代用燃料汽车—二十一世纪的汽车，迎接挑战之四

本文对乙醇、甲醇、天然气、氢气等代用燃料的资料情况，对环境以及对发动机性能的影响进行了分析介绍。并就这些代用燃料汽车所要解决的关键技术进行分析说明。     

代用燃料汽车技术(一)——世界汽车技术发展跟踪研究(五)

能源结构调整和降低环境污染促进了当代各类型代用燃料汽车产业和技术的发展，概括介绍了气体燃料汽车技术；包括天然气，液化石油气和氢燃料汽车，含氧燃料汽车技术：包括甲醇，乙醇和二甲基醚，再生能源汽车技术，植物油，还介绍了代用燃料的理化性能和使用特点及代用燃料汽车技术，展望了世界各主要国家的代用燃料的产业发展，技术进展及应用前景。     

关于汽车选择清洁代用燃料的思考(一)

简述了汽车动力装置及燃料的现状与发展趋势、国外汽车公司开发醇燃料汽车的简况。详细分析比较了CNG、DME、甲醇及乙醇等不同燃料的性质、毒性和安全性、排放性能、使用经济性和方便性等，认为选择汽车清洁代用燃料首先应考虑甲醇及乙醇。     

天然气作业汽车燃料的应用及发展

由于天然气具有价格便宜，储藏丰富和排放染低等优点，因此被认为是很有前任的车用发动机代用燃料。分析了天然气的燃料特性，介绍了天然气在车用发动机上的应用情况和目前主要研究内容。简述了气缸内直接喷射天然气方案的实施。     

汽车的未来动力天然气汽车的发展与现状

目前国内外都在大力发展代用燃料汽车（AFV）．全球已实际使用的代用汽车燃料有：压缩天然气（CNG）、液化天然气（LNG）、液化石油气（LPG）、甲醇、乙醇、电能等。CNG、LNG的原料为天然气．故称为天然气燃料．汽车也称天然气汽车（NGV）。LPG是湿天然气的组分．并从湿天然气中回收制得的．习惯上也将LPG与CNG、LNG一起均称为天然气燃料．汽车也称天然气汽车。     

发动机代用燃料的开发与应用

本文介绍了国内外发动机代用燃料的开发与应用现状，并综合内外的研究结果指出，天然气、氢气、醇类、煤是未来发动机极有希望的代用燃料。     

生命周期评价及天然气基车用替代燃料的选择

介绍了生命周期评价方法在车用替代燃料选择方面的研究,通过实地考察我国天然气制甲醇联产二甲醚工艺,结合车辆技术,对天然气基代用燃料,包括压缩天然气、甲醇汽油、二甲醚的生命周期能量消耗和温室气体排放进行了评估,并与石油基燃料进行了比较,同时对燃料制备工艺与车辆技术进步所造成的影响进行了讨论。     

甲醇(M100)在车用发动机上的应用研究

对甲醇代用燃料进行了研究，针对国内使用范围极其广泛的492Q火花点火式发动机，讨论了甲醇作为汽车代用燃料的可行性，并进行了大量发动机台架试验和汽车的道路试验，并给出了试验结果。     

烧掺水甲醇汽油的汽车燃油系统

以掺水甲醇作汽车代用燃料是今后汽车燃料无铅化和低排放的一个发展趋势。全国的肥厂联产粗甲醇将给生产厂和全国运输业带来可观的经济和社会效益。发展掺水甲醇汽油燃油系统的关键是生产一种双浮子室化油器。在掺水甲醇汽油燃油系统基础上发展内燃蒸汽机，可能使我国汽车业在燃料代用、节能和降低排放方面走在世界前列。     

康明斯代用燃料发动机

自20世纪70年代以来，随着全世界范围的环保意识的增强环保法规的制定和完善。对发动机排放的要求越来越高在进一步提高柴油和汽油发动机排放性能的同时，世界上代用燃料的研究和开发越来越重视康明斯是最早进行代用燃料技术开发的发动机公司之一。康明斯在这一领域内比其他制造商投入了更多的财力和物力进行研究和开发。     

