乙醇与柴油互溶性研究及混合燃料对柴油机排放性能的影响

乙醇可由生物质能源转化得到,可作为含氧清洁燃料与柴油混合用作柴油机燃料。以正丁醇为助溶剂促进乙醇在柴油中的溶解,形成稳定的混合燃料;同时以该混合燃料作为柴油机燃料,参照GB 20891-2014《非道路移动机械用柴油机排气污染物排放限值及测量方法(中国第三、四阶段)》测试柴油机的常规排放、非常规排放规律,探究其对柴油机排放性能的影响。结果表明,正丁醇作为助溶剂,可促进乙醇与柴油互溶,在乙醇与正丁醇的体积比接近1∶1时可形成稳定的混合燃料,静置10个月以上不分层,在-5℃左右不分层,可用作柴油机燃料;正丁醇的添加方式对其助溶效果影响较小;负荷特性下,与燃用纯柴油相比,柴油机燃用混合燃料时,CO和NO_x排放量分别减少13.96%～46.73%和1.35%～16.92%,VOCs排放量增加1.94%～32.43%,PM_(2.5)排放量减少5.81%～44.37%。柴油与醇类燃料混合燃烧可以实现在减少NO_x排放量的同时减少PM_(2.5)排放量。     

柴油性能对车用发动机的影响

柴油是柴油机的主要燃料,其使用性能和技术指标的控制对发动机正常工作有着深远的影响。文章简要介绍了发动机的工作原理,综述了柴油的物理化学性质对发动机的影响。     

Thermal Evaluation of Diesel/Hydrogen Peroxide Fuel Blend

Thermal properties of fossil fuel are the key fundamental characteristics, which can distinguish any compound as a potential fuel. The performance of diesel fuel blend along with stability and solubility parameter designs are evaluated. The results from the experimental study indicate that the increase in hydrogen peroxide (H₂O₂) amount enhances the cetane number of diesel fuel blend significantly. However, the calorific value decreases as compared to pure diesel fuel. All values performed well according to the ASTM D‐975 diesel testing method. The thermodynamics of the prepared fuel blends also revealed that substantial solubility and diesel/H₂O₂ blend stability are provided even at lower temperatures. Such blends can be used as a feasible replacement of pure diesel fuel.     

Formulation of Canola-Diesel Microemulsion Fuels and Their Selective Diesel Engine Performance

Vegetable oils have been considered as an alternative to diesel fuel due to their comparable properties and performance. However, the high viscosity of vegetable oil causes engine durability problems with long-term usage. Vegetable oil viscosity can be reduced by blending with diesel fuel in thermodynamically stable mixtures using microemulsion fuel formulation techniques. This work focuses on the formulation of microemulsion fuels comprising diesel fuel and canola oil as the oil phase with ethanol and sec-butanol as viscosity reducers as well as 1-octanol and oleyl amine as surfactant/cosurfactant. Selective tests on an instrumented diesel engine were performed for formulated microemulsion fuels and No. 2 diesel fuel for comparison. The results show that formulated microemulsion fuels have fuel properties that meet the ASTM requirements for viscosity, cloud point, and pour point for biodiesel. Even more important, they have phase stability over a wide range of temperatures (−10 to 70 °C). Although all of the microemulsion fuels showed higher fuel consumption than diesel fuel, some of the microemulsion fuels had significantly reduced CO and NO_x emissions as well as reduced particulates when compared to baseline diesel fuel. The research demonstrates the potential of these microemulsion fuels as alternative to neat diesel fuel.     

