行、主蒸汽流量达到最大值,进行摩合试验,消除了机组1瓦、2瓦振动大的隐患。对其他两台机组也进行了最大主蒸汽流量下的摩合试验。有效防止新建机组或经过汽封间隙调整后的机组,在初次试运时,发生机组振动大跳机事件。

After unit 3 in a power plant of a company was put into operation,the unit tripped due to 1 X and 2 X vibration during heavy load test run.the main reason was that the gaps between shrouded gland seal,diaphragm gland seal and shaft end gland seal were relatively small or uneven.when the unit load increased and the main steam flow increased,steam flow excitation would be generated.the main steam regulating valve operated with 365 MW load and the main steam flow reached the maximum under single valve and sequence valve modes respectively.friction test was conducted to eliminate the hidden danger of large vibration of unit 1 watt and 2 watt.Friction tests were also carried out on the other two units under the maximum main steam flow.It can effectively prevent the occurrence of large vibration jump of newly-built units or units adjusted by gland seal clearance during initial commissioning.