Fluid Mechanics and Heat Transfer in Multiphase Energy Systems

本提案中概述的研究计划包括基础研究，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为更高效、更经济和更安全的能源系统开发新的设计方法。本计划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，包括相变和不相变。拟议计划中针对的具体系统包括核电站和常规发电厂的部件、热管、热虹吸管、制冷和空调系统以及流量分配系统。关于两相集箱多次放电的工作包括实验和分析研究，目的是准确预测两相集箱的多次放电(模拟事故期间的CANDU集箱-供料器系统)。三通中两相流动的研究(碰撞和合并)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的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热质传递过程。这些结果对核电站安全壳建筑中热管和热虹吸管的设计以及非能动冷凝器的安全分析具有一定的指导意义。总体而言，该研究项目的成果不仅将有助于两相流领域的基础知识，还将对CANDU集线器系统和无源冷凝器的安全分析、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连接点设计模型的生成(目前尚不存在)产生重大影响。拟议研究方案的一个重要特点是培养高素质的人员。7名研究生(博士和硕士)将在该项目中接受高级培训。

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.