基于拓扑优化的相变温控系统导热增强体布局设计理论和方法

Phase Change Material (PCM) which could absorb or release heat during the phase change process can be used as short-term high power cooler and temperature controller for the large fluctuations in the thermal environment，and this thermal control mechanism is significant for the temperature control system design of high-precision equipment in that harsh thermal environment. However, the low thermal conductivity of PCM limits the diffusion of heat and severely impact the ability to control temperature of it. So it is the key to improve the thermal performance of PCM. For the temperature control system with the heat transfer enhancer, the mechanism to enhance the heat transfer performance by embedding the heat transfer enhancer in PCM is discussed and how to obtain the optimal layout design of heat transfer enhancer is studied, the objective of this project is to establish the systematical layout design theories and methodology of thermal conductivity enhancer in PCM based on topology optimization. There are three aspects proposed in this project as follows: (1) The formulation, models and solution methods of topology optimization problem for the layout design of the thermal conductivity enhancer in PCM in different environments such as short-term high-power large fluctuations in the thermal environment will be studied; (2) Fast numerical analysis method of the structural thermal diffusion problem which can consider the effect of natural convection heat transfer in liquid PCM and the process of phase change will be presented and used as an analysis tool for optimization design; (3) Some innovative solutions will be proposed for practical engineering applications, the PCM thermal control experiments will be excused to verify the design solutions and design theory.

相变材料能够通过相变吸热实现短时高发热功率器件的冷却,以及通过不断的相变吸热和放热实现大波动热环境的温度控制。该温控机制对高功率大波动等苛刻热环境下的高精密设备的温控系统设计意义重大。但相变材料低的热传导系数限制了热扩散，严重影响了相变温控能力的发挥。因此，提高相变材料传热性能成为关键问题。本项目针对相变材料内嵌入导热增强体式的温控系统，研究导热增强体对相变温控性能的影响机理及其在相变材料中的布局设计，建立基于拓扑优化的相变材料内嵌导热增强体创新布局设计的系统理论和方法。具体包括： 1）研究短时高功率和大波动热环境等不同热环境下不同要求的相变材料内嵌导热增强体布局设计的拓扑优化问题的提法、模型建立和求解方法； 2）研究建立考虑相变过程和液态相变材料自然对流换热影响的结构热扩散问题的快速等效分析方法，为优化设计提供分析工具；3）针对典型工程应用，提出几种创新布局设计方案并进行试验验证。

密切结合国家重大需求，针对相变材料内嵌入导热增强体式的温控系统，研究导热增强体对相变温控性能的影响机理及其在相变材料中的布局设计问题，建立相变材料内嵌导热增强体创新布局设计的系统理论和方法，取得了一系列具有创新性的研究成果。具体包括：提出相变材料内嵌多孔金属导热增强体的梯度设计理论和方法，建立基于拓扑优化的导热增强体布局优化设计方法。发展了面向热匹配调控的可调热膨胀系数的超材料与超结构设计方法。给出了面向工程应用的三种典型相变换热系统分析与设计。在国内外重要期刊发表学术论文14 篇（SCI论文10篇）， 授权发明专利2项，获批软件著作权 3项，超额完成项目指标。项目执行期间，课题组成员积极开展国际学术交流和实质性合作研究。负责组织和参与组织国内学术会议3次；参加国际会议9人次，其中做特邀报告1 次，参加国内会议14 人次，做邀请报告1次；申请人在基金的支持下晋升为正教授，共毕业硕士研究生9人。