Experimental Study Bubble Dynamics for Nucleate Pool Boiling of Water and electrolyte solutions

Investigating of boiling process due to the high heat transfer rate is one of the attractive fields for resarchers , many applications in industry such as petroleum, petrochemical, nuclear power plants, refrigeration and power cycles. Nucleate pool boiling heat transfer experiments were conducted on a smooth horizontal cylinder Stainless steel at atmospheric pressure and saturation temperature. water and electrolyte solutions including NaCl/water and Na2SO4/water over a wide range of concentrations (50-300 gr/lit )were used as the testing fluid. The experiments were conducted in a glass container. Wall temperature was measured using four thermocouples and the average value was reported. A high-speed digital video camera was applied to capture the dynamics of the bubble nucleation process. Bubble dynamics is the most important sub-phenomenon, which basically affects the nucleate pool boiling heat transfer coefficient. In this article, bubble departure diameter values were experimentally measured for heat fluxes. experimental results show that bubble diameter increases with increasing heat flux. In addition, experimental results show that the bubble departure diameter increase with increasing electrolyte concentration.and also, For electrolyte solutions, because of the high interfacial tension, large bubbles were observed . According to a statistical study of Cole there is a best fitting by data compared to other models.

Keywords:

Bubble departure , Heat transfer , Pool boiling , electrolyte solutions