函数的几个重要特性

Some fundamental characteristics of exergy

基于(火用)的普遍化表达式及其推论,得出了热力学体系(火用)函数的三个重要性质。热力学系统的(火用)值在寂态等于零,其它任何状态都大于零。不同形式的(火用)之间可相互转换,体系的总(火用)可能有不同的表现形式,总(火用)的变化量才等于各种形式(火用)的变化量之和。自发过程的方向就是体系(火用)减少的方向,(火用)可作为自发过程的方向判据。

From the generalized expression of exergy and its derivation, three Fundamental Characteristics of Exergy are obtained. Only in the dead state, does the exergitic value of a thermodynamic body equal zero, it is above zero in any other states. The different forms of exergy can transform each other, the total exergy of a body can display some other forms, the variance of total exergy of a body equals that of all the specific forms of exergy in the body. Along a spontaneous process, the exergitic value decreases, which can be used as the orientation criterion of the spontaneous process.