新建船舶尾管后轴承高温磨损的原因与改进

剖析船舶在运行过程中艉管后轴承高温报警的案例,从多个方面阐述了轴承磨损的诱发原因,并提出了相应的改进方法,给船厂在提高船舶轴系安装质量方面带来了实际效果。     

轴承支承长度及间距对船舶轴系振动特性影响

针对某船舶轴系进行了不同位置、不同支承长度的轴承条件下固有振动特性分析.得到了不同位置不同支承长度的轴承对船舶轴系固有振动特性的影响.计算结果表明,不同位置轴承支承长度的变化对船舶轴系固有振动特性的影响有很大的不同.在所有的轴承中,船舶前后艉架轴承和船舶艉管轴承对船舶轴系的振动特性影响最大,同时这些轴承工作条件恶劣,在船舶正常运行过程中支承长度会发生很大的变化,因此在船舶运行过程中必须时刻注意这些轴承的性能变化.     

大型船舶艉管轴承结构参数优化设计

推进轴系在船舶动力装置中起着重要的作用,船舶艉管轴承在船舶非正常运行过程中,往往出现高温报警。基于径向滑动轴承的水动力润滑机理,建立了某大型船舶艉管轴承油膜润滑的数学模型,采用超松弛迭代法计算流体动力润滑二维Reynolds方程,分析了船舶艉管轴承间隙比和沟漕位置对轴承承载力的影响。通过对艉管轴承的优化设计,改变了艉管轴承的沟槽位置及轴承间隙,提高了轴承的承载力,该船在再次试航和实际营运中艉管轴承未再出现高温报警。     

船舶推进轴第轴承油膜刚度的计算研究

分析国外在船舶推进轴系轴承油膜刚度计算方面的缺陷，根据船舶推进轴系的工作特点，提出了一种较为切合实际的航船推进系轴承油膜刚度的计算方法，并进行了实船计算。     

船舶主机安装误差对船舶轴系安装质量的影响

文章针对船舶轴系校中校核有效性问题进行分析和讨论,分析在主机安装误差变化范围内,中间轴承和艉轴承负荷、安装状态的法兰开口及偏移等参数的变化特点,得出船舶主机安装误差范围、轴承负荷控制误差范围、连接法兰偏移值误差范围之间的关系,并提出了保障船舶轴系安装质量的精度控制方面的建议。     

船舶主机主轴承温度数字化检测系统设计与实现

船舶主机(柴油机)主轴承的温升直接影响着主机的工作性能和运行安全,利用多个温度传感器组成传感器网络,结合单片机形成高精度温度采集检测系统,分布在船舶主机各主轴承监测点上,实现了对主机主轴承温度多点温度检测。这种检测系统精度高,抗干扰能力强,实时性好。本文针对主机的特点,构建主轴承温度测控系统,该系统可以对主轴承温度进行准确的自动监测和实时报警,为主轴承的工作状态提供使用管理依据。该系统在主机温度检测系统及其船舶机舱自动化方面具有广泛的应用价值,此项技术也可作为船舶机电设备故障监测的重要手段。     

船舶轴系的合理轴承间距的研究

在综合考虑轴承许用比压、轴承安装误差以及轴系横振等限制条件下,以船舶轴系的轴承负荷分配的合理性为目标,分析了船舶轴系的合理轴承间距问题,给出了轴系计算模型及方法,并以SDTS船舶轴系实验台为例进行计算,得到了轴系合理轴承间距下的优化校中状态,轴系热态运行工况明显改善。     

船舶艉管后轴承高温分析及防范

针对近年来在建船舶屡次发生艉管后轴承高温,导致主推进系统无法正常工作的情况,以发生后轴承高温问题的船舶为研究对象,从轴系设计、轴系安装校中及后期调试、艉管滑油选用、船舶吃水及浅水效应等方面进行分析,从而找到相应的防范措施。     

