Experimental investigation of two-phase pumpless loop with aqueous anionic surfactant as working fluid

This paper studies a two-phase loop thermosiphon as a potential cooling solution for thermal management of insulated gate bipolar transistors (IGBTs). Water-based two-phase thermosiphon is initially analyzed. The flow instabilities of the loop and impact of different parameters such as heat flux, valve control near the inlet, and static head in the reservoir on thermosiphon performance are investigated. Heat transfer coefficients are deduced, and the best operable conditions of the loop are determined. A modification to the working fluid water is brought by adding fixed concentrations of sodium lauryl sulfate (SLS), and its thermal performance is investigated next. A minimum in surface temperature with an increase in surfactant concentrations was observed. The enhancement in heat transfer performance was determined using the relative heat transfer coefficient. An improvement of 28% and 25% at 18.7 and 29.4 W/cm(2) , respectively, were observed.