十六烷值添加剂对乙醇柴油发动机燃烧与排放影响的研究

为降低柴油机的碳烟颗粒排放,配制了乙醇体积分数分别为10%、20%和30%的乙醇柴油混合燃料,利用与0#柴油临界互溶温度优化高碳醇助溶剂的添加比例.同时为改善发动机的燃烧,在混合燃料中添加了十六烷值添加剂.在2102QB型直喷式柴油机上进行试验.结果表明,由于乙醇的掺入使混合燃料十六烷值下降,着火延迟期增加.十六烷值添加剂可以提高混合燃料的十六烷值,恢复发动机的压燃着火特性,但十六烷值添加剂对混合燃料发动机的排放影响较小.柴油机燃用乙醇柴油混合燃料后,烟度大幅下降.ESC十三工况下颗粒比排放减少超过60%,氮氧化物排放相当,碳氢和CO的排放总量有所下降.研究表明,柴油机燃用比例不超过30%的乙醇柴油混合燃料时,在保持其动力经济性的基础上,可大幅降低碳烟颗粒排放.     

PODE掺混比对电控共轨柴油机排放特性的影响

为了降低柴油机排放、提高热效率,将体积分数为10%、20%、30%和70%的聚甲氧基二甲醚(PODE)掺混于柴油中制得PODE/柴油混合燃料,标记为P10、P20、P30和P70,在一台四缸增压中冷电控共轨柴油机上开展了PODE掺混比对混合燃料燃油经济性与排放特性的试验,并采用热重分析仪研究了混合燃料的蒸发性能。结果表明:随PODE掺混比增加混合燃料的初始失重温度、终止失重温度和峰值失重温度均向低温区域偏移,峰值失重率增大;随PODE掺混比增加,柴油机的排气温度降低,有效热效率显著提升,混合燃料的HC、CO和烟度排放逐渐降低,而NOx排放有所增加;在ESC试验循环下P30的HC、CO和PM排放量较柴油分别降低了25%、16%和51%,均低于国V排放限值,且CO2排放量也明显减小。     

生物柴油产业链分析

生物柴油是指由植物油、动物油脂等制备得到的单烷烃酯类。它是一种环境友好、清洁排放的燃料,因此是非常理想的石油柴油替代燃料。本文从生物柴油产业链中的原料来源、生产工艺、产品应用以及其效益等方面对这种新型的清洁燃料进行了简单介绍。总之,生物柴油是一种很有发展前景的生物质燃料。     

柴油汽车掺烧LPG降低黑烟排放技术

研究了柴油机掺烧液化石油气(LPG)以降低黑烟排放的技术方案，并开发出了一种以独特型板调节装置为特征的机械控制式柴油/LPG双燃料供给系统。发动机不改变原有结构加装该系统后即成为柴油/LPG双燃料发动机，可以同时燃烧柴油和LPG两种燃料，并且在整个工作范围内，随着工况变化能够按照预先优化设定的型板型线规律而自动调节柴油／LPG供给量比例，使烟度降低50％以上，同时满足经济性、动力性以及操作性能等要求，此外，也可以切换为单独燃烧柴油，而不改变发动机的原有性能。该系统结构简单、成本低廉，非常适合于改装城市在用公交车，降低其黑烟排放。     

电喷汽油机燃用乙醇/汽油混合燃料排放及催化转化特性研究

研究多点电喷汽油机燃用不同掺混比的乙醇/汽油混合燃料时的排放及催化器的转化性能.结果表明,在汽油机参数未做任何调整的情况下,与汽油机相比,乙醇/汽油混合燃料汽油机催化器之前的CO排放降低,降幅接近15%;HC排放在大负荷时略有升高;NOx排放基本相同;乙醇对排放物催化转换效率的影响与电喷汽油机的转速、负荷和空燃比控制策略有关.用气相色谱分析仪测录的未燃乙醇排放在大负荷时略有升高,甲醇排放量变化不大,乙醛排放量随乙醇含量增大而增大,经三效催化转化器后,可以被控制在接近零排放的水平.在怠速工况,随乙醇含量增加,CO、HC和NOx的排放与汽油机相比略有降低.     

基于燃油消耗的北京农用机械排放清单建立

农业机械作为重要的非道路移动源之一,排放的尾气是氮氧化物(NOx)和可吸入颗粒物(PM10)的主要来源之一.介绍了基于燃油消耗量的排放清单建立方法,排放因子为单位质量燃料消耗的污染物排放量,活动水平为燃料消耗量.根据NON-ROAD模型,农用柴油机械CO、THC、NOx和PM10排放因子分别为37.71 g·kg-1、9.38 g·kg-1、51.58 g·kg-1和8.23 g·kg-1,汽油机械CO、THC、NOx和PM10排放因子分别为405.25 g·kg-1、236.05 g·kg-1、3.88 g·kg-1和5.01 g·kg-1.根据燃料消耗量估算了北京2007年农用机械尾气排放量,HC、CO、NOx和PM10排放量分别为1 643.6 t、4 615.4 t、4 296.2 t和701.6 t.与道路机动车排放量相比,农用机械排放分别占1.26%、0.50%、2.91%和4.33%.基于GIS的北京农用耕地分布,建立了农机污染物排放的空间分布.根据不同月份的燃油消耗量分析时间分布,1-2月份排放较低,3-4月份排放较高.     

