Overview of Past, Present and Future Marine Power Plants

In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.

Performance of Marine Power Plant Given Generator, Main and Distribution Switchboard Failures

Power generation is one of the most essential functions of any plant for continuous functioning without any interruption. A marine power plant （MPP） is the same section. In the present paper, the authors have tried to find the various reliability characteristics of an MPR A marine power plant which is a composition of two generators and in which one of them is located at the stern and another at the bow, both associated to the main switchboard （MSB）. The distribution switchboards （DSB） receive power from the MSB through cables and their respective junctions. Given that arrangement, a working based transition state diagram has been generated. With the help of the Markov process, a number of intro-differential equations are formed and solved by Laplace transform. Various reliability characteristics are calculated and discussed with the help of graphs.

Research on Monitoring and Earlywarning System of Marine Organisms for the Intake of Nuclear PowerPlants

An monitoring and earlywarning system is proposed for marine organisms and the cause of water intake blockage is analyzed. Based onthe intelligent sensing technology, computer software and hardware technology and digital signal processing technology, the buoy monitoring platformsystem is developed by internet of things technology, cloud computing and the application of large data. Remote realtime monitoring of aquatic organisms and foreign bodies is realized based on underwater acoustic detection and low light imaging technology. Data processing center is established to store, analyze and process monitoring information and display it in real time, and provide emergency decision support. Through development and test of relevant key equipments, the reliability of cold source system of nuclear power plants is improved, which effectively reduces theinfluence of marine biological invasion on security and economic operation of the units.

TRANSPORT OF RADIONUCLIDES ALONG MARINE FOODCHAIN

A compartment model is employed to calculate the radionuclide concentrations in the ocean currents for a nuclear accient scenario where the long-lived 137Cs is totally discharged into the sea. The radionuclide concentrations in both the waters of Daya Bay and the adjacent South China Sea are considered. Using the concentration factors for the marine organisms: fish, crustacea and mollusca, their radionuclide concentrations are also estimated. In this way, the whole body radiation doses received by an individual due to ingestion of marine organisms from the Daya Bay and the South China Sea are calculated.

Radiation dose rate estimates to marine biota resulting from the routine radioactive releases of the nuclear power plants in Daya Bay

Five marine organisms in Daya Bay are selected for estimating the dose rates. Internal exposure and its 5 pathways are also considered. The concentrations of 43 kinds of background and additional radionuclides in seawater are from the survey of background radioactivity and the prediction of routine radioactive releases of the 4 reactors. Point source dose distribution functions are used to estimate the dose rates to various organisms from a and β radiation.

Discussion on Foundation of Offshore Wind Turbine

This paper briefly describes the classification and composition of offshore wind turbine foundation structure,and focuses on different structural forms of offshore wind turbine foundation.The advantages,disadvantages and application fields of offshore wind turbine foundations with different structures are compared and analyzed.Finally,some suggestions on the construction of offshore wind power foundation are put forward.

抗裂剂在核电站混凝土中的应用研究

为预防核电站大体积混凝土在早期出现收缩开裂的情况,本文采用双重调控技术优化设计混凝土配合比(温度场和膨胀历程调控)替代布置冷却水管的抗裂方案,对核电站混凝土裂缝进行控制。配合比中选择P·N 42.5水泥、大掺量矿物掺合料和掺量8%的抗裂剂,其中,抗裂剂具有降低早期水化放热速率以及全过程补偿混凝土收缩变形的作用,同时制备的混凝土的工作性能、力学性能及耐久性均满足设计要求。结果表明:经过有限元仿真抗裂风险计算分析,采用抗裂方案的核电站主体结构,开裂风险系数小于0.7,混凝土基本不会开裂,符合设计施工要求。

基于位敏传感器的对中监测系统

为了实时掌握柴油机动力装置的对中状态,设计了一种基于位敏传感器的对中监测系统。首先提出了基于位敏传感器的位姿变化测量方法,形成包含位姿变化的非线性方程组,通过位姿转换获得对中变化;其次通过传感器支架组件实现对方程组常量的高精度测量,通过软硬件设计形成测量系统,设计了基于简单牛顿法的复合迭代算法,保证方程组快速、准确求解;最后对测量系统的精度进行了分析,并采用四维平台进行了验证。试验结果表明:对中监测系统噪声小,偏差量噪声在0.005 mm以下,开口角噪声在0.01°以下;精度受激光入射方向影响较大,最佳入射方向下,偏差量监测精度可达0.02 mm,开口角监测精度可达0.019°。该系统将用于国产柴油机动力装置的对中监测。

