A cycle is proposed as a development of the Lenoir cycle, in which the working fluid is expanded isentropically from its peak pressure down to a point where its temperature is equal to T1, the initial temperature. The gas is then compressed isothermally back to the initial pressure. Prove that the thermal efficiency of the cycle is given by
where T2 is the maximum temperature achieved in the cycle.
Calculate the thermal efficiency of the cycle if the initial pressure is 10 bar and the maximum pressure is 35 bar. Compare this to the Carnot efficiency achievable between the temperature limits and explain why this cycle would not be used in practice.
[49.9%; 71.4%]