烃类添加剂改善M100甲醇发动机冷起动的试验研究

针对M 100甲醇发动机在低温环境下起动困难的问题,在M 100甲醇中添加烃类添加剂,改善甲醇发动机的低温起动性能.按体积比在M 100甲醇中分别添加15%汽油、8.5%异戊烷、10%石油醚作为添加剂,采用试验的方法测量了-20℃,-10℃,0℃三种环境温度下,甲醇发动机的起动性能.结果表明:甲醇中添加15%的汽油、8.5%的异戊烷、10%的石油醚,-20℃时M 100甲醇发动机可以正常起动,起动时间小于3.5 s,在-10℃时起动时间小于2.5s,在0℃时起动时间小于1.5s;环境温度为-10℃时,增大首循环喷射脉宽有利于缩短起动时间,首循环喷射脉宽从110 m s增大到130 m s,添加上述比例添加剂后,M 100甲醇发动机的起动时间分别缩短0.2s,0.2s,0.05s.     

埋地燃气管道带压开孔技术应用

埋地管道铺建时预留的分支管道接口不合适,需要在管道带压正常运行的状态下进行开孔施工.介绍了埋地燃气管道带压开孔技术的专用设备组成、操作方法、步骤和技术要点.实践证明:这项带压开孔技术的应用会更加广泛.     

Measurement of hydrocarbon and carbon monoxide emissions during the starting of automotive DI Diesel engines

Most of hydrocarbon (HC) and carbon monoxide (CO) emissions from automotive DI Diesel engines are produced during the engine warm-up period and are primarily caused by difficulties in obtaining stable and efficient combustion under these conditions. Furthermore, the contribution of engine starting to these emissions is not negligible; since this operating condition is highly unfavorable for the combustion progress. Additionally, the catalytic converter is ineffective due to the low engine temperature. In conjunction with adequate engine settings (fuel injection and fresh air control), either the glow plugs or the intake air heater are activated during a portion of the engine warm-up period, so that a nominal engine temperatures is reached faster, and the impact of these difficulties is minimized. Measurement of gaseous pollutants during engine warm-up is currently possible with detectors used in standard exhaust gas analyzers (EGA), which have response times well-suited for sampling at such transient conditions. However, these devices are not suitable for the measurement of exhaust emissions produced during extremely short time intervals, such as engine starting. Herein, we present a methodology for the measurement of the cumulative pollutant emissions during the starting phase of passenger car DI Diesel engines, with the goal of overcoming this limitation by taking advantage of standard detectors. In the proposed method, a warm canister is filled with an exhaust gas sample at constant volumetric flow, during a time period that depends on the engine starting time; the gas concentration in the canister is later evaluated with a standard EGA. When compared with direct pollutant measurements performed with a state-of-art EGA, the proposed procedure was found to be more sensitive to combustion changes and provided more reliable data.     

电厂用柴油发电机组的电气控制

针对电厂用柴油发电机组应急、快速启动、可靠性高的特点,结合实际调试应用中遇到的问题,依据技术协议要求,提出一种功能要求全面的典型设计思路,为今后电厂用柴油发电机组的电气控制设计提供一定的依据。     

单体泵柴油机起动过程控制策略研究

为减小柴油机起动过程中的磨损,同时兼顾排放,设计了基于Ramp控制的单体泵柴油机起动控制策略。试验表明,选用合适的初始喷油量、起动Ramp数值和起动供油提前角等起动参数后,可实现单体泵柴油机可靠起动,烟度可控制在0.5 m-1以内。     

基于Java Web Start的铁路调度查询系统研究

论述了铁路局运输调度查询系统的重要性,介绍了Java Web Start技术的原理及优点,并以铁路局实时运行图查询系统为例说明了其具体实现方法,详细说明了该技术对于环境的要求,并给出了设置Web站点的具体步骤.同时,重点论述了JNLP文件的编写方法和.jar文件的签名方法.使用Java Web Start技术可以方便地实现实时列车运行图的查询,可以为铁路局相关运输生产管理部门提供准确、及时完备的列车运行信息,为合理组织各项运输作业提供科学的依据.     

机械传动车辆起步及连续加速过程性能仿真研究

基于部件的工作原理或试验结果,在Matlab/Simulink环境下,建立了某型机械传动车辆动力传动系统的模块化动态仿真模型,采用该仿真模型模拟了在不同驾驶模式下,车辆起步及连续加速过程中的动力性和燃油经济性。     

轿车冷起动/暖机工况排放优化

根据欧3/欧4排放法规的要求,对捷达/宝来轿车装备的1.6L2VRSH型发动机冷起动/暖机工况排放进行了优化。通过采取合理选择催化转换器、空燃比标定优化、调整点火提前角、加装二次空气系统等措施,可使1.6L2VRSH型发动机分别满足欧3、欧4排放标准。     

城市轨道交通供电系统35 kV母联主动式自投方案研究

分析了目前城市轨道交通供电系统中三种35 kV母联自投启动方案的优缺点.提出了基于保护跳闸信号的主动式自投启动方案,缩短了自投的动作时间,使自投范围更加准确,且在变电所反向供电运行方式下仍可准确动作.     

基于运用逆流程工艺的港口节能技术分析

节能技术多种多样,改变港口工作流程,依靠精准的控制实现逆流程工作也是一种很好的尝试,通过理论分析与实际运行,结果表明,节能效果显著。