1000 MW超超临界机组汽泵跳闸引发MFT原因分析及改进

Reason Analysis of Boiler MFT of 1000MW Ultra-Supercritical Unit Caused by Steam Feed Pump Tripping and Optimization

某电厂1000 MW超超临界机组在调试期满负荷运行时,单台100%容量汽泵跳闸导致锅炉MFT保护动作,通过对跳闸过程的详细分析,找出事故的根本原因为汽泵密封冷却水系统的设计不合理,导致机组高负荷运行时系统可靠性降低,存在重大安全隐患。在此基础上,提出汽泵密封水系统的管路改造方案和除氧器水位控制逻辑优化控制措施,有效排除了机组高负荷运行时的安全隐患,为同类型机组在设计、调试及运行方面提供参考。

The trip of a single 100%capacity steam feed pump caused the action of boiler MFT protection at full load during commissioning period of a 1000 MW ultra-supercritical unit in a power plant.Through detailed analysis of the tripping process,it is found that the root cause of the accident is the unreasonable design of the seal water system of steam feed pump,which leads to the reduction of system reliability and the existence of major safety hidden dangers when the unit operates under high load.On this basis,the pipeline renovation scheme of steam feed pump seal water system and the logical optimization control measures of deaerator water level control are put forward,which effectively eliminates the hidden safety hazards of the unit under high load operation and provides reference for the design,commissioning and operation of similar units.