冶金桥式起重机FMEA分析及其应用研究

发布时间：2019-02-15 21:33

【摘要】：冶金桥式起重机主要用于冶金车间炼钢、锻造、热处理等冶金过程中的物料吊运,其利用等级高,工作极其繁重,各机构运行和制动频繁,且起升载荷接近或等于额定载荷。同时,冶金车间工作环境温度高、灰尘大、工作环境恶劣。又因冶金桥式起重机承受载荷变化多样、危险面大、危险因素多、作业环境复杂等特点造成桥式起重机事故发生率较高。据不完全统计,在2006年~2011年间发生的370起起重机事故中,冶金桥式起重机事故128起,占事故总数的37.54%,居各类起重机事故之首。因此,对冶金桥式起重机进行故障模式及其影响分析是非常有必要的。不仅可以有效降低冶金桥式起重机故障发生率,提高系统可靠性,从而降低或消除事故发生率,减少维护成本,提升企业的经济效益。针对FMEA在冶金桥式起重机上的应用,本文主要做了如下工作:(1)统计分析了近年来的起重机事故案例,通过分析确定了桥式起重机事故发生比例,易发生事故的环节,设备主要失效形式以及事故中易失效的结构或零部件。结合事故案例,归纳整理冶金桥式起重机关键零部件及金属结构的故障模式,并就各个故障模式产生机理进行了阐述。(2)以某钢厂450t冶金桥式起重机为研究对象,对其进行了传统形式的FMEA完整分析。并基于模糊置信算法及灰色关联决策,以450t冶金桥式起重机主起重机构为例,进行了故障危险度评价的改良计算。在传统的FMEA分析风险优先数评级中,发生度、检测度与严酷度的评价均基于简单的打分评级,存在很大的主观因素影响。采用模糊置信算法,以置信度的形式,用含概率的模糊等级评价故障模式的三个风险因子。对于故障模式风险因子等级无法确定的情况,采用置信结构进行区间评价或不完全评价,这样避免了在信息不全面的条件下主观臆断的情况,提升了FMEA风险评价的适用性和准确性。(3)基于冶金桥式起重机FMEA分析与状态监测,参与开发了冶金桥式起重机健康监测与预报可视化系统。并基于该系统对450t冶金桥式起重机易失效区域进行了结构应力监测,监测数据可供设备管理人员实时了解起重机金属结构关键部位的应力状态。设备管理人员可通过提取应力时程曲线,对结构进行疲劳寿命估算,确定结构的疲劳状态,以便及时作出调整,对结构潜在故障进行预处理,将故障消除在潜伏期。
[Abstract]:Metallurgical bridge crane is mainly used for lifting materials in metallurgical process such as steelmaking, forging and heat treatment in metallurgical workshop. Its utilization grade is high, the work is extremely heavy, the operation and braking of each mechanism are frequent, and the lifting load is close to or equal to the rated load. At the same time, metallurgical workshop working environment high temperature, dust, bad working environment. The accident rate of bridge crane is high due to the characteristics of metallurgical bridge crane, such as varied load, large hazard surface, many risk factors and complex working environment. According to incomplete statistics, among 370 crane accidents from 2006 to 2011, 128 accidents occurred in metallurgical bridge cranes, accounting for 37.54 of the total number of accidents, ranking first among all kinds of crane accidents. Therefore, it is necessary to analyze the fault mode and influence of metallurgical bridge crane. Not only can the accident rate of metallurgical bridge crane be reduced effectively, the system reliability can be improved, thus the accident rate can be reduced or eliminated, the maintenance cost can be reduced, and the economic benefit of the enterprise can be improved. In view of the application of FMEA in metallurgical bridge crane, the main work of this paper is as follows: (1) the case of crane accident in recent years is statistically analyzed. The main failure forms of equipment and the structure or parts that are prone to failure in accidents. Combined with the accident case, the fault modes of key parts and metal structures of metallurgical bridge crane are summarized, and the generating mechanism of each failure mode is expounded. (2) taking 450 t metallurgical bridge crane in a steel plant as the research object, In this paper, the traditional form of FMEA complete analysis is carried out. Based on fuzzy confidence algorithm and grey correlation decision, the improved calculation of fault risk evaluation is carried out by taking 450 t metallurgical bridge crane as an example. In the traditional FMEA analysis risk priority rating, the degree of occurrence, the degree of detection and the severity of the evaluation are based on a simple rating, there are a lot of subjective factors. The fuzzy confidence algorithm is used to evaluate the three risk factors of the fault mode in the form of confidence degree and fuzzy grade with probability. When the risk factor level of the fault mode can not be determined, the confidence structure is used for interval evaluation or incomplete evaluation, which avoids the subjective assumption under the condition of incomplete information. The applicability and accuracy of FMEA risk assessment are improved. (3) based on the FMEA analysis and condition monitoring of metallurgical bridge crane, a visual system for health monitoring and prediction of metallurgical bridge crane is developed. Based on the system, the structural stress monitoring of 450 t metallurgical bridge crane is carried out. The monitoring data can be used for equipment managers to understand the stress state of the key parts of crane metal structure in real time. The equipment manager can estimate the fatigue life of the structure by extracting the stress time history curve and determine the fatigue state of the structure so as to adjust the structure in time to pretreat the potential faults of the structure and eliminate the faults in the latent period.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH215

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