Driving segment simulation for determination of the most effective driving features for HEV intelligent control

This paper presents a methodological approach for determination of the most effective driving features for hybrid electric vehicle intelligent control, using the driving segment simulation. In this approach, driving data gathering is first performed in real traffic conditions using Advanced Vehicle Locator systems. The vehicle's speed time series are then divided into small segments. Subsequently, 19 driving features are defined for each driving segment, and the influence of the driving features on the vehicle's fuel consumption (FC) and exhaust emissions is investigated, using driving the driving segment simulation. The simulation approach is also verified by experimental test. Finally, the driving features are ranked by a new approach based on the definition of an effectiveness index and a correlation analysis. The results demonstrate that the velocity-dependent driving features such as ‘energy’, ‘mean of velocity’, ‘displacement’ and ‘maximum velocity’ are more effective on vehicle's FC and exhaust emissions. However, because of high dependency between these features, this study suggests independent driving features among the most effective driving features.     

IMO未来燃油标准方案及影响分析

简要介绍了IMO目前正在审议中的MARPOL附则VI关于未来船用燃油标准建议案的情况,分析探讨了IMO未来船用燃油标准将对航运业、炼油业等带来的重大影响。     

The viability of pure vegetable oil as an alternative fuel for large ships

Heavy fuels are likely to remain the dominant fuel source for two-stroke, low-speed diesel engines for large ship propulsion for the next decade or more. There is however, potential for increased use of pure vegetable oils (PVO) as an alternative and, by emitting lower levels of several pollutants, this can help the attainment of Annex VI of the MARPOL 73/78 convention aimed at large ships using fuels with less than 4.5% sulphur or 1.5% sulphur in SO_X emission control areas The use of alternative fuels can also influence the attainment of the Kyoto protocol that requires greenhouse gas emissions to be reduced by 5% by 2010 compared to 1990. This paper analyses the physical and chemical properties of various pure vegetable oils as an alternative to heavy fuel oil for large ship propulsion.     

主机排气阀座脱落和漏水的原因探析

分析某船韩国制造的L28／32A型主机气缸盖排气阀座在运行中脱落和进、排气阀座漏水的故障原因,在此基础上阐述具体的处理方法,并就同类故障的修理提出对策措施。     

暗室静区反射电平计算中的波束修正模型

在微波暗室静区反射电平计算时常采用点源发射模型模拟天线的特性，它适用于低频段或方向性差的天线。但在微波频段，由于天线有较强的方向性而不宜采用点源发射模型。采用菲涅尔一基尔霍夫绕射理论导出了适用微波频段的发射模型。通过分析讨论指出，在暗室的静区反射电平计算时，采用该模型较之点源发射模型而言将更接近实际。     

CNG汽车的试验研究

对58辆改装后的CNG／汽油两用燃料汽车，在相同试验条件下，分别燃用汽油，CNG时的动力性，燃料消一及排放等进行对比试验，可以看出，改装后的CNG汽车其燃用CNG时加速性能与燃用汽油相比下降较大，但燃料消耗量有所下降且怠速排放明显下降，同时，就在试验中存在的问题进行了讨论。     

车用尾气催化剂工作性能的模拟与分析方法

建立了包含催化剂温度特性、空燃比特性和空速特性在内的车用尾气催化剂工作性能模型 ,给出了载体的开口率、内部表面积、排气阻力等性能参数的计算公式 ,并介绍了在实际应用中对催化剂催化性能和耐久性能的分析方法。     

微型汽车发动机尾气污染排放分析

建立了用于模拟车辆实际运行状况的汽油发动机尾气排放实验测试系统,模拟荣光6450B微型车的不同行驶工况,对其主要有害排放物HC、CO、NOx进行采样,并对各排放物与行驶工况相对应的排放趋势及原因进行了分析。分析结果表明,不同行驶工况和行驶状态对HC、CO和NOx的排放影响较大,各行驶工况中,怠速、加速及减速比例越高,各有害气体的排放越高;当行驶工况匀速比例较高时,排放相对较低。     

排气系统振动噪声特性分析及改进

某微型客车在800-1 900 rpm有明显的"嘟嘟"声及排气噪声偏大。本文采用仿真和试验相结合的方式,分析排气系统的振动、背压、消声器传递损失、尾管噪声、插入损失和功率损失特性。分析结果表明排气尾管发生共振,放大发动机高次谐波分量,是引起本排气噪声问题的主要原因。通过多方案分析比较,确定一合理优化方案,其排气噪声降低1-5dB(A),主驾驶员右耳噪声降低0.5-2.5 dB(A),满足功率损失比、插入损失和背压差标准要求,"嘟嘟"声明显减弱,声品质提高。     

机动车冷启动排放试验研究

在底盘测功机上,采用NEDC循环,对汽油车和柴油车分别在常温和低温环境下冷启动排放进行试验,研究车辆冷启动的排放情况。试验结果表明:常温冷启动状态下,催化器激活之前的排放在整个排放测试循环中所占的比重比较大,其中汽油车的冷启动排放占到整个循环排放量的50%以上,柴油车也达到了20%以上。汽油车低温冷启动下,催化器激活之前排放所占比重超过90%。