中小型LNG运输船推进系统选型分析

为了促进LNG运输船主动力推进装置方面的研究,推动LNG运输船推进系统的转型,通过对LNG运输船几种推进方式特点的对比分析,为中小型LNG运输船主推进系统的选型提供参考。     

霍尔油位传感器的应用设计

目前,油位传感器普遍采用铍青铜电刷加厚膜电阻形式,作为一类技术成熟的油位传感器,有着无可比拟的价格和技术优势,虽在行业中占据主导地位,但这种传感器也有难以克服的缺陷,在正常通电状态下一般很难达到预期的设计寿命。随着油价上涨,劣质汽油流入市场,汽油中硫磷等腐蚀性物质对厚膜电阻腐蚀严重;耐乙醇汽油的丁晴橡胶浮子在生产过程中残留有硫元素,溶解在汽油中会腐蚀厚膜电阻,这两方面是导致油位传感器使用寿命降低的关键因素。     

A method to measure the eco-efficiency of diesel locomotive

Brazilian railroads transport over 490 million tons a year using diesel-electric locomotives. These locomotives emit several pollutants into the atmosphere and because of that, the railroads seek to reduce emissions and achieve global emission standards. Thus, it is important to analyze the environmental impact of the use of diesel and alternative fuels to reach environmental standards. This paper makes use of a method based upon the World Business Council for Sustainable Development (WBCSD) metrics to evaluate the locomotives’ eco-efficiency. The method was applied to Estrada de Ferro Vitória a Minas (EFVM). Different scenarios representing the exchange of fuel sources and technologies were developed, tested and analyzed. The impacts were evaluated by seven eco-efficiency performance indicators and compared with United States Environmental Protection Agency (EPA) standards. The results offered cost savings and emissions reduction opportunities.     

燃料电池系统氢循环方案综述

燃料电池氢循环主要作用是维持电堆内氢气循环量,保持堆内的水平衡。好的氢循环设计方案对提高燃料电池寿命、可靠性、以及整车的经济和动力性都有着至关重要的作用。文章从成本、效率、技术成熟度、资源可行性等角度分析了不同氢循环方案的优缺点,同时指出未来氢循环研发的热点和方向。     

喷气燃料静电消除技术研究

详细分析了喷气燃料中产生静电的原因,静电引起火灾的条件,讨论了避免静电产生的措施和消除静电荷的办法,研究了静电消除器的设计方法、材料选择、性能特点和应用注意事项.多年的应用及测试数据证明,自感应静电消除器能高效地消除喷气燃料输送过程中产生的静电荷,能确保喷气燃料使用中的静电安全.     

石嘴山市星海湖大桥主桥结构设计

石嘴山市星海湖大桥是该市一座重要的城市桥梁,主桥跨径100m,桥面宽度达48m,为下承式钢箱系杆提篮拱桥,主体结构采用栓焊结合钢结构,桥面系采用钢-混结合梁结构。介绍了本桥的主要结构尺寸、构造细节,以及本桥的设计特色,为高寒地区建设此类桥梁提供借鉴。     

氢燃料电池汽车简易加氢站设计

为了面对能源与环境问题,国家与地方政府正在大力推动氢燃料电池汽车产业的发展,目前国内主流的汽车生产企业基本上都已经启动了氢燃料电池汽车的研发工作。然而,受限于我国加氢站建设周期长,成本高,流程复杂等问题,使得全国的加氢站数量十分稀少,许多汽车生产企业研发出来的氢燃料电池汽车面临着加氢的巨大挑战,一些偏远地方的汽车生产企业甚至到了无氢可加的境地。为了缓解氢燃料电池汽车的加氢问题,拓宽氢燃料电池汽车的使用场景,本文提出了一种简易加氢站的设计方法,期望该方法可为加氢困难的汽车生产企业提供借鉴,加速氢燃料电池汽车产业的发展。     

An investigation of different methods for the prevention of parametric rolling

The parametric rolling of modern containerships is emerging as a serious problem, to the extent that its effects warrant a study into its prevention. In light of this, two methods for reduction of parametric rolling are proposed and examined by physical model experiments. The first is a sponson attached to the side of a ship, the purpose being to decrease the rate of change of the rollrestoring moment. The second is an antirolling tank to increase roll damping. By conducting free-running model experiments for a 6600-TEU post-Panamax container ship with sponsons under typical parametric rolling conditions, it was found that the sponsons could decrease the magnitude of parametric rolling. The antirolling tank could prevent parametric rolling completely in certain conditions, even in severe head seas. Using the damping coefficients from experimentally derived data of a model ship with an antiroll tank, a numerical simulation was established. The numerical model was then compared with the free-running model experiments. The results indicated that the numerical model could qualitatively verify the experimental results. Finally, an attempt to optimise the size of an antirolling tank for preventing parametric rolling for the subject post-Panamax container ship in the North Pacific Ocean is presented.     

现场绝缘耐压试验容量的选择

通过对电气安装工程电气设备现场交流耐压试验容量的计算,提出了针对不同容量的被试电气设备在现场开展交流耐压试验时试验仪器设备的选型方案,结合现场实际应用情况,阐述了现场大容量交流耐压设备的应用前景。     

便携式速度传感器测试台在上海地铁6、8号线的应用

车载信号设备中的速度传感器故障存在定位较难的问题。简要介绍了霍尔式速度传感器的工作原理和主要技术指标。描述了便携式速度传感器测试台的组成及工作原理,并介绍了便携式速度传感器测试台的操作方法和测试方式。便携式速度传感器具有便携,易操作且使用灵活等创新点,能有效减少试车时间,提升速度传感器故障的排故能力。