Performance Characteristics of n-Butanol-Diesel Fuel Blend Fired in a Turbo-Charged Compression Ignition Engine

In this study, n-butanol-diesel blends were burned in a turbo-charged, direct injection diesel engine where the brake thermal efficiency, (BTE) or brake specific fuel consumption, (BSFC) was compared with that of ethanol-diesel or methanol-diesel blends in another study by other authors. The test blends used were B5, B10 and B20 (where B5 is 5% n-butanol by volume and 95% diesel fuel-DF). In this study, the BTE was higher and the BSFC improved more than in the other study. Because of improved BTE with increasing brake mean effective pressure, BMEP, the BSFC reduced, however the increased shared volume of n-butanol in DF increased BSFC. Adding n-butanol in DF slightly derated the torque, brake power output with increasing speed, and caused a fall in exhaust gas temperatures, (EGT) which improves the volumetric efficiency and reduces compression work. Therefore, a small-shared volume of n-butanol in DF fired in a turbo-charged diesel engine performs better in terms of BTE and BSFC than that of ethanol or methanol blending in DF.

Preparation and emission characteristics of ethanol-diesel fuel blends

The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water(0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection(DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon(HC), and carbon monoxide(CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas.

1,1-Dibutoxybutane as a Petroleum Diesel Fuel BlendingComponent and Their Mixture Performance

Effect of 1,1-dibutoxybutane （DBB） addition on petroleum DF （diesel fuel） performance has been studied. The study wasstarted by preparing DBB from decomposition of 1 -butanol on manganese impregnated on activated carbon （Mn/AC） catalyst at 450 ℃ in stainless steel reactor. The product was distilled at 200 ℃ and the residue obtained was analyzed by GC-MS and HSQC NMR toconfirm its structure and purity. The DBB-DF mixtures were prepared at different compositions and determined their excess molarvolume, homogeneity, phase stability, ignition quality, lubricity, cold flow quality, energy content, and viscosity. The addition of DBBinto DF formed a homogeneous mixture and had a good phase stability. The mixtures gave positive excess molar volume values overthe whole concentration ranges. The ignition quality and lubricity of the mixtures increased without lost in cold flow quality. Slightdecreased in viscosity and energy content per mass unit were observed.

Study on Application of Pour Point Depressant for Diesel Fuel

Taking into account the actual crude slate processed at the refinery, it is necessary to make reasonable combination and blending of crude oils. In order to cope with high wax content in diesel fuel it is proposed to appropriately regulate the refining process scheme and add additives to refined products. This measure after being applied in the production practice has brought about good results and has met the needs of commercial production.

掺混比例对航空煤油/柴油的着火和碳烟排放影响

航空煤油/柴油掺混作为一种典型的宽馏程燃料,具有提升着火能力、改善低温冷起动并对柴油机结构可靠性影响较小等潜在性能.基于电加热定容燃烧弹,耦合纹影法、广域低通化学发光法和高频背光消光法等光学诊断方法,研究了不同航空煤油掺混比例对航空煤油RP-3/柴油掺混燃油喷雾、着火和碳烟排放特性的影响.结果表明:在航空煤油中掺烧柴油,有利于提高掺混燃油的着火能力,但同时也会提高碳烟排放,产生明显的红外信号.随着柴油掺混比例的增加,冷态喷雾体积几乎没有变化,但在高温蒸发环境下,喷雾锥角及体积均略微下降.添加25%(体积分数)的柴油可明显缩短着火滞燃期,且碳烟面积和碳烟质量规律与纯煤油相近,随着柴油组分的进一步增加,碳烟面积和碳烟质量都相应明显增加.此外,掺混25%柴油的航空煤油掺混燃油,可大幅提高燃油的着火性能,且碳烟排放维持在较低水平;航空煤油中添加较少比例的柴油适合在航空发动机中使用,从而成为一种比纯航空煤油更有潜力的单一燃料.

微界面强化混合柴油加氢精制中试研究

基于微界面强化技术,以混合柴油为原料,在催化剂装填量为2 L的上行式固定床装置上开展了柴油加氢精制中试研究。考察了反应压力、反应温度、V(氢)/V(油)和空速等工艺参数及不同类型催化剂对微界面强化柴油加氢精制脱硫脱氮性能的影响。研究结果表明,在工艺条件考察范围内微界面强化加氢脱硫效果明显优于常规上行式反应器,随着生成油中w(硫)的降低,2者差异程度缩小。以w(硫)为1.58%的混合柴油为原料,采用HRC-1催化剂,与常规上行床柴油加氢相比,脱硫率为99.75%时,微界面强化加氢的反应压力可降低3 MPa以上;在反应压力高于5.0 MPa时,微界面强化加氢脱氮率大于98.2%。以w(硫)为1.02%的混合柴油为原料,采用HRC-2和HRC-3级配催化剂,在空速为0.8 h_(-1)、反应压力5.7 MPa、反应温度365℃的条件下,V(氢)/V(油)≥500时,微界面强化加氢生成油中w(硫)等主要指标均可满足国Ⅵ柴油标准要求。该工艺可为中低压下微界面强化混合柴油加氢工业放大提供参考。

