COMPOSITIVE EMISSION CONTROL SYSTEM OF GASOLINE VEHICLE

The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite （S.I.） engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.

Dynamic emission characteristics and control strategies of air pollutants from motor vehicles in downtown Beijing,China

This study combined the real-time monitoring and investigation of traffic flows to comprehensively analyze the road traffic flow and vehicle structure in downtown Beijing.A dynamic emission inventory of motor vehicle air pollutants in downtown Beijing in 2021 was established,and the impact of these emissions on air quality was simulated and quantified,and different emission reduction control scenarios were proposed to evaluate their environmental improvement effects and explore measures to mitigate the impact of pollution emissions.The results show that the high traffic flow and the structure of the motor vehicle emissions in downtown Beijing are the main causes of severe motor vehicle pollution.Monitoring data shows that traffic flow in central Beijing is dominated by small passenger vehicles,while the vehicle mix is better than in other regions,with 72.0%of vehicles meeting"National V"or higher emission standards.However,to achieve higher air quality goals,further reducing vehicle emissions is necessary.Based on dynamic traffic flow,the average daily emissions of nitrogen oxides(NOX),particulate matters(PM_(2.5))and volatile organic compounds(VOC)from motor vehicles in central Beijing are 17.7 tons,0.6 tons and 14.0 tons,respectively,accounting for 23.0%of the city’s average daily motor vehicle emissions.If a zero-emission zone for motor vehicles were implemented in central Beijing,the annual average emission level of pollutants will be reduced by 10.4%to 21.0%.The designation of ultra-low emission zones for motor vehicles could be effective in improving the air quality in the center of Beijing.

Advances in emission control of diesel vehicles in China

Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region

The Yangtze River Delta（YRD） region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality.Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants（e.g.,CO,HC and PM_（2.5）） in the YRD region.Even in Shanghai,where the emission control implemented are more stringent than in Jiangsu and Zhejiang,we observed little to no reduction in NOx emissions from 2000 to 2010.Emission-reduction targets for HC,NOx and PM_（2.5） are determined using a response surface modeling tool for better air quality.We design city-specific emission control strategies for three vehicle-populated cities in the YRD region：Shanghai and Nanjing and Wuxi in Jiangsu.Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards,the limitation of vehicle population and usage,and the scrappage of older vehicles is applied,Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020.Therefore,additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles.

A Brief Account of Domestic Vehicle Diesel Engines and Their Emission Control

Ⅰ. Briefing domestic vehicle diesel engines Before the 1970s, domestic vehicle diesel engines were mainly applied to heavy vehicles, while medium and light vehicles were powered chiefly with gasoline engines.

Multi-process and multi-pollutant control technology for ultra-low emissions in the iron and steel industry

The iron and steel industry is not only an important foundation of the national economy,but also the largest source of industrial air pollution.Due to the current status of emissions in the iron and steel industry,ultra-low pollutant emission control technology has been researched and developed.Liquid-phase proportion control technology has been developed for magnesian fluxed pellets,and a blast furnace smelting demonstration project has been established to use a high proportion of fluxed pellets(80%)for the first time in China to realize source emission reduction of SO_(2)and NO_(x).Based on the characteristics of high NO_(x)concentrations and the coexistence of multiple pollutants in coke oven flue gas,low-NO_(x)combustion coupled with multi-pollutant cooperative control technology with activated carbon was developed to achieve efficient removal of multiple pollutants and resource utilization of sulfur.Based on the characteristics of co-existing multiple pollutants in pellet flue gas,selective non-catalytic reduction(SNCR)coupled with ozone oxidation and spray drying adsorption(SDA)was developed,which significantly reduces the operating cost of the system.In the light of the high humidity and high alkalinity in flue gas,filter materials with high humidity resistance and corrosion resistance were manufactured,and an integrated pre-charged bag dust collector device was developed,which realized ultralow emission of fine particles and reduced filtration resistance and energy consumption in the system.Through source emission reduction,process control and end-treatment technologies,five demonstration projects were built,providing a full set of technical solutions for ultra-low emissions of dust,SO_(2),NO_(x),SO_(3),mercury and other pollutants,and offering technical support for the green development of the iron and steel industry.

An optimal energy management development for various configuration of plug-in and hybrid electric vehicle

Due to soaring fuel prices and environmental concerns, hybrid electric vehicle(HEV) technology attracts more attentions in last decade. Energy management system, configuration of HEV and traffic conditions are the main factors which affect HEV's fuel consumption, emission and performance. Therefore, optimal management of the energy components is a key element for the success of a HEV. An optimal energy management system is developed for HEV based on genetic algorithm. Then, different powertrain system component combinations effects are investigated in various driving cycles. HEV simulation results are compared for default rule-based, fuzzy and GA-fuzzy controllers by using ADVISOR. The results indicate the effectiveness of proposed optimal controller over real world driving cycles. Also, an optimal powertrain configuration to improve fuel consumption and emission efficiency is proposed for each driving condition. Finally, the effects of batteries in initial state of charge and hybridization factor are investigated on HEV performance to evaluate fuel consumption and emissions. Fuel consumption average reduction of about 14% is obtained for optimal configuration data in contrast to default configuration. Also results indicate that proposed controller has reduced emission of about 10% in various traffic conditions.

