Exergy variations for forced convection of nanofluid through a pipe equipped with twisted tape turbulators have been simulated via Finite volume method. Roles of height ratio, pitch ratio and Reynolds number on variation of nanofluid hydrothermal treatment, second law efficiency (eta(II)) and exergy loss (X-d) were presented. Suitable formulas for (X-d) and (eta(II)) are provided. Results reveal that exergy drop reduces with enhance of Reynolds number and height ratio. Second law performance rises with augment of height ratio while it reduces with augment of pitch ratio. (C) 2018 Elsevier Ltd. All rights reserved.