An experimental power plant at the Natural Energy Laboratory of Hawaii generates electricity from the temperature gradient of the ocean. The surface and deep-water temperatures are 27? c and 6? c respectively. (a) what is the maximum theoretical efficiency of this power plant? (b) If the powerplant is to produce 210 kW of power, at what rate must heat be extracted from the warm water? At what rate must heat be absorbed by the cold water? Assume the maximum theoretical efficiency. (c) The cold water that enters the plant leaves it at a temperature of 10? c. What must be the flow rate of cold water through the system? Give your answer in kg/h and in L/h.

Solution 45P Step 1 a) Equation for maximum theoretical efficiency is, = 1 - (T /T ) C H Where, T - Cmperature of the cold reservoir TH- Temperature of the hot reservoir TC 6 = 273 + 6 = 279K (Provided) T = 27 = 273 + 27 = 300K (Provided) H Therefore, maximum efficiency, = 1 - (279K /300K) = 1 - 0.93 = 0.07 or, = 7%