生物柴油:汽车燃料的革命

在美国,有越来越多的私人车辆以及政府部门和公司的车辆开始使用生物柴油。一些科学家认为,用“生物柴油”作燃料,也许可以闯出一条新路来。     

卡车在低温环境下使用高凝点标号柴油的安全性研究

在目前国力下,我国卡车广泛使用柴油机为动力的动力源。由于我国地域辽阔,南北温差大,当天气突然变冷和在比较寒冷的季节或地区时,柴油凝点选择不当,柴油流动性变差,柴油或者柴油机进油管容易被冻凝固,车辆难以运行,导致事故发生。为解决高凝点标号柴油不冻或不凝固,提高卡车柴油机在低温环境下使用高凝点标号柴油的安全性,通过多次研究和试验运用,在不改变车辆内部结构的情况下,研制了复合管技术,利用热交换原理使卡车柴油机冷却系统产生的热量对柴油直接加热,解决了柴油被冻凝固难题,促进了柴油流动。同时柴油冷却了冷却水,实现了能量互补与交换。加热后的柴油得到充分雾化燃烧,保障了柴油机正常运行,全面提高了卡车的动力性、经济性和安全性,减少了尾气和热量排放,彻底解决了柴油机车的安全运行,2015年取得国家发明专利。     

生态燃料

澳大利亚堪培拉市开始试用新型生态燃料。它由柴油(84.5%)、酒精(15%)和乳化剂(0.5%)混合而成。其中酒精主要以食品工业和木材加工工业的废弃物为原料制取。成本较低。乳化剂是该国专利产品,也是关键成份,主要用以解决柴油和酒精不     

别再小瞧地沟油

在巴西的坎皮纳斯市，许多公交车上都喷上了“此车用生物柴油驱动”的字样．坎皮纳斯华人社团巴中联合会总干事宋天乐先生告诉我们，他们的工厂炼制的生物柴油，按一定比例与柴油配制成生物燃料，供当地的公交车使用，这些喷了字样的公交车就是用他们的生物燃料驱动的。     

Cold Flow Properties of Fatty Esters

This article is devoted to the study of cold flow properties of neat esters of branched chain alcohols with fatty acids and blends of these esters with fossil diesel fuel. According to determined CFPP values the influence of alcohol branching on the fuel filterability is negligible. Fossil fuel blending with fatty esters of branched alcohols up to 10 vol % does not substantially change the cold flow properties of fossil fuel. The low-temperature properties of fossil diesel and fatty acid methyl/ethyl ester (FAME/FAEE) blends with low ester content (up to 10 vol %), prepared mainly from oils/fats with higher share of saturated fatty acids namely palm oil, tallow and lard, were also measured. The obtained results show that studied esters do not change low-temperature properties of fossil fuel in the blends with the low esters content of 3–5 vol %, although their own CFPP is over the value permissible by the standard EN 14 214. However, current standard EN 590 specifies to meet all parameters of the standard EN 14 214 also for FAME assigned for blended fuels entirely. The proposal to repeal the CFPP limit for esters assigned for blending is fully justified, without any negative effects on fuel quality.     

Optimization of Biodiesel Production from Jojoba Oil

The use of fatty acid methyl ester (FAME), produced from agricultural oils as a fuel in diesel engines has been proposed as an alternative to diesel from fossil resources. Vegetable oils are produced from numerous oil seed crops. Of the several renewable sources and yet not widely known, jojoba oil appears to be promising scope for cultivation in arid and semi arid areas. The chemical structure of jojoba oil allows its use as a constituent in many lubricating oil formulation. In the present work, the process of synthesis of methyl esters from jojoba oil as alternative vegetable oil, using a basic catalyst, has been developed and optimized by application of the Factorial Design and Response Surface Methodology. According to this study, the maximum yield of esters (83.5%) can be obtained, working at the maximum level of initial concentration of catalyst (1.35%) and a medium level for the operation temperature (25°C). The model has been proven to adequately describe the experimental range studied and allows to scale-up the process.     

Experimental Study on the Potential Application of Cottonseed Oil–Diesel Blends as Fuels for Automotive Diesel Engines

This paper presents the results of an experimental study on the direct application of cottonseed oil–diesel blends as fuel for diesel engine vehicles without using additional retrofit mechanical systems. The use of biofuels is one of the main actions promoted by the European Union and member states in an effort to tackle global warming, enhance energy security and contribute to regional development. Here, the possibility to blend cottonseed oil directly with fossil diesel as a fuel for diesel engines is examined. This option has lower cost and larger well-to-wheel greenhouse gas benefits than fatty acid methylesters. The paper presents measurements of important fuel properties, density, viscosity, cetane number and cold flow characteristics. In addition, a common rail Euro 3 compliant diesel car is tested using 10% v/v cottonseed oil–diesel blends in order to examine the effects on performance and emissions of regulated pollutants and CO₂. Furthermore, particle emission characteristics are studied, including total and solid particle number concentrations and particle size distributions over driving cycles and steady state modes. The results indicate that the test fuel presents good operating characteristics and limited effects on regulated emissions and vehicle performance. These results would justify further research on the direct use of vegetable oils as automotive fuels.     

