Abstract: A new monitoring method of non-contact running status of cooling tower fan blades is proposed based on elaborating the  monitoring technique of running status of cooling tower fan blades and analyzing the reason of fan blade fracture. The method is called blade tip timing monitoring method. And a new monitoring system of non-contact running status of cooling tower fan blades is developed on the basis of the technology of the blade tip timing monitoring method and Single-Chip Microcomputer（SCM）. The system will shut down the fan and output a forecast alarm when the blade breaks down and deforms, so the blade accident will be prevented. It is proved that the monitoring method can greatly improve the reliability of the fan running status monitoring and effectively prevent the accident of the blades, so the monitoring method and system have a wide application value.

Key words: cooling tower fan, blade, running status, non-contact, blade tip timing

摘要： 在阐述冷却塔风机运行状态监测技术现状以及对风机叶片断裂原因进行分析的基础上，提出一种新型非接触式冷却塔风机叶片运行状态监测方法——叶尖计时监测法，并将叶尖计时监测法与单片机技术相结合，研制出一种非接触式冷却塔风机叶片运行状态监控系统，实现在叶片发生断裂、变形时监控系统控制风机停机并报警，从而预防叶片事故的发生。生产实践证明，此监测方法明显提高了风机运行状态监测的可靠性，能有效地避免叶片故障的发生，具有良好的推广应用价值。

关键词: 冷却塔风机, 叶片, 运行状态, 非接触式, 叶尖计时