Optimum Efficiency for a Simple Two-Level Heat Engine

Investigating an optimized efficiency of an engine is crucial for minimizing wastage. The simple two level heat engine was introduced to calculate the efficiency at maximum power.In this paper, we explore the optimum efficiency of a simple two-level heat engine that consists of two distinct energy levels coupled with two thermal baths with distinct temperatures. By employing unified energy converter criteria, we determine the optimized efficiency under two optimum operations scenario, situated between the maximum and minimum efficiency values. The minimum efficiency is associated with either zero efficiency or efficiency at maximum power. We further express the optimum efficiency in terms of scaled parameters such as power-wise, period-wise and efficiency-wise as a function of Carnot efficiency. Finally, a figure of merit is introduced to evaluate overall engine performance, reveals that the second optimization criterion exhibits better performance compared to the first criterion with the entire range of Carnot efficiency.