增压柴油机气门导管橡胶密封性研究

针对柴油机气门导管的漏油和磨损问题，提出了气门导管安装不同密封材料的密封结构,从理论上对橡胶密封结构的作用机理进行了分析,并通过不同结构的部件和整机的漏油量对比试验，结果证实改进装配工艺后使密封件安装完好对密封机油是有效的，且密封件采用氟橡胶的效果最明显。此结构既能减少进入进、排气道的机油量,降低颗粒排放,又能减轻气门杆和气门导管的磨损，从而在实际机型中得到应用。     

注塑级PPES/PPS共混合金热性能及结晶性能的研究

通过熔融挤出、注塑成型的方法制备了配比不同的含二氮杂萘酮结构的聚芳醚砜(PPES)和聚苯硫醚(PPS）的共混物，对材料的热性能及结晶性能进行了研究。热失重研究表明，在所组成范围内PPS的加入并未降低共混物的热性能，但使共混物的热变形温度有所降低；PPES的加入使PPS的结晶受到阻碍，当PPES质量分数达80％时，PPS产生了晶格缺陷，从而不能形成完善的球晶，退火过程有利于提高共混物的热变形温度，使PPS形成更完善的球晶。     

聚乙烯醇-羟乙基纤维素共混膜的制备及性能

以羟乙基纤维素(HEC)和聚乙烯醇(PVA)为原料,通过溶液浇铸共混制备不同含量的羟乙基纤维素/聚乙烯醇(HEC/PVA)共混膜,用傅立叶红外分析(FT-IR)、扫描电子显微镜(SEM)进行表征,并考察了HEC/PVA膜的力学性能.结果表明:当PVA质量含量为40％时,共混膜的力学性能较纯HEC有显著提高;温度越低膜的溶胀度越小,但当温度升到60℃以后,膜的溶胀度几乎不变化,说明膜在高温下尺寸的稳定性很好;随着温度的升高,膜的含水率不断增加,制备的共混膜的使用温度不要超过80℃.     

温度敏感性PVP/CHI共混水凝胶的制备与溶胀性能

制备了戊二醛交联的PVP/CHI共混水凝胶,讨论了CHI∶PVP(质量比)、引发剂用量、交联剂用量、反应温度等主要条件对凝胶溶胀性能的影响.温度敏感性实验表明,凝胶分别在33℃、37℃出现最大平衡溶胀率,即具有多重温度敏感性.随着PVP含量的升高,凝胶在33℃时对温度的敏感程度升高、37℃时对温度的敏感程度降低,交联度增加使凝胶的温度敏感程度降低.另外,PVP含量升高使CHI结晶度降低,进而使PVP/CHI凝胶的玻璃化转变温度Tg降低.     

微生物丙三醇的生产及研究进展

丙三醇通常是由油脂皂化,水解和丙烯合成来进行生物的化工产品,由微生物生产是新的研究开发领域。生产丙三醇的微生物有醇酒酵母,细菌、耐渗透压酵母、单细胞藻类。微生物合成丙三醇在生物原料、生产机制、提取等方面各具特点。虽然目前微生物途径丙三醇产业化潜力仍面临较大竞争压力,但从近来对微生物丙三醇的研究进展看,可以预见随着对丙三醇消费的不断增加和产品成本的降低,因地制宜发展微生物生产丙三醇前景是好的。     

载热体加热炉在甘油生产中的应用

甘油的生产大多采用蒸汽加热方式进行蒸发、蒸馏,在蒸汽供应量不足的情况下,用载热体加热炉替代蒸汽供热,消除了二效蒸发蒸汽冷凝水热量损失的现象,综合能耗下降10%.     

Determination of Acylglycerols and Glycerol in Castor:Soybean Biodiesel Blend Produced by a Base/Acid-Catalyzed Process

This paper describes the production of the methyl biodiesel blend of hydroxylated vegetable (castor oil) and soybean oils by a base/acid‐catalyzed process and the first simultaneous determination by gas chromatography of the levels of total and free glycerol, mono‐, di‐ and triacylglycerols based on the standard method ASTM D 6584. Best results were observed for transesterification carried out in 6:1 (methanol:oil), sodium hydroxide 1 % w/w at 60 °C for 1.5 h. The analytical method not only produced curves with good linearity, but also had a coefficient of determination (r²) above 0.997 and accuracy between 70 and 141 % at relative standard deviations (RSD) lower than 10 %. The matrix effect (ME) was investigated and only diolein was found to have a significant matrix effect. The method was robust when applied to different chemical compositions of biodiesel. Results showed that the acid value and the contents of mono‐, di‐, and triacylglycerols, total and free glycerol were within the limits set by standardized methods and that biodiesel may be produced from soybean and castor oil blends.     

