生物柴油-柴油混合燃料的理化特性研究

对生物柴油-柴油混合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（生物柴油含量分别为0％，20％，100％）的混合燃料的密度、粘度、表面张力、十六烷值、闪点、润滑性、硫含量、冷滤点、凝固点等理化性质的测试和研究，初步探讨了生物柴油含量对混合燃料物性参数的影响规律。     

柴油机燃用F-T柴油与0号柴油混合燃料的燃烧特性

根据实测的喷油器针阀升程和示功图,开展了直喷式柴油机燃用F-T柴油与0号柴油混合燃料时燃烧特性的研究．试验用燃料为0号柴油、含25%和50%F-T柴油的混合燃料以及100%F-T柴油．结果表明,在相同工况下,随着混合燃料中F-T柴油比例的增加,喷油延迟角增大,而喷油持续期变化不大．滞燃期随着F-T柴油比例的增加而缩短,其中当F-T柴油的比例由0增至25%时,滞燃期缩短最为明显,此后进一步增加F-T柴油的比例,滞燃期缩短幅度减小．随着混合燃料中F-T柴油比例的增加,预混燃烧放热峰值降低,扩散燃烧放热峰值增大,燃烧持续期略有延长,缸内最高燃烧压力和气体最高平均温度降低,最大压力升高率显著下降,发动机的燃烧噪音和机械损失减小,有效燃油消耗率和有效热效率得到改善．     

甲醇/生物柴油/F-T柴油混合燃料燃烧特性与排放特性研究

选取煤基燃料F-T柴油和甲醇,并辅以生物柴油,配制成甲醇/生物柴油/F-T柴油混合燃料,在未做调整的四缸增压中冷柴油机上进行试验研究。结果表明:混合燃料的燃烧放热率峰值、压力升高率峰值和缸内压力峰值均随混合燃料中生物柴油比例的增加而增加,且对应的相位延迟;外特性下燃用混合燃料时,碳烟、氮氧化物的排放量明显降低,在低转速下一氧化碳降低幅度较大,混合燃料对甲醛也有较大幅度的减排作用。     

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％、10Yoo、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一柴油混合燃料的理化特性经验关系式。     

压燃式发动机燃用F-T柴油/生物柴油混合燃料的燃烧及振动特性研究

为实现F-T柴油与生物柴油性能互补,构建高品质清洁替代燃料,文章将F-T柴油掺混10%,20%,30%的生物柴油配制成混合燃料,利用四缸增压柴油发动机台架进行转速为2 000 r/min的负荷特性试验,并与0号柴油进行对比。试验结果表明:随着生物柴油添加量的逐渐增大,混合燃料的滞燃期小幅度增大,燃烧始点提前,燃烧持续期增加;混合燃料的压力升高率随着生物柴油添加量的增大而增大,但均低于0号柴油;混合燃料振动信号的有效值及平均幅值随生物柴油含量的增加而增加,但均小于0号柴油;随着生物柴油添加量的增大,混合燃料的振动信号的峭度随之增加,燃烧冲击随之增大,其中,负荷为150 N·m时,混合燃料B30FT的峭度最大,比0号柴油高17.3%。     

棉籽油生物柴油的理化特性研究

通过对不同配比的棉籽油生物柴油的密度、粘度、十六烷值、热值、闪点、冷凝点、残炭量、硫含量等理化性质的测试,初步探讨了棉籽油配比对生物柴油理化特性参数的影响规律,以期找到合适的棉籽油配比,为其在柴油机试验台上的后序试验研究提供一系列的基础数据.研究结果表明:除闪点和凝点外,棉籽油其它理化特性与棉籽油的配比变化成明显的线性关系;受生物柴油的密度、粘度、十六烷值、热值和残炭等指标的限制,棉籽油配比不宜过高.     

乙醇-柴油混合燃料的理化特性的研究

为了有助于开展乙醇柴油混合燃料在发动机上的应用研究，本文开展了不同乙醇掺混比例柴油乙醇混合燃料的主要理化特性的研究。采用数值计算的方法研究了不同乙醇掺混比例对混合燃料的低热值、十六烷值的影响；开展燃料的蒸馏特性试验、粘温特性试验，研究了不同乙醇掺混比例(EO，E10，E20，E30)对混合燃料的蒸馏特性、粘温特性的影响，并对混合燃料的粘温特性试验结果进行数值回归；采用相溶特性试验研究了不同乙醇掺混比例的混合燃料(EO—E100)的相溶特性，以及助溶剂对混合燃料相溶特性曲线的影响。研究结果表明：随着乙醇掺混比例的增加，混合燃料的低热值、十六烷值、粘度逐渐降低，混合燃料的低温蒸馏特性较强，助溶剂可有效解决乙醇柴油的相溶问题。     

生物柴油燃料特性的研究

植物油及其衍生物被用作柴油的代用燃料,其中甲酯被定义为“生物柴油“.燃用生物柴油可降低汽车尾气中有害排放物HC,CO和颗粒物PM的浓度,降低CO2的净排放量.文章着重讨论了生物柴油的热值,CN,IV和低温流动性等参数,认为不饱和双键的数目和位置对燃油品质的影响极大.     

