首页>
外文期刊>Nanoscience and Nanoengineering
>Nanostructured Architectures on the Heater Surface at Nanofluids Boiling and Their Role in the Intensification of Heat Transfer
【24h】
Nanostructured Architectures on the Heater Surface at Nanofluids Boiling and Their Role in the Intensification of Heat Transfer
A major problem of modern science and industry is intensification of a heat transfer. One of the most promising ways for its solution is use of nanofluids as heat carrier and coolant that is capable to operate at high specific heat fluxes. In the course of nanofluids boiling porous sediments of nanoparticles are formed on the heating surfaces and provide a stable nucleate boiling mode. Whereas the specific heat fluxes grow up to 300-400% compared with water there is observed a significant increase of heat transfer coefficients, which is probably associated with the increase of porosity, roughness and wettability of heating surface. In order to clarify this question we studied the process of nanostructures formation in the course of different nanofluids boiling on the surface of Ni/Cr- heater. The morphology and topography of artificial coatings were studied and the results were compared with the values of the basic boiling parameters: specific heat flux and heat transfer coefficient. The conclusions based on experimental results are: maximum values of the specific heat flux and the heat transfer coefficient refer for nanofluids consisting of a mixture of nanoparticles with anisometric shape. While boiling process in on they are able to create nanostructures with the most developed surface roughness and porosity. Most likely, this is due to the highest density of nucleation sites and the area of heat transfer surface formed in these nanostructures.
展开▼
