Estimation of cost and CO2 emissions with a sustainable cross-border supply chain in the automobile industry: A case study of Thailand and neighboring countries

CO₂ emissions are increasing because of the growth in the cross-border supply chain, which is leading the locations of assembly plants and suppliers to spread across a wider area. Given that one passenger vehicle needs more than 20,000 components and parts, the automobile industry exploits the cross-border supply chain. Recently, the free cross-border movement of people, goods, capital, and information has accelerated in Asia. Therefore, a sustainable cross-border supply chain is required to reduce both CO₂ emissions and cost. This study estimates total CO₂ emissions per vehicle including production and transportation processes in Thailand and neighboring countries and the change in CO₂ emissions based on future policy scenarios that consider the automobile market and locational conditions in 2030. The results show that locating production close to the place of consumption and the electricity emissions factors in each country should be considered.     

换气与压缩过程对汽油机燃烧特性的影响研究

针对增压气道喷射汽油机进行了发动机换气与压缩过程对燃烧特性的影响研究,对比了两种状态下的气门升程与配气正时,基于发动机试验台架测试数据,重点分析了发动机动力性、经济性和燃烧特性。试验数据表明了配气相位的改变对燃烧有较大的影响,可使燃烧效率大幅度提高,爆震倾向减小。同时基于AVL-fire软件进行发动机进气与压缩过程三维CFD分析,分析结果表明:对燃烧特性的影响不能仅靠瞬态滚流比和缸内平均湍动能进行判断,真正影响燃烧的是火花塞附近湍动能的变化,即发动机换气与压缩过程对燃烧特性的影响来自压缩上止点火花塞附近的湍动能。     

甲醇发动机缸内EGR分层的研究

针对一台具有螺旋进气道的点火式甲醇发动机,采用进气道加装EGR管的方式实现了EGR和新鲜充量的分开引入。应用CFD仿真软件Fire模拟了不同EGR通入时间、不同燃烧室凹坑形状等对EGR分层的影响。结果显示,加装EGR管能够实现EGR的分层,EGR的通入时长和燃烧室凹坑形状都对EGR的分层产生影响。当燃烧室凹坑形状为浅圆柱型、新鲜充量的通入压力为100kPa、EGR通入压力为160kPa时,在300°BTDC(压缩上止点前)停止通入,能够形成火花塞周围EGR浓度低、越远离燃烧室顶部EGR浓度越高的EGR分层结构。同时,在保证EGR率和燃油消耗量相同条件下,通过改变点火提前角,分析分层EGR和均质EGR对甲醇发动机缸内燃烧的影响。分层EGR能有效地提高缸压峰值、缩短燃烧滞燃期、提前燃烧始点,有利于发动机缸内燃烧的改善。     

喷油器参数对船用低速机燃烧特性 影响的仿真研究

对某船用低速二冲程柴油机在不同喷油器参数下的喷油及燃烧过程进行了三维CFD性能仿真分析。结果表明：随着喷油器喷孔数量增多,燃油蒸发雾化质量更好,进而对燃烧过程和排放物生成产生明显影响;同样,随着喷油器喷孔夹角减小,燃油蒸汽分布的区域更广,进而对燃烧过程和排放物生成产生明显影响;研究能够为喷油器参数优化,燃油喷射系统改进提供参考。     

汽车节能技术与应用实例

受石油危机的影响,汽车节能工作受到了世界各国的普遍重视。本文首先分析了影响油耗的主要因素,并从发动机节能技术和整车的节能原理与技术方面介绍了汽车节能减排技术,并就发动机节能技术中的稀燃技术和发动机增压技术做了具体的分析与探讨,并举出实例。     

