Abstract:

In the process of constructing new power systems, coal-fired units are undergoing a fundamental transition from base-load power sources to regulating power sources. Their critical auxiliary equipment faces systematic safety risks due to prolonged operation in conditions deviating from the design specifications. To this end, an in-depth analysis of the specific failure mechanisms of critical auxiliary equipment in coal-fired power plants under deep peak-shaving and rapid start-stop operating modes was carried out. Major prominent safety issues were sorted out, including pulverizer deflagration under low loads, cavitation and vibration of feed water pump sets, fan air short-circuiting, and unstable water level control of high-pressure heaters. Technical countermeasures covering equipment body adaptive retrofits, intelligent monitoring and early warning as well as optimized operation control were put forward. A modern management framework integrating dynamic risk control and full-life-cycle health management was constructed. The results indicate that under the new operating mode, non-design operating conditions such as deep peak shaving and rapid start-stop of coal-fired units can trigger changes in auxiliary equipment failure modes and pose safety hazards due to equipment coupling. A three-pronged system strategy combining technical retrofits, risk-predictive operation and maintenance, and market policy compensation can comprehensively prevent and control the safety risks of auxiliary equipment and enhance the operational reliability of the units.

Key words: new power system, coal-fired power plants, auxiliary equipment, safety issues, coping strategies