汽油机添加氢改善排放特性的研究

作者用两种气缸盖在单缸汽油试验机上进行了加氢试验研究。试验结果表明,加氢能够降低CO、HC、NO_x排放物浓度,并扩大低有害排放物的稀薄混合气区域,该区域相当于稀的经济油耗区,因而同时提高了经济性。例如,在最低油耗点,与燃用汽油的发动机相比较,燃用氢-汽油混合燃料(加氢重量比率X_h=3%)时,CO浓度明显降低(CO浓度为220ppm)。低速、低负荷时效果较好。试验结果还表明,具有不同性能燃烧室的气缸盖,加氢后对降低有害排放物浓度均有效果。本文还进行了加氢改善排放特性的理论分析,从而为实际应用提供依据。     

氢-汽油双燃料发动机性能试验研究

介绍一种氢—汽油双燃料发动机，这种双燃料发动机装有余热制氢装置，可用甲醇制取氢并燃用氢与汽油混合燃料。作者对余热制氢装置及氢—汽油双燃料发动机的各项性能进行试验研究。试验结果表明，装有余热制氢装置的氢—汽油双燃料发动机功率和扭矩有所提高，外特性和负荷特性燃油消耗率下降5．3％一7．5％；怠速排放中CO和HC均有所减少。     

LPG／汽油双燃料发动机排放规律的试验研究

介绍LPG／汽油双燃料发动机的排放特性,主要分析燃用LPG时发动机的排放规律,并对比分析了燃用汽油和燃用LPG时发动机的排放规律。     

LPG-汽油双燃料发动机试验研究

选用澳华液化石油气（LPG）有限公司生产的汽车用石油气燃料供给管理配于EQ6100－I型发动机，改装成LPG－汽油双燃料发动机，进行性能测试分析。试验结果表明，在不改变原机压缩比和点火提前角时，燃用液化石油气的动力性下降，最大功率为原机的90％；最大扭矩为原机的92％。燃用LPG比燃用汽油的当量比油耗低，节能率在5％左右。怠速排放试验表明，燃用LPG的CO，HC排放浓度分别为燃用贩50％和36％。     

高比例甲醇汽油的发动机台架试验研究

M100是一种具有代表性的高比例甲醇汽油。通过在发动机上分别燃用93#汽油和M100甲醇汽油两种燃料,对比两种燃料的动力性、经济性以及排放性能,并对其进行分析。试验表明,在发动机上使用灵活燃料控制器后,M100甲醇汽油具有良好的适应性。与燃用93#汽油相比,M100甲醇汽油的动力性和经济型提高。常规排放的尾气中CO,HC和NOx显著降低,而非常规排放物甲醛排放增加。     

低比例甲醇汽油在通用小型汽油机中的试验研究

在ST188通用小型汽油机未做调整的情况下,试验研究了燃用低比例甲醇汽油(M10和M20)对发动机性能的影响.试验结果表明,通用小型汽油机燃用甲醇汽油后,随甲醇含量的增加动力性呈下降趋势;与93#标准汽油相比,甲醇汽油虽然油耗率有所上升,但能耗率相当;比较甲醇汽油与汽油的常规排放物发现,甲醇汽油对CO的降低有明显作用,对HC的排放有升高作用,对NOx的排放有所增加,但增加幅度不大.     

电喷汽油机燃用醇汽油混合燃料的试验研究

研究了多点电喷汽油机燃用醇汽油混合燃料的性能。研究结果表明:在汽油机参数未做任何调整的情况下,醇汽油混合燃料发动机的动力性与汽油机相比有所降低,燃料经济性改善,有效热效率提高。随醇类燃料体积分数的增大,CO排放明显改善,THC排放略有升高,NOx排放的变化不明显。醇汽油混合燃料发动机的醛类排放物明显升高,汽油机的未燃甲醇排放较高,未燃乙醇排放变化不明显。     

摩托车发动机电控喷射LPG/汽油双燃料系统的试验研究

介绍了电控喷射LPG／汽油双燃料系统及控制方法,并进行了系统和原机对比的排放试验及LPG喷射量对发动机性能的影响试验。试验结果表明：LPG／汽油双燃料系统可以大幅降低CO、HC排放;在稳态工况下,较小的LPG喷气量变化,对发动机混合气空燃比和动力性影响不大,而对排放性能影响较大。     

M15甲醇汽油在4G15S汽油机上的试验研究

在4G15S汽油发动机上分别对燃用M15甲醇汽油与燃用93#汽油时的动力性、经济性、常规及非常规排放性能等进行了试验研究。试验表明,该汽油机与M15甲醇汽油具有良好的适应性;与燃用93#汽油相比,动力性略有下降,燃油消耗率增加,尾气排放中CO,HC,NOx明显降低,甲醛排放增加。     

