Ecological Optimization of Generalized Irreversible Chemical Engines

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Lingen Chen ◽  
Dan Xia ◽  
Fengrui Sun
Keyword(s):  
Mass Transfer ◽  
Entropy Production ◽  
Production Rate ◽  
Power Output ◽  
Optimization Criterion ◽  
Ecological Function ◽  
Maximum Efficiency ◽  
Entropy Production Rate ◽  
Output Entropy ◽  
Ecological Optimization

Optimal ecological performance of generalized irreversible chemical engine cycles with both linear and diffusive mass transfer laws are derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the power output and the entropy production rate of the chemical engines. In this paper, the relations between the ecological function, power output, entropy production rate and the efficiency of a chemical engine cycle with irreversibilities of mass transfer, mass leakage and internal dissipation, in which the mass transfer, are derived. This paper also derives the maximum ecological function and the corresponding power output, entropy production rate and efficiency, the maximum power output and the corresponding ecological function, entropy production rate and efficiency, and the maximum efficiency and the corresponding ecological function, power output and entropy production rate. The results can provide some theoretical guidelines for the design of practical chemical engines.

The Ecological Optimal Performances of an Irreversible Four-Heat-Source Refrigerator

2014 ◽  
Vol 1008-1009 ◽  
pp. 1101-1105
Author(s):  
Li Ya Xu
Keyword(s):  
Heat Source ◽  
Entropy Production ◽  
Cooling Rate ◽  
Production Rate ◽  
Optimization Criterion ◽  
Coefficient Of Performance ◽  
Entropy Production Rate ◽  
Mode Of Operation ◽  
Reasonable Use ◽  
Ecological Optimization

Using finite-time thermodynamics, optimal analysis on a class of four-heat-source refrigerator for Newton’ heat transfer law is done based on the ecological objective function. The ecological optimal performances of refrigerator are derived. An ecological optimization criterion is proposed for the best mode of operation of the refrigerators, which consists of maximizing a function representing the best compromise between the cooling rate and entropy production rate. We investigate the ecological optimization performance and derive the optimal cooling rate, coefficient of performance and entropy production rate for the refrigerators. Moreover, there are some advantages in using the ecological optimization criterion; it is especially beneficial for determining the reason able use of energy and protecting the ecological environment. The conclusions obtained here are of importance in the optimal design and reasonable use of the energy of real four-heat-source refrigerators, such as absorption refrigerators, adsorption refrigerators, and so on.

scholarly journals Spin Isoenergetic Process and the Lindblad Equation

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 503 ◽  
Author(s):  
Congjie Ou ◽  
Yuho Yokoi ◽  
Sumiyoshi Abe
Keyword(s):  
Magnetic Field ◽  
Entropy Production ◽  
Production Rate ◽  
Power Output ◽  
Entropy Production Rate ◽  
Leading Order ◽  
Quantum Thermodynamics ◽  
Lindblad Equation ◽  
Markovian Approximation ◽  
Work Done

A general comment is made on the existence of various baths in quantum thermodynamics, and a brief explanation is presented about the concept of weak invariants. Then, the isoenergetic process is studied for a spin in a magnetic field that slowly varies in time. In the Markovian approximation, the corresponding Lindbladian operators are constructed without recourse to detailed information about the coupling of the subsystem with the environment called the energy bath. The entropy production rate under the resulting Lindblad equation is shown to be positive. The leading-order expressions of the power output and work done along the isoenergetic process are obtained.

scholarly journals Entropy Production Rate for Avascular Tumor Growth

2011 ◽  
Vol 02 (06) ◽  
pp. 615-620 ◽  
Author(s):  
Elena Izquierdo-Kulich ◽  
Esther Alonso-Becerra ◽  
José M Nieto-Villar
Keyword(s):  
Tumor Growth ◽  
Entropy Production ◽  
Production Rate ◽  
Entropy Production Rate ◽  
Avascular Tumor

scholarly journals Measurement of entropy production rate in compressible turbulence

