Consistency of optimizing finite-time Carnot engines with the low-dissipation model in the two-level atomic heat engine  

作　　者：Yu-Han Ma C P Sun Hui Dong 

机构地区：[1]Graduate School of China Academy of Engineering Physics,Beijing 100193,China [2]Beijing Computational Science Research Center,Beijing 100193,China

出　　处：《Communications in Theoretical Physics》2021年第12期78-85,共8页理论物理通讯（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)(Grants No.11534002,No.11875049,No.U1730449,No.U1530401,No.U1930403);the National Basic Research Program of China(Grant No.2016YFA0301201);the China Postdoctoral Science Foundation(Grant No.BX2021030)。

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 generationΔS^(ir)on the operation timeτ,i.e.ΔS^(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 ofη_(C)<<2(1-δ)/(1+δ),whereη_(C)is the Carnot efficiency,andδis the compression ratio in energy level difference of the heat engine cycle.In the large-η_(C)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 boundη_(C)=η_(C)/(2-η_(C)).

关 键 词：finite-time thermodynamics low-dissipation model quantum heat engine efficiency at maximum power irreversible entropy generation 

分 类 号：O414.1[理学—理论物理]