Equation Calculating Internal Energy Change Derived from the Clausius Inequality

Abstract

In the paper, the relations of heat or work between a reversible process and its realistic process are discussed, which could be applied to the chemical reactions and Rossini and Frandsen experiment and so on. It is proved the ratios of work to temperature and internal energy change to temperature are all the state function in the reversible process, otherwise, the Clausius inequality will be violated. In an isothermal process of reversible Stirling cycle, the internal energy change is equal to zero for the gas. Thus, the new equation calculating the internal energy change has been obtained for the gas, namely that dU=CVdT, it is convenient and easy calculative.

Confirmation of the First Law of Thermodynamics in Theory and Extended Bernoulli Equation

“…The Equation (2a) can be derived from the Clausius inequality. The real gases obey the Equation (2a) had been proven [5]. The ideal gas, real gases, liquids, and solids all obey the Equation (2a) too.…”

“…We know that the internal energy change of ideal gas does not depend on the volume and pressure. The internal energy change of real gas had been proved to be the temperature function and without any relation with the volume and pressure by author [5]. The heat and work are taken as positive if the energy is supplied to the system and negative if the energy is lost out of the system.…”