基于FTA的锅炉回转式空气预热器故障模型建立与应用

Establishment and Application of Fault Model for Rotary Air Preheater Based on FTA

空气预热器的可靠性对燃煤发电机组锅炉运行安全和节能至关重要,而传统的故障诊断主要依靠技术人员的生产经验,存在故障定位时效性差、事故防范措施不全面等问题。基于大量燃煤发电机组锅炉回转式空气预热器故障案例分析,建立了空气预热器故障树模型,较为完整地揭示了空气预热器故障类型之间的逻辑关系。通过最小割集分析得到20个最小割集,确定了空气预热器故障模式;通过结构重要度计算定量分析了25类故障对空气预热器故障的贡献大小,标识出了空气预热器故障的薄弱环节,实现了对各类故障危险等级的准确评估。在故障树模型建立的基础上,对1起中心驱动回转式空气预热器停转事件进行了原因分析。结果表明:基于故障树分析(FTA)法的空气预热器故障模型不仅为采取突出重点、系统科学的防范措施提供了直接依据,还对故障的迅速定位有很好的指导意义。

The reliability of air preheater is very important to the operation safety and energy saving of coal-fired power generation boiler. However, the traditional fault diagnosis mainly relies on the production experience of technicians, which has the problems such as poor timeliness of fault location and incomplete accident prevention measures. Based on a large number of case analyses of rotary air preheater for coal-fired generating units, the fault tree model of rotary air preheater is established, and the logical relationship between the fault types is completely revealed by the tree structure. With the help of minimal cut set analysis, 20 minimum cut sets are obtained, and the fault modes of the air preheater can be determined. The contribution of 25 kinds of faults to the air preheater failure is analyzed quantitatively by calculating the structural importance, weak link in the fault of air preheater has been identified and the risk level of faults can be assessed accurately. Based on the establishment of fault tree model, the cause of a centrally-driven rotary air preheater stall is analyzed. The results show that the fault diagnosis model of the air preheater based on fault tree analysis(FTA) not only provides a direct basis for taking highlighted and systematical preventive measures, but also provides a good guidance for the rapid fault location.