扩机爆破振动对运行中水轮机组的影响

Influence of blasting vibration on turbine units

水电站扩机工程施工过程中，研究爆破振动对邻近建筑物，特别是水轮机组的影响，有着重要的意义．以深溪沟水电站新增灌排洞施工为背景，通过对爆破施工条件下水轮机组运行状态的监测，得到了爆破振动影响下水轮机组振动的相关特性，分析了扩机爆破振动对运行中的水轮机组的影响．结果表明，实测水轮机组自振频率（约为100Hz），高于中远区爆破振动主频；爆破振动使水轮机组产生受迫振动，导致其振动峰值显著增大．改变装药量虽然会引起受迫振动主频的变化，但受迫振动的频率仍然偏离自振频率带，并不会引起水轮机共振．而如果装药量过大或爆心距过小，则可能导致水轮机组的峰值振速超出规范值，影响水轮机组的安全运行．

During the extension project of a hydropower station,it is of great importance to study the influence of the blasting vibration on adjacent buildings, especially on the turbine units. This paper gets the peak particle velocity （PPV） and the basic frequency of the turbine units under the action of blasting vibration, and analyzes the influence of blasting vibration on turbine units by monitoring the condition of the running status of turbine units, with a background of the construction of a new irrigation and drainage hole in Shenxigou Hydropower Station. The results show that the natural frequency of vibration of turbine u- nits of 100 Hz is higher than the main frequency of blasting vibration of intermediate and long distance; and the basting vibration leads to forced vibration on the turbines, with PPV getting much bigger. Even though changing the charge can lead to the change of the forced frequency; the forced frequency is much different from the natural frequency, which couldn＇t lead to the resonance. But if the charge is too much or the blast center distance is too short, the PPV may get beyond the standard, affecting the operation of turbine units.