船舶主机排烟温度高故障处理与反思

从一起MANB&W5L50MC型主机排烟温度高、增压器喘振故障出发,分析主机排烟温度高及主机喷油器泵压试验台故障原因,提出主机喷油器泵压试验方法。     

主机单缸排烟温度高故障分析

从一起MANB&W5S60MC型主机因更换排气阀致单缸排烟温度高报警自动降速故障出发,分析主机单缸排烟温度高产生的原因,提出主机排气阀液压系统故障预防措施。     

阀式调节高压油泵回油管阻塞导致单缸排温高故障一例

<正>某轮SULZER 6RND 76-M主机(回油阀式终点调节高压油泵),近期第四缸单缸排烟温度高。1故障经过(1)第一次故障某日航行,该主机第四缸排烟温度突然升高,达450～500℃(正常为380℃),烟囱冒黑烟,而且主机     

某轮VIP故障致主机单缸爆压过高的处理

介绍某轮主机某缸爆炸压力过高、排烟温度过低的原因和解决过程,讨论该类型主机高压油泵可变喷油定时机构的原理和检修要点。     

船舶主机排温偏高的原因及修理措施

排烟温度偏高是柴油机频发故障，严重影响了柴油机的可靠性，安全性和经济性。通过分析影响船舶主机排气温度异常偏高的原因，经检查测试，得知是由于废气涡轮增压器故障而引起排烟温度升高。     

某轮副机不能单机运行的原因分析及采取的措施

排烟温度是发动机的重要参数，发动机排烟温度高一直是困扰轮机管理人员的首要问题，针对这一问题，从分析引起排烟温度的原因入手，提出解决办法，并为更换旧发动机缸套提出了新的方法。     

某港作船2号主机排温过高浅析

某港作船采用2台型号为6CLM-22的主机，功率为1470kW，额定转速750r／min，采用脉冲增压。2号主机在一次检验后不久的运转中，发现同负荷下，其排烟温度明显高于1号主机。为分析问题方便，将有关参数列于表1，以便分析比较。     

CH轮主机排烟异常高温的排查

CH轮因船龄超过20年,在国内沿海航行时,主机工况在短时间内迅速变差,排烟温度高,甚至只能开"前进一",船速无法满足上海港的进港要求,公司指示船舶在汕头锚地抛锚,提供岸基支持,查清了故障缘由,改善了主机工况,船舶在上海港顺利进港靠泊,并通过更换备件彻底修复故障。     

某轮主机排烟温度过高原因分析

根据某轮主机的具体技术状态，对整个装置进行了全面分析，找出了进气道尤其是空冷器器脏堵造成排烟温度升高的原因，并经处理排除了故障，从而保证了主机的正常运转。     

对微机控制集中监视系统特殊故障的研究

对某轮微型计算机控制的集中监视系统检测显示主机排烟温度异常这一故障现象，从理论上进行了较深入的分析和探讨，并阐述了故障的查找和处理过程，又从管理的角度邮在工作中应注意的问题．     

Experimental uncertainty of a physical model of a tanker moored to a terminal in a port

This paper presents the uncertainty modelling of experimental results for a physical model of a tanker moored to a terminal inside a port. The physical model was built for an oil terminal at the port of Leixões in Portugal. The model incorporates the new modified port layout, as well as a future 300 m extension of the port outer north breakwater to enhance operational conditions. The physical model tests were performed on a scale of 1:80 in the Portuguese Civil Engineering Laboratory (LNEC). A generic mooring system of four mooring lines and two fenders is simulated using a nonlinear spring system. Decay tests are carried out to evaluate the natural periods of the moored model. Then, tests are carried out for the moored model in waves. The major aim of the experimental study is to obtain novel results for the wave elevation and direction at various locations inside the port, the ship motions at six degrees of freedom, and loads on mooring lines and fenders including the modified port layout. As the physical model measurements are subjected to different types of uncertainties, a systematic uncertainty analysis is carried out here, following ITTC guidelines and recommendations, to quantify all possible sources of uncertainties. The results are discussed, and several conclusions are reached. Based on the experimental results, the presented physical model study may replicate the results for waves and motions with uncertainties less than 9% of the significant amplitudes. The assessment of the applied nonlinear spring model reveals load predictions on the moorings, with uncertainties less than 4% of the maximum mooring loads.     

