【摘 要】
：
The efficiency at the maximum power(EMP)for finite-time Carnot engines established with the low-dissipation model,relies significantly on the assumption of the inverse proportion scaling of the irreversible entropy generation △S(ir)on the operation time τ
【机 构】
：
Graduate School of China Academy of Engineering Physics,Beijing 100193,China;Graduate School of Chin
论文部分内容阅读
The efficiency at the maximum power(EMP)for finite-time Carnot engines established with the low-dissipation model,relies significantly on the assumption of the inverse proportion scaling of the irreversible entropy generation △S(ir)on the operation time τ,i.e.△S(ir)∝ 1/τ.The optimal operation time of the finite-time isothermal process for EMP has to be within the valid regime of the inverse proportion scaling.Yet,such consistency was not tested due to the unknown coefficient of the 1/τ-scaling.In this paper,we reveal that the optimization of the finite-time two-level atomic Carnot engines with the low-dissipation model is consistent only in the regime of ηC?2(1-δ)/(1+δ),where ηC is the Carnot efficiency,and δ is the compression ratio in energy level difference of the heat engine cycle.In the large-ηC regime,the operation time for EMP obtained with the low-dissipation model is not within the valid regime of the 1/τ-scaling,and the exact EMP of the engine is found to surpass the well-known bound η+=ηC/(2-ηC).
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