While only having 3% efficiency, OTEC is a renewable energy technology that unusually uses the ocean as one of these systems, which are potentially useful to locals with deep ocean access. For 10 points each:
[10e] Name these systems that convert thermal energy to mechanical or electrical work, whose most common modern variant uses the heat from internal combustion.
ANSWER: heat engines [accept just engines]
[10h] Since OTEC heat engines involve heat extraction while flowing from heat source to sink, they are best modeled with these cycles, which ideally have isentropic compression and expansion.
ANSWER: Rankine cycle
[10m] Pencil and paper may be helpful. Assuming Carnot’s theorem applies, what is the maximal Carnot efficiency of an OTEC heat engine that operates between a surface temperature of 300 Kelvin and a benthic temperature of 100 Kelvin?
ANSWER: 2/3 [accept equivalents like 66.67%]
<Jim Fan, Physics>