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

热交换器在两股流体之间传递能量，是发电、化学加工、食品加工、纸浆和造纸以及制冷行业中许多重要过程的关键部件。如果高质量的软件模型可用于设计，热交换器可以做得更小，成本更低，更节能。然而，目前，只有简化的设计模型可用于涉及两相流和相变的过程，因为传热和传质现象的复杂性。因此，设计者不能准确地预测性能与几何形状或操作条件的细化之间的联系。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目前相对简单的方法，有机会提高这些热交换器的能效和性能。多年来，我的研究计划一直专注于开发先进的，详细的，流体流动，传热和两相流中的传质的数学模型。 最近，我们建立了第一个椭圆形尖锐界面模型的两相降膜流管道。未来五年的研究将集中在开发新的创新理论模型，用于液体和气体-蒸汽混合物的降膜流动，并伴有冷凝，蒸发或吸收现象。这些新模型是精确软件工具的长期愿景的一部分，这些软件工具将能够优化复杂的热交换器。这些工具将帮助设计人员发现设计中的低效之处，并了解设计改进如何影响性能。* 拟议研究工作的高质量将通过严格关注液体和气体-蒸汽混合物之间界面处复杂的传热和传质现象的基本原理、模型的验证以及有效实施模型的新数值求解方法来确保。* * 11名HQP（3名博士，3名硕士，5 B. Sc.）本文提出完成后，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，开发，应用和销售新的软件工具，或为设计或咨询进行CFD建模。新的，更精确的模型和数值求解方法将有利于加拿大工业作为未来的软件工具的基础，这将使设计复杂的热交换器的公司具有竞争优势。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。未来的新模型将适用于冷凝器、蒸发器、吸收器、蒸馏/脱盐系统和热管的设计。**

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.**