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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=685235
• 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 /流体系统能源效率并减少温室气体排放的能源效率的增加的驱动下，研究人员正在利用基于熵的设计作为新兴工具，以识别和最大程度地减少系统流量损失。用于系统分析的热力学第二定律的使用已得到很好的建立，但是在较小的程度上，在整个流场整个流场的局部熵产生速率方面的程度要小得多。特别是，多相流中的熵传输具有突出提高能量转化和效率的新方法的重要潜力。这项研究建议检查在多相流中，用液滴和颗粒在多相流中进行对流热和熵传输过程。提出了数值和实验研究，以更好地了解运输现象。检查了两种特定多相系统的应用：具有铜氯（Cu-CL）周期的热化学氢产生，以及对结冰表面的液滴影响。 2）解决方案准确性； 3）实验测量。这些应用集中在CU-CL周期中的多相流和表面的结冰（即船舶；架空电源线）。在前一种情况下（CU-CL循环），在熔融CUCL的热恢复过程和铜（II）氯化物液滴干燥过程中，液滴的固化发生。在后一种情况（结冰）中，在液滴撞击过程中的热流和表面上的冰积聚包括通过未透明的表面膜和冰的传导，对流冷却，冻结液滴通过冻热的释放，动能能量和动态冷却和过冷的液滴。 ***该研究的目标是开发新的设计工具，以积极地纳入熵和第二定律，以更准确，健壮的预测和测量多相和液滴和颗粒的测量。特定的应用涉及CU-CL周期和表面（船舶；架空电源线）的结冰。这些目标是扩展基于熵设计的方法，以通过最小化熵产生来提高多相流的能效，并通过测量和表征流动不可逆性来对多相过程提供新的见解。该研究计划的另一个目标是使用基于熵的设计来提高CU-CL周期的热效率，以便在大型工业规模的运营规模上证明商业生存能力。**