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为了节约燃料,已有不少人对柴油掺水乳化油的使用和燃烧进行研究.然而,要深入地研究掺水乳化油的燃烧,应需对其燃烧速率进行计算.在以前的燃烧速率计算中,大都采用燃烧纯柴油时相同的计算方法,而没有考虑乳化油燃烧本身新具有的特点,如乳化油中的水份蒸发吸热,燃烧产物中各物质组成成份和纯柴油燃烧时的不同等,因而使其计算精度受到影响.为了精确地计算掺水乳化油的燃烧速率,需根据乳化油燃烧的特点,对计算中所用的能量守恒方程、质量守恒方程和工质热力性质计算式进行修正.在能量守恒方程中,除考虑燃料燃烧放热量dQ_E/d?,缸壁传给气缸内工质的热量dQ_w/d?,工质对外所做的功pdV/d?和工质内能的变化dU/d?外,还需考虑乳化 相似文献
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<正> 柴油掺水乳化所制成的乳化油可以作为柴油机的燃料,具有省油和降低排气烟度与温度等优点,是一种节能技术。 1 柴油掺水乳化的作用为了改善柴油机混合气形成的质量及燃烧过程,除了改进燃烧室的结构形状、进气道的形式和喷油系统外,也可采用柴油掺水乳化的技术。由于柴油掺水,使柴油机混合气的形成和燃烧过程增加了新的促进因素,提高了混合气形成的速度,改善了混合气的质量,有促进燃烧趋于完全的作用。 相似文献
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采用含氧燃料和EGR同时降低直喷式柴油机碳烟和NOx排放的试验研究 总被引:6,自引:0,他引:6
在一台TY1100轻型直喷式柴油机上,研究了碳酸二甲酯(DMC)作为含氧燃料添加剂对柴油机烟度和性能的影响。结果表明,在发动机燃油和燃烧系统不作变动的条件下,随着DMC在柴油中添加比例的增加,排气烟度逐步下降,热效率提高。当添加比例在10%-15%时,烟度降低40%-50%,热效率增加了6.9%,发动机功率基本不变。添加碳酸二甲酯并采用EGR可以同时降低碳烟和NOx。研究表明,柴油中添加15%DMC,在12%左右的EGR下,与原机比较,烟度降低了35%,NOx排放降低了33%。混合燃料的放热规律与纯柴油相比差异不大,但预混燃烧量增加,扩散燃烧速率快,发动机最高燃烧压力、温度和压力升高率偏高。 相似文献
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在R175A柴油机不做任何调整的条件下,进行了标定转速2 600 r/min下10%含水量的油包水包油(以下简称10%O/W/O)乳化油、柴油的负荷特性试验,考察了纯柴油(0#柴油)、含水10%O/W/O乳化油以及进气中氧气含量提高到23%、24%、25%富氧燃烧10%O/W/O时的NO、CO、HC、烟度的排放特性和燃料经济性。试验结果表明:与柴油相比,10%O/W/O乳化油可以同时降低柴油机的NO、碳烟排放,NO的排放可以降低29%,碳烟排放可以降低25%,同时改善经济性,满负荷时可以降低油耗15%,HC和CO的排放则有所上升。当进气含氧量提高到23%、24%的体积分数时,燃用10%O/W/O乳化油时,烟度从3.7 BSU下降至2.3 BSU,HC和CO的排放浓度低于柴油排放,满负荷时可以降低油耗14%,此时,NO的浓度略高于柴油的排放。 相似文献
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介绍了东营站热媒加热炉上应用HPE乳化油的概况;结合HPE乳化油燃烧的工作机理,分析了乳化油节能、降污的原因;指出使用乳化燃料可以降低原油加热成本,提高输油企业的经济效益. 相似文献
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针对HPE乳化油燃烧的工作机理,分析了乳化油节能、降污的原因。同时,结合HPE乳化油在东临输油管道加热系统中的应用,得出使用乳化燃料,可以降低原油加热成本,保护环境,提高输油企业的经济效益和社会效益。 相似文献
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本文建立在大量的试验基础上,对燃烧柴油加水乳化油和纯柴油作对比,在不同机型上测量其排气成分和烟度值,证明柴油机加水乳化油对于降低NOx和颗粒排放有明显的作用。 相似文献
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柴油机低温火焰预混合燃烧的试验研究 总被引:1,自引:0,他引:1
柴油机实现低温火焰预混合燃烧,可降低最高燃烧压力,抑制火焰传播速度,有效地减少NOx的排放.本文通过在1135型柴油机中采用适当减少压缩比、提高喷油速率、相应推迟喷油定时、用少量燃油预喷射及乳化柴油等技术,进行了降低气缸平均燃烧温度的比较试验,获得了NOx和碳烟排放明显降低和燃油耗率得到改善的效果. 相似文献
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柴油机燃用乳化油的试验研究 总被引:1,自引:0,他引:1
本文以试验研究为基础,对柴油机燃用乳化油的节能效果,以及对柴油机起动性能、振动、噪声、排气成份和烟度等做了试验研究,并对乳化油生成及节能机理进行了论述。试验结果表明,柴油机燃用乳化油节油率在2%~3%;对降低排气烟度和排气温度有显著作用;减少了废气污染;振动噪声也有所降低。 相似文献
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研究了在柴油机上燃用二甲醚(DME)-乳化柴油混合燃料的排放特性,分析了在乳化柴油中添加DME能降低柴油机废气排放的机理,并且与燃用柴油以及乳化柴油时的排放效果进行了比较。研究结果表明:在乳化柴油中添加10%含量的DME能显著降低NOx和烟度的排放,尤其是在高负荷时,能明显降低HC和CO的排放。与燃用乳化柴油相比,即使在部分负荷时,也不会对NOx排放产生不良的影响。 相似文献
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《Applied Thermal Engineering》2007,27(13):2314-2323
The scarce and rapidly depleting conventional petroleum resources have promoted research for alternative fuels for internal combustion engines. Among various possible options, fuels derived from triglycerides (vegetable oils/animal fats) present promising “greener” substitutes for fossil fuels. Vegetable oils, due to their agricultural origin, are able to reduce net CO2 emissions to the atmosphere along with import substitution of petroleum products. However, several operational and durability problems of using straight vegetable oils in diesel engines reported in the literature, which are because of their higher viscosity and low volatility compared to mineral diesel fuel.In the present research, experiments