日本福岛核事故后的海洋放射性监测进展

全面总结日本福岛核事故后不同核素通过海洋途径排放的放射性总量;介绍多个国家开展的海洋放射性监测工作;基于海洋放射性本底与各国制定的限值标准,对福岛核事故后海洋放射性监测结果进行评价;最后对国内外的海洋放射性监测工作进行展望,从海洋环境安全角度出发,提出建立我国海洋放射性数据库的必要性.

热冲击和加氯后亚热带海区浮游植物细胞数量的动态变化

近年来,随着电厂在河口和港湾等生态脆弱区和敏感区的急剧增多,电厂冷却系统热冲击和加氯对浮游生物造成的伤害已成为沿海地区非常严峻的生态安全问题。为探明冷却系统升温和加氯联合作用对亚热带海区浮游植物的影响程度,针对滨海电厂的实际运作情况,在室内对采自浙江省乐清湾海域的四季浮游植物进行了不同水平的热冲击和加氯胁迫,并观察了这些浮游植物细胞数量在15d内的动态变化。结果表明,热冲击、加氯和季节均显著影响浮游植物细胞数量的恢复(p<0.001),其中,加氯的影响最大,季节次之,热冲击影响最小,但热冲击增强了氯对浮游植物的毒性。自然水温越高、升温幅度越大,细胞数量恢复越慢。春、秋、冬季自然水温较低时,升温4～12℃后,细胞数量仅需1～6d即可恢复到对照组水平;夏季自然水温较高,升温4～8℃后,细胞数量需4～9d恢复到对照组水平,但升温12℃后,细胞数量在15d内未能恢复到对照组水平。加氯浓度越高,细胞数量恢复越慢。加氯1.0～1.8mg·L?1后,浮游植物生长虽受影响,但大多能在15d内恢复;而加氯5.6mg·L?1后,其生长受到完全抑制,细胞数量在15d内未恢复到对照组水平。

船舶机舱监测和报警系统的设计与实现

机舱检测和报警系统是现代化船舶自动化机舱的重要组成部分,针对国内部分船舶机舱检测和报警系统产品在功能和显示模式方面都无法完全满足自动化机舱发展的需要等缺点,采用了VC++可视化建模、数据库、网络等技术,设计和开发了船舶机舱监测和报警系统。该系统具有网络化和模块化结构,检测和报警采样点共735个,覆盖了机舱所有重要设备。为了简化系统结构和降低硬件成本,监测、报警、操作和控制功能全部由软件实现。仿真试验表明,系统的功能完善,显示模式多样化,有利于进行故障预测和诊断,也为船舶维修提供了较为充分的综合数据信息。该系统已经作为新一代大型船舶轮机模拟器的仿真子系统投入应用。

船舶动力装置可组态智能故障诊断系统设计

旋转机械是许多船舶动力装置的核心设备,其设备状态与安全性直接关系到船舶航行的安全。为了保障船舶安全正常航行,针对当前船舶动力装置故障诊断系统的不足,研究开发了基于旋转机械监测诊断技术、数据库技术、网络技术以及组态式软件技术的船舶动力装置可组态智能故障诊断系统,介绍了该系统的体系结构、硬件结构、软件功能、网络技术及特点。该故障诊断系统只需修改少量配置文件即可实现对不同船舶动力装置的监测诊断,具有较高的灵活性和可扩展性。

船舶轮机仿真器引入虚拟现实技术的研究

提出在船舶轮机仿真器中引入虚拟现实技术。提出虚拟机舱，虚拟集控室，虚拟驾驶台，虚拟控制仪表板的新概念并讨论其可实现性。给出应用虚拟环境系统ＶＲＴ生成的可交互油船模型。作者认为综合应用计算机生成的动态３ 维图形，高画质图象投影和多媒体技术，可获得比物理模拟更真实的仿真效果。从而使船舶轮机模拟器具有良好的动态视景。

