An ocean thermal energy conversion (otec) power plant built in hawaii in 1987 was designed to operate between the temperature limits of 86of at the ocean surface and 41 o f at a depth of 2100 ft. about 13,300 gpm of cold seawater was to be pumped from deep ocean through a 40-inch diameter pipe to serve as the cooling medium or heat sink. if the cooling water experiences a temperature rise of 6 o f and the thermal efficiency is 2.5 percent, determine the amount of power generated. take the density of seawater to be 64 lbm/ft3 .

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.