浅析麦基嘉克令吊臂头滑车轴承拆装

在船舶作业中,各种机械故障问题在所难免,尤其是很多自带船吊的杂货船,其克令吊在装卸货过程中就时常会出现一些险情。在杂货船松字号型船舶上,克令吊臂头滑车轴承故障率相对高些,本文从该种船型克令吊臂头滑车轴承出现损坏原因及维修保养等方面入手,给同样类型船舶类似情况提供了一些经验,希望能够引发后续船舶作业人员重视,为安全生产贡献自己的力量。     

船舶艉管轴承的设计与应用

为了避免船舶试航时，艉管轴承发生高温等非正常情况可能导致船舶轴系再次进船坞的拆检、修复；航行时艉管轴承的失效将导致船舶轴系故障，甚至主机停车等严重威胁船舶航行安全的事故，对艉管轴承合金（成分），艉管轴承结构（止动螺钉等），艉管轴承油楔（压力区）进行了设计研究。通过对船舶艉管轴承的设计研究与应用，可以改进船舶（轴系）的建造质量，改善船舶艉管轴承的工作状态，减少船舶艉管轴承发生故障的概率。研究结果可为船舶研发、设计和工程技术人员提供有益的参考和信息。     

自升式抛石整平平台船的设计与应用

针对长江口深水航道治理工程恶劣的作业环境,将海上施工平台的概念引用到水下抛石整平施工工艺中,研究的主要内容包括设备的施工作业方式、平台的结构、平台自浮的拖航稳定性、平台支腿靴板对基础的压力、平台升降装置、抛石整平机构及作业时的稳定性等,阐述了平台船的特点和先进性,以及在今后大型水工工程中的应用前景。     

安哥拉某EPC堆场建设管理体会

安哥拉某堆场的建设,遇到地质变化引起软基处理方案变更、施工初期人员设备投入不足导致施工工序不紧凑、当地开山料的选择余地大、设计标准调整等特殊情况.在解决这些问题的过程中,提出现场问题的处理原则、合理选择设计指标、确定检验验收标准的优先顺序、设计服务等问题,供类似项目参考.     

How much can public private partnership really do for urban transport in developing countries?

A few cities in some of the larger developing countries in Latin America and Asia have made increasing use of multi-year concessions or franchises, competitively awarded to private companies, for construction and operation of urban transport infrastructure and for provision of public transport services. In view of the strong prospective growth of developing-country cities with large transport needs, and the rise in the emerging economies of potential new sources of private capital, it is important to see how effective PPP has so far been in this area. The experience is analyzed principally by thorough comparative review of what has actually happened for some of the main users to date: Bogotá, Santiago, São Paulo, Seoul, and several cities in both China and India. Despite delays and mistakes that have been made in development of most of the projects, the overall results, already delivered and in prospect, are very positive and urban public transport is benefiting substantially, with significant side effects on poorer people's access to work and to services, air pollution levels and road accident rates. The widest and most important advantage of the PPP arrangements, as compared with more conventional short-term contracting, is found to be the innovations, technical and managerial, developed, and, in particular, the mutual capacity building of the countries' private and public sectors and their more effective interaction. The experience in the six countries covered suggests that other developing-country cities may be best assisted to develop sound urban transport PPPs more rapidly through provision of help on chosen items among 7 elements that have proved particularly crucial but sometimes weak in the projects reviewed: Civic consultation systems, Land-use/Transport strategic planning, Land/property market management, Monitoring systems, Progressive policies, Economic regulation, and Public institutional framework for PPPs.     

小溪滩船闸混凝土结构裂缝控制技术

船闸工程底板、闸室墙、输水廊道顶面和侧面、门槛顶面和侧面等部位极易出现贯穿性的规则裂缝。通过理论分析和现场实践,从设计、材料、施工3个层次提出了船闸混凝土裂缝控制方法,主要包括调整构造钢筋直径和钢筋间距、设置施工宽缝、调整冷却水管、优化混凝土配合比、采用全断面浇筑工艺、控制分层浇筑时间间隔等措施,取得了较好的控裂效果。     