掺烧不同比例乙醚对船用柴油机燃烧和排放性能的影响

为研究掺烧不同比例的乙醚对柴油机燃烧及排放特性的影响,以4190Z L C-2型船用中速机为研究对象,利用AVL_FIRE仿真软件构建燃烧室高压循环模型,在全负荷工况下对比实测与仿真缸压和放热率曲线,验证模型的准确性。在全负荷工况下,通过仿真模拟实验,在柴油中分别掺混体积分数为0%、5%、10%、15%的4种比例的乙醚,研究其对柴油机燃烧和排放特性的影响。结果表明:与燃烧纯柴油相比,使用柴油-乙醚混合燃料,缸内最大爆发压力和缸内最高温度均有所下降,对应的曲轴转角也稍有延后。增加乙醚的掺混比例,CO和NO的排放量均呈现降低趋势,碳烟排放略有增加。在反应过程中,乙醚加入延长了混合燃料的滞燃期,油气混合更加充分,放热过程稳定,提升柴油机的稳定性。当乙醚掺混体积分数为15%时,NO排放量较原机降低12.7%,CO排放量降低7.8%,碳烟排放量增大10.7%。

定容弹内柴油/丁醇混合燃料燃烧特性研究

In this paper,the spray and combustion characteristics of diesel/butanol-blended fuels were studied within a high-temperature and high-pressure constant volume chamber equipped with a single-hole injector.Two blends with 80%diesel/20%butanol and 60%diesel/40%butanol mixed by volume were tested in this study.The pure diesel B0 was also tested here as a reference.The spray penetration,flame lift-off length,and soot optical thickness were obtained through high-speed schlieren imaging,OH*chemiluminescence,and diffused back-illumination extinction imaging technique,respectively.The thermogravimetric curves of different fuels were obtained through a thermogravimetric analyzer.The results showed that butanol/diesel blends presented a longer ignition delay(ID)and flame lift-off length compared with pure diesel,and such finding was mainly caused by the lower cetane number and higher latent heat of vaporization of n-butanol.With the increase in the n-butanol ratio,soot production in the combustion process decreased significantly.Given the shorter ID period,the soot distribution of pure diesel reached a steady state earlier than the blends.

正丁醇/生物柴油混合燃料的中低温着火特性

通过一台新开发的超高压快速压缩机,进行了不同比例的正丁醇/生物柴油混合燃料在当量比为0.3~1.0、压力为1~6MPa以及温度为700~975 K条件下的自着火特性研究.结果表明:混合燃料的着火延迟时间随着温度、压力和当量比的升高而减小.此外,混合燃料的着火延迟时间随着正丁醇比例的增加而增大,但随着温度的升高,着火延迟时间对正丁醇的比例不敏感.采用已有的详细动力学模型进行了模拟研究并与试验结果进行了对比.通过对正丁醇/生物柴油自着火特性的化学动力学分析,研究了自着火过程中正丁醇和生物柴油之间的化学相互作用.结果表明:正丁醇的加入极大程度抢夺了生物柴油低温反应产生的自由基,削弱了生物柴油的低温反应路径.

柴油机燃用菜籽油-柴油混合燃料的试验研究

文章在一台双缸直喷柴油机上开展了燃用菜籽油-柴油混合燃料时的发动机性能、燃烧和排放特性研究,并与燃用柴油时相比较。研究结果表明:当菜籽油的掺混比(体积分数)不大于20%时,混合燃料的运动粘度和密度接近于柴油;在低负荷工况下,燃用混合燃料时的燃烧开始时间与柴油几乎相同,但缸内压力峰值和放热率相对较高;在高负荷工况下,燃用混合燃料时的燃烧开始时间略早于柴油,特别是VD50;在低负荷工况下,燃用VD50时的燃油消耗率最高,有效热效率最低;随着发动机负荷的逐渐增加,燃用混合燃料与柴油时的燃油油耗率差异逐渐减小,有效热效率也不断提高;在低负荷工况下,燃用混合燃料时的碳烟排放量较高,高负荷时则与之相反;在低负荷工况下,燃用混合燃料时的NOx排放量略低于柴油,高负荷时则几乎相同;在整个负荷范围内,燃用混合燃料时的CO和HC排放量均较高。

