Photothermal Energy Conversion in Nanofluids

该奖项由2009年《美国复苏和再投资法案》(公法111-5)资助。热辐射与纳米流体的相互作用尚未得到广泛研究。这项研究涉及当足够强的热辐射入射到纳米流体上时发生的基本热传输现象。具体地说，辐射将导致悬浮的纳米颗粒的局部加热，进而引起液体的加热或沸腾。这一建议通过一系列的实验和分析来解决相关现象。智力上的功绩。这项研究解决了悬浮纳米颗粒选择性吸收热辐射的速度等问题。这项研究的一大部分旨在确定汽泡是否以与加热表面相同的方式从受热的纳米颗粒中成核。因此，将实现启动沸腾所需的入射辐射通量的确定。将确定纳米颗粒对热辐射的响应所获得的温度，以及在纳米颗粒表面启动沸腾所需的过热程度。将寻求最佳的纳米流体颗粒尺寸和颗粒负载分布，以最大限度地吸收太阳能，同时最小化长波辐射。更广泛的影响。基于纳米流体的直接吸收太阳能集热器具有比传统太阳能集热器更高的效率，这是一个有前途的应用开发。这可能会导致具有成本效益和效率的太阳能收集系统。此外，新型化学反应的启动和控制可以通过照射独特的纳米流体来实现。高中生将参与基于太阳能的科学项目。将为本科生开发教学模块。将通过在大众媒体上发表意见和社论文章，努力让公众了解太阳能的研究和开发情况。

AWARD ABSTRACT0932720PhelanThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The interaction of thermal radiation with nanofluids, which are nanoscale colloidal suspensions, has not been extensively examined. This research deals with fundamental thermal transport phenomena that occur when sufficiently intense thermal radiation is incident upon a nanofluid. Specifically, the irradiation will cause localized heating of the suspended nanoparticles, and, in turn, induce heating or boiling of the liquid. This proposal addresses the relevant phenomena through a series of experiments and analyses. Intellectual Merit. This research addresses questions such as the rate at which suspended nanoparticles selectively absorb thermal irradiation. A large component of the research is aimed at determining whether a vapor bubble nucleates from a heated nanoparticle in the same manner as compared to from a heated surface. Hence, determination of the incident radiative flux necessary to initiate boiling will be achieved. The temperatures obtained by the nanoparticles in response to the thermal irradiation, and the level of superheat required to initiate boiling at the surface of the nanoparticle will be determined. The optimum nanofluid particle size and particle loading distributions to maximize solar absorption while concurrently minimizing long-wavelength emission, will be sought. Broader Impacts. A promising application development of nanofluid-based, direct-absorption solar thermal collectors with efficiencies higher than conventional solar collectors. This may lead to cost effective and efficient solar energy collection systems. Furthermore, the initiation and control of novel chemical reactions may be brought about by irradiating unique nanofluids. High school students will be engaged in solar-energy-based science projects. Teaching modules will be developed for undergraduate students. An effort to involve and inform the general public regarding solar energy research and development will be made through publishing opinion and editorial articles in the popular media.