在用轻型汽油车的净化技术和使用状况

介绍了为达到全国即将实施的相当于欧Ⅰ的排放标准 ,对在用轻型汽油车进行改造的几种技术方案 ,为我国大量的在用轻型汽油车如何达到排放法规的要求提供借鉴。     

分车型实施国Ⅳ排放标准的建议

CVEC建议重型柴油车推迟半年实施；轻型柴油车适当顺延；轻型汽油车实施国Ⅳ可按期实施；重型汽油车可提前一年实施。     

扬州实施国IV标准 二手车影响大

从2012年5月1日起，未上牌轻型汽油车和外省市转入扬州市的轻型汽油车，必须达到国IV排放控制要求。否则不予办理登记手续。     

基于PCA-GRU的轻型汽油车NOx排放预测

为建立一种轻型汽油车NOx排放预测模型,在昆明市内采用便携式车载排放测试系统（Portable Emission Measurement System,PEMS)对一辆轻型汽油车进行实际行驶污染物排放（Real Drive Emission,RDE）测试;利用主成分分析算法（Principal Component Analysis,PCA）对影响轻型汽油车排放的特征参数进行降维,将降维后的数据作为门控循环单元神经网络（Gated Recurrent Unit,GRU）的输入,建立基于PCA-GRU的排放预测模型,对轻型汽油车的NOx的排放量进行瞬时预测。结果表明,PCA-GRU模型对NOx的预测结果的平均绝对误差为0.133mg/s,绝对系数为0.88,相比于单一的GRU模型,分别提高了42.4%和8.6%。该排放预测模型可以实现对轻型汽油车NOx排放较准确的预测,具有一定的工程价值。     

轻型汽油车适用国Ⅲ法规的蒸发排放控制与分析

介绍了国Ⅲ排放法规,以大量的试验数据为依据,阐述了我国现阶段轻型汽油车执行当前排放法规的现状。通过分析整车、零部件以及外部因素对整车蒸发排放的影响,确定了轻型汽油车蒸发排放物的来源、分布以及控制方法。通过炭罐-油箱系统进行了车辆蒸发试验,确定了HC生成的机理和浓度变化过程,为进一步的匹配工作奠定了基础。     

中国在用轻型汽油车排放现状调查与分析

对我国市场上133辆在用轻型汽油车进行了工况法和双怠速排放及市售燃油质量调查与分析,并提出了对在用车排放管理的几点建议。     

最后的2座“堡垒”——柴油车、重型汽油车全国实施国Ⅳ在即

按照国家有关汽车排放标准和内燃机燃料类型,汽车可分为燃气汽车(点燃式)、重型柴油车(压燃式)、轻型柴油车(压燃式)、重型汽油车(点燃式)、轻型汽油车(点燃式)等5类(重、轻型之分是以汽车总质量3.5 t为界),而双燃料汽车、混合动力汽车和纯电动汽车等则是非单一燃料或非内燃机类型. 按照环境保护部早已作出的2次行政调整,全国销售柴油汽车实施国IV标准的时间是2013年7月1日.在此之前,单一燃料汽车中,全国汽车销售未实施国Ⅳ标准的,就剩下柴油车和重型汽油车这2座"堡垒"了,而燃气汽车、轻型汽油车已于2011年内实施.     

电喷系统控制对轻型汽油车油耗的影响

面对日益严格的油耗及排放法规要求,整车电喷系统控制需要兼顾排放性、经济性、动力性和驾驶性.本文选取一辆轻型汽油车,搭载1.5L自然吸气发动机,通过调整电喷系统控制数据,进行WLTC(国六排放循环)油耗试验,研究电喷系统控制数据对轻型汽油车油耗的影响.     

汽油车OBD在用核心技术及其发展方向

介绍了汽油车OBD的失火监测技术、三元催化器劣化诊断技术和氧传感器故障诊断技术等三大在用核心技术。结合OBD的三大核心技术,对美国OBDⅡ和欧盟EOBD技术的发展历程进行了分析,在此基础上阐述了轻型汽油车OBD技术的发展方向。     

轻型汽油车海拔环境排放和油耗特性的研究

海拔高度增加会导致空气密度减小,氧含量下降而使发动机的燃烧变差,污染物排放增加,整车油耗也会发生变化。因此有必要对不同海拔地区的汽油车排放及油耗情况进行研究,目前国内对相关领域的研究还处于空白。本文利用我中心海拔环境仓对两辆轻型汽油车进行各海拔高度环境下的排放及油耗试验,并对其在相应条件下排放污染物的排放量和油耗情况进行分析和比较,最终得出轻型汽油车的排放及油耗随海拔高度的变化规律。     

国产轻型汽油车蒸发排放现状与分析

本文简述了汽油车污染物的来源及控制汽车车蒸发排放的必要性，比较分析了常用的两种蒸发排放测量方法，基于大量测量结果说明了国产轻型车蒸发排放现状，试验分析了蒸发排放影响因素。     

天津市在用车辆排放车载测试试验研究

车载排放测试设备OBS-2200先在实验室整车转鼓试验台上与定容采样系统CVS进行对比试验,验证了其对各项排气污染物测量的有效性后,装在选出的有代表性的74辆轻型汽油车上,沿选取的天津市区典型的行驶路线,对车辆的道路排放进行实时测试。依据获取的测试数据,分析了在用车辆的排放现状与车辆状况(采用的排放控制技术、车龄和行驶里程等)之间的关系;并对天津市在用车辆的排放特征进行了分析评估。     

Experimental investigation and comparison of nanoparticle emission characteristics in light-duty vehicles for two different fuels

