热力学第二定律克劳修斯表述的误解及其后果  

The misunderstanding of Clausius statement of the second law of thermodynamics and its aftermath

作　　者：薛提微 过增元[1] Tiwei Xue;Zengyuan Guo(Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Department of Engineering Mechanics,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学工程力学系热科学与动力工程教育部重点实验室,北京100084

出　　处：《科学通报》2018年第25期2666-2672,共7页Chinese Science Bulletin

基　　金：国家自然科学基金(51621062)资助

摘　　要：简单介绍了热力学第二定律的卡诺表述,详细分析了克劳修斯为改进卡诺表述所做的相关工作.分析表明,热力学第二定律的克劳修斯表述应该是:"热功转换和热量在不同温度间转换的等价定理",而不是"不可能把热从低温物体传到高温物体而不引起其他变化",后者只是在证明转换等价定理过程中应用到的基本原理;热力学第二定律的克劳修斯表述本身描述的都是可逆过程,从而才能够导出热力循环的克劳修斯等式和描述物体转换含量的熵.把克劳修斯表述理解为"不可能把热从低温物体传到高温物体而不引起其他变化",会导致认为热力学第二定律是描述过程方向性和不可逆性的规律.其后果是,错误地认为最小熵产原理能够用于导热过程输运定律的导出和传热过程的优化.As with the first law of thermodynamics, the second law of thermodynamics has been proven by countless examples. The Clausius statement of the second law of thermodynamics given in most of the literatures is ＂heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time＂. After carefully studying Clausius＇ mechanical theory of heat published from 1850 to 1865, we found that this is not true. Actually, Clausius already clearly stated that the second law of thermodynamics is ＂Theorem of the equivalence of the transformation of work to heat and the transformation of heat at a higher to a lower temperature＂. The former statement is only a basic principle that can lead to the theorem of the equivalence of transformations. In addition, all processes in derivation of the theorem of the equivalence of transformations and proof of the equivalence between Clausius statement and Kelvin statement are reversible processes. The statement ＂Heat can never pass from a colder to a warmer body without some other change＂ only illuminates the spontaneous natural phenomenon in opposite direction that heat flows from high temperature to low temperature, which tells that heat at different temperatures are nonequivalent. Admittedly, Clausius discussed the process irreversibility and thereby obtained Clausius Inequality. But he only used the state change to measure the process irreversibility, which did not involve the concept of space, time and speed. Clausius just expressed that the process irreversibility will reduce heat efficiency and did not focus exclusively on the laws of process irreversibility. The misunderstanding of viewing Clausius statement as ＂Heat can never pass from a colder to a warmer body without some other change＂, easily produces such a viewpoint that the second law of thermodynamics is the rule about process direction and irreversibility, consequently leading to the faulty assumption that the minimum entropy generation principle can be

关 键 词：热力学第二定律 克劳修斯表述 转换等价定理 熵 

分 类 号：O414.1[理学—理论物理]