A Study of Smog Issues and PM_2.5Pollutant Control Strategies in China

The increased occurrence of smoggy days in major Chinese cities is of major concern to the general public. This paper explores the major sources of PM2.5 pollutants, a key contributor to the smog in Beijing, one of China’s largest cities. Evidence indicates that the secondary PM2.5 particles formed through NOx, SOx, NH3, VOCs, etc. have a strong impact on human health. As a result, PM2.5 pollution control should not simply focus on controlling particulate emission, but should involve adopting an integrated multi-pollutant control strategy. In addition to identifying the major sources of PM2.5, this paper explores its impact on environmental and human health. Although the intention of this research is not to provide solutions for reducing PM2.5 pollution, the paper analyzes the United States’ experience with establishing PM2.5 standards and mandates. Specifically, this paper focuses on the air quality control strategies adopted in California since the 1940s and draws parallels with present-day China. The research suggests that adequate government regulation, public awareness, regional collaboration and industrial compliance are keys to successfully controlling PM2.5 pollution.

Environmental consequences of an ultra-low emission retrofit in coal-fired power plants from a life cycle perspective

To make coal-fired power generation more environmentally friendly,China has initiated a series of ultra-low emission ret-rofits to the air pollution control(APC)system of the existing power plants.In this study,a life cycle assessment(LCA)is conducted to analyze the environmental net benefits for the typical ultra-low emission retrofit of a 1000 MW power plant.The key processes,substances,and APC devices are verified and discussed.The results confirm that the retrofit effectively decreases the environmental stress of acidification potential(AP),eutrophication potential(EP),and photochemical ozone creation potential(POCP)by 69%-79%,which can be attributed to significantly reduced emissions at the stack.However,the retrofit has also increased other impact categories by 24%-79%,primarily due to the consumption of additional elec-tricity and adsorbents.The retrofit of selective catalytic reduction,electrostatic precipitator(ESP),and wet limestone flue gas desulfurization devices has a dominant effect on the impacts of EP,human toxicity potential(HTP),and AP.A newly installed wet ESP shows some environmental benefits(only for AP),but causes considerable burdens,in particular for the investigated impact categories global warming potential(GWP),marine aquatic ecotoxicity(MAETP),and abiotic depletion fossil(ADP fossil).The obtained results indicate that the hidden environmental consequences,which are associated with the production of energy and materials,need to be examined more comprehensively to inform the development of ultra-low emission technologies and strategies effectively.

Air pollution and its control in China

The rapid growth of China’s economy has led to severe air pollution characterized by acid rain,severe pollu-tion in cities,and regional air pollution.High concentrations are found for various pollutants such as sulfur dioxides(SO2),nitrogen oxides(NOx),and fine particulates.Great efforts have thus been undertaken for the control of air pollution in the country.This paper discusses the development and application of appropriate technologies for reducing the major pollutants produced by coal and vehicles,and investi-gates air quality modeling as an important support for policy-making.

基于实时交通流的上海市机动车碳污同源排放清单

为满足交通碳污减排政策多样化、差别化和精细化发展需求,扩大交通排放测算范围、提高测算准确度和时空分辨力,提出了一种基于实时交通流的高时空分辨力机动车碳污同源排放清单构建方法,综合交通模型、IVE模型和相关算法建立了覆盖上海全市的机动车碳污同源排放清单。结果显示,二氧化碳、氮氧化物周排放规律相近,呈现出明显的周末低工作日高的特征;二氧化碳分时变化规律呈现明显的双峰,而氮氧化物受重型车影响,峰值出现在夜间;由于各车型的碳污分担率不同且活动区域不同造成了上海市机动车二氧化碳和氮氧化物排放的空间分布差异明显;碳污同源排放清单中,NOx、PM、CO、VOCs、CO_(2)的月均排放量分别为5160t、440t、1.7×10^(4)t、732t和2.46×10^(6)t;排放分担率表明,NOx、PM等污染物主要来自重货车及大货车排放;CO、VOCs和CO_(2)排放来源以小客车排放占比最高。

区块链技术在能源互联网中的应用研究进展

随着国家的可持续发展战略,能源互联网成为继智能电网之后能源领域的一个重要发展方向。区块链技术因其去中心化、匿名、可追溯等特性受到人们的广泛关注,为能源互联网的发展提供了新方案。因此,区块链技术在构建能源互联网中发挥着重要作用。全面介绍了区块链技术在电网分散存储与控制、智能电网中的点对点(peer-to-peer, P2P)交易、电动汽车、碳排放交易4个方面的应用与部署。与此同时,还阐述了区块链技术在能源互联网应用过程中所面临的挑战并对未来的发展趋势进行了展望。

