An idealised working gas of constant specific heat capacity is heated sensibly and…

PHYSICS · Multi-part · Fermi University Physics · Thermal, Statistical & Complex Systems · The laws of thermodynamics · The laws of thermodynamics

Energy from Physics, Ch Heat engines on fuel: exergy, real cycles, biomass and the nuclear heat source

Problem

An idealised working gas of constant specific heat capacity is heated sensibly and reversibly from

T_1 = 350\,\mathrm{K}

T_2 = 950\,\mathrm{K}

before entering a cycle that rejects heat to surroundings at

T_0 = 300\,\mathrm{K}

. ((a)) Find the entropic mean temperature

T_m

of the heat addition. ((b)) Find the reversible efficiency

\eta = 1 - T_0/T_m

this implies, and compare it with the Carnot efficiency evaluated at the top temperature

T_2