Performance of CNT-water nanofluid as coolant fluid in shell and tube intercooler of a LPG absorber tower

This study presents the performance of CNT-water nanofluid in low concentrations (0.0055%, 0.055%, 0.111% and 0.278%) as a cooling fluid which is utilized in a shell and tube intercooler of a LPG absorber tower. Heat exchanger was simulated by ASPEN HTFS+ 7.3 software and its thermal performance was evaluated. Then the results were analyzed and compared with cooling water performance. It was observed that for maximum CNT volume fraction which is 0.278%, the overall heat transfer coefficient and heat transfer rate increased about 14.5% and 10.3% respectively, compared to water. This advantage can decrease the heat transfer area of the heat exchanger which will leads to decrease the manufacturing cost for the heat exchanger. The outlet temperature of the hot fluid decreased with increasing the CNT volume fraction whereas the pressure drop due to the solid nanoparticles suspended in water was too low. Also, increasing both the nanofluid and the hot fluid mass flow rates, it leads to increase the heat transfer rate. Moreover, when increasing either the coolant or the hot fluid inlet temperatures, the outlet temperature of the hot fluid increases. But when using the nanofluid, increasing intensity of the outlet temperature of the hot fluid was less.