Investigating the effect of turbulator, nanofluid and geometry on the thermal performance of shell and tube heat exchangers

the shell and tube heat exchanger with the percentage of baffle cutting and the number of different tube passes in four different modes (use of water fluid on the shell side and tube containing supercritical carbon dioxide gas without the presence of turbulator, use of water fluid on the shell side and tube containing supercritical carbon dioxide gas with the presence of turbulator, the use of water-aluminum oxide nanofluid on the side of the shell and tube containing supercritical carbon dioxide gas without the presence of turbulator and also the use of water-aluminum oxide nanofluid on the side of the shell and tube containing supercritical carbon dioxide gas with the presence of an turbulator) are studied using HTRI software. The results show that the highest value of the heat transfer coefficient on the shell side and, as a result, the appropriate thermal efficiency is related to the case where the baffle cut is 30%. On the other hand, with the increase in nanofluid concentration, the pressure drop on the shell side increases from 4.48 to 5.66%. the results show that the use of a microfin turbulator is more suitable than a twisted tape turbulator and the use of a microfin turbulator increases the heat transfer coefficient on the shell side by 5.76 to 12.77% compared to the use of a twisted tape turbulator. Also, it increases the heat transfer coefficient of the pipe side by 62 and 78% on average, respectively, compared to the case without the turbulator.