阻燃抑爆柴油的燃烧性能和排放研究

以-10号军用柴油为基础油配置阻燃抑爆柴油,在WP10.290发动机上进行了台架实验,考察了使用阻燃抑爆柴油时的动力性、经济性和排放性。结果表明:燃用阻燃抑爆柴油相比于燃用-10号军柴会一定程度上降低输出功率和扭矩,动力性能下降2.31%~4.26%;燃用阻燃抑爆柴油时平均质量燃油消耗率较燃用军用柴油时增加了5.74%。体积燃油消耗率与军用柴油相比,平均增加了4.32%;能够降低NO的排放,NO的排放量相较于-10号军柴降低了7%~19%;能够降低排气温度,相比较于-10#军柴,阻燃抑爆柴油的排气温度最大可以降低19.5℃。     

隧道混合燃料火灾燃烧蔓延特性实验研究

隧道火灾一直是火灾科学研究领域的重要问题之一。近年来,隧道火灾中由于燃油泄漏而引起的火蔓延现象是一个新兴的研究热点。利用小尺寸(1:10)的隧道火灾模拟实验平台,开展了薄油、窄油池机制下不同混合比例下正丁醇-柴油燃烧特性实验研究。结果表明,根据正丁醇比例,可将正丁醇-柴油混合燃料分为两类。当正丁醇比例不大于20%时,主火焰蔓延速度线性增大,闪燃火焰则由间断变为持续存在且波长由14.17 cm减小到8.42 cm;油面温升速率逐渐增大;当正丁醇比例大于20%时,主火焰蔓延速度接近正丁醇蔓延速度(3.33 cm/s),闪燃火焰持续存在且波长在8.3 cm左右;油面温升速率基本相同。研究结果为认识隧道混合燃料火灾燃烧特性提供了参考。     

Fuel recovery from waste oily sludge using solvent extraction

Solvent extraction was used to recover oil from waste sludge generated from the storage of crude petroleum. Different solvent-to-sludge mass ratios were used for two solvents, methyl ethyl ketone (MEK) and LPG condensate (LPGC). Several parameters were compared, such as oil recovery as a percent of the original sludge mass, and reduction in carbon residue, ash content, and asphaltene content. A 4:1 solvent-to-sludge ratio was found to be optimum for both solvents. The MEK extraction recovered 39% by mass of the sludge as recovered oil. The LPGC recovered 32%. The amount of asphaltenes in the fuel oil was related to the concentration of fuel oil in the solvent phase during the extraction, suggesting that asphaltenes are extracted mainly by the fuel oil components, not the solvent. The physical properties and metal content of the recovered oil were measured. The recovered oil was distilled to provide diesel fuel. This diesel fuel contained high levels of sulfur and carbon residue, as well as a high diesel index, indicating the fuel requires further treatment prior to use as a fuel.     

温度分层环境下火灾烟气羽流上升高度公式分析

对小尺度空间温度分层环境下柴油有焰火及棉绳阴燃火烟气运动进行了实验和数值模拟.结果表明,在分层环境下,烟气与环境空气温度差造成的浮力在某一高度消失并转为负值,致使烟气停止上升而向横向扩展.Morton积分公式低估了烟气羽流上升的最大高度,且在相同出口条件及分层环境下,柴油烟雾比棉绳烟雾下降趋势快,上升高度小,其原因在于积分公式中自相似卷吸及烟气为空气假设.引入烟气密度修正系数和自相似修正系数,对Morton公式进行了修正和讨论.     

天然腐殖酸对柴油在寒旱区黄土上吸附特性的影响

选用西北寒旱区黄土为供试土样,通过热力学和动力学吸附试验研究了干旱区低有机质黄土对柴油的吸附行为,以及提取的天然腐殖酸对柴油在黄土上吸附行为的影响。结果表明,无论是否加入腐殖酸,柴油在黄土颗粒上的吸附都符合Freundlich方程,且腐殖酸质量浓度对柴油的吸附量有显著影响。在27℃时,加入10 mL质量浓度为40 mg/L的腐殖酸溶液后,柴油在黄土上的饱和吸附量由12.034mg/g减小为7.407 mg/g,且吸附量随温度的升高而降低,表明吸附为自发的放热过程。描述柴油在黄土上吸附动力学的最优方程为Elovich方程,其次为双常数方程。无论是否加入腐殖酸,黄土对柴油的吸附都在短时间内达到平衡。对吸附影响因素的分析结果表明,柴油在黄土上的吸附随溶液pH值的增大而降低;黄土颗粒粒径越小,柴油在土样上的吸附量越大。