Question

Solve the following problem in Thermodynamics: Carnot Cycle A heat engine receives heat from a source at 2000 K at a rate of 500 kW, and rejects the waste heat to a medium at 300 K. The net output from the engine is 300 kW. Determine the maximum energy that can be driven out of the engine theoretically using Carnot Cycle. Compare the observed work-efficiency with the expected efficiency of the heat engine? How much energy is lost due to unknown irreversible factors involved in the complete mechanically

Answer 1

1)

carnot efficiency = 1 - Tsink / Tsource = 1 - 300/2000 = 85%

Work output / Power input = 85%

work output = 0.85 x 500kW

= 425 kW

2) actual work output = 300kW

actual efficiency = 300 /500 = 60%

3)enegy loss = theoretical work output - actual work output = 425 - 300 = 125kW