预喷与后喷参数对柴油机排放影响的试验研究

为了探究预喷射与后喷射对柴油机尾气中有害物质的影响,通过高压共轨柴油机台架试验,在不同的预喷与后喷参数下对柴油机尾气中有害物质的排放进行测试.试验结果表明:针对柴油机进行燃油预喷射可有效抑制尾气中NOx的产生,但烟度值有所升高;加入燃油后喷射后,NOx与烟度值均呈现减小趋势;随着近后喷射燃油喷射量的增加,尾气中烟度值呈先减小后增加趋势,NOx排放的变化无明显规律;根据试验数据确定了YN33发动机在各个工况下的最优排放点,在该排放点,尾气中各种有害物质排放均有所下降.     

直喷汽油车市区工况低温排气污染物及颗粒物排放研究

对汽油车在低温情况下市区工况尾气污染物和颗粒物排放进行测试,并与常温下市区排放进行比较,得到低温对尾气污染物和颗粒污染物排放的影响,得出结论:在低温市区工况,车辆尾气排放和颗粒物排放呈倍增加,冬季减少车辆在市区的短途出行及采取其他清洁出行措施是改善城市空气质量的有效手段。     

奔驰欧Ⅴ重卡油耗测试

欧洲绝大多数卡车生产商用SCR(尾气催化后处理技术)来满足欧Ⅳ及2009年即将实行的欧Ⅴ尾气排放标准.但是令人难以置信的是,厂商们纷纷声称该技术在满足高尾气排放标准的同时,在欧Ⅲ标准油耗基础上更有5%的燃油节余.为了验证这一说法,我们接受了梅塞德斯·奔驰公司的邀请,对一辆40吨的欧Ⅴ标准牵引车进行燃油消耗水平测试.     

瞬态工况下汽车有害排放物分析

为达到模拟汽车在实际道路上行驶的瞬态工况,文章利用底盘测功机,在不同工况下给汽车加载不同的负荷,并进行测试。通过对瞬态工况下排放试验测试数据的处理和分析,得出了汽车尾气排放中CO,HC,NOx在不同速度和加速度变化时的变化趋势与规律。测试结果表明,在行驶速度较低时,尾气中CO和HC的排放量较大,NOx的排放较小;行驶速度较高时,CO和HC的排放量较小,而NOx的排放较大。     

基于电控单体泵对4D44柴油机的优化研究

为了使传统直列泵柴油机满足国Ⅲ排放法规,在尽量不改变柴油机本体的前提下对燃油、进气和燃烧系统进行了优化。燃油喷射系统采用集成电控单体泵,高压油管长度和喷油器参数进行了优化;优化改进了进气道;重新设计了燃烧室;针对国Ⅲ排放法规测试特点进行了电控参数的优化。通过对整机进行13工况试验测试,表明优化改进后的柴油机排放性能得到明显提高,并达到国Ⅲ排放标准。     

ISG混合动力汽车加速扭矩补偿策略与仿真

针对装用废气涡轮增压共轨柴油机的ISG混合动力汽车急加速时燃油消耗和排放上升的问题,通过采用电机瞬态加速扭矩补偿控制策略,对整车进行加速工况优化,可以在满足整车动力性的同时极大地改善混合动力汽车的燃油经济性,并减少尾气排放。     

机动车道路排放的实时测试系统开发及试验研究

在OEM-2100基础上开发了一种机动车道路排放实时测试系统,并在实际道路上进行了轻型车的实时排放测试。计算了路段排放因子和排放总量,分析了车辆各行驶工况所占时间和排放量比例以及平均排放率,研究了各工况下机动车尾气污染物的贡献率,为准确测定交通流中单车污染物提供一种可行的方法。该测试系统为建立排放模型提供数据依据,对于评价交通控制改进措施和智能交通系统对排放的影响具有重要的意义。     

