共查询到19条相似文献,搜索用时 140 毫秒
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主要探究了清净剂对汽车发动机燃烧室、进气阀积碳及尾气排放的影响。制备出了一种聚醚胺清净剂、一种聚烯胺清净剂,通过M111法分别检测两种清净剂对燃烧室和进气阀沉积物的影响。并将聚醚胺、聚烯胺清净剂进行复合,通过台架试验检测复合清净剂对燃烧室、进气阀积碳和耗油量的影响。通过双怠速试验检测复合清净剂对汽车尾气排放中HC、CO的影响。结果表明复合清净剂中聚醚胺含量为300ppm聚烯胺含量为200ppm时效果最佳,能够降低碳排放与燃烧室、进气阀积碳。复合清净剂在降低碳排放方面效果显著。 相似文献
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车用乙醇汽油清净性的好坏直接影响汽车发动机的使用性能,加入清净剂可以改善和保持发动机的良好工况,减少油耗和尾气排放。采用模拟沉积物试验板法对车用乙醇汽油和加入清净剂的车用乙醇汽油进行检验,得出未加清净剂和加入清净剂的车用乙醇汽油的清净效果,可以评价车用乙醇汽油清净剂。实验结果表明,车用乙醇汽油清净剂能够很好地起到去除进气阀沉积物的作用,用加入实验助剂的方法,能够更加有效的评价车用乙醇汽油清净剂的使用效果。 相似文献
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G. Jones 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1971,21(2):39-47
The degree of partial detergence accomplished by passing representative subsamples of several lots of greasy wools at controlled alkaline pH values (generally constant in each experiment) through the same bath of water at 50°c has been followed by estimations of loss of grease as well as loss of all soiling materials. The degree of detergence usually tends to rise to a maximum and then often falls off as is usual when detergent concentration is increased in other systems. As the pH of the detergence is raised, the maximum attained rises and the fall-off generally occurs earlier, at least up to pH 10.0. The course of detergence varies with the kind of alkali and its purity. Inorganic salts and amyl alcohol raise the maximum and increase the rate of fall-off of the self-detergence. Other methods of raising the degree of detergence are explored. The maintenance of maximum detergence for all wools is a complex problem. 相似文献
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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。 相似文献
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聚醚胺对高弹性-高伸长率环氧树脂胶粘剂力学性能影响的研究 总被引:1,自引:0,他引:1
用聚醚胺(D230,D400,T403)和聚醚胺(D2000)作为混合固化剂,用浇铸成型法制备了系列环氧树脂结构胶粘剂。目的是通过配方设计、简化工艺研制出系列具有高弹性-高伸长率的环氧树脂胶粘剂。并与普通改性脂肪胺(593#)和聚醚胺(D2000)作为混合固化剂,聚醚多元醇(HF220)作为改性剂的环氧树脂体系进行了比较。实验用SEM法对树脂浇铸体断面微观形貌进行了观察,用动态DMTA法对树脂玻璃化转变温度(Tg)进行了测定,并对固化物的拉伸强度、断裂伸长率、以及断面形貌进行了测定,考察了聚醚胺相对分子质量、结构、官能度对拉伸强度、断裂伸长率和应力-应变的影响。动态力学分析法(DMTA)结果显示:体系的玻璃化转变温度(Tg)随着聚醚胺(D2000)加入量的增加而降低,当m(D400)∶m(D2000)=35∶100,Tg为16.63℃,达到最低,说明材料在低温也具有较好的柔弹性。通过扫描电镜(SEM)观察,证明聚醚胺对环氧树脂具有优异的相容性,对环氧树脂起到了增柔-弹性化的作用。 相似文献
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Homogeneous charge compression ignition of LPG and gasoline using variable valve timing in an engine
Kitae Yeom 《Fuel》2007,86(4):494-503
The combustion characteristics and exhaust emissions in an engine were investigated under homogeneous charge compression ignition (HCCI) operation fueled with liquefied petroleum gas (LPG) and gasoline with regard to variable valve timing (VVT) and the addition of di-methyl ether (DME). LPG is a low carbon, high octane number fuel. These two features lead to lower carbon dioxide (CO2) emission and later combustion in an LPG HCCI engine as compared to a gasoline HCCI engine. To investigate the advantages and disadvantages of the LPG HCCI engine, experimental results for the LPG HCCI engine are compared with those for the gasoline HCCI engine. LPG was injected at an intake port as the main fuel in a liquid phase using a liquefied injection system, while a small amount of DME was also injected directly into the cylinder during the intake stroke as an ignition promoter. Different intake valve timings and fuel injection amount were tested in order to identify their effects on exhaust emissions and combustion characteristics. Combustion pressure, heat release rate, and indicated mean effective pressure (IMEP) were investigated to characterize the combustion performance. The optimal intake valve open (IVO) timing for the maximum IMEP was retarded as the λTOTAL was decreased. The start of combustion was affected by the IVO timing and the mixture strength (λTOTAL) due to the volumetric efficiency and latent heat of vaporization. At rich operating conditions, the θ90-20 of the LPG HCCI engine was longer than that of the gasoline HCCI engine. Hydrocarbon (HC) and carbon monoxide (CO) emissions were increased as the IVO timing was retarded. However, CO2 was decreased as the IVO timing was retarded. CO2 emission of the LPG HCCI engine was lower than that of the gasoline HCCI engine. However, CO and HC emissions of the LPG HCCI engine were higher than those of the gasoline HCCI engine. 相似文献
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