Reversible Carnot and Philips heat engines with a real gas as a working body

Abstract

In the article, on the basis of the theory of thermodynamic potentials, a study was made of the quasistatic Phillips and Carnot heat engines in which a comparative analysis was made of their work both for cycles with a working body, an ideal gas, and for cycles with a working body, real gas. On the basis of the conducted research, it was established that the existing formulation of the Carnot theorem is valid only for the working fluid “ideal gas”. In general, based on the above calculations, the Carnot theorem can be formulated, for example, like this: “The efficiency of a reversible heat engine is maximum, does not depend on the properties of the heat engine and is a function of the temperatures of only hot and cold tanks: η=1-ƒ(t1,t2), where ƒ(t1,t2) is a function only of the temperatures t1 and t2 of the hot and cold tanks. This formulation is valid only for working fluid ideal gas. In the case of using real gas as a working fluid, the efficiency of a heat engine, in addition to dependence on the temperatures of hot and cold tanks, is a function of the thermodynamic characteristics of the working fluid and the type of heat engine, and reaches its maximum value for this type of working fluid and engine type if there is reversibility the system under consideration».

Keywords

• ideal gas
• isothermal expansion of an ideal gas
• thermodynamic potential
• helmholtz's energy
• cyclic processes
• carnot cycle
• philips cycle
• adiabatic expansion of an ideal gas
• chemical potential