Operation characteristics of a small-scale capillary pumped loop

This paper presents an experimental investigation of a capillary driven two-phase loop, configured on a capillary pumped loop (CPL) mode and designed for the thermal management of up to 50 W. Tests were performed with an internally grooved evaporator with a hollow polyethylene porous structure using acetone and anhydrous ammonia as the working fluids. For a range of power applied to the evaporator, the system presented reliable start-ups and continuous operation for several hours for each working fluid. As compared to acetone, anhydrous ammonia system showed a better heat transport capability. The capillary evaporator depriming and re-priming was also experimentally investigated. The results showed that the proposed CPL configuration is able to handle the porous structure dryout and promote its rewetting without major external interference.