喷水推进器功率特性与航速相关性研究

通过对某船喷水推进系统的分析,研究了喷水推进器的功率特性(功率与转速的关系)与航速的关系.先由喷水推进动力学方程引出喷水推进器功率特性在喷水推进系统稳态特性和动态性能研究中的作用,然后分析了KaMeWa71SⅡ喷水推进器的转速特性,将转速特性变换成力矩特性后,分析了该力矩特性,并将其与螺旋桨相应特性作了对比.根据转速特性获得的3个不同航速下的喷水推进器功率与转速的关系曲线,分析了航速对功率特性的影响,同时也将其与螺旋桨的相应特性曲线作了对比.研究所得出的结论是:喷水推进器的功率特性不是唯一的,装船之后它的功率特性受航速影响,但这个影响不像螺旋桨那么显著.据此推得,喷水推进系统在“船—泵—机”的匹配设计以及实际使用中,主机一般不会超负荷.

船舶柴油机曲轴的模态分析

通过建立船舶柴油机曲轴的三维几何模型,结合ANSYS软件对曲轴的细节特征和约束进行简化.采用Lanczos法进行自由模态分析,获得曲轴前5阶固有频率和振型向量,并求得曲轴振动中的危险区域.

QFD理论在舰船动力装置概念设计中的应用

针对舰船动力装置传统概念设计阶段存在的问题,研究了将QFD理论应用到舰船动力装置概念设计中的方法,并讨论了需求分析质量屋和方案设计质量屋的构建方法及相关算法、方案的综合模糊评价等实施过程中的相关问题,同时以CODAD型动力装置传动装置概念设计为算例对所研究的内容进行了验证。结果表明:该研究方法将为舰船动力装置概念设计提供科学的指导,并为设计质量的提高奠定一定的理论基础。

转动惯量对船用核动力主泵瞬态特性的影响研究

采用压水堆热工水力瞬态分析程序RELAP5 /MOD3,对船用核动力主泵发生断电事故后在3种不同转动惯量下的瞬态特性进行了定量研究;研究结果表明,较大的泵转动惯量可以减轻事故的后果,有利于改善反应堆的安全性。

阳江核电厂附近海域生物辐射影响评价研究

随着辐射防护理念的发展,环境中生物所受到的辐射影响日益引起人们的关注。使用ERICA项目中推荐的辐射影响评价方法,对阳江核电厂运行后对附近海域中海洋生物的辐射影响进行预测和评价。剂量率估算结果显示,阳江核电厂的液态放射性流出物对附近海域海洋生物造成的辐射剂量率不会超过7.47×10-3μGy.h-1,远低于国际上推荐的保护生物的辐射剂量率控制值,也低于本底辐射剂量率。因此,阳江核电厂正常运行后对附近海域中的海洋生物不会造成不利的辐射影响。

液力偶合器通用外特性的数学建模

先从舰船推进系统的稳、动态特性研究的需求分析,引出建立液力偶合器数学模型的必要性。从船舶动力装置原理的角度,叙述了液力偶合器用机理建模法推得的力矩外特性的一般解析式。运用液力偶合器制造厂家提供的试验曲线,根据机理建模原理用数值计算法确定外特性一般解析式在各特定条件下的各系数具体值。再运用人工神经网络方法,将液力偶合器力矩外特性从若干个线工况推广到整个工作范围都适用的面工况。最后对所用的液力偶合器外特性数学模型的多法并用的建模法进行了小结。

基于支撑平台的船舶动力模拟训练系统研制

设计了一种基于仿真支撑平台软件的船舶动力装置模拟训练系统的研制方案,论述了利用MINIS仿真支撑系统、Intouch组态软件、X3D技术、现代CAD技术和网络技术开发其全工况模拟训练系统的方法,并结合应用实例介绍了系统的软件组成及其特点。实践证明,该方案在保证仿真精度的同时降低了系统的开发成本,缩短了研制周期,是研制船舶动力装置训练模拟系统的理想选择。