低比例甲醇汽油对电喷汽油机排放影响的实验研究

在HH465Q-1E电喷发动机上进行了低比例甲醇汽油混合燃料的掺烧试验,结果表明与93#汽油相比燃用M5,M10,M15时发动机的动力性、经济性均得到改善。中低转速时,HC和CO排放物都显著降低,但在高转速时排放均有所增加,而NOx排放在中低转速时,有明显的提高,在高转速时降幅明显。M15中添加添加剂后排放有显著的改善。     

城市公交车辆的发展方向分析

随着城市规模不断扩大以及城市人口和车辆的快速增加,以汽车为主要工具的城市交通消耗的燃油将会随之增加。当前,城市交通所面临的问题日益严重,开发清洁燃料汽车成为实现城市交通可持续发展的战略选择。介绍了电动汽车的不同种类及特点,尤其是混合动力汽车的优点和局限性,指出了我国城市电动公交车辆的发展方向。     

490QA柴油机的改进设计

本文介绍了４９０ＱＡ直喷式柴油机改进设计．试检证明,其废气排放、烟度、噪声等指标全面达到现行国家标准的要求,可以较好满国内１～１．５ｔ轻型汽车的配套要求．     

几种汽车替代燃料的技术经济比较

随着世界经济的发展和人们物质生活水平的不断提高，世界各国对能源的需求量不断增加。能源问题成为世界各国最关心的问题之一，寻找新的替代能源势在必行，分析了目前世界对一次能源，特别是石油的需求增长情况，指出了能源使用中存在的一些问题，并针对汽车燃料的使用情况，从物理化学性质，能量特点，排放特点及经济性几个方面比较了几种汽车替代能源，通过比较发现在几种替代燃料中，氢能的综合经济效益最高，但目前在生长、储运及加载的成本等方面还存在一些问题，尚不能大规模投入使用。在这样的情况下，甲醇是比较合适的汽车替代燃料。     

柴油机加装柴油机氧化催化器和催化型颗粒 捕集器装置性能评定试验研究

为了研究加装柴油机氧化催化器(DOC)和催化型颗粒捕集器(CDPF)装置的柴油机性能,探讨DOC与CDPF的净化效率和再生特性随试验循环数的变化规律,搭建了柴油机高原试验台,并按13试验循环进行了性能评定试验。结果显示,在全负荷工况下,随着试验循环数的增加,发动机的进气量、转矩、功率和油耗均比未装DOC和CDPF的原机略有下降。同时,在排气后处理装置的后端,烟度和CO排放均趋向零,而NO_2排放增加,NO排放减少。将第1试验循环与第13试验循环进行比较后可以发现,DOC和CDPF的前端温度均比后端低,而排气后处理装置经13试验循环后仍具有较高的净化效率。与原机相比,加装排气后处理装置的发动机,经性能评定试验后的外特性有所下降,但在排气后处理装置后端的烟度和CO排放趋近于零,而NO_2/NO比例随发动机转速增加先升后降。此外,DOC和CDPF的后端温度低速时上升明显,后随转速升高而降低,直至趋于稳定,而CDPF的压差随转速增加先升后降。此时,捕集效率和再生效率仍保持较高水平。     

Potential for reducing GHG emissions and energy consumption from implementing the aluminum intensive vehicle fleet in China

The automobile industry in China has rapidly developed in recent years which resulted in an increase in gasoline usage and greenhouse gas (GHG) emissions. Focus on climate change has also accelerated to grow pressure on reducing vehicle weight and improving fuel efficiency. Aluminum (Al) as a light metal has demonstrated a great potential for weight savings in applications such as engine blocks, cylinder heads, wheels, hoods, tailgates etc. However, primary Al production requires intensive energy and the cost of Al is more than traditional steel, which may affect the total benefits realized from using Al in automobiles. Therefore, it is very essential to conduct a study to quantify the life cycle GHG emissions and energy consumption if the plan is to achieve fleet-wide Al intensive vehicles.     

