Endoreversible modeling, optimization and 3-D graphical illustration for a non-isothermal three-reservoir chemical pump based on Lewis criterion

ABSTRACT An endoreversible three-reservoir non-isothermal chemical-pump (NICP) cycle is modeled by equivalent combined-cycle method, taking it as combined-cycle of endoreversible two-reservoir NICP driven by endoreversible two-reservoir non-isothermal chemical-engine. Applying finite-time thermodynamics and considering heat-and-mass-transfer coupling effect following Lewis criterion, 3-D graphical illustration of NICP cycle is obtained, and expressions of rate of energy pumping (REP) and vector coefficients-of-performance (COPs) are derived. Effects of some fixed parameters on general relationship surface of REP and COPs are analyzed. At a fixed total mass-transfer coefficient, optimal distribution of mass-transfer coefficient is studied, and optimal relationship surface of three-reservoir NICP is obtained. Influence of working fluid physical properties on performance of three-reservoir NICP is analyzed and compared. 3-D graphical illustrations for three-reservoir NICP are conducive to understanding cycle processes. Results indicate that as both heat-transfer flow rate and mass-transfer flow rate increase, REP increases and vector COPs decrease. 3-D optimal relationship surface of REP and vector COPs is monotonically decreasing. Compared with three-reservoir heat-pump, REP of three-reservoir NICP increases by 114.16%, while vector COP decreases by 4.43%. Compared with three-reservoir isothermal-chemical-pump, REP of three-reservoir NICP increases by 896.91%, and vector COP increases by 135.24%. Mass-transfer process has detrimental effect on heat-transfer process. The physical properties of working fluid have no qualitative influence on performance of three-reservoir NICP, but only quantitative influence. General and optimal relationships of three-reservoir NICP include five special cases: those of two- and three-reservoir heat-pumps with Newton's heat-transfer law, those of two- and three-reservoir isothermal-chemical-pumps with diffusive mass-transfer law, and that of two-reservoir NICP following Lewis criterion. Main contributions herein are establishments of physical and mathematical models of endoreversible three-reservoir NICP and its 3-D graphical illustration, as well as REP and COP analyses and optimizations.