微小尺度结构诱导涡系调控和抑制超临界二氧化碳传热恶化的机理研究

超临界二氧化碳动力循环是新兴能源领域最具应用前景的能量转换系统之一。作为实现热功转换的工作介质，超临界二氧化碳在近临界点参数条件换热过程中面临的传热恶化问题，严重影响换热装置及系统的运行安全，也给流动传热性能的预测带来了极大难度。.拟申请的课题基于通过局部微流动控制改变传热特性的思想，研究微小尺度结构诱导涡系调控和抑制超临界二氧化碳传热恶化的机理。以实验研究为主，有机结合理论分析和数值模拟，研究微小尺度扰流结构在超临界二氧化碳流场中诱导涡系拟序结构的生成、发展和耗散特性，揭示诱导涡系与浮升力引发流动变迁的相互作用机制，掌握诱导涡系对超临界二氧化碳传热恶化特征的调控和抑制机理及作用规律。以试验数据为基础，研究诱导涡系作用下的超临界二氧化碳流动传热共性特征，采用机器学习建模方法，构建诱导涡系作用下超临界二氧化碳传热流阻的量化数学模型。为超临界二氧化碳换热装置的设计和优化提供技术基础。

Supercritical carbon dioxide power cycle system is one of the most promising energy conversion systems in the new energy field. As the working medium of thermal-power conversion, supercritical carbon dioxide faces the problem of heat transfer deterioration in the near critical point condition, which seriously affects the operation safety of heat exchanger, and also brings great difficulty to the prediction of flow and heat transfer performance..In order to regulate local heat transfer characteristics through flow control, the mechanism and prediction method study of micro structure induced vortex regulating and restraining the heat transfer deterioration in supercritical CO2 are performed in this project. Based on the experimental research, combined with theoretical and numerical analysis. it is aimed to study the evolution mechanism of vortex induced by micro structure in the supercritical carbon dioxide flow field, and reveal the interaction mechanism between the induced vortex structure and the flow transformation caused by buoyancy, and master the mechanism, as well as the action law of induced vortex on the heat transfer deterioration characteristics. Based on the test data, it is aimed to study the common characteristics of supercritical carbon dioxide flow and heat transfer with the effect of induced vortex, and constructs a quantitative mathematical model of heat transfer and friction factor by using machine learning method.