Optimization of a Carnot Cycle Engine by Using Finite Speed Thermodynamics and the Direct Method

摘要

A model for a Carnot cycle engine in a closed system is proposed. By using the direct method and the first law of thermodynamics for processes with finite speed, an optimization method of this cycle/engine is developed and presented. A comparison between the results of our optimization based on the speed of the process and the Curzon-Ahlborn optimization based on duration time shows a significant difference. The Curzon-Ahlborn optimization is "too optimistic" in comparison with an engineering optimization based on finite speed thermodynamics (using the direct method), for operation condition corresponding to maximum power output of the engine. It is shown that being concerned with "engineering optimization aspects", the finite speed thermodynamics (FST) approach is more appropriate in the design of thermal machines.