Glycerin will be cooled in a counterflow double-tube heat exchanger. The inner steel tube has a diameter of 1 inch and a negligible thickness. The inside diameter of the shell is 2 inches. For him, water flows through the tube at 0.6 kg/s and glycerin flows through the annular space at 5 kg/s. Taking average water temperatures and glycerin as 20 and 40 C, respectively, determine the total heat transfer coefficient of this exchanger.