Development of Advanced Numerical Models for Two-Phase Heat and Mass Transfer Processes in Energy Systems

热交换器在两个流体之间传递能量，是发电、化学加工、食品加工、纸浆和造纸以及制冷行业许多重要过程中的关键部件。如果有高质量的软件模型可供设计，热交换器可以变得更小、更便宜、更节能。然而，由于传热传质现象的复杂性，目前只有简化的设计模型可用于包含两相流和相变的过程。因此，设计者无法准确预测性能与几何形状或运行条件的改进之间的关系。为了获得更好的设计，必须遵循昂贵且耗时的原型测试过程。通过创建更准确的理论模型来取代当前相对简单的方法，存在着提高这些换热器的能效和性能的机会。 多年来，我的研究计划一直专注于开发先进的、详细的两相流中流体流动、传热和传质的数学模型。我们最近建立了第一个椭圆尖界面模型，用于管道中的两相降膜流动。未来五年提出的研究将集中于开发新的创新理论模型，以研究具有冷凝、蒸发或吸收现象的液体和气体-蒸汽混合物的降膜流动。这些新型号是精确软件工具的长期愿景的一部分，这些工具将使复杂的热交换器能够进行优化。这些工具将帮助设计师发现设计中的低效之处，并了解设计改进如何影响性能。 通过严格关注液体和气体-蒸汽混合物之间复杂的传热和传质现象的基本原理，对模型的验证，以及有效实施模型的新的数值求解方法，将确保拟议研究工作的高质量。 培训HQP 11人(博士3人，硕士3人，学士5人)。是提议的。完成后，研究生将有能力监督其他研究人员继续进行模型开发，在初创公司工作以开发、应用和销售新的软件工具，或执行CFD建模以进行设计或咨询。 新的、更准确的模型和数值解方法将使加拿大工业受益，因为它将成为未来软件工具的基础，这些工具将为设计复杂热交换器的公司提供竞争优势。缩短上市时间和优化设计将降低这些公司的开发、制造和运营成本。未来的新型号将适用于冷凝器、蒸发器、吸收器、蒸馏/海水淡化系统和热管的设计。

A heat exchanger transfers energy between two fluid flows and is a key component in many important processes in the power generation, chemical processing, food processing, pulp and paper, and refrigeration industries. Heat exchangers could be made smaller, less costly, and more energy efficient if high quality software models were available for design. Presently, however, only simplified design models are available for processes involving two-phase flow and phase change because of the complexity of the heat and mass transfer phenomena. Thus, designers cannot predict accurately the connection between performance and the refinement of the geometry or operating conditions. A costly and time-consuming prototype testing process must be followed to obtain a better design. The opportunity exists to improve the energy efficiency and performance in those heat exchangers by creating more accurate theoretical models that will replace the current relatively simple methods. Over many years, my research program has focused on the development of advanced, detailed, mathematical models of the fluid flow, heat transfer, and mass transfer in two-phase flows. We recently created the first elliptic sharp-interface model for two-phase falling film flow in ducts. The research proposed for the next five years will focus on developing new innovative theoretical models for flows of a falling film of liquid and a gas-vapour mixture with condensation, evaporation, or absorption phenomena. These new models are part of a long term vision of accurate software tools that will enable optimization of complex heat exchangers. The tools will help designers find inefficiencies in designs and see how design refinements affect the performance. The high quality of the proposed research work will be ensured by a strict focus on the fundamentals of the complicated heat and mass transfer phenomena at the interface between the liquid and the gas-vapour mixture, on validation of the models, and on new numerical solution methods to efficiently implement the models. The training of 11 HQP (3 Ph.D., 3 M.Sc., 5 B.Sc.) is proposed. After completion, graduate students will have the ability to supervise continued model development by other researchers, to work at a start-up company to develop, apply, and sell new software tools, or to perform CFD modelling for design or consulting. The new, more accurate models and numerical solution methods will benefit Canadian industry by serving as the basis for future software tools that will give a competitive edge to companies that design complex heat exchangers. Reduced time to market and optimized designs will reduce development, manufacturing, and operating costs for those companies. Future new models will be applicable for the design of condensers, evaporators, absorbers, distillation/desalination systems, and heat pipes.