摘要
针对某大型火电厂发生的煤斗振动破坏故障,结合电厂事故记录和现场勘察测量结果,初步判断该振动属于冲击型结构动力学瞬态响应问题;利用有限元方法,通过结构静力学和瞬态动力学计算,模拟煤斗静平衡状态和产生振动的过程。计算结果表明,数值模拟所描述的煤斗振动规律及破坏规律符合煤斗现场勘察的实际振动规律和破坏规律,说明最初对煤斗振动性质的判断是较为可信的。计算结果同时表明煤斗发生破坏的直接原因是煤斗支撑框架刚性的左右不对称性。在此基础上,又进一步推断煤斗振动的激励来自于煤料的堵塞,并从煤斗自身结构的特殊性、截面收缩率、煤料潮湿性及材料间摩擦系数等多方面出发,分析了产生煤堵的原因。最后在结合相关经验的基础上,提出了高分子双曲型内衬及阻落装置方案,以解决煤斗产生振动的问题。
Violent vibration with component broken appeared in scuttles of a thermal-electric power station.With help of the accident record and the on-spot inspection, transient response induced by some kind of impact was initially concluded to be the cause of this vibration.Using FEM,transient dynamic analysis and static analysis were simulated to study a scuttle system.Numerical results showed that the simulation of the scuttle vibration and damage were basically in accordance with the actual ones,which revealed that the initial judgement was reliable.Results also indicated the broken was caused by the stiffness asymmetry in the braced frame.Based on this,it was inferred that the vibration was excited by the impulsion to the scuttle from falling coal which was previously jammed and then collapsing.Many factors of coal jamming were analyzed,including structure features,reduction of cross section area,coal humidity and friction factor.Two treatments,hyperbolic inner lining made by high polymer material and anti-drop device,were finally presented to reduce impact and vibration.
出处
《振动与冲击》
EI
CSCD
北大核心
2009年第1期186-190,共5页
Journal of Vibration and Shock
关键词
冲击
振动
有限元
煤斗
堵煤
impact
vibration
FEM
coal scuttle
coal jamming