In recent years, particle number emissions rather than particulate mass emissions in automotive engines have become the subject with controversial discussions. Recent results from studies of health effects imply that it is possible that particulate mass does not properly correlate with the variety of health effects attributed to engine exhaust. The concern is now focusing on nano-sized particles emitted from I. C. engines. In this study, particulate mass and particle number concentration emitted from light-duty vehicles were investigated for a better understanding of the characteristics of the engine PM from different types of fuels, such as gasoline and diesel fuel. Engine nano-particle mass and size distributions of four test vehicles were measured by a condensation particle counter system, which is recommended by the particle measurement program in Europe (PMP), at the end of a dilution tunnel along a NEDC test mode on a chassis dynamometer. We found that particle number concentrations of diesel passenger vehicles with DPF system are lower than gasoline passenger vehicles, but PM mass has some similar values. However, in diesel vehicles with DPF system, PM mass and particle number concentrations were greatly influenced by PM regeneration. Particle emissions in light-duty vehicles emitted about 90% at the ECE15 cycle in NEDC test mode, regardless of vehicle fuel type. Particle emissions at the early cold condition of engine were highly emitted in the test mode.     

轻型汽车CO2排放测量不确定度评定

CO₂排放是汽车污染物排放检测的一项重要技术指标,它表征的是汽车排出污染物的多少和车辆能耗高低的参考标准之一,用以控制汽车使用中产生的污染物排放量,避免对环境产生损害。按照GB 18352.6-2016《轻型汽车污染物排放限值及测量方法(中国第六阶段)》的规定使用全球统一的轻型车测试循环工况进行常温下冷启动后污染物排放试验,并对测量结果进行不确定度评定。文章阐述了轻型汽油车CO₂排放测试所用的测试原理、法规工况曲线、测试设备、数学模型等,通过分析影响试验结果的各因素来源,综合计算得出轻型车CO₂排放测试结果的扩展不确定度和相对扩展不确定度。     

轻型汽油车国Ⅲ与国Ⅱ法规蒸发污染相关性分析

通过对大量的试验数据进行统计和分析,确定现阶段我国轻型汽油车适用国Ⅲ法规的蒸发排放现状。同时通过比较国Ⅱ和国Ⅲ试验数据,计算出2个排放水平之间的差异和数值关系。最后展望更加严格的排放法规以及应对措施。     

Effects of gasoline, diesel, LPG, and low-carbon fuels and various certification modes on nanoparticle emission characteristics in light-duty vehicles

This study was focused on experimental comparisons of the effects of various vehicle certification modes on particle emission characteristics of light-duty vehicles with gasoline, diesel, LPG, and low-carbon fuels such as bio-diesel, bioethanol, and compressed natural gas, respectively. The particulate matter from various fueled vehicles was analyzed with the golden particle measurement system recommended by the particle measurement programme, which consists of CVS, a particle number counter, and particle number diluters. To verify particle number and size distribution characteristics, various vehicle emission certification modes such as NEDC, FTP-75, and HWFET were compared to evaluate particle formation with both CPC and DMS500. The formation of particles was highly dependent on vehicle speed and load conditions for each mode. In particular, the particle numbers of conventional fuels and low-carbon fuels sharply increased during cold start, fast transient acceleration, and high-load operation phases of the vehicle emission tests. A diesel vehicle fitted with a particulate filter showed substantial reduction of particulate matter with a number concentration equivalent to gasoline and LPG fuel. Moreover, bio-fuels and natural gas have the potential to reduce the particulate emissions with the help of clean combustion and low-carbon fuel quality compared to non-DPF diesel-fueled vehicles.     

Exhaust nanoparticle emissions from internal combustion engines: A review

This paper reviews the particle emissions formed during the combustion process in spark ignition and diesel engine. Proposed legislation in Europe and California will impose a particle number requirement for GDI (gasoline direct injection) vehicles and will introduce the Euro 6 and LEV-III emission standards. More careful optimization for reducing particulate emission on engine hardware, fuel system, and control strategy to reduce particulate emissions will be required during cold start and warm-up phases. Because The diesel combustion inherently produces significant amounts of PM as a result of incomplete combustion around individual fuel droplets in the combustion zone, much attention has been paid to reducing particle emissions through electronic engine control, high pressure injection systems, combustion chamber design, and exhaust after-treatment technologies. In this paper, recent research and development trends to reduce the particle emissions from internal combustion engines are summarized, with a focus on PMP activity in EU, CARB and SAE papers and including both state-of-the-art light-duty vehicles and heavy-duty engines.     

轻型汽车实际行驶排放评估方法研究

按照轻型汽车实际行驶排放测试流程,采用便携式排放测试系统测量3辆满足《轻型汽车污染物排放限值及测量方法(中国第五阶段)》要求的轻型汽车实际行驶排放,并使用欧盟提出的移动平均窗口法对排放数据进行处理。结果表明:冷起动阶段的CO,NO_x和PN排放占整个试验总排放的比例分别为69.9%,23.1%和68.8%。将冷起动阶段排放纳入计算时,CO,NO_x和PN的排放结果分别比剔除冷起动阶段排放的结果高19.5%,4.3%和16.3%。温和驾驶时车辆CO_2排放较低,导致过多窗口无法落入正常区域,窗口不能满足正常性要求。欧盟提出的移动平均窗口法不适合直接用于评估中国轻型汽车实际行驶排放,对基本公差tol1进行修正,随着tol1的增加,落入正常区域的窗口随之增多,试验通过正常性要求的比例也随之增大,但tol1的修正会带来巨大的标定工作量。