Autoignition of butanol isomers/n-heptane blend fuels on a rapid compression machine in N_2/O_2/Ar mixtures

Ignition delay times of butanol isomers/n-heptane mixture were measured using a rapid compression machine at compressed pressures of 15,20 and 30 bar,in the compressed temperature range of 650–830 K and equivalence ratio of 1.0.Sensitivity analysis and reaction fluxes analysis were performed using a detailed mechanism of blend fuels so as to evaluate the impact of n-heptane addition and temperature variation on the ignition and combustion process.Over the experimental conditions in this study,the blend fuels displays apparent low and high temperature reactions and a negative-temperature-coefficient(NTC)behavior.With increasing butanol isomers mole fraction in the mixtures,the ignition delay times increase.It is worth noting that the suppression to n-heptane ignition from tert-butanol is very limited.The ignition delay time of 40/60 tert-butanol/n-heptane mixture is smaller than other three kinds of blends.With the increasing of tert-butanol mole fraction,the increasing range of its ignition delay time is very large.Moreover,compressed pressure has a limited effect on the ignition of blend mixture at low temperature but certain influence at medium temperature arrange.Tert-butanol/n-heptane mixture is not sensitive to the pressure.The chemical analysis indicates that butanol isomers also present the NTC behavior because of the low temperature reactivity radicals pool produced by n-heptane.Reaction fluxes analysis shows that the n-heptane addition has little impact on the reaction path.Sensitivity analysis shows that for the pure n-butanol,2-butanol and iso-butanol fuel,H-abstraction from the?-carbon plays the dominant role in the reactions having the inhibiting effect on the low-temperature branching,while the H-abstraction from the?-carbon can promote the ignition;for tert-butanol/n-heptane mixtures,reaction R16.H2O2(+M)<=>OH+OH(+M)plays the leading role.For n-butanol/n-heptane,iso-butanol/n-heptane mixtures,the major promoting reactions include some H-abstraction from n-heptane and OH branching reactions,the influence of H-abstraction from?-carbon is weaken;For 2-butanol/n-heptane,tert-butanol/n-heptane mixtures,R16 plays an absolutely dominant role,while the major inhibiting reactions add some elementary reactions of small radicals.

Research on the Physical Property of Diesel-Gasoline Blend Fuel

In this paper, physical property parameters including density, viscosity and surface tension of different contents of diesel-gasoline blend fuel were measured and analyzed. The experiments were performed on the diesel gasoline blend fuels with 4 different volume fractions of diesel(20%, 40%, 60% and 80%) at temperature from 5℃ to 65℃. The influence of temperature and diesel content on the blends' properties was summarized based on experimental data, formulas about the material parameters were established, and the accuracy of these formulas was verified. Besides, saturated vapor pressure, freezing point and flash point of the blend fuel have also been measured and analyzed, and a database of the material parameters of the blends was also established.

丁醇柴油混合燃料在轻型车模拟工况试验研究

通过模拟2种整备质量柴油轻型车在整车运转循环中的运行,计算出典型发动机工况并进行了丁醇柴油混合燃料影响的台架试验。试验结果表明:柴油轻型车可以燃烧30%丁醇体积比例的丁醇柴油混合燃料,其燃油经济性所受影响不超过7%;轻型车整备质量明显影响发动机运行工况,导致其排放受丁醇比例的影响呈现不同的变化规律;丁醇柴油混合燃料的使用不会导致柴油轻型车HC的过度排放,但使CO排放恶化,特别对质量较小的轻型车。此外,丁醇的加入虽然使有些工况NOx排放小幅度增加,但柴油机烟度排放明显降低,为采用EGR手段降低柴油轻型车原始NOx排放腾出了更大的EGR率提升空间。

柴油机燃用乙醇柴油燃料的燃烧与排放特性

对燃用多种比例乙醇柴油的柴油机燃烧与排放特性进行了试验研究。测试了 5 %～ 2 5 %乙醇柴油燃料以及柴油和乙醇的基本物理性质 ,在ZS1 1 0 0柴油机上对各种比例的乙醇柴油测试了发动机在主要工况下的性能与排放特性 ,并用光学可视化方法研究了柴油、1 5 %乙醇柴油、1 5 %乙醇柴油加十六烷值改进剂的燃烧过程。

