摘要
理想气体绝热可逆方程中将理想气体的定压摩尔热容和定容摩尔热容比定义为绝热指数,绝热指数对于热力学及热工计算来说,算得上是一个重要参数。但对于混合理想气体的绝热指数如何计算,一般教材和文献报道较少。利用绝热可逆过程熵不变的原则推导出了混合理想气体的绝热指数计算公式,并通过数学推导,发现对于单原子和双原子混合理想气体,在绝热可逆膨胀过程中每一组分的熵变情况和整体熵不变不同,双原子气体熵减少,单原子气体熵增加,同时也表明绝热指数的大小介于单原子理想气体和双原子理想气体绝热指数之间,且可以根据两种气体的物质的量的比对其进行调节。
In the adiabatic reversible equation of ideal gas,the constant pressure molar heat capacity and constant volume molar heat capacity ratio of ideal gas are defined as adiabatic index.Adiabatic index is an important parameter for thermodynamic and thermal calculation.However,how to calculate the adiabatic index of mixed ideal gas is rarely reported in general textbooks and literature.Based on the principle of entropy invariance in adiabatic reversible process,the calculation formula of adiabatic index of mixed ideal gas is derived.Through mathematical derivation,it is found that for single atom and diatomic mixed ideal gas,the entropy change of each component is different from the overall entropy invariance in the process of adiabatic reversible expansion,the entropy of diatomic gas decreases and the entropy of monatomic gas increases.It also shows that the adiabatic index is between the adiabatic index of monatomic ideal gas and diatomic ideal gas,and can be adjusted according to the ratio of the amount of matter of the two gases.
作者
董玉林
李全华
DONG Yu-lin;LI Quan-hua(School of Chemistry,Chemical Engineering and Life Science,Wuhan University of Technology,Wuhan 430070,China)
出处
《武汉理工大学学报》
CAS
2021年第9期85-87,92,共4页
Journal of Wuhan University of Technology
关键词
混合理想气体
绝热指数
熵
熵变
mixture of ideal gases
adiabatic index
entropy
entropy change
