Fluid Mechanics and Heat Transfer in Multiphase Energy Systems

本提案中概述的研究计划涉及基础研究，旨在提高我们对能源系统中遇到的流体流动、热量和传质过程的理解。这种更好的理解将使我们能够开发出更高效、更经济、更安全的能源系统的新设计方法。在这个项目中提出的研究跨越了与多相系统相关的相当广泛的研究领域，有或没有相变。拟议计划中针对的具体系统包括核电站和传统发电厂的部件、热管、热虹吸管、制冷和空调系统以及流量分配系统。两相集水头多次排放的研究包括实验和分析研究，旨在准确预测两相集水头的多次排放（模拟事故期间的CANDU集水头-馈水系统）。提出的三通（冲击和结合）两相流的研究旨在产生新的实验数据和理论模型（目前文献中缺乏），可用于推进多相流分配系统的设计，以及确定简单和低成本相分离器的可能设计。回流冷凝的研究将遵循严格的方法来模拟相关的传热和传质过程。这些结果对核电厂安全壳内热管和热虹吸管的设计以及被动冷凝器的安全性分析具有一定的指导意义。总体而言，该研究项目的结果不仅有助于两相流领域的基础知识，而且对CANDU引水系统和无源冷凝器的安全性分析，简单，低成本相分离器的开发以及多相流分配系统中使用的结设计模型的生成（尚未获得）具有重大影响。拟议的研究计划的一个重要特点是培养高素质的人才。7名研究生（博士和硕士）将在该项目接受高级培训。

The research program outlined in this proposal involves fundamental studies aimed at improving our understanding of the fluid flow, heat, and mass transfer processes encountered in energy systems. This improved understanding will enable us to develop new design methodologies for more efficient, economical, and safe energy systems. The studies proposed in this program span a fairly wide area of research relevant to multiphase systems, with and without phase change. The specific systems targeted in the proposed program include components in nuclear and conventional power plants, heat pipes, thermosyphons, refrigeration and air-conditioning systems, and flow distribution systems. The work on multiple discharges from two-phase headers involves experimental and analytical studies aimed for the accurate prediction of multiple discharges from two-phase headers (simulating the CANDU header-feeder system during accidents). The proposed research on two-phase flow in tee junctions (impacting and combining) aims to produce new experimental data and theoretical models (currently lacking in the literature) that could be used in advancing the design of multiphase flow-distribution systems, as well as identifying possible designs for simple and low-cost phase separators. Research on reflux condensation will follow a rigorous approach in modeling the pertinent heat and mass transfer processes. These results are relevant to the design of heat pipes and thermosyphons, and the safety analysis of passive condensers in the containment building of nuclear power plants. Overall, the results of this research program will not only contribute to fundamental knowledge in the area of two-phase flow, but also have significant impact on the safety analysis of CANDU header-feeder systems and passive condensers, the development of simple, low-cost phase separators, and the generation of (yet unavailable) design models for junctions used in multiphase flow-distribution systems. An important feature of the proposed research program is the training of highly-qualified personnel. Seven graduate students (doctoral and master's) will receive advanced training in this program.