工程热力学中关于不可逆绝热过程的分析  

Analysis of Irreversible Adiabatic Process about Engineering Thermodynamics

作　　者：高经武[1] 张志香[2] 

机构地区：[1]中北大学理学院 [2]中北大学机电工程学院,山西太原030051

出　　处：《机械管理开发》2010年第1期12-12,204,共2页Mechanical Management and Development

摘　　要：指出了文献中关于不可逆绝热过程分析存在的问题,认为按照热力学第一定律闭口系统能量方程式,闭口系统绝热膨胀过程对外所作的功等于热力学能降,而非膨胀功等于热力学能降。终压相同时,可逆绝热膨胀过程对外所作的功等于膨胀功,不可逆绝热膨胀过程对外所作的功小于膨胀功,其对外所作的功仅是膨胀功的一部分,是排斥大气所作功与有用功之和,故不可逆过程对外所作的功小于可逆过程的膨胀功,而不是其"膨胀功"小于可逆过程的膨胀功。并运用反证法和算例进行了证明。The error was pointed out in the analysis of irreversible adiabatic process in the article . It is thought in this paper that the external work of closed system in the adiabatic expansion process is equal to the reduction of thermodynamic energy, but not the expansion work. When the termination pressure in the reversible adi.abatic expansion process is equal to that in the irreversible adiabatic expansion process, the external work in the former is equal to the expansion work, however that in the latter is less than the expansion work. The external work in the irreversible adiabatic expansion process is the part of the expansion work, which is the sum of the available work and the work used to repel air. So the external work in the irreversible adiabatic expansion process is less than that in the reversible adiabatic expansion process, but not the expansion work. The viewpoint was validated using negative approach and the example.

关 键 词：工程热力学 闭口系统 不可逆过程 绝热过程 

分 类 号：TK123[动力工程及工程热物理—工程热物理]