汽油发动机积炭的形成、清除机理及汽油清净剂的研究进展

发动机经过长期运转以后,在燃烧室、燃油喷嘴、进气阀等部位会形成大量的碳质沉积物,严重影响发动机的效率、操作性能和尾气排放。为解决发动机的积炭以及尾气排放问题,汽油清净添加剂成为现代清洁汽油不可或缺的组成部分。本文综述了积炭的形成机理：积炭的形成过程分为引发和生长两个阶段,同时积炭的形成受到金属表面温度、燃油组成、喷射速率等众多因素的影响。指出利用某种特殊结构的有机胺类物质对金属表面的吸附作用及其对胶质的分散作用可以清除金属表面已经形成的积炭。此外,对汽油清净剂的组成、发展以及性能评价方法作了详细介绍。     

甲醇作为车用汽油调合组分的利弊分析

介绍了甲醇汽油的毒理特性,分析了其潜在危害。基于国内外研究成果,对甲醇汽油对发动机动力性能和燃烧性能的影响、甲醇汽油的常规污染物与非常规污染物的排放形成和控制、甲醇汽油的腐蚀性和溶胀性以及甲醇汽油的稳定性和清净性等进行了讨论。     

甲基叔丁基醚（MTBE）对汽油性能的改善

本文介绍了甲基叔丁基醚对汽油辛烷值、饱和蒸汽压、馏程、发动机动力性能的影响，检测了排放尾气和火花塞积炭情况，说明甲基叔丁基醚是一个很好的汽油添加剂。     

含水甲醇汽油的应用性能研究

通过理化分析、台架实验和行车实验,比较了自制的含水甲醇汽油M50W、M40W和93#市售汽油的物化性能和使用效果。结果表明,发动机使用M50W、M40W动力性优于93#市售汽油,油耗增加3%~7%。尾气排放中HC、CO、CO2显著降低,NOx排放改善不明显,甲醛排放增高。     

含铅汽油对航空活塞式发动机性能的影响探讨

当前航空活塞式发动机要求能够使用无铅或者低铅航空汽油,但是国内传统航空汽油的含铅量较高,如100号航空汽油、95号航空汽油等。在应用中发现,使用含铅汽油,发动机容易出现故障。重点分析含铅汽油对航空活塞式发动机性能的影响,在分析含铅汽油主要成分和燃烧产物基础上,揭示了含铅汽油对发动机性能的影响,进而以发动机抖动实例进行探讨,分析含铅汽油的影响,并提出几点发动机养护策略,对正确使用含铅汽油,减少对活塞式发动机性能影响有一定参考价值。     

醇汽油混合燃料的应用研究

能源短缺和环境保护双重压力使得醇类燃料的应用研究日益突出。从应用分析的角度,通过发动机台架试验,研究了M30、M50、E10对发动机动力性、经济性及排放性能的影响,并与93#汽油进行了对比分析,而在试验过程中发动机的结构参数未作任何调整。     

京标B(国Ⅲ)清洁汽油的开发与质量控制

为2008年北京"绿色奥运"作准备,中国石化股份公司要求向北京供应的汽油应符合京标B(国Ⅲ标准).为了适应这一需要,中国石化股份公司镇海炼化分公司从改进生产工艺、优化汽油调合方案等方面展开科研技术攻关,不断提高汽油的品质,生产出了符合欧Ⅲ排放标准的京标B汽油,硫、苯、烯烃含量等主要指标均达到了高标准环保汽油的要求.     

京标B(国Ⅲ)清洁汽油的开发与质量控制

为2008年北京“绿色奥运”作准备，中国石化股份公司要求向北京供应的汽油应符合京标B（国Ⅲ标准）。为了适应这一需要。镇海炼化股份有限公司从改进生产工艺、优化汽油调合方案等方面展开科研技术攻关，不断提高汽油的品质，生产出了符合欧Ⅲ排放标准的京标B汽油，硫、苯、烯烃含量等主要指标均达到了高标准环保汽油的要求。     