were designed to study the effect of reducing Jatropha oil’s viscosity by increasing the fuel temperature (using waste heat of the exhaust gases) and thereby eliminating its effect on combustion and emission characteristics of the engine. Experiments were also conducted using various blends of Jatropha oil with mineral diesel to study the effect of reduced blend viscosity on emissions and performance of diesel engine. A single cylinder, four stroke, constant speed, water cooled, direct injection diesel engine typically used in agricultural sector was used for the experiments. The acquired data were analyzed for various parameters such as thermal efficiency, brake specific fuel consumption (BSFC), smoke opacity, CO2, CO and HC emissions. While operating the engine on Jatropha oil (preheated and blends), performance and emission parameters were found to be very close to mineral diesel for lower blend concentrations. However, for higher blend concentrations, performance and emissions were observed to be marginally inferior. 相似文献
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The aim of this study is to determine the availability of pomegranate seed oil biodiesel (POB) as an alternative fuel in diesel engines and evaluate engine performance and emission characteristics of pure hydrogen enriched POB using diesel engine. For this purpose, the intake manifold of the test engine was modified and hydrogen enriched intake air was supplied throughout the experiments. Physical properties of POB and its blend with diesel fuel were also determined. The results showed that measured physical properties of POB are comparable with diesel fuel. According to engine performance experiments, although POB utilization has slight undesirable effects on some engine performance parameters such as brake power output and specific fuel consumption, it can be used as alternative fuel in diesel engines, by this way CO emission can be improved. Finally, hydrogen enrichment experiments indicated that pure hydrogen addition causes a slight improvement in both engine performance and exhaust emissions. 相似文献
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This paper discusses the influence of biodiesel on the engine combustion characteristics. The considered fuel is neat biodiesel from rapeseed oil. The considered engine is a bus diesel engine with injection M system. The engine characteristics are obtained by experiments and numerical simulation. The results obtained with biodiesel are compared to those obtained with mineral diesel under various operating regimes. In this way, the influences of biodiesel usage on the injection pressure, injection timing, ignition delay, in-cylinder gas pressure and temperature, heat release rate, exhaust gas temperatures, harmful emissions, specific fuel consumption, and on engine power are analyzed. Furthermore, the relationships among fuel properties, injection and combustion characteristics, harmful emissions, and other engine performance are determined. Special attention is given to possible explanations of higher NOx emission in spite of lower in-cylinder gas temperature. 相似文献
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电控共轨柴油机燃用乳化柴油的耐久性试验研究 总被引:1,自引:0,他引:1
在未对发动机进行任何调整的前提下,对柴油机进行了400h耐久性试验研究。试验用电控共轨柴油机满足国Ⅲ排放标准,试验用乳化柴油(以下简称E10)由90%柴油、6.4%水及3.6%乳化剂组成。耐久性试验期间,试验用柴油机功率、油耗、烟度和排气温度等参数稳定,柴油机无不良反应,未发生如起动困难、自动停车等故障;耐久性试验后,该柴油机动力性、经济性、排放性能等参数变化都很小。 相似文献