【作者】 程香；

【导师】 陈志平；

【作者基本信息】 浙江大学 ， 化工过程机械， 2007， 硕士

【摘要】 煤浆制备装置作为煤液化工艺初始阶段的关键设备直接影响到煤液化工艺的整个阶段。目前，用于煤液化的煤浆制备装置鲜有报道，随着煤液化项目的不断深入开展，对煤浆制备装置的研究迫在眉睫。国内外采用计算流体力学(CFD)方法对纵型固液混合装置内的多相流动所进行的理论研究的文献相对较少。本文应用CFD软件FLUENT 6.2，选用多重参考系法(MRF)、RNG k-ε湍流模型以及Mixture混合物多相流模型，首先对设计工况下煤粉捏合器的内部流动过程进行了数值模拟，得到了详细的内部流场分布；然后，用实验数据对模拟结果进行了验证，结果表明两者吻合较好，证明该种数值模拟方法是正确可靠的。同时针对两种不同的煤粉进料方式-竖直管进料和斜插管进料，进行了数值分析比较，根据两种进料方式下内部流场的分布状况，判断出煤粉从竖直管进料要比从斜插管进料好。为了进一步对煤粉捏合器进行优化设计，按照上述方法本文从改变旋转轴的转速、改变煤粉跟溶剂油的进口流量、改变搅拌桨叶形式以及改变搅拌桨叶外端与混合槽壁间距几个方面重新进行了数值模拟与分析。结果表明，对于该混合槽，最优的设计参数为旋转轴的转速和物料的进口流量都采用设计值、桨叶采用斜45°圆盘涡轮桨、桨叶外径取Φ253mm。本文的研究结果对煤浆制备装置的设计与优化有一定的参考意义。更多还原

【Abstract】 As the key equipment of the initial stage of coal liquefaction technology, coal slurry preparation device directly affects the entire coal liquefaction process. Currently, there are rarely reports about coal slurry preparation device which is applied in the coal liquefaction industary. With the continuous deepen of coal liquefaction project, the research on coal slurry preparation device is imminent. At home and abroad, few theoretical researches on the multiphase flow in longitudinal solid-liquid mixing device by using computational fluid dynamics(CFD) method have been done.Under design conditions, the flow in coal kneading device was studied in this paper by using CFD package FLUENT 6.2 . The multi-reference frame(MRF)、 RNG k-ε tuburlent model and Mixture multi-phase flow model were used in the simulation. In terms of this method, a detailed internal flow distribution was obtained by numerical simulating the flow of coal kneading device. Then, the experimental datum were used to verify the simulation results, and they agreed very well, which proved that this numerical simulation method was accurate and reliable. At the same time, two different coal feeding methods - coal from the vertical pipe and from the inserted tube, were separately simulated and analyzed. According to the internal flow distributions under two different coal feeding methods, we made a judgement that the former feeding method was better than the latter.To further optimize the coal kneading device, some other simulations were done by changing the rotating speed of shaft 、 the import flow of coal and oik the form of impeller and the space between blade outer end and mixing tank.Results showed that: for this mixing tank, the given design values of rotating speed of shaft and the import flow of materials are optimal, and impeller which is six-slant-blade Rushton turbine with 253mm diameter should be adoptedThe results are of reference to the design and optimum of coal slurry preparation device.更多还原