大型柴油机振动分析.pptVIP

内燃机气门故障分析 气门间隙是指气门完全关闭时，气门杆尾端与摇臂之间的间隙。它的作用是补偿气门受热后的膨胀量。间隙过大：进、排气门开启滞后，缩短了进排气时间，降低了气门的开启高度，改变了正常的配气相位，使发动机因进气不足，排气不净而功率下降。 此外，还会使配气机构零件的撞击增加，磨损加快。无间隙或间隙过小：发动机工作后，零件受热膨胀，将气门推开，使气门关闭不严，造成漏气，功率下降，并使气门的密封表面严重积碳或烧坏，甚至气门撞击活塞。气门间隙的调整是通过调整摇臂上的螺钉来实现的。 现场案例 停机检查，右6缸排气门座约2/5圈偏磨，排气门磨出台阶，气门导管磨成椭圆形。如上图所示。 内燃机气门故障分析 现场案例 * This is an introduction to the analysis of engines and compressors. Audience - Operators, mechanics and other front line people who know about how a compressor works but who may not have used analysis equipment. - This presentation is probably not suitable for management level because it does not talk about the business case for analysis. * What is Diesel Engine Analysis? Diesel engine analysis is a non-intrusive process of gathering engine operating data and evaluating it to assess the engine’s performance and mechanical condition. The data typically consists of: ·?? cylinder pressure versus crank angle position ·?? vibration versus crank angle position ·?? ultrasonic (high frequency) versus crank angle position Data is collected either periodically using portable equipment (most cost-effective) or continuously using a permanently mounted data acquisition system. What Diesel Engine Analysis is not Diesel engine analysis, on its own, is not a comprehensive predictive maintenance program. Rather, it is one of many predictive maintenance tools that make up a maintenance program. Other predictive maintenance methods include: spectrum analysis, lube oil analysis, fuel and water composition analysis, and the use of borescopes or videoscopes are essential to an integrated predictive maintenance program. * Analysis programs attempt to meet these objectives * Cost criticality protection diagnosis amount of data fleets of machinery contrast GT and PR 往复设备状态监测的特殊性 哨兵系统通过采集和实测柴油机表面相位振动信号，提取信号的特征参数，并对其进行分析与计算。实现了在不解体情况下，对柴油机活塞、气缸套之间的磨损、气阀漏气和主轴承磨损状况的诊断。柴油机各主要运动部件机械状态的好坏，直接影响其可靠性和利用率。 柴油机的机械状态进行监测与诊断，主要采用振动分析法、动态分析法、热力参数分析法（比油耗等）、油液分析法、： 相位振动分析法具有诊断速度快、准确率高、诊断部位准确和能实现在线