Water is pumped through a heat exchanger consisting of tubes 8 mm in diameter and 6 m long. Th e velocity in each tube is 12 cm/s. Th e water temperature increases from 20°C at the entrance to 30°C at...

Water is pumped through a heat exchanger consisting of tubes 8 mm in diameter and 6 m long. Th e velocity in each tube is 12 cm/s. Th e water temperature increases from 20°C at the entrance to 30°C at the exit. Calculate the pressure diff erence across the heat exchanger, neglecting entrance losses but accounting for the eff ect of temperature change by using properties at average temperatures