Question

You design a steam engine that uses water at the freezing point and water at the boiling point (both at regular atmospheric pressure) to generate useful work. Calculate the Carnot efficiency of this heat engine.

You invent a superheated steam engine that can generate steam as hot as 590 °C. If this heat engine uses water at the freezing point as the cold object, calculate the Carnot efficiency of this new heat engine.

Answer 1

For a carnot engine maintained at temperature T1 and T2 (T1<T2) efficiency is given by

1) The engine is maintained at temperature of freezing point of water i.e., 0 degree Celsius and boiling point of water i.e., 100 degreee Celsius

So, the temperature expressed in kelvin are

So, efficiency is

2) The temperatures are freezing point of water and steam at 590 degree celsius

So, efficiency is