A power plant operates with a heat source reservoir at 350^{o}C and a heat sink reservoir at 30^{o}C. It has a thermal efficiency of 55% of the Carnot engine thermal efficiency for the same temperature levels. What is the thermal efficiency of the plant?

Calculations:

Given:

Temperature of source, T_{1} = 350^{o}C = 350 + 273 = 623 K

Temperature of sink, T_{2} = 30^{o}C = 30 + 273 = 303 K

h
_{Carnot} = 100 x (1 - T_{2}/T_{1}) = 100 x (1 - 303/623) = 48.64%

Thermal efficiency of the plant = 55% of the Carnot engine efficiency (given)

= 0.55 x 48.64 = 26.75%