柴油机燃用F-T柴油与0号柴油混合燃料时的性能与排放研究

开展了直喷式柴油机燃用F-T柴油与0号柴油混合燃料时性能与排放的研究,试验用燃料为O号柴油、含25%和50%F-T柴油的混合燃料以及100%F-T柴油.结果表明,在相同工况下,随着混合燃料中F-T柴油比例的增加,滞燃期缩短,预混燃烧放热峰值降低,扩散燃烧放热峰值增大,最高燃烧压力略微降低,发动机的燃油消耗率和有效热效率得到改善.在负荷特性上,发动机的CO2、HC、CO、NOx和碳烟排放随着F-T柴油的加入而降低,其中CO和碳烟在中高负荷时降低幅度最为显著.当F-T柴油掺混比例由0增至25%时,碳烟排放降低效果最为明显,此后随着F-T柴油的继续增加,碳烟排放降低幅度减少.     

柴油机燃用F-T柴油与0号柴油混合燃料时的性能与排放

开展了直喷式柴油机燃用F-T柴油与0号柴油混合燃料时性能与排放的研究,试验用燃料为0号柴油、含25%和50%F-T柴油的混合燃料以及100%F-T柴油。结果表明,在相同工况下,随着混合燃料中F-T柴油比例的增加,滞燃期缩短,预混燃烧放热峰值降低,扩散燃烧放热峰值增大,最高燃烧压力略微降低,发动机的燃油消耗率和有效热效率得到改善。在负荷特性上,发动机的CO_2、HC、CO、NO_x和碳烟排放随着F-T柴油的加入而降低,其中CO和碳烟在中高负荷时降低幅度最为显著。当F-T柴油掺混比例由0增至25%时,碳烟排放降低效果最为明显,此后随着F-T柴油的继续增加,碳烟排放降低幅度减少。     

The effect of biodiesel and bioethanol blended diesel fuel on nanoparticles and exhaust emissions from CRDI diesel engine

Biofuel (biodiesel, bioethanol) is considered one of the most promising alternative fuels to petrol fuels. The objective of the work is to study the characteristics of the particle size distribution, the reaction characteristics of nanoparticles on the catalyst, and the exhaust emission characteristics when a common rail direct injection (CRDI) diesel engine is run on biofuel-blended diesel fuels. In this study, the engine performance, emission characteristics, and particle size distribution of a CRDI diesel engine that was equipped with a warm-up catalytic converters (WCC) or a catalyzed particulate filter (CPF) were examined in an ECE (Economic Commission Europe) R49 test and a European stationary cycle (ESC) test. The engine performance under a biofuel-blended diesel fuel was similar to that under D100 fuel, and the high fuel consumption was due to the lowered calorific value that ensued from mixing with biofuels. The use of a biodiesel–diesel blend fuel reduced the total hydrocarbon (THC) and carbon monoxide (CO) emissions but increased nitrogen oxide (NO_x) emissions due to the increased oxygen content in the fuel. The smoke emission was reduced by 50% with the use of the bioethanol–diesel blend. Emission conversion efficiencies in the WCC and CPF under biofuel-blended diesel fuels were similar to those under D100 fuel. The use of biofuel-blended diesel fuel reduced the total number of particles emitted from the engine; however, the use of biodiesel–diesel blends resulted in more emissions of particles that were smaller than 50 nm, when compared with the use of D100. The use of a mixed fuel of biodiesel and bioethanol (BD15E5) was much more effective for the reduction of the particle number and particle mass, when compared to the use of BD20 fuel.     

Investigation on emission characteristics of alcohol biodiesel blended diesel engine

The present study analyzes the emission pattern of Decanol combined Jatropha biodiesel (JBD100) fueled diesel engine and compared with conventional diesel fuel (D100). Experiments were conducted in a single-cylinder, 4-stroke naturally aspirated diesel engine with an eddy current dynamometer at a constant speed of 1800 rpm. Modified fuel was prepared using a mechanical agitator, in which the Decanol concentration was varied from 10 to 20% to JBD100. The physicochemical properties of Decanol combined biodiesel are within ASTM limits. JBD100 promotes a lower level of carbon monoxide (CO) hydrocarbon (HC), and smoke emissions with notable increases in NO_x and carbon dioxide (CO₂) emissions. An inclusion of 20% Decanol in JBD100 reduces the NO_x, Smoke, CO, and HC emission by 7.4%, 4.4%, 5.7%, and 5.9%, respectively, under full brake power.     

