【作者】 胡义；

【导师】 杨建国； 周瑞平；

【作者基本信息】 武汉理工大学 ， 轮机工程， 2011， 博士

【摘要】 国际海运是国际贸易中最主要的运输方式,远洋船舶运输量占国际贸易总运量中的三分之二以上。船舶推进系统是船舶动力装置的重要组成部分,对船舶的正常航行起着至关重要的作用。作为其主要组成部分的柴油机和齿轮箱,其工作状态的好坏直接影响船舶的可靠性和生命力。本文作者旨在寻求一种经济可靠且对二者都适用的故障诊断方法。在综合分析国内外柴油机和齿轮箱故障诊断技术研究和应用的基础上,作者选取基于轴系扭振信号的故障诊断方法进行船舶推进系统故障诊断研究,通过仿真分析得到了相应的判据,以实际测试数据加以试验分析验证,取得的主要研究结论如下：(1)针对船舶推进系统的结构特征,基于参数化特征建模技术,建立了从柴油机曲轴连杆机构、齿轮箱、轴系到螺旋桨的船舶推进系统参数化建模平台。该建模平台各部分既相互独立,又可通过定位坐标实现整个推进系统的集成建模。该集成模型基于UG软件,采用VC、数据库进行二次开发,模型具有广泛的通用接口,能导入其它分析软件女ANSYS.MSC系列软件PATRAN、ADAMS等进行后续的计算分析。该建模平台简化了船舶动力装置研究人员的建模过程,使之专注于推进系统结构性能的分析与研究。(2)以船舶推进轴系为研究对象,分析了传统推进轴系扭转振动模型的建立方法。推导出基于刚度矩阵单元的齿轮扭转振动模型,该模型解决了实体模型分析中难以考虑传动比的问题。推导出齿轮啮合耦合振动模型,实现了齿轮箱振动中的弯-扭-轴-摆耦合振动的综合分析。采用不同方法对圆盘模型的固有频率进行计算和对比分析,揭示了简化的当量模型计算结果与梁模型、实体建模存在较大偏差,为提高推进轴系扭振分析计算精度提供了有益的思路和方法。分析了船舶轴系扭振对于主要组成部分刚度和转动惯量的敏感性,评估了其对固有频率的影响。(3)分析了轴系在工作过程中受到的激励源,应用轴系扭转响应分析中的频率响应分析与瞬态响应分析的基本理论,以10000吨级江海直达货船推进系统作为计算分析模型,针对柴油机工作过程的故障,分析了不同谐次下各个气缸故障时的频率响应振动幅值与相位特征。针对齿轮箱的轮齿故障,提出了故障态齿轮啮合刚度算法,基于该算法分析了不同齿轮上轮齿故障时的瞬态响应特征。此外,考虑柴油机与齿轮箱均出现故障时,分析了叠加信号特性。(4)分析了气体激励力与往复惯性力对柴油机瞬时转速的影响。提出了基于角振动极坐标图作为故障诊断依据的方法。当柴油机仅受气体激励力时,仿真得到了柴油机单缸故障时的扭振信号,分析了故障态下角振动极坐标图的特征。将单缸故障拓展到双缸故障,扩大了极坐标法的适用性。(5)概述了WP10-240型柴油机的试验台架的基本情况以及实测的基本方案,采集处理得到了柴油机逐缸熄火时的瞬时转速。通过极坐标法验证性地比较了柴油机在单缸熄火下信号的特性,发现与仿真结果有较好的吻合性,验证了基于角振动极坐标法的有效性。同时,以MAN B&W 6L 16/24型柴油机为研究对象,使用极坐标法进行了单缸故障诊断,进一步验证了该方法的有效性。更多还原

【Abstract】 International shipping is the main mode of transport in international trade. More than two-thirds of international trade is carried out by means of ocean-going shipping. Ship propulsion system is an important part of marine power plant, which plays a vital role on the vessel’s normal navigation. As main components, the working state of diesel engine and gearbox affects directly the reliability and vitality of the ship. This article is intended to find a valid and economical method which can diagnose the diesel and gear box simultaneously. Based on the comprehensive analysis of research and application on diesel engine and gear box fault diagnosis from domestic and foreign research results, this article adopts the method of fault diagnosis based on torsional vibration signals from ship propulsion systems. Through simulation analysis, the appropriate criteria are obtained and verified by analyzing actual test data, the main research findings are as follows:(1) According to the structural characteristics of ship propulsion systems, based on parametric feature modeling technology, a parametric modeling system of marine propulsion system was established, which includes the components such as the linkage mechanism of diesel engine crankshaft, gear box, shaft and propeller. Every part of the system is independent from each other, and the entire propulsion system integration modeling may be achieved through positioning coordinates of every part. The procedure is performed in UG, where VC and Databases served as tools for secondary development. Models, with a wide range of common interface, can import to other analysis software such as ANSYS, MSC Patran, Adams, then subsequent analysis can be carried out. This system simplifies the modeling process of marine power plant for researchers, so that much more attention can be paid on the issue of analysis and research on structural performance of marine propulsion system.(2) For the study of ship’s propulsion shafting, traditional method to build torsional vibration model of propulsion shafting is analyzed. Torsional vibration model for gears based on stiffness matrix unit can be derived from the differential equation of gear vibration which solves the problem that it is difficult to take fluctuate of transmission ratio for the entity model into account. Furthermore, some effort was put into the gear meshing coupling vibration models. By modeling the bending-torsional-longitudinal-swing coupling vibration system, meshing stiffness matrix formula was derived theoretically. The result on natural frequency for disc models from difference method is obtained from calculation and analysis, which revealing the results from simplified model are different from beam model and solid model, providing some useful ideas and methods to increase accuracy in the analysis of torsional vibration for propulsion shafting. The sensitivity of torsional vibration from the effect of stiffness and inertia is analyzed, and their influence on the natural frequency is assessed.(3) The excitation source for marine propulsion shaft during operation was briefly discussed. Based on the response analysis theory, the method of frequency response analysis and transient response analysis for shaft torsional vibration was given. In order to get the amplitude and phase characteristics during the fault of a certain cylinder, a 10,000 DWT River-Sea Cargo Ship was presented as an example. In this process, two kinds of fault were considered. The first one, marine engine failure, was simulated, which obtaining the frequency response characteristics such as vibration amplitude and phase in different harmonic order when the failure of each cylinder. The second one, marine gearbox failure, was performed by making faults in teeth for different gears, transient response characteristics will come out, similarly. Some research about the conditions when diesel engine and gearbox both work in failure was mentioned.(4) A lot of analysis was performed to look into the effect of gas excitation force and reciprocating inertia force on marine engine. A novel polar presentation method was introduced, which can be used to locate fault cylinder. When engine was forced by gas excitation force merely in simulation, torsional vibration signal for single-cylinder failure can be simulated and failure criterion in polar plot was given. At the same time, something about twin cylinder failure was mentioned, which expanded the applicability of polar presentation method.(5) For the experimental part of this thesis, power plant with MAN B&W 6L 16/24 and WP10-240 came into view, respectively. Plant with WP10-240 was taken as key object. There are some introductions about the basic condition of this test platform and the test scenario, from which the instantaneous angular speed (IAS) when every cylinder turn into failure were obtained. Besides, analysis about the angel characteristic during one cylinder failure and polar plot for plant with MAN B&W 6L 16/24 was given. It means that a complete analysis using polar presentation method was performed, which verified the effectiveness of this method.更多还原