Emergy transport by surface tension-driven convection

通过表面张力驱动的对流进行能量传输

• 批准号: 5188-2008
• 负责人: Ward, Charles
• 金额: $ 3.37万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=449784
• 关键词: Emergy; transport; surface; tension; driven

Water plays such an important role in our daily lives that it has justifiably received enormous scientific attention; however, the polar nature of the molecular interactions in water make it one of the most difficult substances to understand. These interactions have been found to give water a previously undefined surface property, the surface-thermal capacity. This property determines the amount of thermal energy transported by surface tension-driven convection. When water evaporates in the absence of forced or natural convection, and at low temperatures, where radiation is negligible, it had been thought that only thermal conduction transported thermal energy to the water-vapour interface where the phase change process takes place. But these recent studies have indicated that if the design of the evaporator is such that surface tension driven- convection is active, then the thermal energy transported to the interface by surface tension-driven convection can dominate that transported by thermal conduction! In some of our experiments, surface tension-driven convection transported up to 60% of the energy required to evaporate the liquid at the measured rate. Once this new mode of energy transport was understood, a new type of evaporator was designed, built and tested. It proved to be a more efficient evaporator than conventional evaporators, and the University of Toronto has applied for a patent on the evaporator, and established a company that has as its objective the exploitation of the patent. We propose four interrelated projects that have as their objective furthering our understanding of the surface-thermal capacity of water, and extending the range over which it can be applied.

水在我们的日常生活中扮演着如此重要的角色，它无疑受到了巨大的科学关注;然而，水中分子相互作用的极性性质使其成为最难理解的物质之一。这些相互作用被发现赋予了水以前未定义的表面性质，即表面热容量。这个性质决定了由表面张力驱动的对流输送的热能的量。当水在没有强制或自然对流的情况下蒸发时，在低温下，辐射可以忽略不计，人们认为只有热传导才能将热能传递到发生相变过程的水-蒸汽界面。但最近的研究表明，如果蒸发器的设计使得表面张力驱动的对流是活跃的，那么通过表面张力驱动的对流传输到界面的热能可以支配通过热传导传输的热能！在我们的一些实验中，表面张力驱动的对流传输了高达60%的能量，这些能量是以测量的速率蒸发液体所需的。一旦理解了这种新的能量传输模式，就设计、制造和测试了一种新型的蒸发器。它被证明是一种比传统蒸发器更有效的蒸发器，多伦多大学已经申请了蒸发器的专利，并成立了一家公司，其目标是利用该专利。我们提出了四个相互关联的项目，其目标是进一步了解水的表面热容量，并扩大其应用范围。