车用汽油的品质及经济性评价

介绍了评价汽油品质的综合指标,对汽油池组分构成与汽油辛烷值标号、密度、发热值之间的关系进行了分析;评述了汽车发动机特性对汽油品质的要求及对汽油燃效的影响,研究了不同辛烷值标号、不同调和组分汽油的使用经济性,提出了正确选择辛烷值标号的方向。     

国产汽油进气阀沉积物的生成特性研究

对国产催化裂化汽油形成进气阀沉积物(IVD)的机理进行了研究,明确了烯烃、芳烃及非烃组分的沉积物生成特性,并对汽油馏分、胶质含量和发动机工作温度等影响因素进行了系统的分析考察,为改善国产汽油的清净性能、研发与国产汽油相适应的高效清净剂提供了理论基础.     

煤基燃料油品特性与煤制油产业发展分析

基于最新汽油、柴油和航煤质量标准,结合我国市场对成品油需求走向,本文探讨了煤直接液化油、煤间接液化油、加氢煤焦油、煤油共炼产品、甲醇制汽油（MTG汽油）和聚甲氧基二甲醚（DMM_n）等煤基油品的馏分结构与性质,分析了它们对煤制油产业发展的影响。文章指出国家绿色可持续发展需要低硫、低烯烃、低芳烃和高抗爆性能的交通运输燃料,需要降低柴汽比,增产航空煤油。煤基油品的硫氮等有害物质含量低、清洁性很好。除了MTG汽油外,煤基油品的柴汽比过高,需要与石油产品协同发展以满足我国未来的成品油市场需求。费托合成工艺能够直接生产优质柴油和航空喷气燃料油组分,是煤制油产业发展的主要技术路线;煤直接液化工艺所产汽煤柴油馏分性质均不理想,需要持续改进提高;煤油共炼工艺在成品油质量方面弥补了煤直接液化工艺的不足,可作为一条新的煤制油途径。煤焦油加氢可以生产出质量指标达到或接近国Ⅵ标准的车用柴油调和组分,是一条高效利用煤炭加工过程副产品的煤制油技术路线。MTG汽油和DMM_n是优质汽油和柴油组分,能改善炼油企业成品油的柴汽比结构和交通运输燃料产品质量,应加大低成本工艺技术研发、扩大产能。     

国内外清洁汽油质量分析及发展趋势

同发达国家相比,我国在清洁汽油的具体指标方面还存在较大差距,汽油质量始终面临着蒸气压高、辛烷值分布差,尤其是烯烃含量过高的压力,长远看,硫、苯、氧等指标含量也将面临着更大压力。结合我国汽油生产现状,调整炼油装置结构,降低汽油中烯烃和硫含量,将是我国汽油中长期发展的方向。     

航空汽油发展概述及前景展望

航空汽油是航空燃料的重要组成部分。本文论述了国内外航空汽油从车用汽油、含铅航空汽油到无铅航空汽油,从低辛烷值到高辛烷值航空汽油的发展历程。比较含铅航空汽油和无铅航空汽油标准发现,辛烷值、铅含量、净热值、芳烃含量等技术指标的要求均有所区别。分析认为,标准技术指标不同的主要原因在于调合航空汽油的基础油不同。同时,本文指出了使用国产100号航空汽油易造成火花塞积铅、气门烧蚀及气缸密封性降低等问题。目前美国联邦航空局已经对12家企业生产的102号无铅航空汽油进行审定,计划在2018年取代现有含铅航空汽油。由于环境保护和节能减排的要求,无铅化及生物汽油都是未来航空汽油的发展方向。     

Gasoline displacement and NOx reduction in an SI engine by aqueous alcohol injection

Substitution of bio-fuels for fossil fuels in gasoline engines is conventionally achieved by premixing ethanol and gasoline before use. The drawbacks are the high purity ethanol (>95%) required for mixing to prevent phase separation and the invariable fraction of ethanol throughout the drive cycle. In this study, an independently controlled set of aqueous alcohols injectors were installed at the manifold alongside the gasoline injectors. Aqueous alcohols with high water content can be injected as a substitutional fuel for gasoline. The fraction of ethanol can be controlled to achieve best engine performance and emissions. Engine tests showed that, at highway driving condition, the engine compensated for the aqueous alcohol and reduced gasoline flowrate. However, at high-load running, the ECU (Engine Control Unit) no longer reads the feedback signals to reduce gasoline supply and the engine burned at fuel-rich conditions; both the engine performance and emissions deteriorated.     

