CAREER: Supercritical Insulation for Energy and Cost Efficiency (SCIENCE)

电力在日常生活中扮演着越来越重要的角色。事实上，我们无法想象现代社会在没有电力的情况下工作。从粮食生产到通信、交通、卫生、金融、教育、研究、执法等等，我们都依赖于它。电力消耗的持续增长以及传统非电气应用的电气化需要更高的功率密度，这通常是当今技术无法实现的，并需要范式转变。有许多新兴技术有可能实现这种转变，它们的共同点是需要具有独特性能的电绝缘材料。该研究项目的重点是了解一类有前途的材料（称为“超临界流体”）的物理特性，以便为各自的应用量身定制。此外，对超临界流体物理性质的基本理解可以填补自然科学其他领域的知识空白。该项目填补了高压工程领域的一个重要空白。多项活动，从事K-12学生，本科生和研究生以及博士后突出，包括在高压工程课程开发。这项工作将采用综合方法，在格鲁吉亚理工学院的既定项目基础上，吸引高中教师、高中生、本科生和研究生。超临界流体表现出不同于理想气体的介电行为，并证明基础研究可以扩展这一领域的知识。虽然一些SCF的化学和热性质已经被研究并记录在文献中，但只有很少的介电研究存在。特别是，没有已知的理论来描述电离，附着，激发和雪崩过程，甚至在均匀场中的击穿行为也是未知的。发展这些过程的透彻理解和制定理论将是具有挑战性的。数值方法和实验技术的结合将用于完善我们的模型，并进一步了解这类材料。对超临界流体介电强度的基本理解有望使直流断路器的设计成为可能，直流断路器是多端高压直流输电的关键部件，能够实现可再生能源的跨大陆交换。预计这种开关设备对于电动飞机和船舶上的DC配电系统同样重要。运输部门的电气化将有助于减少对化石燃料的依赖，并减少二氧化碳的排放。SCF还可以使静电电动机和发电机成为可行的，因为它们能够直接与高压输电网连接，它们的电磁特征大大减少，并且它们不依赖于稀土磁体。除了这些在电力和能源方面的应用，超临界流体可能使高能物理和医疗应用的粒子加速器更便宜，对加速研究和降低医疗成本有很大好处。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Electrical power plays an increasingly important role in everyday life. In fact, we could not imagine modern society to work without electrical power. We depend on it for everything from food production to communication, transportation, health, finances, education, research, law enforcement and many more. The continuous increase in electrical power consumption as well as the electrification of traditionally non-electrical applications, require higher power densities, which are often not achievable with today’s technology and call for a paradigm shift. There are many emerging technologies with the potential to enable such a transition, which have in common that they need electrically insulating materials with unique properties. This research project is focusing on understanding the physics of a promising class of materials, called “supercritical fluids,” so that they can be tailored for their respective application. Furthermore, the fundamental understanding of the physical properties of supercritical fluids could fill knowledge gaps in other areas of natural sciences. This project fills an important gap for workforce in high-voltage engineering. Multiple activities to engage K-12 students, undergraduate and graduate students as well as post-docs are highlighted including curriculum development in the high-voltage engineering. The work will use an integrated approach to engage high school teachers, high school students, undergraduate students and graduate students building on established programs at the Georgia Tech. Supercritical fluids show a dielectric behavior that is different from that of ideal gases and justify fundamental research to expand the knowledge in this area. While chemical and thermal properties of some SCFs have been investigated and documented in the literature, only very few dielectric studies exist. In particular, there is no theory known that describes the ionization, attachment, excitation, and avalanche processes, and even the breakdown behavior in uniform field is mostly unknown. Developing a thorough understanding of these processes and formulating a theory will be challenging. A combination of numerical methods and experimental techniques will be used to refine our models and further our understanding of this class of material. Fundamental understanding of the dielectric strength of supercritical fluids is expected to enable the design of DC circuit breakers, a crucial component of multi-terminal high voltage DC power transmission, enabling transcontinental exchange of renewable energy. Such switchgear is expected to be equally important for DC distribution systems on electric aircraft and ships. The electrification of the transportation sector will help reduce the reliance on fossil fuels and reduce the emission of carbon dioxide. SCFs could also make electrostatic motors and generators feasible with their ability to interface directly with the high voltage transmission grid, their much reduced electromagnetic signature, and their independence from rare earth magnets. Besides these applications in power and energy, supercritical fluids might enable more affordable particle accelerators for high energy physics and medical applications, with big benefits to accelerate research and lowering costs of medical treatment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.