Efficiëntie van de Carnot-cyclus

In a Carnot cycle, the known quantities are the temperature of the hot reservoir, T-h, and the temperature of the cold reservoir, T-c.

The ideal gas absorbs heat Q-h during its isothermal expansion at T-h and rejects heat Q-c during its isothermal compression at T-c.

Since the internal energy of an ideal gas depends only on its temperature, it remains constant during these two steps. Using the first law of thermodynamics, the absorbed heat can be calculated. While Q-h depends on the gas’s volumes before and after the expansion, Q-c depends on the gas’s volumes before and after the contraction.

For the adiabatic processes in the Carnot cycle, the relationship between the temperature and volume of gases can be used. The four equations can be combined to relate the ratio of heat exchanged and the temperatures of the reservoirs.

When combined with the expression of the efficiency of a heat engine, it implies that the efficiency of a Carnot cycle depends only on the temperatures T-c and T-h.