基于生态驾驶的智能网联汽车协同跟车模型研究

为提高道路通行能力、减少能源消耗,文章介绍了一种基于智能网联汽车生态驾驶的协同跟车模型。该协同跟车模型由感知层、决策层和控制层3个层级组成,控制策略是将车辆动力学与无线通信技术相结合,在模拟的复杂交通环境中实现感知、控制和获取周围信息,集成了以最小化驾驶间距为模型的预测控制(MPC)策略,以改善交通流的可持续性。生态驾驶控制器的性能是通过车辆自身的速度和加速度2个状态量进行燃油消耗和排放量的评估来实现。最后,验证了控制器的动态特性具体体现在3个方面:跟车行为、燃油效率提高及减少二氧化碳排放,所提出的控制器能够有效地减少跟车过程中的燃油消耗和排放。

轻型汽油车排放控制故障诊断方法及离线诊断技术研究

排放控制故障是轻型汽油车常见故障,影响行车舒适性,也会加快车辆老化速度,带来安全方面的威胁、隐患。基于此,首先分析了轻型汽油车排放控制故障以及其原因,在此基础上,探讨了相关故障的诊断方法以及离线诊断技术,并就离线诊断技术原理、作业框架、重点技术进行分析,最后结合模拟实验论述离线诊断技术的工作优势,服务后续相关故障诊断工作。

整车排放测试中不同工况对污染物排放的影响

汽车数量增多使得大量污染物排放增加,从而对环境造成严重影响。这篇文章采用先进测量技术调查了整车在不同测试条件下的排放表现,旨在减少污染物排放。研究详细探讨了城市和高速行驶过程中的典型排放问题,并指出发动机状态、操作情况与周围环境显著影响污染水平。文中介绍了实验设计、数据处理及结果分析方法,从而推导出改善建议。

基于驾驶习惯改善的车辆尾气控制研究

随着全球气候变化问题日益严重,减少尾气排放已成为汽车行业的重要发展方向。本文探讨了不良驾驶行为下车辆尾气的排放情况,通过所得数据建立了不良驾驶行为-排放的回归方程。从所得结果看,所建立方程可较好预测尾气排放情况,并根据预测结果提出驾驶行为的改善措施。

我国机动车排放污染防治对策研究

随着我国经济建设的有效推进,人们生活水平日益提升,机动车已成为必不可少的代步工具,也是人们生产生活的得力助手。然而,随着机动车数量的增加,尾气排放问题日益严重,移动源污染已成为我国大中城市空气污染的重要来源,不利于社会的可持续发展。基于此,对机动车排放污染防治对策展开研究,分析机动车排放造成严重污染的原因,选择先进的技术手段防治机动车污染排放。

低速货车的污染物排放特性

为分析实际道路行驶时低速载货汽车的排放特征,该研究利用车载测试系统(portable emission measurement system,PEMS)在国道和乡村道上对6辆低速货车的污染物排放进行了测试,结果表明:不论在国道还是在乡村道上,污染物排放速率与车速的变化密切相关。乡村道上车辆的行驶速度变化较多,各污染物瞬时排放速率也呈现剧烈的波动。在国道和乡村道上,低速载货汽车匀速工况的比例最高,平均比例分别为68.33%和63.77%。在2种道路条件下,4种污染物平均排放因子均为加速行驶模式下最高,匀速次之,减速模式下最低。CO在加速模式下的平均排放因子分别是匀速和减速模式下的1.86和2.30倍;HC在加速模式下的平均排放因子分别是匀速和减速模式下的1.32和1.42倍。对于NOx,加速模式下的平均排放因子分别是匀速和减速模式下排放因子的1.57和3.09倍。而对于PM,加速模式下的平均排放因子分别是匀速和减速模式下排放因子的1.22和1.39倍。颗粒物粒径分布结果表明,2种道路颗粒物粒径分布规律类似。但在乡村道上颗粒物数量浓度高于国道上颗粒物数量浓度,平均高约32.0%。该研究成果为低速载货汽车的排放控制提供了技术参考。

基于机动车排放的自适应信号控制模型

从减少交叉口机动车排放量的角度,分析了信号控制对机动车排放影响因素的作用机理,阐述了信号配时–行驶工况–机动车排放三者之间的关系;根据机动车行驶工况变化对排放的影响,建立了车辆完全停车、不完全停车以及不停车3种状态下的机动车排放计算模型;以交叉口车均排放增加量最小为优化目标,确定了信号配时方案的优化方法.以长春市某典型信号交叉口实测数据进行模型验证,结果表明交叉口机动车排放量降低了6.43%.

基于遗传算法的交叉口信号控制多目标优化

从城市交叉口的通行效益、环境保护两方面出发,综合考虑车辆延误、排队长度、尾气排放量三个性能指标,以配时参数为优化变量建立了平面交叉口信号控制多目标优化模型,其权重系数与环境污染程度有关;然后采用遗传算法求解该模型,得到最优信号配时方案;最后通过实例分析模型的有效性。实例结果表明,当空气质量良好时,最优配时方案下的车辆延误、排队长度、尾气排放总量比原始信号配时的对应三个指标值分别降低了9.51%、1.21%、6.24%;当环境严重污染时,最优配时方案下的车辆延误、排队长度、尾气排放总量分别降低了7.21%、1.01%、10.24%。可以看出该多目标优化模型不仅提高了交叉口的通行效率,同时降低了车辆的尾气排放。