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《舰船科学技术》2019,(2)
大型船舶轴系故障具有多变性,导致当前故障识别方法无法有效对各种类型的大型船舶轴系故障进行准确识别,为了提高大型船舶轴系故障识别的效果,设计一种新型的大型船舶轴系故障非接触式监测方法。首先采集大型船舶轴系故障识别信号,采用小波对其进行去噪,然后换提取大型船舶轴系故障识别信号特征,最后采用最小二乘支持向量机设计大型船舶轴系故障识别的分类器,并进行了具体的大型船舶轴系故障识别模拟实验。与其他大型船舶轴系故障识别方法相比,本文方法通过小波抑制了大型船舶轴系故障识别信号中的噪声干扰,提高了大型船舶轴系故障识别成功率,加快了大型船舶轴系故障识别的训练时间,建立更高效率的大型船舶轴系故障识别分类器。 相似文献
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不能定位故障发生模块,处于轴系中的具体位置,进而造成故障清除时间较长,是普通船舶轴系故障监测方法存在的主要弊端。为解决上述问题,建立新型SOM大型船舶轴系故障监测方法。通过船舶轴系故障表现形式分析、轴系故障特征提取,完成故障的特征诊断。在此基础上,通过自组织轴系故障网络的搭建、船舶数据处理,完成SOM大型船舶轴系故障监测方法的建立。设计对比实验结果表明,新型方法与普通方法相比,能够准确定位故障发生模块在轴系中所处位置,大大缩减清除故障所需时间。 相似文献
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船舶推进轴系安装是船舶建造中重要的一环,轴系安装应按批准的轴系校中计算结果和对应的安装工艺进行。能否正确合理进行轴系安装,直接影响到船舶航运安全.因轴系校中不良而引起的故障时有发生,特别是近年来.大型低速柴油机轴系也出现因轴系校中不良而引起的轴系故障。 相似文献
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分析某船舶在低速航行时艉轴的异常噪声,通过故障排除和理论分析的方法研究了轴系异常噪声的根源和产生机理:船舶轴系受多个载荷作用,导致船体、螺旋桨轴和艉轴承产生变形,在艉轴承中心线与螺旋桨轴颈中心线之间形成一个变形角,船舶在低速航行时,轴系变形产生的回旋运动对艉轴承润滑性能的影响以及二者之间的相互耦合是轴系产生振动并产生噪声的根本原因。同时提出船舶在设计、生产及使用过程时避免轴系声响的控制方法。 相似文献
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J. E. Davies 《Maritime Policy and Management》2013,40(3):249-261
The simulations performed show that demand for quality tankers has to increase by 30% for a two-tier tanker market to emerge. The two-tier freight structure will only last for 3–5 years due to contracting induced by higher freight rates. This means that OPA does not by itself result in higher freight rates for tankers that comply with the requirements. If Western Europe also closes their trades to substandard tankers, a two-tier market emerges and quality tankers obtain a premium. The paper presents a simulation model for international tanker markets. The non-linear complementary equilibrium model solves for a sequence of static equilibria in segmented tanker freight markets, shipbuilding and scrapping markets. Freight markets are segmented according to quality requirements for tankers. The model specifies three tanker classes and one—quality tankers—can operate both market segments. 相似文献
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Siri Pettersen Strandenes 《Maritime Policy and Management》1999,26(3):249-264
The simulations performed show that demand for quality tankers has to increase by 30% for a two-tier tanker market to emerge. The two-tier freight structure will only last for 3-5 years due to contracting induced by higher freight rates. This means that OPA does not by itself result in higher freight rates for tankers that comply with the requirements. If Western Europe also closes their trades to substandard tankers, a two-tier market emerges and quality tankers obtain a premium. The paper presents a simulation model for international tanker markets. The non-linear complementary equilibrium model solves for a sequence of static equilibria in segmented tanker freight markets, shipbuilding and scrapping markets. Freight markets are segmented according to quality requirements for tankers. The model specifies three tanker classes and one quality tankers can operate both market segments. 相似文献
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阐述了化学品船不锈钢液货舱产生腐蚀的原因、钝化膜的形成机理及对不锈钢液货舱进行整体酸洗钝化的工艺,提出了化学品船不锈钢液货舱酸洗钝化的方案选择。 相似文献
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关于原油船油舱清洗时的静电问题 总被引:1,自引:0,他引:1
罗宏昌 《交通部上海船舶运输科学研究所学报》1999,22(1):23-30
油船原油卸完后需清洗油舱,无论是用热水冲洗,还是用蒸汽蒸舱后再用热水冲洗,油舱空间内均会产生静电,并由此可能引发油舱爆炸事故。首先介绍对7艘原油船17个油舱进行冲洗时的静电测试结果。结果验证了,清洗油舱时,油舱空间内确会产生大量的带电油水雾,甚至产生飘动的带电油水雾云团。然后介绍清洗油舱时静电放电规律和防患措施。 相似文献
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