Answer 7_5_4
(a) (i) Use this equation:
Efficiency = (360 - 280) ÷ 360 = 0.222 (= 22.2 %)
(ii) To get 5 MW, rate of energy exchange must be:
Heat flow = 5.0 ÷ 0.222 = 22.5 MW
(iii) Rate at which energy is passed to seawater = 22.5 MW - 5.0 MW = 17.5 MW
(b) Any two of
There will be friction within the heat engine.
There will be heating in the generator windings as a current passes through the wires.
Losses to the atmosphere;
Variations in sea temperature.
(c) Any one of
Price of oil is expensive.
It has to be transported to the site.
Waste products might have to be treated.