Falling Film Absorption Performance Enhancement of SiO2 Binary Nanofluids for Absorption Application

A lot of studies on the abnormal enhancement of thermal conductivity of nanofluids have been carried out experimentally and theoretically. Nanofluids are defined as the suspensions where nano-sized particles (under 100-nm diameter) are stably suspended in base fluid. It is well known that the suspended nanoparticles with a high thermal conductivity can greatly enhance the effective thermal conductivity of the nanofluids. Nanofluid is one of the most prospective working fluids of absorption system because it can not only remove the heat effectively, but also improve the mass transfer performance. The objectives of this study are to measure the vapour absorption rate and heat transfer rate for the falling film flow of binary nanofluids with the additives, and to compare each enhancement of heat and mass transfer under the same conditions of binary nanofluid. Also, this study is to observe stability of nanofluids for 10 days. The binary nanofluid is H2O/LiBr with nanoparticle of SiO2 of 10-20 nm in diameter. And the surfactant is 2E1H. The vapour absorption rate and heat transfer rate increase with increasing the mass flow rate of the solution. It is found that the heat and mass transfer enhancements from the nano-particles become higher than those from the surfactant.