A non-equilibrium phenomenological (two-points) theory of mass and heat transfer. Forces, system-source interactions and thermodynamic cycle applications

Abstract

Classic heat and mass transfer assessment bases on a “single-point” (equilibrium point) theory (SPT), where the departure from the equilibrium point proportionally drives the interaction. This paper continues author's past works [M.D. Staicovici, Internat. J. Heat Mass Transfer 43 (22) (2000) 4153–4173, 4175–4188; Internat J. Refrigeration 23 (2) (2000) 153–167] with a non-equilibrium phenomenological theory of mass and heat transfer, characterized as a “two-points” theory (TPT). The notions of coupled, non-coupled and mixed transfer and the theory two points (equilibrium and ideal) for a system—source type interaction are introduced. Natural forces governing the coupled and non-coupled transfer are given for physical/chemical interactions. The paper shows mixed transfer phenomenological coefficients and proves three theory basic theorems. According to TPT, the non-coupled mass and heat transfer is proportional to the departure from the equilibrium point, but the mixed transfer, unlike SPT, is maximized when equilibrium point approaches the ideal point. TPT is applied to the cyclic mass and heat transfer analysis, using mass conservation law, first principle of thermodynamics and the natural force conservation property, what proves to be similar to Clausius integral, but having the advantage of practical utility. TPT is applied to a mixed transfer cycle of heat pipe type and to a comparative TPT/CAN study concerning the maximum power output of the Carnot irreversible cycle. In case of the heat pipe, for the first time a non-empirical explanation concerning its high heat transfer is given, identifying heat pipe working with the mixed transfer maximization conditions. Concerning the finite-time thermodynamics application, theories are essentially concordant to hope to be coupled in future for a more realistic cycle calculation.