Prediction of vehicle CO2 emission and its application to eco-routing navigation

Transportation sector accounts for a large proportion of global greenhouse gas and toxic pollutant emissions. Even though alternative fuel vehicles such as all-electric vehicles will be the best solution in the future, mitigating emissions by existing gasoline vehicles is an alternative countermeasure in the near term. The aim of this study is to predict the vehicle CO₂ emission per kilometer and determine an eco-friendly path that results in minimum CO₂ emissions while satisfying travel time budget. The vehicle CO₂ emission model is derived based on the theory of vehicle dynamics. Particularly, the difficult-to-measure variables are substituted by parameters to be estimated. The model parameters can be estimated by using the current probe vehicle systems. An eco-routing approach combining the weighting method and k-shortest path algorithm is developed to find the optimal path along the Pareto frontier. The vehicle CO₂ emission model and eco-routing approach are validated in a large-scale transportation network in Toyota city, Japan. The relative importance analysis indicates that the average speed has the largest impact on vehicle CO₂ emission. Specifically, the benefit trade-off between CO₂ emission reduction and the travel time buffer is discussed by carrying out sensitivity analysis in a network-wide scale. It is found that the average reduction in CO₂ emissions achieved by the eco-friendly path reaches a maximum of around 11% when the travel time buffer is set to around 10%.     

EGR对重型柴油机性能影响的试验研究

以某带有高压共轨喷射系统和废气涡轮增压系统的直列6缸重型柴油机为试验对象,研究了EGR率对其燃油消耗率、NOx和烟度等排放参数的影响,同时还着重研究了EGR耦合喷射压力和喷射定时参数调整及EGR冷却温度对以上参数的影响。结果表明,EGR能有效改善柴油机NOx排放水平,但会导致经济性下降、碳烟排放增加,也会给HC和CO排放带来负面影响;EGR耦合喷射参数的折中策略改善了消光烟度和(NOx+HC)的排放,同时降低了燃油消耗以及PM和CO的排放;降低EGR温度可提高柴油机的使用性能。     

基于专利分析的氢燃料电池电堆结构研究

氢燃料电池电堆作为氢燃料电池的核心部件,其结构对于氢燃料电池在车辆等领域中稳定可靠的应用具有重要影响。然而目前对于氢燃料电池电堆的研究大多集中在电堆的核心部件自身方面,如膜电极、双极板、扩散层、密封件和端板等,而对于电堆的结构集成方面涉及较少。文章从专利分析的角度对氢燃料电池电堆结构技术进行分析和解读,以期为氢燃料电池电堆结构技术的研发和专利布局带来一些帮助。     

燃油消耗量因素分析在客车购置中的系统应用

随车成品油价格不断上涨,如何降低燃油成本,成为道路运输企业当前的重要课题,一方面从客车产品上找答案,另一方面在驾驶员操作上作文章。本文即从客车百公里燃油消耗量因素分析出发,探讨客车购置中获得良好燃油消耗量的技术条件和要求。     

沥青混凝土路面集料加工性指标研究

沥青混凝土路面发生早期破坏的现象屡见不鲜,路面集料质量管理失控是其主要原因之一。通过对沥青混凝土路面集料加工性指标的研究,在料场管理模式和合同管理方面采取切实可行的措施来确保路面集料质量和稳定供应,可为沥青混凝土路面工程提供质量保证。     

轻质固化粉煤灰回填软土地基路堤工后沉降分析

回填轻质固化粉煤灰可以提高路堤的临界回填高度,在满足路面工后沉降控制指标的基础上．可以取代软基处治,缩短工期,降低工程造价。运用型有限元软件．计算和分析轻质固化粉煤灰作为路堤回填材料的土压力及其表面的沉降变形,并进行轻质固化粉煤灰路基回填的沉降分析和试验段观测,可为固化粉煤灰在软土地基路堤回填工程中的应用提供理论依据。     

Development of a driving cycle for the measurement of fuel consumption and exhaust emissions of automobiles in Bangkok during peak periods

The exhaust emissions and fuel consumption rates of newly registered automobiles in Thailand are currently assessed using the standard driving cycle of the Economic Commission of Europe (ECE). Because of the highly different driving conditions, the assessment results may not reflect realistic amounts of emissions and fuel consumption for vehicles in Bangkok traffic, which is well known for its congestion. The objective of this study is therefore to develop a new driving cycle for vehicles traveling on Bangkok’s main roads during peak traffic hours. This paper first presents the development of a method for selecting representative road routes with traffic conditions that are representative of traffic in Bangkok for conducting real-world driving speed data collection. These real-world data are obtained by driving a car equipped with a speed-time data logger along those selected road routes. Several driving characteristics, including various profiles of microtrips, are analyzed from the collected speed-time data, and a number of target driving parameters are then defined for use as a set of criteria to justify the best driving cycle. A procedure for generating driving cycles from the analyzed real-driving data is also developed, and the method to select the cycle that is most representative of Bangkok traffic is described. Comparisons found in the study show that the target driving parameters of the newly developed driving cycle are much closer to those obtained from the real-world measured data than those calculated from the presently used European drive cycle. This would imply that the obtained driving cycle will produce more realistic results of the emissions and fuel consumption assessment tests for vehicles traveling in Bangkok. The methods developed in this study for route selection and driving cycle construction can easily be adopted by other big cities to develop their own vehicle driving cycles. Furthermore, although the developed methods are for passenger cars, similar approaches can be applied to develop driving cycles for other types of vehicle, such as city buses and pick-up trucks.     

地铁复合式屏蔽门系统火灾特性分析

复合式屏蔽门系统是在全封闭屏蔽门的上方安装组合式电动风阀,并接入车站机电控制系统.当站台发生火灾时,该系统可根据火灾发生在站台端部还是站台中部,有针对性地启动不同火灾模式,既能解决传统站台排烟方案对新规范的适应性问题,也能有效解决一直以来站台中部楼扶梯口排烟困难的问题.通过各地不同类型的车站实测得出,排烟效果较为理想,...     

“通程”号超大型耙吸挖泥船开发设计

阐述了708研究所自主开发设计的国内第一艘超大型挖泥船,采用全通甲板,适用于深、远海作业;泥舱舱容达18374m3,最大挖深可达85m,为目前中国设计建造的最大舱容、最大挖深的深水疏浚工程船;疏浚设备(即:泥泵、水下泵、高压冲水泵等)采用全变频电力驱动,泥舱首次采用箱形泥门形式。