高原条件下柴油机性能影响及恢复研究进展

柴油发动机是物资运输、工业生产、工程建筑和军用装备重要的动力源,高原环境中大气压力、环境温度、空气含氧量均不同程度降低,导致柴油机缸内燃烧急剧恶化,对其使用状况产生较大限制。总结了高原环境对柴油机动力性能、起动性能、排放特性等方面造成的影响,从增压系统优化、喷油策略优化、含氧燃料优化3个角度,综述了高原条件下柴油机性能恢复的前沿技术,并探讨了下一步的可能发展方向,包括燃烧机理研究、高原含氧燃料、富氧燃烧技术。     

天然气/柴油双燃料发动机研究现状分析

随着世界传统能源的日益匮乏,以及排放污染问题的日益加重,天然气天然气/柴油双燃料发动机的开发和应用成为发动机行业新的研究热点。从传统燃料发动机面临的问题、新型燃料发动机发展前景和天然气发动机的特点分析了天然气/柴油双燃料发动机研究背景;综述了天然气/柴油双燃料发动机研究现状,提出了天然气/柴油双燃料发动机需要继续研究的方面,对开发和设计天然气/柴油双燃料发动机提供了一定的参考价值。     

天然橡胶/顺丁橡胶并用胶在汽车发动机悬置材料中的应用

模拟天然橡胶(NR)/顺丁橡胶(BR)并用胶作汽车发动机悬置材料在使用过程中的受力状态,研究NR/BR并用胶的物理性能和阻尼性能。结果表明:随着BR用量增大,NR/BR并用胶的t_(10)和t_(90)延长,F_(max)增大,强伸性能降低,压缩疲劳温升提高,老化后拉伸强度和拉断伸长率降幅增大;NR/BR并用可以避免NR在低温下阻尼过高问题;为避免NR/BR并用胶压缩疲劳温升加剧,NR/BR并用比不宜大于70/30。     

基于WinCC生产监控系统在柴油机涂装线上的应用

介绍了基于西门子上位软件WinCC的生产监控系统在柴油机整机涂装线的应用情况,从生产数据记录、设备运行状态实时监控、故障记录及查询等几个方面做了详细的应用情况分析,生产监控系统对于提高产品涂装质量、减少故障停工维护时间、提高生产效率有重大作用。     

单硬脂酸甘油酯的生产及应用

就单硬脂酸甘油酯生产工艺及应用作一概述。     

V-W-Ti-Si/堇青石催化剂柴油机脱硝反应动力学

采用固定床反应器,以自制的V-W-Ti-Si/堇青石为催化剂,在消除内外扩散影响的基础上,考察了氨选择性催化还原反应(NH_3-SCR)过程,建立了幂指数型的脱硝反应动力学模型,并通过线性拟合确定了模型参数。结果表明,在自制的V-W-Ti-Si/堇青石催化剂上,NO,NH_3和O_2的反应级数分别为0.93,0,0.24,活化能为25.99 kJ/mol,模型拟合的相对误差在10%左右,可用于指导柴油机尾气脱硝催化剂反应过程研究与开发。     

甘油的生产应用现状及技术开发新进展

甘油用途广泛,是一种极好的平台化学物,但传统需求量难以消化近年突增的甘油产品,以其为原料开发高附加值产品渐成潮流。介绍了甘油的生产应用现状及开发利用新途径,指出对其应用技术开发具有广阔前景。