【作者】 欧礼坚；

【导师】 叶家玮；

【作者基本信息】 华南理工大学 ， 船舶与海洋结构物设计制造， 2010， 博士

【摘要】 推进装置是船舶动力的核心,与船舶航行的快速性、经济性、安全性等性能紧密相关。船舶推进装置作为一个系统,由主机、轴系和螺旋桨三部分组成,其故障发生的原因是多种多样的。作为推进装置的重要组成部分,螺旋桨不但自身会发生桨叶磨损、变形和折断等故障,而且螺旋桨故障也会产生周期变化的离心力和水动力,将进一步导致轴系和主机故障的发生。为了实现推进装置故障的监测与诊断,提高船舶航行的安全性,本文拟对船舶螺旋桨及推进装置故障诊断技术进行研究。本文研究的思路是通过分析螺旋桨不同故障工况时的水动力性能和流场特点,并研究其对轴系振动和主机性能的影响,提出螺旋桨桨叶折断故障诊断技术、螺旋桨导致轴系振动故障诊断技术和螺旋桨导致主机故障诊断技术。目前,船舶推进装置故障的诊断技术的研究主要集中在船舶主机故障诊断技术方面。然而,推进装置作为动力系统,其三个主要组成部分互相作用、互相影响,对于其故障的监测与诊断技术,应作为一个系统去研究。论文研究了船舶螺旋桨故障诊断技术、螺旋桨导致船舶轴系故障技术和螺旋桨导致主机故障的诊断及治理技术。因此,本论文能够较系统、深入地研究因船舶螺旋桨导致推进装置故障产生的机理、提高诊断技术水平、能够较高效和准确地排除故障,提高船舶航行的安全性。本文采用理论研究、CFD和有限元数值分析、模型试验和实船应用等相结合的方法进行研究。拟解决的关键问题包括:螺旋桨不同故障工况的水动力性能和流场变化特点的研究;螺旋桨故障诊断技术的研究;螺旋桨导致轴系振动故障诊断技术的研究;针对推进装置的故障,提出相应故障治理技术和方法,并在实船实践应用。首先,对不同故障工况下的常规螺旋桨和导管螺旋桨水动力性能和流场特点进行研究,获得了螺旋桨的推力、扭矩、侧向力和脉动压力等水动力载荷的变化规律及螺旋桨流场特点和变化趋势。采用基于CFD方法的常规螺旋桨定常水动力性能研究,并结合模型试验,得到了常规螺旋桨某1桨叶折断时的折断量与其推力、扭矩的变化关系以及螺旋桨直径切割量与推力、扭矩变化关系。基于CFD方法的导管螺旋桨非定常水动力性能进行研究,对导管螺旋桨某1桨叶不同位置折断工况进行非定常数值解析,获到了不同工况时螺旋桨推力、扭矩、侧向力和导管内壁脉动压力随时间的周期变化关系;并研究伴流场不均匀程度、导管与叶梢之间的间隙值的大小等参数对导管螺旋桨水动力性能的影响。研究获得螺旋桨不同故障工况下的水动力载荷,为下一步对推进装置的故障诊断关键技术的研究提供数据信号和水动力载荷。其次,研究螺旋桨桨叶折断故障的诊断技术。通常,故障诊断的数据或信号是通过传感器和数据采集系统获取。为了简化信号提取和处理的细节,将更多精力集中在故障诊断技术的研究,本文建立基于CFD方法的导管螺旋桨状态监测与诊断系统,通过提取导管内壁的压力脉动数据,并分析压力脉动数据的变化规律来诊断螺旋桨桨叶折断故障。CFD数值计算结果可看作为理想状态下传感器和数据采集系统获得的信号。通过对导管螺旋桨某1桨叶不同位置折断时导管内壁的脉动压力时间波形图进行对比分析和FFT变换,提出了波形分析法和频谱法相结合的导管螺旋桨桨叶折断故障诊断技术。并尝试通过改变信号处理时的窗函数,对比分析以便获取更合适的信号处理方法。第三,研究螺旋桨折断导致轴系振动故障的诊断技术。螺旋桨桨叶折断产生了离心力和水动力侧分力,导致轴系产生剧烈的回旋振动。对轴系回旋振动的研究,在合理简化计算模型的基础上,最重要的因素是准确确定螺旋桨的水动力侧向力,该力是周期变化的,并受桨叶折断位置及工作伴流场的影响。本文对螺旋桨不同故障工况下轴系回旋振动的研究,采用的水动力载荷均为对应工况下准确计算值。采用有限元法对轴系回旋振动进行瞬态分析,对螺旋桨在不同故障工况下,通过改变螺旋桨的转速、不均匀伴流场等参数,获得在离心力、水动力载荷的作用下的轴系回旋振动时间位移响应曲线。对回旋振动的时间位移响应曲线进行FFT变换获得频谱图,并合成螺旋桨轴心轨迹图,通过研究分析,提出了振动法和轴心轨迹法相结合的螺旋桨导致轴系振动故障的诊断技术。最后,结合船舶推进装置故障的特点,提出因螺旋桨引起推进装置故障的治理技术和方法,并在实船上成功应用,为故障诊断和治理提供了典型案例。分析了基于远程网络的推进装置故障诊断专家系统的原理,选取基于行为的诊断模式。诊断系统由船载专家、公司专家和研究机构三级诊断子系统组成,子系统采用客户/服务器模式结构。更多还原

