Capillary Pumped Loop Startup: Effects of the Wick Fit on Boiling Incipience

摘要

The onset of boiling in a capillary pumped loop evaporator is experimentally studied. The evaporator of the system contained a porous material in which the working fluid (n-pentane) was vaporized. The system was started up with the evaporator completely flooded, and boiling was initiated by application of a heat load. A specific flat plate evaporator was designed where the distance between the heating plate and the wick can be controlled. The two parameters studied were confinement and power applied (600 W maximum). The superheat needed to initiate boiling was strongly dependent on the quality of the contact between the heating plate and the wick and on the power applied. The initial superheat played a decisive role in the behavior of the system at startup. From the beginning, there were strong couplings between the physical phenomena occurring in the evaporator and the