多因素数学模型在温州瓯江口浅滩围涂工程研究中的应用

建立了波浪、潮流、盐度、悬沙、底床冲淤等多种因素数学模型,在模型验证的基础上,对瓯江口温州浅滩围涂工程海区的波浪场、潮流场、盐度场、悬沙场、底床冲淤场进行了数值模拟研究,对温州浅滩围涂工程对瓯江泄洪、瓯江南北口分流比、乐清湾养殖业、瓯江口港口航道及状元岙深水区、南口口外滩地的影响进行了分析论证。分析研究结果表明,温州浅滩围涂工程是可行的。     

Matching biological traits to environmental conditions in marine benthic ecosystems

The effects of variability in environmental conditions on species composition in benthic ecosystems are well established, but relatively little is known about how environmental variability relates to ecosystem functioning. Benthic invertebrate assemblages are heavily involved in the maintenance of ecological processes and investigation of the biological characteristics (traits) expressed in these assemblages can provide information about some aspects of functioning. The aim of this study was to establish and explore relationships between environmental variability and biological traits expressed in megafauna assemblages in two UK regions. Patterns of trait composition were matched to environmental conditions and subsets of variables best describing these patterns determined. The nature of the relationships were subsequently examined at two separate scales, both between and within the regions studied. Over the whole area, some traits related to size, longevity, reproduction, mobility, flexibility, feeding method, sociability and living habit were negatively correlated with salinity, sea surface temperature, annual temperature range and the level of fishing effort, and positively associated with fish taxon richness and shell content of the substratum. Between the two regions, reductions in temperature range and shell content were associated with infrequent relative occurrences of short-lived, moderately mobile, flexible, solitary, opportunistic, permanent-burrow dwelling fauna and those exhibiting reproductive strategies based on benthic development. Relationships between some traits and environmental conditions diverged within the two regions, with increases in fishing effort and shell content of the substratum being associated with low frequencies of occurrence of moderately mobile and moderately to highly flexible fauna within one region, but high frequencies in the other. These changes in trait composition have implications for ecosystem processes, with, for example, reductions in permanent-burrow dwellers within one of the regions potentially compromising the ability of the assemblages to process and store chemicals and waste products. However, the connections between environmental conditions and trait composition are complex and incorporate many factors. Experimental investigations will be necessary to determine the extent and consequences of these important relationships.     

辐射沙洲海域深水港开发建设水动力泥沙问题研究

综合使用水文泥沙特征分析、卫星遥感分析、冲淤演变分析、潮流泥沙数学模型计算、波浪数学模型(SWAN模型、缓坡方程、多向不规则波Boussinesq方程)计算、波流冲刷物理模型试验、泥沙淤积计算、骤淤计算与分析等多种手段对辐射沙洲中的如东海域深水港开发建设的水动力泥沙问题进行了研究,为深水港开发建设提供了科学依据。研究表明:通过采取必要的工程措施,在辐射沙洲海域中进行深水港开发建设是可行的。     

基于ARM的嵌入式通讯平台设计

文章介绍了以NXP的ARM7 TDMI内核控制器为核心的嵌入式通讯平台的设计,包括CAN、工业以太网、USB、RS232、RS485、UART、无线等目前流行的各种通讯方式的设计以及液晶显示、触摸屏、按键的硬件设计,给出了比较完整的方案设计和硬件连接,同时对于所采用的操作系统进行了简单介绍。     

辐射沙洲研究开发的进展

对辐射沙洲研究开发的若干文献进行了归纳总结和综述,包括辐射沙洲的发现、成因、物质来源、形态特征、表层沉积物组成、演变、水动力泥沙环境、开发利用等。     

大力推进信息化建设 提升企业综合竞争力

结合企业计算机应用的实际,以及造船生产劳动强度大、劳动环境恶劣、船用配件和材料种类繁多等特点,介绍在造船工业中,将设计、制造、管理等集为一体纳入计算机综合管理的集成系统,目的在于寻求一种采用计算机技术挖掘企业内部潜力,提高工作效率、推进企业信息化、加快企业生产和管理现代化、提升企业综合竞争力的新途径。