熵产生判据的推演及做功对熵变影响的探讨  

Deduction of Entropy Production Criterion and Discussion of Entropy Change by Work

作　　者：孟超 郑佩珠 Meng Chao;Zheng Pei-zhu(School of Materials Science&Engineering,Beijing Institute of Fashion Technology,Beijing 100029,China)

机构地区：[1]北京服装学院,北京100029

出　　处：《江西化工》2023年第4期122-124,共3页Jiangxi Chemical Industry

基　　金：福州大学能源与环境光催化国家重点实验室开放课题(SKLPEE-KF202203)

摘　　要：克劳修斯不等式和熵产生判据都是热力学第二定律的核心表述。虽然克劳修斯不等式主要用于热力学系统过程可逆性判断,而熵产生判据更多归属于不可逆热力学,但是二者却是同源的,二者之间的数学联系鲜有说明。本文基于克劳修斯不等式,借鉴熵流和熵产生的概念,在温度均匀和不均匀两种条件下,推演出封闭系统熵产生(d_(i)S)“d_(i)S≥0”,该方法简单,其中对于内部温度不均匀封闭系统的推导是初次报道;针对热力学第一定律中传热和做功两大途径,关于传热对熵变的影响已有较多报道而做功对熵变的影响未有讨论,因此,本文分析和探讨了做功对熵变(dS_(功))的影响进而得到“dS_(功)≥0”的新判据,该判据说明,无论系统对外做功或从外界得到功,系统因做功过程引起的熵变不会减小,当过程不可逆时该熵变大于0,可逆时等于0,该影响不同于传热熵变。Clausius inequality and entropy generation criterion are both core expressions of the second law of thermodynamics.Although Clausius inequality is mainly used to judge the reversibility of thermodynamic system processes,and entropy generation criteria is more attributed to irreversible thermodynamics,the two are cognate,and the mathematical relationship between the two is rarely explained.Based on the total entropy criterion extended from Clausius inequality,by using the concepts of entropy flow and entropy production for reference,the“d_(i)S≥0”has been deduced and obtained under both uniform and non-uniform temperature conditions.This method is simple and the derivation of a closed system with uneven internal temperature is first reported.In view of the two main approaches of heat transfer and work in the first law of thermodynamics,there have been many reports on the impact of heat transfer on entropy change,while the impact of work on entropy change has not been discussed,this paper discusses“entropy change by work”,and a new criterion of“dSW≥0”is obtained.This new equation shows that no matter the system does work externally or gets work from the outside,the entropy of the system will not decrease due to the process of work.The entropy change by work is greater than 0 in irreversible process,while it is equal to 0 in reversible process.This effect is different from the entropy change of the heat source.

关 键 词：热力学第二定律 克劳修斯不等式 总熵判据 熵变 

分 类 号：G64[文化科学—高等教育学] O6[文化科学—教育学]