Experimental Study on Pool Boiling Heat Transfer of Perfluoroalkyl Surfactant Solutions

In this work, pool boiling heat transfer of three kinds of aqueous perfluoroalkyl surfactant solutions were investigated experimentally. Specifically, applied surfactants were Perfluoroalkyl Quaternary Ammonium Iodide (PQAI), Perfluoroalkyl Phosphate (PPA) and Perfluoroalkyl Polyether (PPE) in the concentration range of 5-400 ppm. It is found the perfluoroalkyl surfactants have outstanding effect on reducing the surface tension of based fluid. The surface tension of water could be reduced by similar to 50 mN/m as the tiny addition. Boiling curve and bubble behavior were measured under the heat flux of 10-80 W/cm(2). The results show that the bubble behavior of surfactant solutions is influenced by their absorption and amphiphilic characteristics. It can be seen that the perfluoroalkyl solutions could effectively enhance heat transfer performance and the enhancement is more obvious as increasing concentration. Moreover, aqueous surfactant solutions have the higher heat transfer coefficient (HTC) at the lower heat flux. PQAI solution has the biggest enhancement at the heat flux of 10 W/cm(2) when the concentration is kept as 300 ppm, which reduces the superheat of heating surface by 49.3% and HTC increases by 109% than the deionized water. (C) 2020 Elsevier Ltd. All rights reserved.