摩托车燃油蒸发炭罐控制技术研究

针对摩托车国Ⅲ燃油蒸发排放标准要求,以豪豹HB125摩托车为试验样车进行燃油蒸发炭罐控制系统的设计研究。结果表明,所设计的燃油蒸发炭罐控制系统不仅能较大程度地降低燃油蒸发排放水平,满足国Ⅲ燃油蒸发标准要求,其尾气排放也满足国Ⅲ排放标准要求。     

轻型汽油车N_2O排放影响因素的研究

以1辆满足国五排放标准的轻型汽油车为试验样车,以三种不同含硫量的汽油为燃料,分别在FTP75和US06测试循环下,使用全流稀释排放测试系统对车辆N_2O排放的影响因素进行了研究。研究结果表明:测试工况会对车辆的N_2O排放产生影响,在冷起动工况的开始阶段,由于催化剂没有达到正常的工作温度,车辆会产生较多的N_2O排放;无论何种工况,随着燃油硫含量的增加,车辆的N_2O排放呈现上升的趋势;随着车辆里程的不断增加,车辆的N_2O排放存在一定程度的劣化。     

乙醇汽油对摩托车燃油蒸发污染物排放结果影响及原因分析(1)

乙醇汽油作为缓解石油资源短板和改善环境的一种代用燃料,国际和国内在推广乙醇汽油方面也做了很大的努力,汽油中添加一定比例的乙醇之后,可以改善机动车尾气排放,有效改善环境,但机动车使用乙醇汽油对燃油蒸发污染物排放控制系统提出什么要求呢?本文就乙醇汽油对摩托车燃油蒸发污染物排放的影响进行试验,并对其原因进行分析。     

现代汽车的排放控制技术

首先介绍汽车废气成分,然后从技术角度阐述当前汽车业普遍使用的3种排放控制技术：降低燃油消耗、对废气进行处理以及排放性能监测,使读者对现代汽车排放控制有所了解。     

EGR对车用柴油机性能影响的试验研究

结合某废气涡轮增压和高压共轨小型4缸柴油机国Ⅳ排放达标工作,进行了计算机在线实时控制EGR对柴油机性能影响的试验研究,通过试验分析了EGR对NOx、烟度、排气温度、燃油消耗率的影响规律,并对EGR率与喷油提前角的匹配作了进一步的研究。结果表明,为降低柴油机NOx排放,不同工况应采取不同的EGR率;烟度、排气温度、燃油消耗率均随着EGR率的增加而增大;EGR率和喷油提前角应实现良好的匹配,才能保证NOx排放和燃油消耗率都能达到要求,其中小EGR率匹配小喷油提前角,大EGR率匹配大喷油提前角。     

Performance Design of an Exhaust Superheater for Waste Heat Recovery of Construction Equipment

Although fuel cost has been the largest portion of annual operating costs of construction equipment, it is possible to save the energy and reduce cost using fuel economy enhancement technology. In this study, an organic Rankine cycle is applied to an excavator in order to recover waste heat, reproduce it into electrical energy, and consequently reduce the fuel consumption by 10 %. A design process was carried out to develop an exhaust gas superheater that recovers the waste heat from exhaust gas through a composite-dimensional thermal flow analysis. A one-dimensional code was developed to perform a size design for the exhaust gas superheater. The ranges for the major design parameters were determined to satisfy the target of the heat recovery, as well as the pressure drop at both fluid sides. Performance analysis was done through onedimensional design code results, which were compared with three-dimensional CFD analysis. By utilizing a 3D commercial code, the arrangement of the tubes was selected and the working fluid pressure drop was reduced through a detailed layout design. The design procedure was verified by a performance evaluation of the prototype, which yielded only a 7 % tolerance in heat recovery.     

Electromagnetic valve train for gasoline engine exhaust system

Electromagnetic valve train (EMVT) in camless engine offers large potential for both part load fuel economy and high load engine torque. However, it is more difficult to be applied on exhaust system than intake system. Because the gas pressure brings high demands for driving force, especially at high engine speed and full load. Based on the working characters of actuator, a method by increasing the transient currents in windings during valve’s opening motion is suggested to overcome the gas pressure. But this will cause more energy losses and heat. In order to make the EMVT used on exhaust system better, quantitative analysis is carried out against the additional power consumption caused by gas pressure under different conditions. Furthermore, an approach is introduced to define the optimal exhaust valve opening motion at full load conditions. It aims at making a better compromise between the engine power output and exhaust valves’ power consumption, thus both the efficiency of EMVT and engine performance are enhanced.     

