复合定形相变材料混炼装置的研制及分散工艺研究

发布时间：2018-12-15 10:55

【摘要】：共混法是制备相变储能材料的一种常用方法,通过将相变材料和支撑材料组分在熔融状态下进行机械共混,从而得到组分均匀的储能材料,由于共混制备工艺简单,生产成本比较低,近年来得到研究人员的广泛重视。目前的共混通常是通过简单混合实现的,但是在混合过程中难以改变材料结构特征,从而难以使制备材料的性能得到根本的提升,通过改变材料混合时的场环境(热场、真空场和超声场等)使材料的结构特征发生改变,进而提升材料的性能是在机械共混的基础之上逐步发展起来的制备方法。本文设计并搭建了一套基于超声辅助真空作用的混炼装置,并用于石墨烯纳米片/聚乙二醇(GNPs/PEG)相变材料的制备,通过多物理场耦合仿真分析确定出制备装置机械部分的参数,并通过FLUENT软件模拟了不同条件下的混合特性,并与实验结果进行了比对。本文的主要内容如下:1.利用UG设计实验装置的腔体部分,在考虑复合场作用条件下腔体和盖口处密封圈所能承受的压强的基础上,通过ANSYS workbench进行多物理场耦合仿真,确定腔体内径、壁厚等关键参数。2.在结构设计的基础上,搭建一套超声辅助真空混炼装置,根据实验要求对超声波发生器,真空泵和热电偶等装置选型,并搭建起一套满足多种材料制备工艺需求的实验系统。3.在GAMBIT绘制流体网格的基础上,利用FLUENT软件通过动网格的方法模拟复合场下复合相变材料的流变性能,并分析不同场强(超声波功率和真空度等)对材料混合效果的影响。4.通过制备石墨烯纳米片/聚乙二醇(GNPs/PEG)复合材料,测试实验装置的共混效果,在实验过程中,通过选取不同的实验条件,比较不同实验条件下对复合材料热稳定性、抗热变形性和热导率等指标的影响,并与仿真结果进行比较。
[Abstract]:Blending is a common method for preparing phase change energy storage materials. By mechanical blending of phase change materials and support materials in molten state, homogeneous energy storage materials can be obtained. The cost of production is relatively low, in recent years, researchers pay more attention to it. At present, blending is usually achieved by simple mixing, but it is difficult to change the structural characteristics of the materials during mixing process, so it is difficult to improve the properties of the prepared materials fundamentally, by changing the field environment (thermal field) when the materials are mixed. The vacuum field and ultrasonic field make the structure of the material change and then improve the properties of the material. The preparation method is developed step by step on the basis of mechanical blending. In this paper, a mixing device based on ultrasonic assisted vacuum is designed and built, and it is used in the preparation of graphene nanochip / polyethylene glycol (GNPs/PEG) phase change material. The parameters of the mechanical part of the preparation device are determined by multi-physical field coupling simulation. The mixing characteristics under different conditions are simulated by FLUENT software, and the results are compared with the experimental results. The main contents of this paper are as follows: 1. The cavity part of the experimental device is designed by using UG. On the basis of considering the pressure of the cavity and the sealing ring at the cover under the action of the composite field, the coupling simulation of the multi-physical field is carried out through ANSYS workbench to determine the cavity inner diameter. Key parameters such as wall thickness. 2. On the basis of structural design, a set of ultrasonic assisted vacuum mixing device was built, and the ultrasonic generator, vacuum pump and thermocouple were selected according to the experimental requirements. And set up a set of experimental system to meet the needs of various materials preparation process. 3. On the basis of drawing fluid mesh by GAMBIT, the rheological properties of composite phase change material under composite field are simulated by FLUENT software through dynamic grid method, and the influence of different field intensity (ultrasonic power and vacuum degree etc.) on material mixing effect is analyzed. 4. By preparing graphene nanosheet / polyethylene glycol (GNPs/PEG) composite, the blending effect of the experimental device was tested. In the process of the experiment, the thermal stability of the composite was compared under different experimental conditions by selecting different experimental conditions. The effects of thermal deformation resistance and thermal conductivity are compared with the simulation results.
【学位授予单位】：陕西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

【参考文献】