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

热交换器在两种流体之间传递能量，是发电、化学加工、食品加工、纸浆和造纸以及制冷工业中许多重要过程的关键部件。如果有高质量的软件模型可供设计，热交换器可以做得更小、更便宜、更节能。然而，由于传热传质现象的复杂性，目前对于涉及两相流和相变的过程只能采用简化的设计模型。因此，设计人员无法准确预测性能与几何形状或操作条件的改进之间的联系。为了获得更好的设计，必须遵循一个昂贵且耗时的原型测试过程。通过创建更精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源效率和性能。******多年来，我的研究计划一直集中在发展先进的，详细的，流体流动的数学模型，传热，以及两相流的传质。我们最近创建了第一个椭圆锐界面模型，用于管道中的两相降膜流动。未来五年的研究将集中于开发新的创新理论模型，用于液体和气体-蒸汽混合物的下降膜流动，包括冷凝、蒸发或吸收现象。这些新模型是精确软件工具长期愿景的一部分，将使复杂的热交换器优化。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。***将严格关注液体和气体-蒸汽混合物界面上复杂的传热传质现象的基本原理，模型的验证，以及有效实现模型的新的数值求解方法，以确保高质量的研究工作。******拟培养11名HQP（3名博士，3名硕士，5名学士）。完成后，研究生将有能力监督其他研究人员的持续模型开发，在一家初创公司工作，开发、应用和销售新的软件工具，或为设计或咨询执行CFD建模。******新的，更精确的模型和数值解决方法将使加拿大工业受益，作为未来软件工具的基础，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.**