催化裂化汽油脱硫助剂的研究

汽油中硫化物的存在加重了汽车尾气中污染物的排放,对环境的影响很大。而且会缩短汽油诱导期,对发动机的影响也很大。因此,降低汽油中的硫含量势在必行。本文旨在开发一种用于流化催化裂化过程的添加剂,以降低催化裂化汽油中的硫含量,为生产清洁汽油做出贡献。     

Measurement of number and size distribution of particles emitted from a mid-sized transportation multipoint port fuel injection gasoline engine

This study was carried out to characterize the engine-exhaust particulate emissions from a typical multipoint port fuel injection gasoline engine used in transportation sector. Though gasoline engine showed no visible tail pipe emissions yet its particle concentrations were comparable to mineral diesel, particularly at high engine loads. Average sizes of particles emitted in gasoline exhaust are found to be way smaller than particles emitted in diesel exhaust under similar operating conditions. The peak particle concentrations for mineral diesel never go below 40 nm size however for gasoline engine, it was as low as 20 nm for most engine operating conditions. Within a very limited operating range, gasoline engine performance was superior to its diesel counterparts in terms of particulate size and number distribution however it deteriorates very quickly as soon as the fuel-air mixture becomes closer to stoichiometric ratio, typically under high engine load and speed conditions.     

Investigation of purified sulfate turpentine on engine performance and exhaust emission

This study deals with an experimental work that aims to examine effects of purified sulfate turpentine obtained from a kraft pulp mill in Turkey on an engine performance and exhaust emissions of a spark ignition engine. Three fuel samples are used to test the performance and emission of a 1300 cc engine manufactured by TOFA?. They are pure gasoline with 98-octane number and two other gasoline-turpentine fuel samples obtained by blending gasoline with turpentine in ratios of 5% and 10% on basis of total mass of the fuel. The thermophysical properties of the fuels are acquired by density, viscosity, flash and fire points, sulphur content, heating value and distillation tests. The experimental results showed that the turpentine has a positive effect on the engine performance parameters, such as brake power, thermal efficiency, mean effective pressure and specific fuel consumption. The turpentine also increases pollutant NO_x, unburned hydrocarbon contents and exhaust temperature, but it decreases CO concentration in the exhaust. It is observed that utilization of the sulfate turpentine alone is not viable and it needs to be used as an additive into gasoline to some extent, thereby providing a viable alternative to pure gasoline.     

航空活塞式发动机燃料简介

航空活塞式发动机燃料主要用于航空活塞式发动机,又称"航空汽油"。介绍了航空活塞式发动机燃料的品种牌号与选用、组成与加工工艺、性能要求与主要指标以及贮存和使用中的注意事项等内容,以期为油料专业初学者和相关专业工作人员提供帮助。     

Investigation on combustion and emissions of DME/gasoline mixtures in a spark-ignition engine

Dimethyl ether (DME) has a lot of good properties and is thought to be one of the best alternative fuels for IC engines in the future. In order to improve the efficiency, combustion stability and emissions performance of a spark-ignited (SI) gasoline engine at stoichiometric condition, an experimental study aiming at improving engine performance through DME addition was carried out on a four-cylinder SI engine. The engine was modified to be fueled with the mixture of gasoline and DME which were injected into the engine intake ports simultaneously. A hybrid electronic control unit (HECU) was dedicatedly developed to control the injection timings and durations of gasoline and DME. The spark timing was adjusted to reach the maximum brake torque (MBT) without knocking. Various DME fractions were selected to investigate the effect of DME addition on engine performance, thermal efficiency, combustion characteristics, cyclic variation and emissions under stoichiometric conditions. The experimental results showed that thermal efficiency, NOx and HC emissions are improved with the increase of DME addition level. The combustion performance was improved when DME addition fraction was less than 10%. CO emission first decreased and then increased with the increase of DME enrichment level at stoichiometric condition.