二甲醚／柴油混合燃料在压燃式发动机上的应用

为探索二甲醚/柴油混合燃料作为柴油机替代燃料的应用性能,对D20二甲醚/柴油混合燃料的喷雾特性进行了试验研究;同时,开展了直喷式柴油机燃用二甲醚/柴油混合燃料动力性能、经济性能及排放性能研究。结果表明:在同样的环境背压下,D20混合燃料的油束与柴油相比较,贯穿度有所缩短,喷雾锥角有所增大;柴油机燃用二甲醚/柴油混合燃料时,通过适当调整循环油量,发动机的动力性可以超过原柴油机,最低当量比油耗下降4.5%,烟度指标下降70%以上,NOx排放降低30%~50%;二甲醚/柴油混合燃料是一种能实现高比功率、低排放的石油替代燃料。     

Numerical analysis of the effect of inhomogeneous pre-mixture on the pressure rise rate in an HCCI engine using multi-zone chemical kinetics

The HCCI (Homogeneous Charge Compression Ignition) engine is an internal combustion engine under development, which is capable of providing both high diesel-like efficiency and very low NO_x and particulate emissions. However, several technical issues must be resolved before the HCCI engine is ready for widespread application. One issue is that its operating range is limited by an excessive pressure rise rate which is caused by the excessive heat release from its selfaccelerated combustion reaction and the resulting engine knock in high-load conditions. The purpose of this study was to evaluate the potential of thermal and fuel stratification for reducing the pressure rise rate in HCCI engines. The NO_x and CO concentrations in the exhaust gas were also evaluated to confirm combustion completeness and NO_x emissions. The computational work was conducted using a multi-zone code with detailed chemical kinetics, including the effects of thermal and fuel stratification on the onset of ignition and the rate of combustion. The engine was fueled with dimethyl ether (DME) which has a unique two-stage heat release, and methane which has a one-stage heat release.     

基于传统动力源的重型商用车减碳技术

在全球能源危机和温室效应加剧的大环境下,中国向世界承诺减碳目标：2030年前力争实现碳达峰,2060年前力争实现碳中和。作为节能减排的重点,重型商用车的减碳成效是“双碳”征程中的关键。重点介绍基于传统动力源的重型商用车减碳技术,包括内燃机燃烧、低摩擦、智能变速、轻量化、混合动力等技术在内的动力总成领域,以及包括天然气、含氧燃料、氢氨燃料在内的先进燃料领域。通过不同领域的技术发展以及优势互补,更加高效、低碳、清洁的内燃机仍将在重型商用车领域持续发挥重要作用。     

二甲醚燃料供给系统研究现状及发展趋势

摘要：介绍了国内外二甲醚发动机燃料供给系统研究概况,包括油泵一油管一油嘴系统和共轨式燃料供给系统。二甲醚粘度低导致燃油供给系统磨损和泄漏是二甲醚发动机实用化面临的主要问题。针对可控预混合燃烧二甲醚发动机开发的一种用隔膜泵、磨损自补偿喷油器或者独立润滑喷油器构成的燃料喷射系统,有望从本质上解决上述问题,成为未来的一个发展方向。     

汽油/CNG双燃料发动机的试验研究

将HH368Q汽油机改装成汽油/CNG双燃料发动机,在相同试验条件下,分别对燃用汽油和CNG时的动力性和排放性能进行对比试验,结果表明,改装后的发动机燃用CNG时比燃用汽油时的动力性下降13%;在怠速和中、小负荷工况时排放却比燃用汽油时有明显下降。同时,还对三元催化反应器对燃用CNG时的催化效率和CNG作为代用燃料时发动机存在的问题进行了讨论。     

Combustion development of a Bi-Fuel engine

Environmental improvement and energy issues are increasingly becoming more important as worldwide concerns. Natural gas is a good alternative fuel that can help to improve these issues because of its large quantity and clean burning characteristics. This paper provides the experimental performance results of a Bi-Fuel engine that uses Compressed Natural Gas as its Primary fuel and gasoline as its secondary fuel. This engine is a modification of the basic 1.4-liter gasoline engine. Generally, on the unmodified base engine, torque and power for CNG fuel are considerably lower than gasoline fuel. In this paper, the influence of fuels on wall temperature, performance and emissions are investigated.     

