CONVECTIVE HEAT TRANSFER BEHAVIOR OFAQUEOUS TiO2 NANOPARTICLES SUSPENSION (NANOFLUIDS) FLOWINGTHROUGH COOLING STAVE

摘要

As a kind of Energy-saving and environmentally friendly material, more and more studies on the industrial application of nanoparticles suspension were carried out. Addition of nanoparticles added into the base liquid markedly enhanced thermal conductivity of base liquid. It could improve the heat transfer capacity of the heat exchange device as well. In this work, a new experimental system including a cooling stave is developed to simulate the industrial process. To analyze the convective heat transfer behavior of aqueous TiO2 nanoparticles suspension, three kinds of nanoparticles suspension with different concentration are formulated by two-step method. The convective heat transfer coefficients of nanoparticles suspension are then measured while they’re flowing through the cooling stave. Given the temperature of hot surface, the convective heat transfer coefficient increases with the concentration and the effect of particle concentration seems to be similar in various velocity. However, the convective heat transfer coefficient enhancement decreases with increasing temperature on the hot surface of the stave. The enhancement of suspensions heat transfer convective is analysis based on inhomogeneous fluid behavior. The experimental result also indicates there is huge potential for using this special kind of cooling medium in the steel industrial process.