Optimal performance of a generalized irreversible four-reservoir isothermal chemical potential transformer

Abstract

A new cyclic model of a four-reservoir isothermal chemical potential transformer with irreversible mass transfer, mass leakage and internal dissipation is put forward in this paper. The optimal relation between the coefficient of performance (COP) and the rate of energy pumping of the generalized irreversible four-reservoir isothermal chemical potential transformer has been derived by using finite-time thermodynamics or thermodynamic optimization. The maximum COP and the corresponding rate of energy pumping, as well as the maximum rate of energy pumping and the corresponding COP, have been obtained. Moreover, the influences of the irreversibility on the optimal performance of the isothermal chemical potential transformer have been revealed. It was found that the mass leakage affects the optimal performance both qualitatively and quantitatively, while the internal dissipation affects the optimal performance quantitatively. The results obtained herein can provide some new theoretical guidelines for the optimal design and development of a class of isothermal chemical potential transformers, such as mass exchangers, electrochemical, photochemical and solid state devices, fuel pumps, etc.isothermal four-reservoir chemical potential transformer, coefficient of performance, rate of energy pumping, finite time thermodynamics

Entransy dissipation minimization for liquid-solid phase change processes

“…(18) gives the optimal dimensionless phase boundary position δ /l versus dimensionless time t/t 0 corresponding to the optimal heat exchange strategies of minimum entransy dissipation during phase change processes. Differentiating eq.…”

“…Comparisons of different heat exchange strategiesFrom eq (18),. for the optimal heat exchange strategies of minimum entransy dissipation, the dimensionless phase boundary position δ /l versus dimensionless time t/t 0 during the slab freezing process is the same as that during the slab melting process.…”

Entransy dissipation minimization for a class of one-way isothermal mass transfer processes

“…There are two standard problems in finite time thermodynamics: one is to determine the objective function limits and the relations between objective functions for the given thermodynamic system, and another is to determine the optimal thermodynamic process for the given optimization objectives [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The latter belongs to functional extremum problems and needs to use optimal control theory.…”

Constructal optimization of discrete and continuous-variable cross-section conducting path based on entransy dissipation rate minimization

“…Based on irreversible thermodynamics, some scholars used finite-time thermodynamics (FTT) or entropy generation minimization (EGM) [18][19][20][21][22][23][24][25][26][27][28][29][30] to optimize the heat transfer process, which was also called thermodynamic optimization. The entropy generation minimization is a heat transfer optimization aiming at exergy lost minimization, but the heat transfer mostly focuses on the heat transfer regularity and its transfer speed, not the exergy lost.…”