微泡诱导与超声强化过冷水分阶段结晶的多尺度耦合机理与控制研究

Dynamic-type ice thermal energy storage system based on fluidization ice slurry plays a significant role in electric power peak load shifting, In the research background of supercooled water dynamic ice-making, a new crystallization mode is presented about microbubbles induced with ultrasonic enhanced supercooled water phase nucleation in stages. Some scientific problems of the crystallization process of crystal nucleation and growth, fluid and ultrasonic intervention related have been put forward. A Multiphase, multiscale system is consisted of supercooled water, microbubbles and ice crystals, and three key questions, such as supercooled water dynamic crystallization model, multi-scale modeling and control by stages, have been also analyzed. on this basis, The Euler-Lagrange method and the population balance, microbubble dynamics theory is used, a multi-scale model coupled macroscopic field characteristics and microscopic crystal shape is established, and the mechanism of microbubble and ultrasound factors controlling the water phase nucleation and growth is discussed. By means of high-speed microscopic test and heat analysis, crystal structure and size is researched under the effect of microbubbles induced with ultrasonic enhanced supercooled water phase nucleation in stages. Through the experiment of different scales, multi-scale coupling mechanism of supercooled water crystallization is clarified, the ice phase process of nucleation and growth control law is revealed, and the multi-objective control and optimization of crystallization process also is perfected. I Therefore, this research is very important to develop a new method of supercooled water crystallization, enrich and perfect crystallization theory, and then lay a solid theoretical foundation for expanding the application of ice thermal energy storage and key technology breakthrough.

基于流态化冰浆的动态冰蓄冷系统具有重要的电力移峰填谷作用，以过冷水结晶制取冰浆为研究背景，项目提出一种微泡诱导和超声强化冰晶分阶段成核与生长的结晶模式，针对结晶过程中冰晶成核与生长、流体和超声干预相互关联科学问题，从过冷水、微泡和冰晶所组成的多相、多尺度系统的角度分析过冷水动态结晶模式、多尺度建模与分阶段控制关键问题。采用Euler-Lagrange方法和粒数衡算、微泡动力学理论，建立耦合宏观场特征与微观结晶形为的多尺度模型，探讨微泡特性与超声因素控制过冷水分阶段成核与生长机理；采用高速显微测试和热分析手段，研究微泡诱导一次成核、超声强化二次成核与生长及其对冰晶结构与粒度的影响，通过不同尺度的实验验证，阐明过冷水分阶段结晶的多尺度耦合机理，揭示冰晶分阶段成核与生长的过程控制规律，完善结晶全过程的多目标控制与优化策略。本项研究丰富并完善了结晶理论，为动态冰蓄冷关键技术的突破奠定了理论基础。

近年来，外加超声强化水或溶液结晶的研究己越来越受到科研工作者的重视，超声波及其产生的空化效应对过冷水动态结晶过程具有显著影响，超声空化与过冷水动态结晶过程相互耦合，能控制水的结晶过冷度和改善冰晶尺度特征。超声空化微泡振动、缩放和崩溃等动力学过程促进了晶体的形成，超声波作用下，气泡粒径的变化规律以及气泡的运动特性对结晶过程具有重要影响。.建立联合连续和离散模型的CCDM全耦合模型，采用一种非结构网格颗粒搜索法，计算了颗粒-流体多相系统的流动、传热特性，颗粒间的碰撞、聚并对颗粒粒径及其运动速度、停留时间以及浓度分布具有影响，难以忽略其影响。.研究认为相较于其它方法，粒数衡算理论结合质量衡算、能量衡算，可对耦合传热与微观结晶的现象进行精确量化或优化，比较与分析了不同管壁温度及不同入口流速下管内冰晶颗粒的尺寸及粒度分布特性。粒数衡算与多相流耦合的多尺度耦合结晶建模过程中，在考虑晶粒成核、生长、聚并和破碎的情况下，采用分组法求解粒数衡算方程。模拟了制冰装置内水的动态结晶过程，获得不同温度、溶液流动速度、制冰时间等外界条件下晶粒数密度分布、云图等信息，分析了外界宏观条件对水的动态结晶过程的影响。.搭建了超声作用下过冷水动态结晶显微测试实验台，进行了超声空化泡显微观测实验，观测到超声空化泡具有长大、凝并、崩溃等特征，粒径主要分布在50-100μm范围内；发现超声空化泡诱导了过冷水的异质成核，对水的结晶过冷度具有显著影响，测试了不同冷却速度、不同样品的过冷水动态结晶过程，获得了水的降温曲线和冰晶成核生长过程图像，认为超声波不仅可以提高水的结晶过冷度，还可以有效的细化晶粒。.综上所述，项目提出微泡诱导和超声强化冰晶分阶段成核与生长的结晶模式，对于实现冰浆制备技术的突破，提高动态冰蓄冷系统效率、稳定性及能源利用率具有重要的科学意义和价值。.此外，项目执行期内发表论文11篇，其中6篇论文收录在SCI、EI源刊上，在国际国内学术会议论文集上发表论文11篇；第一发明人授权发明专利13项。培养硕士生7人。获得河南省科学技术进步二等奖1项。