Nozzle flow and atomization characteristics of ethanol blended biodiesel fuel

This study was conducted to investigate the injection and atomization characteristics of biodiesel–ethanol blended fuel. The injection performance of biodiesel–ethanol blended fuel was analyzed from the injection rate characteristics using the injection rate measuring system, and the effective injection velocity and effective spray diameter using the nozzle flow model. Moreover, the atomization characteristics, such as local and overall SMD distributions, overall axial velocity and droplet arrival time were analyzed and compared with these from diesel and biodiesel fuels to obtain the atomization characteristics of biodiesel–ethanol blended fuel.It was revealed that ethanol fuel affects the decrease of the peak injection rate and the shortening of the injection delay due to the decrease of fuel properties, such as fuel density and dynamic viscosity. In addition, the ethanol addition improved the atomization performance of biodiesel fuel, because the ethanol blended fuel has a low kinematic viscosity and surface tension, then that has more active interaction with the ambient gas, compared to BD100.     

Fuel properties of Brassica juncea oil methyl esters blended with ultra-low sulfur diesel fuel

Brassica juncea is a drought-tolerant member of the Brassicaceae plant family with high oil content and a short growing season that is tolerant of low quality soils. It was investigated as a feedstock for production of biodiesel along with evaluation of subsequent fuel properties, both neat and in blends with petroleum diesel fuel. These results were compared against relevant fuel standards such as ASTM D6751, EN 14214, ASTM D975, EN 590, and ASTM D7467. Crude B. juncea oil was extracted from unconditioned seeds utilizing a continuous tubular radial expeller. The oil was then chemically refined via degumming, neutralization and bleaching to render it amenable to direct homogeneous sodium methoxide-catalyzed transesterification. The principal fatty acid detected in B. juncea oil was erucic acid (44.1%). The resulting biodiesel yielded fuel properties compliant with the biodiesel standards with the exception of oxidative stability and kinematic viscosity in the case of EN 14214. Addition of tert-butylhydroquinone and blending with soybean oil-derived biodiesel ameliorated these deficiencies. The fuel properties of B5 and B20 blends of B. juncea oil methyl esters (BJME) in ultra-low sulfur (<15 ppm S) diesel (ULSD) fuel were within the ranges specified in the petrodiesel standards ASTM D975, EN 590 and ASTM D7467 with the exception of derived cetane number in the case of EN 590. This deficiency was attributed to the inherently low cetane number of the certification-grade ULSD, as it did not contain performance-enhancing additives. In summary, this study reports new fuel property data for BJME along with properties of B5 and B20 blends in ULSD. Such results will be useful for the development of B. juncea as an alternative source of biodiesel fuel.     

F-T柴油掺混含氧燃料对高压共轨柴油机性能的影响

在F-T柴油中分别掺混体积分数为10%的甲醇、聚甲氧基二甲醚(PODE)、碳酸二甲酯(DMC),制成3种含氧混合燃料,研究掺混含氧燃料对高压共轨柴油机性能的影响。结果表明:外特性下,相比于0#柴油,M10,P10和D10含氧混合燃料的输出转矩依次降低,动力性低于0#柴油;M10,P10和D10含氧混合燃料的有效燃油消耗率大于0#柴油,经济性降低。在2 000 r/min负荷特性下,相比于0#柴油,M10,P10和D10含氧混合燃料的碳烟分别降低了36.58%,65.76%和67.35%,NOX排放量分别降低了14.82%,11.57%和14.03%,CO排放量分别降低了30.08%,46.88%和38.34%,HC排放量有所升高。     

Influence of fuel properties and composition on NOx emissions from biodiesel powered diesel engines: A review

Biodiesel has proved to be an environment friendly alternative fuel for diesel engine because it can alleviate regulated and unregulated exhaust emissions. However, most researchers have observed a significant increase in NO_x emissions with biodiesel when compared to petrodiesel. The exact cause of this increase is still unclear; however, researchers believe that the fuel properties have been shown to effect the emissions of NO_x. The present work reviews the effect of fuel properties and composition on NO_x emissions from biodiesel fuelled engines. The paper is organised in three sections. The first section deals with the NO_x formation mechanisms. In the following section, the reasons for increased NO_x emissions of biodiesel fuel are discussed. After this, the influence of composition and fuel properties on NO_x emissions from biodiesel fuelled engines has been reviewed. Finally, some general conclusions concerning this problem are summarised and further researches are pointed out.     

Characterization of beef tallow biodiesel and their mixtures with soybean biodiesel and mineral diesel fuel

Tallow is a raw material for biodiesel production that, due to their highly centralized generation in slaughter/processing facilities and historically low prices, may have energy, environmental, and economic advantages that could be exploited. However beef tallow biodiesel have unfavorable properties due the presence of high concentration of saturated fatty esters. One way to overcome these inconveniences is using blending procedures. In this way, blends of beef tallow biodiesel with soybean biodiesel and with conventional mineral diesel fuel were prepared and the quality of the mixtures was monitored with the purpose to study ideal proportions of the fuels. By measurement of the viscosity, density, cold filter plugging point, and flash point, it was demonstrated that tallow biodiesel can be blended with both mineral diesel and soybean biodiesel to improve the characteristics of the blend fuels, over that of the tallow.