Innovative Cooling Technologies Using Nanofluid/Nanosurface Heat Transfer Media

点击翻译按钮获取中文摘要

The use of nano-textured surfaces and nanofluids as heat transfer media is an emerging technology in the field of thermalhydraulics and can significantly benefit Canada in the areas of energy technologies such as solar-thermal energy production, higher efficiency building support systems, and to provided increased levels of safety in high energy systems such as natural gas and nuclear power plants. These systems all employ some form of convective heat transfer and their operational efficiency and safety are dependent on these heat removal mechanisms. This work is directly applicable to these energy systems and to the field of nanotechnology and makes use of advanced instrumentation not previously used in the field of nanofluids. While much applied research on heat transfer enhancement using mechanical methods has been performed, and even some using nanofluids, relatively few systematic studies exist wherein the surface and nanofluid media have been simultaneously studied or optimized. Within this limited available literature the measurement of local velocity, temperature fields and bubble dynamics are lacking however, some of our work indicates that the "boiling crises" in two-phase flow can be increased 3-fold. A general review of most nanofluid boiling research shows that there is a large variability in outcomes which may result from nanofluid agglomeration during testing, lack of surface characterization or control, or poorly characterized nano-dispersions. The objective of this research is to understand the fundamental mechanisms which improve the heat transfer in nano-textured surfaces and nanofluids and provide a high quality set of experimental data with well characterized particles and surfaces. A further extension of nanofluid coolants is in the potential production of medical isotopes. Nano-dispersions have excellent characteristics (small size, large surface areas, and good separation characteristics) for isotope production, and their use in nuclear reactors could solve many of the isotope production problems in Canada today. In order to understand and apply this technology, we will endeavour to provide the highest quality experimental data in this field to date.