【作者】 李守华；

【导师】 谭家隆；

【作者基本信息】 大连理工大学 ， 材料学， 2006， 硕士

【摘要】 经济发展与能源密切相关，而目前能源紧缺，这势必给经济的发展带来阻碍，因此寻找合适的替代能源是必要的。柴油作为内燃机燃料，需求量在能源的总消耗中占有很大比例，因此寻找柴油替代燃料成为缓解能源问题的重要途径。已有研究证明乳化柴油具有显著的节约能源和降低污染的效果，受到越来越多的重视。功率超声技术可以制得稳定性好、质量高的乳化柴油，因此被广泛地应用于柴油乳化领域。但是对于功率超声乳化柴油的原理、机制以及超声能量在乳化过程中的分配情况的研究还鲜有报道。本研究通过考察功率超声声强、作用时间、温度等因素对乳化液内小液滴平均粒径及其分布的影响，建立了功率超声乳化柴油的热力学模型，借助模型对实验结果进行理论分析。 将乳化剂Span 80(亲油性乳化剂HLB值为4.3)和Tween 80(亲水性乳化剂HLB值为15)按一定比例混合得到复配乳化剂，然后将一定量的复配乳化剂加到柴油中，然后在功率超声作用于柴油的过程中，将水逐滴加入。 在一定声强的功率超声作用下，乳化液液滴平均粒径随作用时间的延长而减小，但不是无限减小的，存在临界粒径。达到临界粒径之前，小液滴粒径分布随作用时间延长而趋于均匀。在临界粒径之前，同一时间下，功率超声声强越大，乳化液出现临界粒径的作用时间越短，临界粒径尺寸越小。温度是乳化液制备过程中至关重要的影响因素：对比绝热与恒温两种条件—绝热条件下的小液滴粒径达到临界粒径后，随作用时间的延长而增大；恒温条件下的小液滴粒径达到临界粒径以后，不随作用时间的延长而改变。 在上述实验结果的基础上，本研究对功率超声乳化柴油过程进行了热力学分析，得到了乳化过程中体系内能量的分配情况以及功率超声作用过程中和作用后体系状态的变化。更多还原

【Abstract】 The development of economy is close to energy source, but at present, the source is on short that would hinders the development of economy. So looking for compatible substitute energy source is quite necessary. As the main internal-combustion engine fuel, diesel oil take a great proportion of the consumption of energy source. Therefore, to get an alternative diesel oil is a primary method to solve the problem of source lack. It has been reported that combustion of emulsified diesel oil could save oil and reduce pollution markedly. So it is put on more and more important position. The diesel oil emulsion made by power ultrasound has good quality, and power ultrasound is widely used in emulsion field. But there is no theory research on effect of power ultrasound parameters on emulsion and the action mechanism. This research do great work on building ultrasound emulsified thermodynamics model which can give explanation of the experimental results, through seeing about the effect aspect of power density, process time and temperature, and so on.In term of fixed proportion to mix the surfactant span 80 (a lipophilic surfactant with HLB = 4.3) and tween 80 (a hydrophilic surfactant with HLB=15), then adding them into diesel oil and when the diesel oil is being dealt by ultrasound, adding water drop by drop.At constant power density, the mean size of emulsion drop reduces versus time until reach the critical size. Before the critical size arriving the distribution of droplet size is vary versus time and becomes uniformity. At constant duration, the larger density of power ultrasound, the time is shorter, and the critical size is smaller. Before critical size, the droplet distribution becomes uniformity as the power density increases. Temperature is one of the most important effect factors: comparing heat preservation and constant temperature conditions, the size of droplet under the former condition increases after critical size, but keep the same size for the latter condition.This research analyses the experimental result through thermodynamics methods and educes the energy distribution and the change in the system.更多还原