进油温度对生物柴油燃烧压力及循环变动的影响

在1台两缸直喷式柴油机上对比测试了生物柴油的燃烧特性,分析了进油温度对发动机峰值燃烧压力分布以及循环变动率的影响。结果表明,随着进油温度的增加,生物柴油发动机表现出如下燃烧特性:燃烧延迟,高负荷时延迟更明显;峰值燃烧压力降低,其循环分布向低值偏移;峰值燃烧压力分布最高值增加且其循环变化幅度明显降低,循环变动率降低,循环变动减弱;负荷或转速增加均导致循环变化幅度明显降低,循环变动减弱。研究结果证明,进油温度对燃用生物柴油的燃烧压力及其循环变动有重要影响,进油温度增加可以提高燃烧稳定程度,从而改善燃烧过程。     

缸内直喷汽油机多孔喷油器喷雾特性试验研究

为了研究缸内直喷汽油机多孔喷油器的喷雾特性,建立了定容喷雾试验装置,对不同环境压力和不同喷油压力条件下的自由喷雾和碰壁喷雾过程进行了拍摄,分析了壁面距离和壁面倾角对喷雾特性的影响。研究发现:多孔喷油器与传统的旋流式喷油器的喷雾特性存在较大差异。多孔喷油器的喷雾锥角受环境压力影响较小;随着环境背压的增大,贯穿距离和喷雾锥角呈现先增大后减小的特点;喷雾锥角随着喷射压力的提高略有增加。在碰壁喷雾发展过程中,不同环境压力下喷雾油束与壁面接触面积接近;随着壁面距离的增加,碰壁喷雾高度递减,碰壁后的喷雾高度存在波动;随着壁面倾角的增大,碰壁喷雾高度和增大。在壁面倾角的增大过程中,影响碰壁喷雾半径的因素较多,呈现出较复杂的变化规律。以上研究为多孔喷油器的设计及其与燃烧室的匹配提供了理论依据。     

缸内直喷汽油机喷油及燃烧过程三维数值模拟

对某直喷汽油机部分负荷时的进气、喷油、混合气形成及燃烧过程进行了数值模拟。分析了喷油正时对混合气分布、燃烧性能及排放性能的影响。模拟结果显示,在喷油开始时刻为480°曲轴转角时混合气分布比较理想,达到了分层稀燃的目标。生成物NO的主要来源是参与燃烧的空气中的氮,NO的生成随温度的提高而急剧增加;炭烟生成的条件是高温和缺氧,局部较浓混合气相对缺氧导致炭烟生成。     

新颖的船舶电控喷油柴油机系统

本文介绍了船舶主机上引入一种新颖电子控制喷油系统,大大改善了燃烧效率和耗油量问题,并保证了船舶主机的最佳工作性能。文章重点论述了该系统的特点与功能,结构原理及实验测试数据等。     

Economic factors affecting the registration of lower CO2 emitting aircraft in Europe

We examine the various forces influencing the development and uptake of environmentally beneficial technical changes, focusing on airline technology. Within this context, we consider not only the nature of competition within the final market in which aircraft, an intermediate product, are sold, but also that of the product market itself, the commercial airline industry. The reasons for the gradual reduction in CO₂ per seat per aircraft movement in aircraft design are examined in terms of the real costs of aviation fuel, changes in the nature of the supply industry, the movement towards carbon cap-trade policies, and endogenous technical progress in the technology of the industry. The latter being taken as an empirical proxy for the role market forms play in influencing the fuel efficiency of the types of aircraft used. The results support the existence of these latter forces on the demand for aircraft types, allowing for other influences that affect aircraft technology.     

Optimal development of alternative fuel station networks considering node capacity restrictions

A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is the use of alternative fuel vehicles (AFV). As global GHG emission standards have been in place for passenger cars for several years, infrastructure modelling for new AFV is an established topic. However, as the regulatory focus shifts towards heavy-duty vehicles (HDV), the market diffusion of AFV-HDV will increase as will planning the relevant AFV infrastructure for HDV. Existing modelling approaches need to be adapted, because the energy demand per individual refill increases significantly for HDV and there are regulatory as well as technical limitations for alternative fuel station (AFS) capacities at the same time. While the current research takes capacity restrictions for single stations into account, capacity limits for locations (i.e. nodes) – the places where refuelling stations are built such as highway entries, exits or intersections – are not yet considered. We extend existing models in this respect and introduce an optimal development for AFS considering (station) location capacity restrictions. The proposed method is applied to a case study of a potential fuel cell heavy-duty vehicle AFS network. We find that the location capacity limit has a major impact on the number of stations required, station utilization and station portfolio variety.     

气体燃料/汽油两用燃料汽车自适应燃料点火器

气体燃料 /汽油两用燃料汽车燃用不同燃料时 ,最佳点火提前角相差悬殊。采用自适应燃料点火器可根据发动机使用燃料的不同自动改变点火提前角。论述了单片机控制自适应燃料点火器的软、硬件结构和工作原理。试验结果表明 ,加装自适应燃料点火器后 ,发动机动力性增加 2 .6%～3.1 % ,燃料消耗率下降 2 .6%～ 3.4%。     

列车运行与优化系统的设计

随着世界能源消耗的逐年增长,燃油的节省技术越来越受到重视。本文就GE公司运输系统集团的新一代节油产品列车运行与优化系统设计展开讨论,针对软件模块功能进行介绍,也汇总了在全球应用的现状,最后展望了在中国应用的未来。     

用于发动机开发的气缸内测试技术

描述了用于揭示气缸内过程的光学诊断技术.说明了可在气缸内安装光学通路的可视化发动机特点和激光诊断技术的原理.给出了典型的测试结果,如气体流动、燃油喷射、混合气形成、燃烧及燃烧产物.此外,探讨了光学诊断技术在发动机内部及外部废气再循环研究中的应用.     

世界汽车工业新的技术革命

详细介绍了欧、美、日现代柴油机技术的发展及其在轿车上的应用、新型汽油机的发展、混合动力驱动轿车的发展状况、氢燃料电池技术和均匀充气压燃发动机的研发，并对汽车电子在汽车安全和舒适性方面的作用作了简介，对我国新型发动机的技术状况进行了概述。表明世界汽车工业的新技术革命一直在进行中。