超临界锅炉垂直水冷壁裂纹产生的原因及处理措施  

Reasons and countermeasures for vertical water wall crack of supercritical boiler

作　　者：李宽[1] 郑媛[2] 赵星海[3] 孙海天[1] 

机构地区：[1]国网吉林省电力有限公司电力科学研究院,长春130021 [2]吉林农业工程职业技术学院机电工程系,吉林四平136001 [3]东北电力大学能源与动力工程学院,吉林吉林132012

出　　处：《黑龙江电力》2015年第5期456-459,共4页Heilongjiang Electric Power

摘　　要：针对某电厂超临界运行锅炉垂直水冷壁出口处出现多处裂纹导致锅炉停运的问题,借助锅炉相关运行参数曲线对裂纹的位置、产生原因及外貌特征进行了研究,研究发现:锅炉垂直水冷壁出口处裂纹是由管间较大温差和管温快速变化产生的热应力引起的,管间较大温差一般出现在锅炉转干态后的低负荷工况下,且锅炉给水流量的变化与垂直水冷壁管温的波动存在对应关系;建议尽量减少该型锅炉在转干态后的长期低负荷运行,同时加强对垂直水冷壁出口处壁温的监视,出现较大偏差时及时调整;改进给水自动和给煤自动对水煤比的调整能力,防止负荷变化过程中的水煤比失调。Aiming at the outage of the supercritical boiler caused by several cracks at the vertical water wall outlet in a power plant,this paper studied the location of cracks,reasons for the cracks and characteristics of the appearance according to the related operation parameter curves of boilers. The result shows that the cracks at the vertical water wall outlet are caused by the thermal stress due to the wide temperature difference among pipes and the rapid change of pipe temperature. The temperature difference among pipes becomes wide under the low load working condition after the boiler transferring to dry state,the change of boiler feed-water flow relating to the fluctuation of vertical water wall pipe temperature. Long term low-load operation of boiler transferring to dry state should be shortened,while wall temperature of vertical water wall pipe outlet should be monitored to regulate in time when wide deviation occurs. The regulation of automatic feed-water and feed-coal on coal-water ratio should be improved to prevent the imbalanced ratio during the change of load.

关 键 词：热应力 垂直水冷壁 温差 超临界锅炉 

分 类 号：TK223.3[动力工程及工程热物理—动力机械及工程]