【作者】 蒋青云；

【导师】 朱康玲；

【作者基本信息】 华中科技大学 ， 物理化学， 2007， 硕士

【摘要】 油和水都是国民经济和人民生活中不可替代的资源,随着国民经济的发展,全球性能源危机日渐加剧,以及环境污染的日益严重,油水混合物分离问题受到广泛的重视。旋流式离心分离的方法由于离心力场强度远大于重力场强度,分离速率和效率较高,设备体积小,结构简单,同时避免了化学处理法对水和油资源的二次污染等优点,在各行各业显示出越来越广泛的应用前景。但是目前该法主要是用在对水中脱油的研究,而油中除水的研究则处于初始阶段。针对这种情况,本文以柴油—水为实验物系,从实验和数值模拟两方面对离心力场中液-液两相的传递过程进行了研究,尤其是油中脱水的情况。主要研究内容为:(1)实验研究了两相组成对混合物黏度和相状态的影响,确定了含水量为33 %时为转相点,对应混合物黏度最大。在含水量低于33 %的范围内,油为连续相,水为分散相,随着油中含水量的增加,混合物的黏度也增大。在含水量大于33 %的范围内水为连续相而分散相为油,混合物的黏度则随含水量的增大而下降。(2)通过正交实验,对离心分离器结构参数进行了优化,确定最佳的结构参数为:溢流口直径2mm、底流口直径3.5mm,溢流管长度22mm。(3)实验研究了主要操作条件对分离性能的影响,在最佳的结构参数、原料中水的体积浓度为8.832%,及分流比为0.75时,进口流量在550 L/h~700 L/h范围内,有较高的分离效率,达到85%左右。(4)首次探讨了旋流器内构件对液-液旋流器分离效果的影响,当加实心棒时效果显着,分离效率可达到90%左右,并使原料中含水浓度从8.3%降至1%以下。(5)对液液两相的质量传递过程和动量传递过程进行了理论研究,使用CFD—Fluent软件,通过合理的选择数学模型和正确的设定边界条件,结合流体力学中的旋转流、组合涡理论以及旋流器相关理论和试验结果,对实验条件下的油中除水型旋流器进行了内部流场的数值模拟。在模拟结果、试验结果及理论分析的基础上,提出了实验设备的优化方案。更多还原

【Abstract】 Oil and water are resources which cannot be substituted in the civil economy and the lives of the people. With the development of the national economy, the global energy crisis intensifies, as well as the environmental pollution becomes more serious. Therefore the oil-water mixture separation receives the widespread recognition. Because the centrifugal force field intensity is far bigger than the gravitational field intensity, the segregation rate and efficiency are higher, the equipment volume is small, the structure is simple, and it can avoided the second pollution of the chemistry processing to water and oil resources. The eddy-type centrifugal separation method demonstrates more and more widespread application prospect. But presently this method is mainly used to separate the oil from the water, the research for eliminating water from the oil is just at the preliminary stage.Aimed at this topic, in this paper taking the diesel oil -water as the raw material are researched, make the research of the fluid-fluid two phases’transferring processes in the centrifugal force field from the experiment and the value simulation aspects, especially in the oil dehydrating. The main research contents are followed:(1) The influence of two phases composition on the mixture viscosity and the phase condition was studied. The results showed that the phase change point is when the water content is 33 %, the corresponding mixture viscosity is the biggest. When the water content is lower than 33 %, the oil is the continuous phase, the water is a dispersed phase. The mixture viscosity increases with the increasing of the water content. When water content is bigger than 33%, and the water phase is the continuous phase but the dispersed phase is the oil phase, the mixture viscosity decreases with the increasing of water content drops.(2) Through the orthogonal experiment, the centrifugal separator parameters were optimized. The best structure parameters are: overflow diameter 2mm, underflow diameter 3.5mm, overflow length 22mm.(3) The influence of the main operating condition on the separating performance, when the best structure parameters was investigated, the water volume concentration in the raw material is 8.832%, the split rate is 0.75, and the importing current capacity is within 550 L/h~700 L/h, the higher separation efficiency reaches to about 85%.(4) The influence of the hydrocyclone components on separation efficiency was discussed for the first time, when the solid stick is added, the effect is remarkable, the separation efficiency reach about 90%, and the water content in the raw material changes from 8.3% to fall to below 1%.(5) Using the CFD -Fluent software, the mass transfer process and the momentum transmission processes between the two fluid-fluid phases were theoretically studied, Through reasonably choosing the mathematical model and correctly deciding the boundary condition, combining the circumgyration fluent, the combination whorl theory in the hydromechanics as well as the correlating hydrocyclone theories and the test results, the internal flow field numerical simulation of the water type hydrocyclone under the experimental condition. On the basis of the simulating result, the test result and the theoretical analysis, the optimized plan for the experiment equipment was proposed.更多还原