Experimental investigation on a three-phase closed thermosyphon with glass beads/water

A carbon steel three-phase closed thermosyphon (THPCT), combining the two-phase closed thermosyphon (TPCT) and fluidized bed heat transfer technology, is designed and constructed to investigate the effect of various operating parameters including the filling ratio (40-60%), solid holdup (5-35%) and input power (500-2000 W) on the heat transfer performance. Glass beads are chosen as inert solid particles added into the TPCT using pure water for its stable chemical property and low cost. Experiments are operated under vacuum condition, the actual pressure is about 5-17 kPa and the operating temperature ranges from 30 degrees C to 60 degrees C. The evaporation heat transfer coefficient and overall thermal resistance are considered to evaluate the thermal performance of the THPCT compared with that of the TPCT. The results show that the evaporation heat transfer coefficient increases and the overall thermal resistance decreases by adding glass beads. The maximum rate of increment and reduction are 8.8% and 15.5% at epsilon(s) = 10%, FR = 40% and an input power of 500 W, correspondingly. The influence of various parameters on the performance of the TPCT is not independent. The research results are helpful for the industrial application of the THPCT.