Collaborative Research: Recovery of Waste Heat using Efficient Thermoelectric Devices Based on Laser Sintering of Doped SiGe Nanoparticles

合作研究：利用基于掺杂硅锗纳米粒子激光烧结的高效热电装置回收废热

• 批准号: 1407903
• 负责人: Uwe Kortshagen
• 金额: $ 22.63万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407903&HistoricalAwards=false
• 关键词: Collaborative; Research; Recovery; Waste; Heat

A large amount of energy is wasted through heat dissipation in many industrial processes and consumer systems. This waste of energy occurs as many of the current systems such as refrigerators, automobiles, and industrial process are fundamentally very inefficient and power is wasted as heat. Some of this waste heat could be utilized with low-cost recovery technologies. However, current waste heat conversion devices are very inefficient and are relatively expensive. Hence, research needs to be carried out to find low cost and more efficient solutions for waste heat recovery. The proposed research will investigate a new thermoelectric (thermal-to-electric energy conversion) process for developing efficient waste heat recovery at low cost. The research will also train future scientists and engineers in the energy sector. The principal investigator and co-principal investigator will involve teachers and students in the project and will display materials at the local Science Museum and library as part of outreach and educational activities. The growth of alternative energy technologies will have an important impact on society to meet its energy needs and will lower the nation's dependence on foreign oil thus improving the nation's energy security.Significant progress has been made in thermoelectric power conversion devices with efficiencies reaching over 10%. To realize the commercial potential of thermoelectric devices, further improvements in efficiency, long-term stability at high temperatures and lower cost of fabrication must be realized. A world-wide research effort is being carried out to realize the above goals. Correspondingly, this proposal consists of a multidisciplinary team of a faculty member from the University of Minnesota (Prof. Kortshagen) with research expertise in novel gas phase synthesis of nanoparticles and a faculty member from the University of Virginia (Prof. Gupta) with research expertise in laser processing and device physics. The research plan is to provide understanding of nanograined thermoelectric materials and to achieve further enhancement in efficiency, long-term stability and reduced fabrication costs. The hypothesis of the research is that nanograined materials can enhance the overall thermoelectric device efficiency by reduction of thermal conductivity due to enormous interfacial area causing enhanced phonon scattering and an increase of Seebeck coefficient due to filtering of electron energy producing a higher voltage. Another hypothesis is that nearly fully-dense films and bulk materials can be realized by pulsed laser sintering of nanoparticles to avoid major grain growth by nanosecond heating and cooling rates. The realization of the goals will be achieved through the following tasks: (1) vapor phase synthesis of SiGe nanoparticles of 20 nm in size, (2) p- and n- type doping of SiGe nanoparticles during vapor phase synthesis, (3) nanosecond pulsed laser sintering of vapor phase synthesized nanoparticles of SiGe to achieve close to theoretical density, (4) fabrication of thermoelectric devices and evaluation of high-temperature performance up to 1000 °C, and (5) enhancement of research through collaboration with DOE funded thermoelectric materials and device laboratory at Oak Ridge National Laboratory for fundamental understanding of material and device properties at very high temperatures using state of the art high-temperature characterization facility for crystal structures, electrical and thermal properties.

在许多工业过程和消费系统中，通过散热浪费了大量的能源。这种能源浪费发生的原因是，目前许多系统，如冰箱、汽车和工业过程，从根本上说效率很低，电力被浪费为热量。其中一些废热可以通过低成本的回收技术加以利用。然而，目前的废热转换装置效率非常低，而且价格相对昂贵。因此，需要开展研究，寻找低成本和更有效的解决方案的余热回收。提出的研究将研究一种新的热电（热电能量转换）过程，以开发低成本的高效废热回收。这项研究还将培养未来能源领域的科学家和工程师。首席研究员和联合首席研究员将让教师和学生参与该项目，并将在当地科学博物馆和图书馆展示材料，作为推广和教育活动的一部分。替代能源技术的发展将对满足社会能源需求产生重要影响，并将降低国家对外国石油的依赖，从而提高国家的能源安全。热电转换装置取得重大进展，效率达到10%以上。为了实现热电器件的商业潜力，必须进一步提高效率，在高温下的长期稳定性和降低制造成本。目前正在进行一项世界范围的研究工作，以实现上述目标。相应地，该提案由明尼苏达大学的一位教授（Kortshagen教授）和弗吉尼亚大学的一位教授（Gupta教授）组成的多学科团队组成，前者具有纳米颗粒新型气相合成的研究专长，后者具有激光加工和器件物理的研究专长。研究计划是提供对纳米颗粒热电材料的理解，并进一步提高效率，长期稳定性和降低制造成本。本研究的假设是，纳米颗粒材料可以通过巨大的界面面积导致声子散射增强，从而降低热导率，通过过滤电子能量产生更高的电压，从而增加塞贝克系数，从而提高热电器件的整体效率。另一种假设是，可以通过脉冲激光烧结纳米颗粒来实现几乎全密度的薄膜和块状材料，以避免纳秒加热和冷却速度的主要晶粒生长。目标的实现将通过以下任务来实现：(1)气相合成尺寸为20 nm的SiGe纳米颗粒，(2)气相合成过程中p-型和n型掺杂SiGe纳米颗粒，(3)纳秒脉冲激光烧结气相合成的SiGe纳米颗粒，使其达到接近理论密度，(4)热电器件的制作和高达1000℃的高温性能评价。(5)通过与美国能源部资助的橡树岭国家实验室的热电材料和器件实验室合作，加强研究，利用最先进的晶体结构、电学和热性能高温表征设备，对材料和器件在高温下的性能进行基本了解。