海上油气平台可燃气体探测器的布置、选型、安装和维护

在海上平台油气生产中，有效地利用可燃气体探测器来检测海上生产设备的泄漏状况，并及时采取相应的保护措施，是保证油气生产和人身安全的重要一环。但目前对海上油气平台可燃气体探测器工程设计的系统研究却鲜见于国内外的工程文献中，针对这一现状，在研究国内外现有规范和标准以及工程设计经验的基础上，通过分析可能产生泄漏的工艺设备、可燃气体性质和外部环境等因素来确定可燃气体探测器的物理位置，同时完成可燃气体探测器的选型，并根据现场的工作环境合理安装可燃气体探测器，最后总结探测器使用维护中需要注意的问题。对可燃气体探测器的布置、选型、安装和维护的系统总结和分析研究为海上平台火气系统的设计提供了技术支持，从而进一步保障海上油气平台的生产安全。     

双级轴向旋流非预混燃烧和流动特性分析

本文对双级轴向旋流非预混燃烧器进行了研究,应用CFD数值模拟,探索一级旋流器叶片安装角度和文氏管扩张角的角度变化对燃烧特性和温度场以及流动场的影响规律。研究结果表明：文氏管扩张角依次增大过程中,燃烧室内中心回流区中心前移,旋转射流径向扩张角增大;CH4的浓度沿径向分布更加均匀,降低了燃烧室内最高温度。此外在五种不同文氏管角度和一级旋流器叶片安装角度的结构条件下燃烧室中外回流区域温度均低于内回流区域温度。在一级旋流器叶片安装角为55°、二级旋流器叶片安装角为35°时,燃烧器出现回火现象。     

Improving the physics of a coupled physical–biogeochemical model of the North Atlantic through data assimilation: Impact on the ecosystem

Several studies on coupled physical–biogeochemical models have shown that major deficiencies in the biogeochemical fields arise from the deficiencies in the physical flow fields. This paper examines the improvement of the physics through data assimilation, and the subsequent impact on the ecosystem response in a coupled model of the North Atlantic. Sea surface temperature and sea surface height data are assimilated with a sequential method based on the SEEK filter adapted to the coupling needs. The model domain covers the Atlantic from 20°S to 70°N at eddy-permitting resolution. The biogeochemical model is a NPZD-DOM model based on the P3ZD formulation. The results of an annual assimilated simulation are compared with an annual free simulation.With assimilation, the representation of the mixed layer depth is significantly improved in mid latitudes, even though the mixed layer depth is generally overestimated compared to the observations. The representation of the mean and variance of the currents is also significantly improved.The nutrient input in the euphotic zone is used to assess the data assimilation impact on the ecosystem. Data assimilation results in a 50% reduction of the input due to vertical mixing in mid-latitudes, and in a four- to six-fold increase of the advective fluxes in mid-latitudes and subtropics. Averaged zonally, the net impact is a threefold increase for the subtropical gyre, and a moderate (20–30%) decrease at mid and high latitudes.Surface chlorophyll concentration increases along the subtropical gyre borders, but little changes are detected at mid and high latitudes. An increase of the primary production appears along the Gulf Stream path, but it represents only 12% on average for mid and high latitudes. In the subtropical gyre centre, primary production is augmented but stays underestimated (20% of observations). These experiments show the benefits of physical data assimilation in coupled physical–biogeochemical applications.     

微型燃气轮机圆筒形燃烧室内三维冷态流动数值模拟

对一个复杂的Allied Signal75kw微型燃气轮机筒形燃烧室应用CATIA软件进行实体建模,采用RNGk-ε湍流模型,应用FLUENT软件进行了三维冷态流场的数值模拟研究.计算结果很好地反映了燃烧室旋流和火焰筒壁空气掺混射流对燃烧室内流场分布有着重要的影响,为进一步优化燃烧室的结构设计、改善流场结构和开展燃烧室热态流场的数值模拟奠定了基础.     

我国内燃发电机组行业发展概况及趋势

对我国内燃发电机组行业发展情况进行了回顾,对企业分布、产品发展、进出口数据进行了简要分析,提出了今后市场拓展方向.