混合动力轿车性能的测试研究

介绍了本田Insight混合动力电动轿车在实际道路和汽车转鼓试验台上按照国家标准和欧洲的一系列工况循环下测得的动力性、平均燃油消耗和排放的试验结果。在模拟真实环境的循环下，除了NOx的排放外，Insight的性能明显地优于传统汽油轿车的性能。     

LPG单燃料发动机稀薄燃烧控制策略研究

针对LPG单燃料发动机,基于旋转坐标系的独立气缸模型,提出了一种采用λ型氧传感器的稀薄燃烧控制策略,大大降低了线性氧传感器所带来的高昂成本,并实现了燃气喷射的逐缸控制。试验结果表明,该控制策略在满足系统动力要求的前提下,大大降低了燃气的消耗及废气的排放,具有良好的应用前景。     

柴油-酒精混合燃料发动机的性能研究

在分析柴油—酒精混合燃料物理化学特性的基础上，研究了不同混合比例的柴油—酒精混合燃料发动机的性能。研究表明：柴油醇燃料发动机的有效燃油消耗率较柴油机的升高，而有效能耗率有一定程度的降低；发动机的碳烟排放明显降低，在保持同样排温的前提下，其功率有一定程度的升高，尾气排放明显降低；柴油机使用混合燃料后，滞燃期延长，燃烧持续期缩短。在采用推迟供油的条件下，柴油—酒精混合燃料发动机的尾气排放性能可以得到较大幅度的提高。     

Investigation on Spray Behavior and NOx Conversion Characteristic of a Secondary Injector for a Lean NOx Trap Catalyst

Lean NOx trap (LNT) catalyst has been used to reduce NOx emissions from diesel engines. The LNT absorbs NOx in lean condition and discharges N2 by reducing NOx in rich conditions. Thus, it is necessary to make exhaust gas lean or rich conditions for controlling LNT system. For making a rich condition, a secondary injector was adopted to inject a diesel fuel into the exhaust pipe. In the case of secondary injector, the behavior of spray is easily affected by high temperature (i.e., 250 ～ 350 °C) occurred in the exhaust manifold. Therefore, it is needed to investigate the spray behavior of diesel fuel injected into an exhaust manifold, as well as the conversion characteristics for a lean NOx trap of a diesel engine with LNT catalyst. The characteristics of exhaust emissions in NEDC (New European Driving Cycle) mode were analyzed and spray behaviors were visualized in various exhaust gas conditions. The results show that as the exhaust gas mass flow increases, the spray cone angle becomes broad and the fuel is directed to the flow field. Besides, the cone angle of spray is decreased by centrifugal force caused in exhaust gas flow field. In addition, the effects of nozzle installation degree, injection quantity, and exhaust gas flow on NOx conversion performance were clarified.     

采用柴油添加剂降低柴油机排放的试验研究

在CA6110ZLA8增压中冷柴油机台架上进行0#柴油及0#柴油加5种不同添加剂的比较试验。给出了柴油机排放物(CO,HC,NOx,PM)及燃油消耗率的测试结果。分析了不同成分或不同量的添加剂对柴油机排放和燃油消耗率的影响。     

废食用油代用燃料在柴油机上的试验研究

食用植物油是一种很有前途的代用燃料,它是利用植物的光合作用不断更新生产的一种能源。通过用废食用油制得的柴油机代用燃料,在小型高速柴油机上与0号柴油做了性能对比试验。试验结果表明,与燃用柴油相比,用废食用油作为代用燃料输出功率几乎相同(仅低2%),燃油消耗增加了6%~12%,排气温度降低了20℃,所排出的CO2降低了10%~15%,CO降低了10%~18%,HC降低了47%。