Optimal performance of an endoreversible chemical engine with diffusive mass transfer law

2008 ◽  
Vol 222 (8) ◽  
pp. 1535-1539 ◽  
Author(s):  
L Chen ◽  
D Xia ◽  
F Sun
Keyword(s):  
Mass Transfer ◽  
Optimal Design ◽  
Power Output ◽  
Finite Time ◽  
Optimal Performance ◽  
Finite Time Thermodynamics ◽  
Design And Development ◽  
Optimal Operating ◽  
Diffusive Mass Transfer ◽  
Analytical Relations

The performance of an isothermal endoreversible chemical engine, in which the mass transfer obeys diffusive law, is analysed and optimized in this paper. The analytical relations about power output and efficiency, as well as the optimal relation between the power output and efficiency of the isothermal chemical engine are derived by using finite-time thermodynamics. Moreover, the optimal operating regions are studied. The results obtained herein can provide some new theoretical guidelines for the optimal design and development of a class of chemical engines.

scholarly journals Optimal temperatures and maximum power output of a complex system with linear phenomenological heat transfer law

2009 ◽  
Vol 13 (4) ◽  
pp. 33-40 ◽  
Author(s):  
Lingen Chen ◽  
Jun Li ◽  
Fengrui Sun
Keyword(s):  
Complex System ◽  
Heat Transfer ◽  
Power Output ◽  
Finite Time ◽  
Heat Engine ◽  
Thermal Capacity ◽  
Maximum Power ◽  
Finite Time Thermodynamics ◽  
Maximum Power Output ◽  
Different Temperatures

A complex system including several heat reservoirs, finite thermal capacity subsystems with different temperatures and a transformer (heat engine or refrigerator) with linear phenomenological heat transfer law [q ? ?(T -1)] is studied by using finite time thermodynamics. The optimal temperatures of the subsystems and the transformer and the maximum power output (or the minimum power needed) of the system are obtained.

Thermodynamic Analysis on Thermoacoustic Self-Excited Oscillation

2003 ◽  
Vol 10 (04) ◽  
pp. 391-402 ◽  
Author(s):  
Qing Li ◽  
Feng Wu ◽  
Fangzhong Guo ◽  
Chili Wu ◽  
Jihao Wu
Keyword(s):  
Phase Space ◽  
Power Output ◽  
Finite Time ◽  
Second Harmonic ◽  
Harmonic Wave ◽  
Threshold Value ◽  
Finite Time Thermodynamics ◽  
Entropy Flow ◽  
Excited Oscillation ◽  
Thermodynamic Mechanism

Thermodynamic mechanism of thermoacoustic self-excited oscillation is analyzed in this paper. The law of minimizing entropy flow is obtained basing on the fundamentals of finite-time thermodynamics. The results obtained here show that the thermoacoustic self-excited oscillation, which is a non-isentropic oscillation with power-output corresponding to a limit cycle in the phase space takes place when hot temperature Th exceeds a threshold value [Formula: see text]. The effect of nonlinear terms on the system will lead to the second harmonic wave.

The Influence of Thermal Resistances and Nonperfect Regenerative Losses on the Performance of a Ferroelectric Ericsson Refrigerator

2014 ◽  
Vol 1006-1007 ◽  
pp. 168-172
Author(s):  
Hui Shan Yang
Keyword(s):  
Heat Transfer ◽  
Finite Time ◽  
Optimization Criterion ◽  
Ferroelectric Materials ◽  
Optimal Performance ◽  
Refrigeration Cycle ◽  
Finite Time Thermodynamics ◽  
Performance Parameters ◽  
Linear Heat ◽  
Ecological Optimization

Using the finite-time thermodynamics, the influence of thermal resistances and nonperfect regenerative losses on the optimal performance of a ferroelectric Ericsson refrigeration-cycle is analyzed. Based on the thermodynamics properties of ferroelectric materials and a linear heat-transfer law, the inherent regenerative losses in the cycle are calculated and the fundamental optimum relations and other relevant performance parameters are determined. The ecological optimization criterion of the refrigerator is derived. The results obtained here may reveal the general characteristics of the ferroelectric Ericsson refrigeration cycle.

From Finite Time to Finite Physical Dimensions Thermodynamics: The Carnot Engine and Onsager’s Relations Revisited

2018 ◽  
Vol 43 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Michel Feidt ◽  
Monica Costea
Keyword(s):  
Power Output ◽  
Finite Time ◽  
Irreversible Thermodynamics ◽  
Maximum Efficiency ◽  
Finite Time Thermodynamics ◽  
Heat Flow Rate ◽  
Objective Functions ◽  
Minimum Entropy ◽  
The One ◽  
Physical Dimensions

AbstractMany works have been devoted to finite time thermodynamics since the Curzon and Ahlborn [1] contribution, which is generally considered as its origin. Nevertheless, previous works in this domain have been revealed [2], [3], and recently, results of the attempt to correlate Finite Time Thermodynamics with Linear Irreversible Thermodynamics according to Onsager’s theory were reported [4].The aim of the present paper is to extend and improve the approach relative to thermodynamic optimization of generic objective functions of a Carnot engine with linear response regime presented in [4]. The case study of the Carnot engine is revisited within the steady state hypothesis, when non-adiabaticity of the system is considered, and heat loss is accounted for by an overall heat leak between the engine heat reservoirs.The optimization is focused on the main objective functions connected to engineering conditions, namely maximum efficiency or power output, except the one relative to entropy that is more fundamental.Results given in reference [4] relative to the maximum power output and minimum entropy production as objective function are reconsidered and clarified, and the change from finite time to finite physical dimension was shown to be done by the heat flow rate at the source.Our modeling has led to new results of the Carnot engine optimization and proved that the primary interest for an engineer is mainly connected to what we called Finite Physical Dimensions Optimal Thermodynamics.

Performance optimization for a generalized irreversible four-mass-reservoir diffusion transformer

2008 ◽  
Vol 222 (4) ◽  
pp. 689-701 ◽  
Author(s):  
D Xia ◽  
L Chen ◽  
F Sun
Keyword(s):  
Mass Transfer ◽  
Performance Optimization ◽  
Maximum Rate ◽  
Optimal Performance ◽  
Coefficient Of Performance ◽  
Finite Time Thermodynamics ◽  
Energy Pumping ◽  
Cyclic Model ◽  
Internal Dissipation ◽  
Mass Leakage

A new cyclic model of a four-mass-reservoir diffusion transformer with irreversible mass transfer, mass leakage, and internal dissipation is established in this paper. The optimal relation between the coefficient of performance (COP) and the rate of energy pumping of the generalized irreversible four-mass-reservoir diffusion transformer is derived by using finite-time thermodynamics. The maximum COP and the corresponding rate of energy pumping, as well as the maximum rate of energy pumping and the corresponding COP, are also obtained. Moreover, the influences of these irreversibilities on the optimal performance of the four-mass-reservoir diffusion transformer are revealed. It is found that the mass leakage affects the optimal performance both qualitatively and quantitatively, whereas the internal dissipation affects the optimal performance quantitatively. The results obtained herein can provide some new theoretical guidance for the optimal design and development of a class of four-mass-reservoir diffusion transformers.

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