High heat flux loop heat pipes

Development of an experimental loop heat pipe for application in future space missions

“…The bi-disperse wick is characterized by two capillary radii, being one large and one small, where the small one is located close to the liquid core and the large one close to the vapor grooves, where the thickness of each one is a design parameter. This wick is formed by bonding together clusters of smaller powder particles [5]. This investigation showed that the LHP could reach heat fluxes around 0.7 MW/m 2 .…”

“…Results reported by North et al [5] were the first about LHPs using ammonia as the working fluid, which used a bidisperse wick material in the capillary evaporator. The bi-disperse wick is characterized by two capillary radii, being one large and one small, where the small one is located close to the liquid core and the large one close to the vapor grooves, where the thickness of each one is a design parameter.…”

Development of Thick-Film Thermoelectric Microcoolers Using Electrochemical Deposition

“…For smallthermalloads,high thermalconductivity materialscanbeusedfor conductingheat awayto the heatsink, while for largethermalloads(high heatflux density),highly efficient heat removaltechniquessuchasheatpipes,microchannelsor spraycoolingwould be incorporated into the package [5][6][7]. Miniaturizationof thermoelectriccoolersoffersseveral distinct advantages over currentstate-of-the-art technologythatis established on bulk semiconducting materials.Oneobviousadvantage is thatfor a given moduleconfiguration,the cooling powerper unit areaof thermoelectriccoolersis inverselyproportionalto thethicknessof its thermoelements, or legs.…”

Investigating the effect of powder-mixing parameter in biporous wick manufacturing on enhancement of loop heat pipe performance

“…Since the wick has both large and small pores, effective pore radius and permeability used from monoporous wick are no longer useful parameters; therefore, SEM imaging was used to observe the pore size distribution, while Archimedes method was used to calculate the porosity, as shown in Eq. (2).…”

“…Application of biporous wick to LHP was first suggested by North and Maydanik [2]; however, no related conclusion was provided. Chen et al [3] investigated the effect of the biporous wick material on boiling heat transfer and found that the biporous wick results in significant improvements.…”