2006 ◽  
Vol 76 (4) ◽  
pp. 595-601 ◽  
Author(s):  
M. M Bandi ◽  
W. I Goldburg ◽  
J. R Cressman
Keyword(s):  
Entropy Production ◽  
Production Rate ◽  
Compressible Turbulence ◽  
Entropy Production Rate

scholarly journals Between Waves and Diffusion: Paradoxical Entropy Production in an Exceptional Regime

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 881 ◽  
Author(s):  
Karl Hoffmann ◽  
Kathrin Kulmus ◽  
Christopher Essex ◽  
Janett Prehl
Keyword(s):  
Entropy Production ◽  
Production Rate ◽  
Fractional Diffusion ◽  
Diffusion Equations ◽  
Irreversible Processes ◽  
Entropy Production Rate ◽  
Continuous Space ◽  
One Dimensional ◽  
Fractional Diffusion Equations ◽  
And Diffusion

The entropy production rate is a well established measure for the extent of irreversibility in a process. For irreversible processes, one thus usually expects that the entropy production rate approaches zero in the reversible limit. Fractional diffusion equations provide a fascinating testbed for that intuition in that they build a bridge connecting the fully irreversible diffusion equation with the fully reversible wave equation by a one-parameter family of processes. The entropy production paradox describes the very non-intuitive increase of the entropy production rate as that bridge is passed from irreversible diffusion to reversible waves. This paradox has been established for time- and space-fractional diffusion equations on one-dimensional continuous space and for the Shannon, Tsallis and Renyi entropies. After a brief review of the known results, we generalize it to time-fractional diffusion on a finite chain of points described by a fractional master equation.

scholarly journals Testing the Steady-State Fluctuation Relation in the Solar Photospheric Convection

Entropy ◽  
2020 ◽  
Vol 22 (7) ◽  
pp. 716
Author(s):  
Giorgio Viavattene ◽  
Giuseppe Consolini ◽  
Luca Giovannelli ◽  
Francesco Berrilli ◽  
Dario Del Moro ◽  
...  
Keyword(s):  
Steady State ◽  
Entropy Production ◽  
Production Rate ◽  
Local Level ◽  
Entropy Production Rate ◽  
Quasi Steady State ◽  
The Sun ◽  
Statistical Features ◽  
Local Entropy ◽  
Fluctuation Relation

The turbulent thermal convection on the Sun is an example of an irreversible non-equilibrium phenomenon in a quasi-steady state characterized by a continuous entropy production rate. Here, the statistical features of a proxy of the local entropy production rate, in solar quiet regions at different timescales, are investigated and compared with the symmetry conjecture of the steady-state fluctuation theorem by Gallavotti and Cohen. Our results show that solar turbulent convection satisfies the symmetries predicted by the fluctuation relation of the Gallavotti and Cohen theorem at a local level.

scholarly journals Analysis of Entropy Production in Structured Chemical Reactors: Optimization for Catalytic Combustion of Air Pollutants

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1017 ◽  
Author(s):  
Mateusz Korpyś ◽  
Anna Gancarczyk ◽  
Marzena Iwaniszyn ◽  
Katarzyna Sindera ◽  
Przemysław J. Jodłowski ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Entropy Production ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Catalytic Combustion ◽  
Packed Bed ◽  
Optimization Criterion ◽  
Rational Solutions ◽  
Short Channel ◽  
Flow Friction

Optimization of structured reactors is not without some difficulties due to highly random economic issues. In this study, an entropic approach to optimization is proposed. The model of entropy production in a structured catalytic reactor is introduced and discussed. Entropy production due to flow friction, heat and mass transfer and chemical reaction is derived and referred to the process yield. The entropic optimization criterion is applied for the case of catalytic combustion of methane. Several variants of catalytic supports are considered including wire gauzes, classic (long-channel) and short-channel monoliths, packed bed and solid foam. The proposed entropic criterion may indicate technically rational solutions of a reactor process that is as close as possible to the equilibrium, taking into account all the process phenomena such as heat and mass transfer, flow friction and chemical reaction.

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