Experimental investigations of Dispersion Stability and Thermal Conductivity of Binary Nanofluids
In order to apply the technique that nanoparticles enhance the heat and mass transfer to the ammonia-water absorption refrigeration, 2 types of binary nanofluids were prepared by mixing Al2O3 nanoparticles with polyacrylic acid (PAA) and TiO2 nanoparticles with polyethylene glycol (PEG) to ammonia-water solution respectively. The dispersion stabilities of the binary nanofluids in different mass fractions of nanoparticles and ammonia are investigated by the light absorbency ratio index methods. And the thermal conductivities were measured by transient hot-wire technique on the basis of the dispersion stability. The results show that the dispersion stabilities of the two kinds of binary nanofluids are greatly improved by adding surfactants or increasing the ammonia content. The content of nanoparticles and ammonia as well as the dispersion stability are the key parameters that affect the thermal conductivity of nanofluids. The effective thermal conductivity ratios of the two kind of binary nanofluids increase with the increase of the content of nanoparticles. It is the same with the increase of the ammonia content. The thermal conductivity will decrease with the rising of storage time by the role of natural sedimentation. The thermal conductivity of TiO2 nanofluid is more insensitive to the storage time than Al2O3 nanofluid because of its better dispersion stability.
Yang Liu Yuan Zhang Yanjun Li Du Kai
School of Energy and Environment, Southeast University, Nanjing, China
国际会议
长春
英文
1-6
2011-08-29（万方平台首次上网日期，不代表论文的发表时间）