Experimental study of performance and emission characteristics of DEE-assisted minimally processed ethanol fuelled HCCI engine

The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for reciprocating engines. This study investigates an HCCI engine fuelled with Diethyl ether (DEE) ignition assisted wet ethanol (ethanol with 20% water content). The direct use of wet ethanol could reduce the associated energy required for distillation and dehydration of ethanol. The HCCI engine offers significant benefits in terms of its high efficiency and ultra low emissions. The experiment is conducted with various DEE flow rates and at different air-fuel ratios, for which stable HCCI combustion is achieved. Incylinder pressure, heat release analysis and exhaust emissions were observed. In this study, the effect of DEE on combustion parameters, thermal efficiency and emissions is analysed and discussed in detail. The experimental results indicate that the DEE flow rates have a significant effect on the maximum in-cylinder pressure and its position, thermal efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operating points, brake thermal efficiency is higher than reference mode at lower loads and almost same at higher loads. The emission parameters such as NO, HC and CO are lower than the dual fuel mode which is considered as a reference model for this experiment.     

柴油机新技术应用于二甲醚发动机性能试验研究

将柴油机增压技术、废气再循环技术、共轨式燃料喷射技术应用于二甲醚(DME)发动机，探讨了在各种技术条件下发动机的排放性能、动力性和经济性。结果表明，共轨式燃料系统有利于解决DME燃料的可压缩性和泄漏问题；进气增压技术有利于改善燃烧，降低排放和能量消耗率；废气再循环技术可以有效地降低No2排放；进气增压和适度的废气再循环率相结合，可以同时降低排放和改善能量消耗率，有利于达到超低排放的要求。     

Development of hydrogen-compressed natural gas blend engine for heavy duty vehicles

Natural gas fuel, as an alternative energy source of transportation, has been used widely since it has an advantage of low emission levels. However, new technologies are required in order to meet the reinforced emission regulations. For this purpose, research into the development of hydrogen-compressed natural gas (HCNG) blend engine was carried out to evaluate its feasibility and emission characteristics. The Engine Research Department at the Korea Institute of Machinery and Materials carried out a large number of tests based on various parameter changes that could affect the performance and emission of HCNG engine in different operating conditions. An earlier stage of the research project focused on the lean combustion of a HCNG engine for heavy duty vehicles to meet the EURO-VI standards. An 11-L/6-cylinder CNG engine was used for the test. The effects of the excess air ratio change were assessed based on various content ratios of hydrogen in the natural gas fuel. In the later part of the HCNG research, a stoichiometric mixture operation was suggested to meet reinforced emission regulation without requiring a De-NOx system. Additionally, an exhaust gas recirculation (EGR) system was introduced for the purpose of improving thermal efficiency and durability. The optimal operating conditions were selected to achieve the best thermal efficiency to meet the required emission levels. In this paper, we demonstrate that a HCNG engine can achieve a significant decrease in NOx emissions, as compared to that of a CNG engine, while meeting the requirements of the EURO-VI standards during a transient mode cycle test. EGR can suppress the weakness of stoichiometric mixture combustion strategy, such as the deterioration of the durability and thermal efficiency, while the emission level can be lowered with the use of a three-way catalyst. The possibility of further reduction of emissions and CO2 with EGR was evaluated to access practical application of a HCNG engine in the field. From that evaluation, the HCNG engine with stoichiometric mixture operation for heavy duty vehicles was developed. The emission levels of HCNG engine were 50 % lower when compared to the EURO-VI standards with a greater than 10 % decrease in CO₂ compared to that of a natural gas engine.