Effect of nanofluid on thermal performance of heat pipe with two evaporators; application to satellite equipment cooling

• Potential of nanofluids for cooling of satellite equipment is evaluated.
• A cylindrical heat pipe with two discrete heat sources (evaporators) is considered.
• A reduction in satellite equipment temperature can be observed using nanofluid.
• The use of nanofluid can promote the thermal performance of heat pipe.
• The downsizing of heat pipe becomes possible by adding nanoparticle in basefluid.

A study on the behavior of nanofluid in a cylindrical heat pipe with two heat sources is performed to analyze the nanofluid application in heat-dissipating satellite equipment cooling. Pure water, Al2O3–water and TiO2–water nanofluids are used as working fluids. An analytical modeling is presented to predict the wall temperature profile for the heat pipe assuming saturated vapor and conduction heat transfer for porous media and wall, respectively. The effects of particle concentration levels (φ=0 (distilled water), 2, 4, and 8%), particle diameters (dp=10, 20, and 40 nm) on the local wall temperature, heat transfer coefficient, thermal resistance, and the size of the heat pipe are investigated. It is observed that the better wall temperature uniformity can be achieved using nanofluid which results in lower temperature difference between evaporators and condenser sections. Results reveal that applying nanoparticle with smaller size and higher concentration level increases heat transfer coefficient remarkably by reducing thermal resistance of saturated porous media. It is also found that the presence of nanoparticles in water can lead to a reduction in weight of heat pipe, and thus satellite, under nearly identical condition. The findings of this paper prove the potential of nanofluid in satellite equipment cooling application.