Performance Evaluation of Heat Pipe Heat Exchanger with Nanofluid: An Experimental Study

A heat pipe heat exchanger is fabricated and tested to recapture heat energy in low-temperature applications. The heat transfer fluid used has nanoparticles of zinc oxide suspended in water. The heat transmission performance of the arrangement is evaluated for variable heat supply at distinct mass flow rates. The mass flux for cold and hot air streams is changed for a specific heat input, and observations are recorded. The heat input values are incremented from 25 W to 1500 W while the flow rate of air is incremented from 0.047 to 0.236 m3/s. Maximum effectiveness of 0.28 is noted for heat input of 1500 W at a flow rate of 0.047 m3/s. The variation of heat transfer coefficient is studied for change in flow rate of air and source temperature of the air supplied. It is found that the coefficient of heat transfer increases with source temperature. The enhancement of performance is credited to better thermal conductivity due to the introduction of nanoparticles.