Entropy Based Design and Convective Heat Transfer in Multiphase Flows

基于熵的设计和多相流中的对流传热

• 批准号: RGPIN-2015-05652
• 负责人: Naterer, Greg
• 金额: $ 2.48万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613672
• 关键词: Entropy; Based; Design; Convective; Heat

Driven by the increasing need to improve energy efficiency of thermal / fluid systems and reduce greenhouse gas emissions, researchers are utilizing entropy based design as an emerging tool to identify and minimize system flow losses. The use of the Second Law of Thermodynamics has been well established for system analysis, however to a much lesser extent for spatially tracking the local rates of entropy production throughout a flow field. In particular, entropy transport in multiphase flows has a significant potential to highlight new ways to improve energy conversion and efficiency. This research proposal examines convective heat and entropy transport processes in multiphase flows with droplets and particles. Both numerical and experimental studies are proposed to better understand the transport phenomena. Applications to two specific multiphase systems are examined: thermochemical hydrogen production with a copper-chlorine (Cu-Cl) cycle, and droplet impact on icing surfaces. The research program aims to develop new methods of entropy based design of multiphase systems with droplets and particles, specifically to provide new insight and improvements in: 1) transport processes; 2) solution accuracy; and 3) experimental measurements. The applications focus on multiphase flows in the Cu-Cl cycle and icing of surfaces (i.e., ships; overhead power lines). In the former case (Cu-Cl cycle), solidification of droplets occurs during processes of heat recovery of molten CuCl and drying of copper(II) chloride droplets. In the latter case (icing), the heat flows during droplet impact and ice accretion on a surface include conduction through the unfrozen surface film and ice, convective cooling, release of latent heat by the freezing droplets, and kinetic energy and supercooling of the incoming droplets.  The objectives of the research are to develop new design tools that actively incorporate entropy and the Second Law for more accurate and robust prediction and measurement of multiphase flows with droplets and particles. Specific applications involve the Cu-Cl cycle and icing of surfaces (ships; overhead power lines). The objectives are to extend the methodology of entropy based design so as to improve the energy efficiency of multiphase flows by minimizing the entropy generation and also provide new insight into the multiphase processes by measuring and characterizing the flow irreversibilities. Another goal of this research program is to use entropy based design to improve the thermal efficiency of the Cu-Cl cycle so as to demonstrate commercial viability at a large industrial scale of operation.

在提高热/流体系统能效和减少温室气体排放的需求日益增长的推动下，研究人员正在利用基于熵的设计作为一种新兴工具来识别和最小化系统流量损失。热力学第二定律的使用已经很好地建立了系统分析，然而，在空间上跟踪整个流场的局部熵产率的程度要小得多。特别是，多相流中的熵输运具有重要的潜力，可以突出提高能量转换和效率的新方法。本研究计划探讨多相流中有液滴和颗粒的对流热和熵输运过程。为了更好地理解输运现象，提出了数值和实验研究。研究了两种特定多相系统的应用：铜-氯（Cu-Cl）循环的热化学制氢和液滴对结冰表面的影响。