【Abstract】 Propulsion device, which is closely related with the rapidity, economy and safety of marine navigation, is the core of marine power. As a system, marine propulsion is composed of main engine, shaft and propeller, and its faults are caused for various reasons. As an important part of propulsion, the propeller generates blade abrasion, deformation, fracture and other faults, and the propeller faults also generate the periodic variation of centrifugal force and hydrodynamic force, which will further lead to shaft and main engine faults.To achieve monitoring and diagnosis of propulsion faults and improve the safety of navigation, the key techniques of diagnosis of propeller propulsion faults caused by propeller will be studied in this paper. The idea of this study is that by analyzing the propeller hydrodynamic performance and flow characteristics under different fault conditions and studying the effect of shaft vibration and main engine matching performance, the diagnosis techniques of propeller blade fracture fault, vibration fault caused by propeller and the main engine fault caused by propeller mismatch will be presented. At present, the study of marine propulsion device fault diagnosis technique focuses on main marine engine fault diagnosis technique. However, as a power system, the three main components of propulsion device interact and influence each other, so it should be seen as a system when studying the fault monitoring and diagnosis technique The marine propeller fault diagnosis technique, the fault diagnosis and elimination techniques of marine shaft and main engine faults caused by propeller fault will be studied in this paper. Therefore, the mechanism of propulsion fault caused by marine propeller can be systematically and deeply studied in this paper. At the same time, it can improve the level of diagnosis technique, eliminate the faults more efficiently and accurately, and increase the safety of navigation.In this paper, the theoretical research, CFD and finite element numerical simulation, model testing and full scale ship application are combined to do the research. The key issues which mean to be solved are as follows: the study of the propeller hydrodynamic performance and flow characteristics under different fault conditions, the study of propeller fault diagnosis technique, and the study of the shaft fault caused by propeller. In accordance with propulsion fault, corresponding techniques and methods will be put forward and applied to full scale ships.Firstly, the study of hydrodynamic performance and flow characteristics of conventional propeller and ducted propeller under different fault conditions can help obtain the propeller’s thrust, torque, lateral force and the fluctuating pressure and other variation rules of hydrodynamic loads, and the propeller flow characteristics and trends. The study of conventional propeller steady hydrodynamic performance is based on CFD methods and combines with model test.And then the relationship among fracture quantity and thrust, torque of a certain fractured blade, and the relationship among propeller diameter cutting quantity, thrust and torque will be obtained. The study of ducted propeller unsteady hydrodynamic performance is based on CFD, and then the fracture of a certain blade is numerically analyzed under different positions conditions to obtain relationship among the propeller thrust, torque, lateral force and the duct inner wall fluctuating pressure changes with period and, meanwhile, study the effect, which is performed by wake current field unsteady level and the blade gap value size,upon ducted propeller hydrodynamic performance. The hydrodynamic loads under different fault conditions obtained by the study could provide data signal and hydrodynamic loads for the further study of propulsion device fault diagnosis key techniques.Secondly, the propeller blade fracture fault diagnosis is studied. Generally, the fault diagnosis data or signal is acquired through sensors and data acquisition systems. In order to simplify the details of signal extraction and processing and focus more on the fault diagnosis technique,a ducted propeller condition motoring system based on CFD methods is established in this paper,in which propeller blade fracture faults are diagnosed by extracting the duct inner wall fluctuating pressure data and analyzing fluctuating pressure variation. CFD numerical results can be seen as the signal that the sensors and data acquisition systems obtain under the ideal state. Through contrastive analysis and FFT transform of the ducted propeller inner wall fluctuating pressure-time oscillogram of a certain blade fractured in different positions, a ducted propeller blade fracture fault diagnosis techniques which combines oscillogram analysis method with and spectrum analysis method is put forward.At the same time, in order to obtain more appropriate signal processing methods, change the window function during signal processing and comparative analysis will be tried.Thirdly,a diagnosis techniques of whirling vibration caused by propeller fracture is studied. Propeller blade fracture generates centrifugal force and hydrodynamic lateral force, which leads to a sharp shaft rotating vibration. Based on a reasonable simplified computation model, the most important factor for the study of whirling vibration of shafting is the accuracy of the hydrodynamic propeller lateral force which changes periodically and is affected by the blade fracture position and wake current field. For the study of whirling vibration of shafting diagnosis under different propeller fault conditions, the corresponding hydrodynamic loads are accurately calculated under the corresponding conditions in this paper. Finite element method is adopted to do the transient analysis of whirling vibration of shafting, and then by changing rotation rate and non-uniform wake and other parameters in different fault conditions, shaft rotating vibration time-displacement response curve by the action of centrifugal force and hydrodynamic force is obtained. Spectrum is obtained by FFT transformation of time-displacement response curve, and a propeller axis locus diagram is composed.Then a diagnosis technique of shaft vibration caused by propeller ,which combines vibration method with axis locus method, is put forward by study and analysis.Finally, combining the characteristic of marine propulsion device fault, the corresponding propulsion device fault (caused by the propeller) elimination techniques is presented, and is successfully applied to the full scale ship, which provides typical cases of fault diagnosis and fault elimination. The theory of a propulsion device diagnosis expert system based on remote network is analyzed, and a behavior-based diagnostic model is selected.The diagnosis system consists of shipboard experts, company experts and research institutions—three diagnosis subsystems, and the subsystems adopt client/server structure.更多还原