磨煤机一次风口爆燃原因及控制措施

Reasons of deflagration in primary air inlet of coal pulverizer and its control measures

某电厂300 MW机组磨煤机E正常停运时,磨煤机入口一次风管发生煤粉爆燃,致使膨胀节爆裂、一次风管鼓包变形,影响了机组的安全稳定运行。详细介绍了一次风口爆燃过程并分析了爆燃事故的现象、原因、影响及处理方法,提出并实施了相应的预防控制措施。明确指出磨煤机出口压力急剧变化是这一事故的主要现象,刮板脱落、混烧高挥发分的印尼煤为主要原因。合理改进冷热风自动控制系统、提高检测手段、及时处理制粉系统异常情况为控制该类事故的主要措施。在掺烧高挥发分煤种时,防止磨煤机堵渣和控制一次风温度能避免发生爆燃事故,确保机组稳定运行。

The deflagration of coal pulverizer in the primary air inlet duct was occurred when the coal pulverizer E of 300 MW unit in a power plant was shut down normally. The deflagration caused bursting of expansion joint, bulge deformation of primary air duct and affecting the safe operation of the unit. The deflagration of primary air inlet duct was introduced in detail. The phenomenon, causes, im＇luence and treatment of such deflagration accident were also analyzed. The corresponding prevention measures were proposed and implemented. The rapid pressure change of coal pulverizer outlet was the common phenomena of the accident. The scraper shedding and mixed burning of high volatile Indonesia coal were the main reasons of the accident. Meanwhile, improving the performance of cold and hot air automatic control system reasonably, enhancing the detection means and treating abnormalities of milling system in time were the important measures. Preventing the coal pulverizer from blocking and controlling the temperature of primary air can avoid deflagration accident when mixed burning high volatile coal. And it can ensure the stable operation of units.