Question

e. skisser temperaturpronien u varmt og kaldt vann som en funksjon av rørlengden Engelsk tekst A well-insulated double pipe heat exchanger (counter flow arrangement) is used to exchange heat between hot water and cold water. The tube side of the heat exchanger has an internal diameter of 0.05 m and wall thickness of 0.01m. The shell side of the heat exchanger has an internal diameter of 0.1 m. The hot water flows in the tube side with mass flow rates of 0.2 kg/s, and inlet temperature of 60 °C. The cold water flows in the shell side with mass flow rate of 0.15 kg/s, and inlet and exit temperature of 20 °C and 40 °C respectively. The tubes of the heat exchanger are made from a material having thermal conductivity of k = 20 W/m K. The heat transfer coefficients on the tube side and shell side of the heat exchanger are hi = 250 W/m2 K and ho = 150 W/m2 K respectively. Assuming that both fluids have specific heat capacity of Cp=4181 J/kg K. Calculate: a. the rate of heat transfer to the cold water [W]. b. the exit temperature of the hot water [°C]. the overall product UAs per length of tube for the heat exchanger [W/K m). d. the effectiveness of the heat exchanger [%] e. sketch the temperature profile of the hot and cold water as a function of tube length.