Analyzing Rankine Cycles On the south coast of the island of Hawaii,...

Analyzing Rankine Cycles

On the south coast of the island of Hawaii, lava flows continuously into the ocean. It is proposed to anchor a floating power plant offshore of the lava flow that uses ammonia as the working fluid. The plant would exploit the temperature variation between the warm water near the surface at 130^oF and seawater at 50^oF from a depth of 500 ft to produce power. Figure P8.14 shows the configuration and provides additional data. Using the properties of pure water for the seawater and modeling the power plant as a Rankine cycle, determine

(a) the thermal efficiency.

(b) the mass flow rate of ammonia, in lb/min, for a net power output of 300 hp.