甲醇发动机排放特性的研究

以一台电控M85甲醇燃料发动机为研究对象,在发动机台架上,采用废气分析仪和气相色谱仪,分别研究了甲醇发动机的常规排放和非常规碳氢排放。研究表明:M85甲醇发动机可以实现很低的常规排放,在非常规碳氢排放方面,甲醛在总碳氢排放占有较大的比例,而甲醇的排放接近0。三效催化反应器对甲醛的净化率较低,并且存在随负荷增大,净化率降低的趋势。甲醇的净化率始终接近100％。     

Hydrogen effects on NOx emissions and brake thermal efficiency in a diesel engine under low-temperature and heavy-EGR conditions

Cooled and heavy exhaust gas recirculation (EGR) has been used to control NOx emissions from diesel engines, but its application has been limited by low thermal efficiency or high unburned hydrocarbon emissions. In this study, hydrogen was added into the intake manifold of a diesel engine to investigate its effect on NOx emissions and thermal efficiency under low-temperature and heavy-EGR conditions. The energy content of the introduced hydrogen was varied from an equivalent of 2-10% of the total fuel’s lower heating value. A test engine was operated at a constant diesel fuel injection rate and engine speed to maintain the same engine control unit (ECU) parameters, such as injection time, while observing changes in the carbon dioxide produced due to variations in the hydrogen supply. Additionally, the EGR system was modified to control the EGR ratio. The temperature of the intake gas manifold was controlled by both the EGR cooler and the inter-cooling devices to maintain a temperature of 25 °C. Exhaust NOx emissions were measured for different hydrogen flow rates at a constant EGR ratio. The test results demonstrated that the supplied hydrogen reduced the specific NOx emissions at a given EGR ratio while increasing the brake thermal efficiency. This behavior was observed over constant EGR ratios of 2, 16, and 31%. The rate of NOx reduction due to hydrogen addition increased at higher EGR ratios compared with pure diesel combustion at the same EGR ratio. At an EGR ratio of 31%, when the hydrogen equivalent to 10% of the total fuel’s lower heating value was supplied, the specific NOx was lowered by 25%, and there was a slight increase in the brake thermal efficiency. This behavior was investigated by measuring and analyzing changes in the exhaust gas composition, including oxygen, carbon dioxide, and water vapor.     

Feasibility study on a novel cooling technique using a phase change material in an automotive engine

The size of a cooling inventory is generally designed based on which size can endure the excessive heat load situations that occur sporadically. As a result, cooling systems are often too large for most normal driving modes. There have been numerous efforts to downsize the automotive engine cooling system using novel concepts and strategies. Efficient cooling in automobiles is beneficial in reducing harmful emissions as well as improving fuel economy. A simulation was conducted to validate the feasibility of using a novel cooling strategy that utilized the heat load averaging capabilities of a phase change material (PCM). Three prototypes were designed: full-size, down-sized, and a down-sized prototype with a heat accumulator containing the PCM inside. When the full-size of the cooling inventory was down-sized by 30%, this smaller design failed to dissipate the peak heat load and consequently led to a significant increase in the coolant temperature, around 25 °C greater than that in the full-size system. However, the peak heat load was successfully averaged out in the down-sized system with a heat accumulator. This novel cooling concept will contribute to a substantial reduction in the cooling system in terms of volume and hangover.     

Exergetic environmental assessment of life cycle emissions for various automobiles and fuels

This paper examines material emissions produced during thirteen fuel life cycles for automobiles, on mass and exergy bases. The masses of fuel life cycle emissions are compared with the chemical exergies of these emissions. For the emissions data used, the chemical exergy results suggest that compressed natural gas use in motor vehicles produces emissions that are the most out of equilibrium with the natural environment, relative to all other fuel life cycle paths considered. It is also shown that diesel use in grid-independent hybrid electric vehicles has the lowest chemical exergies of emissions of all thirteen fuel-vehicle combinations under consideration, suggesting a lower degree of potential environmental impact. The exergy methodology presented for assessing the potential for environmental impact may help in the development and design of transportation technologies that are more environmentally benign than those presently used.     

增压柴油机采用多级可变文曲利管式进气系统的实验研究

EGR技术应用在增压柴油机上出现了进排气压逆差导致应用有限的现象。本文采用将原有进气系统改造成由多个文曲利管并联组成的进气系统解决此问题。该系统一方面可由不同文曲利管之间的组合排列达到适应随工况变化的可变进气目的;另一方面,可以借助多个文曲利管的喉部压降能力吸引更多排气达到扩大EGR率的效果。通过流量模拟测试实验获得,采用MVVIPS较传统的串联式和分流式文曲利管系统都取得了更大的流通能力和压降能力;通过内燃机综合测试台架可知,采用MVVIPS系统后,试验用柴油机过量空气系统在不同转速下有着不同的变化;相比较原机的EGR系统,MVVIPS系统的EGR率在每个试验工况下都得到了不同程度的提高;动力性和经济性都在低、中转速下有小幅升高,但在高转速下与原机相差不大;根据稳态十三工况排放数据显示,采用MVVIPS系统后,NOx排放得到了有效控制,CO和微粒排放变化不大,HC排放在怠速及低工况范围内有着较明显的降低。