电缆燃烧性能的实验与仿真研究

在剖析电缆火灾原因的基础上,利用实验方法对阻燃电缆的阻燃性能进行了研究,得出了其在火焰中具有良好的抗火能力;之后利用破坏性实验进一步证明了阻燃电缆的良好抗火性能;然后利用FDS火灾模拟软件对无电缆参与的火灾和有电缆参与的火灾进行了仿真研究,得出了电缆在火灾中是否被引燃主要取决于是否与火焰直接接触的结论;最后,建议人们在电缆防火设计时,重点关注那些容易接触火焰的电缆。     

船用柴油发电机模拟机的设计

柴油发电机是舰船上重要的电源装置,它的性能直接影响到船上的电力系统性能。本文以某船用12相、8极柴油发电机为原型,详细阐述了其模拟机的设计方法。其模拟机的研制,对船上电力系统动态模拟和研究、船用柴油发电机的设计和研制提供了新的手段。     

一种异步电动机故障诊断系统设计

文章分析了传统故障诊断系统的特点,介绍了一种高分辨率谱估计算法-MUSIC算法,并针对该算法特点,提出了一种基于ARM微处理器的异步电动机嵌入式故障诊断系统,重点阐述了系统硬件电路和软件系统的设计,并进行了实验验证。结果表明系统具有硬件电路简单、可操作性较强、实时性可靠等优点。     

Characteristics of a bubble jet near a vertical wall

A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with the basic phenomenon of the interaction between a bubble and a wall, the dynamics of bubbles near rigid walls were studied systematically with the program. Calculated results agreed well with experimental results. The relationship between the Bjerknes effect of a wall and characteristic parameters was then studied and the calculated results of various cases were compared and discussed with the Blake criterion based on the Kelvin-impulse theory. Our analyses show that the angle of the jet＇s direction and the pressure on the rigid wall have a close relationship with collapse force and the bubble＇s characteristic parameters. From this, the application range of Blake criterion can be determined. This paper aims to provide a basis for future research on the dynamics of bubbles near a wall.     

Study of a simple sensor for stress history measurements of a structural member using a piezoelectric element

This paper describes a stress sensor using a piezoelectric element which was developed to monitor features of the stress history of a structural member. The sensor is 90 mm long, 60 mm wide, and 25 mm thick. A stress-level meter can turn on and off different colored light-emitting diodes (LED) according to the changes in a stress level. A stress-level cross counter can display the number of cycles which exceeds a specified stress level during a monitoring period. The sensor is bonded onto a structural member using an adhesive agent. In order to see the performance of the prototype sensor, experiments were carried out using a fatigue-testing machine. The sensor was bonded onto a smooth specimen and multiple repeated stresses were applied to that specimen. There were three main findings. (1) The sensor can operate under a stress range from −150 MPa to 150 MPa, and a frequency from 0.05 Hz to 5 Hz. (2) The stress-level meter can turn the lights of the LED on and off accurately under any stress amplitude and frequency. (3) When the stress frequency is 1 Hz or less, the stress-level cross counter can count accurately the number of cycles which exceed the predetermined stress levels. Received: February 25, 2000 / Accepted: April 11, 2000     

一类运输优化问题求解过程分析

通过对运输决策问题中某种基本情况的研究，建立运力有限情况下单个需求点单一物资运输的研究模型，给出求解模型的算法，通过一个算例进行了验证。与目前文献资料中类似研究模型相比较，在决策中考虑运达概率对运输决策的影响是本文模型的一大突出特点。     

高低型双涡流室双缩口燃烧室的排放特性

为优化某船用柴油机的燃烧室的"油-气-室"匹配,降低有害物排放,运用AVL Fire对原型燃烧室改用不同燃烧室进行额定工况模拟.结果表明,高低型双涡流室双缩口燃烧室能在上涡流室形成"飞轮效应",相对于原型燃烧室,不仅能增加功率,而且能降低Nox和SOOT的排放.对高低型双涡流室双缩口燃烧室设置不同的高低涡流室的半径比r/R和喷油夹角进行计算.结果表明:随着r/R从0.3增加到1.3,Nox和SOOT的排放量均先减少后增多;当r/R为0.7时,Nox和SOOT的排放量均最少.当喷油夹角为140°～165°时,随着喷油夹角的增大,Nox的排放量先减少后增加,随后再减少,最后又升高;SOOT排放量先减小后增大,随后再减小.     

某船用大型可拆卸式滚动轴承设计

文章以船用滚动轴承为研究对象,针对该滚动轴承工作中存在的缺点和不足,设计了一种船用可拆卸式滚动轴承,说明了该滚动轴承的工作原理和主要零部件,并利用三维建模软件UG进行了该滚动轴承的零部件及装配体建模,最后进行了滚动轴承装配体的干涉检查,结果表明,所设计的船用大型可拆卸式滚动轴承运行良好。