不同配比乙醇柴油混合燃料的经济性和排放性

为了研究乙醇柴油混合燃料的经济性和排放性,该文在双缸直喷式柴油机和在用的柴油轿车上分别进行了发动机台架试验和整车底盘测功机试验。结果表明,在不调整柴油机条件下,使用乙醇柴油混合燃料能够在一定程度上改善发动机燃油经济性和降低排气烟度和NOX排放,但HC排放增加。适当减小供油提前角有利于改善乙醇柴油混合燃料发动机经济性和排放特性。对于试验车辆,燃用E10有利于降低汽车在中、高速时的等速工况燃料消耗量和常温下冷起动后PM、NOX排放量。该研究结果对于改善乙醇柴油混合燃料的燃油经济性和排放性具有实用价值。

柴油机掺烧不同比例生物柴油的试验研究

将体积分数为10%2、0%、30%的生物柴油掺混到柴油里组成3种混合燃料,并连同纯柴油共4种燃料,在一台四缸增压中冷柴油机上进行性能、燃烧和排放特性的试验研究.结果表明,柴油机燃用生物柴油与柴油混合燃料的折合油耗率与燃用纯柴油时基本相当;燃用混合燃料的缸内最大爆发压力和压力升高率较低,着火时刻较晚;混合燃料的NOx和碳烟排放与燃用纯柴油时相比均有不同程度的降低,但混合燃料的HC和CO排放只是在1 500r/min时才较纯柴油低,当转速在2 300 r/min时,混合燃料的HC和CO排放更高.

乙醇-丁醇-柴油混合燃料的车辆排放性和经济性

为了研究乙醇-丁醇-柴油混合燃料的车辆排放性和经济性,该文对分别使用乙醇-丁醇-柴油混合燃料和柴油的在用柴油轿车的排放性能和燃油经济性,以及在用柴油客车的自由加速排气烟度排放进行了对比试验。研究结果表明:相对于柴油,在用柴油轿车使用E10(体积比,乙醇10%、丁醇4%、柴油86%)混合燃料的NOX排放减少10.42%,HC+NOX排放减少27.43%,微粒(PM)排放减少2.13%,90和120km/h等速行驶燃料消耗量分别减少7.66%和3.71%;然而CO排放增加31.43%,工况循环综合燃料消耗量增加4.48%。此外,在用柴油客车使用E10混合燃料的自由加速排气烟度排放减少31.11%。该研究结果对于完善乙醇柴油混合燃料的车辆排放性和经济性具有实用价值。

乙醇柴油混合燃料的制备工艺和废气的排放特性

为降低柴油机排放对环境造成的污染 ,用乙醇部分替代柴油 ,探索了乙醇柴油混合燃料的制备方法 ,研究了掺混乙醇及助溶剂对柴油机排放的影响 .结果表明 :无水乙醇可以和柴油以任意比例混溶 ,但痕量水 ( 0 2 %)的添加即导致混合物分层 ,合成的有机助溶剂可保证乙醇 柴油 痕量水体系的稳定性 .基于台架实验 ,考察了掺混1 0 %、2 0 %、3 0 %乙醇对燃料排放性能的影响 .乙醇的最佳掺混比为 2 0 %.在额定工况点 (功率为 1 3kW ,转速为1 5 40r/min)时 ,掺混 2 0 %乙醇的混合燃料可降低烟度 5 5 %,降低HC排放 70 %,降低CO排放 45 %.不添加助溶剂时 ,乙醇的掺混导致排放尾气中产生乙醇、微量乙醛等有机物 .而添加非金属离子助溶剂可使HC、乙醇。

乙醇-柴油混合燃料的理化特性研究

对乙醇 柴油燃料直接影响发动机性能和燃料的使用、存储和运输的几种基本物理化学性质进行了研究。通过对不同比例(乙醇含量分别0.2%、0.5%、1%、2%、5%、10%、15%、20%、25%、75%)的混合燃料的密度、粘度、闪点、表面张力、十六烷值、稳定性和磨损性等理化性质的测试和研究,总结出了乙醇含量对混合燃料物性参数的影响规律,归纳出各种参数随温度变化的规律。以密度为特征参数,拟合出混合燃料粘度、表面张力随密度变化的关系,得到了具有较高精度的乙醇 柴油混合燃料的理化特性经验关系式。

柴油机燃料调合用生物柴油国家标准的编制

对即将发布的柴油机燃料调合用生物柴油(BD100)国家标准的技术要求进行了介绍,对标准制定的背景、国外在用的生物柴油标准及柴油机燃料调合用生物柴油(BD100)国家标准的制定过程、采标情况和主要技术指标和试验方法进行了说明。