General Properties for an Agrawal Thermal Engine

2018 ◽  
Vol 43 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Ricardo T. Paéz-Hernández ◽  
Juan Carlos Chimal-Eguía ◽  
Norma Sánchez-Salas ◽  
Delfino Ladino-Luna
Keyword(s):  
Heat Transfer ◽  
Finite Time ◽  
General Property ◽  
Power Plants ◽  
Optimization Criterion ◽  
Finite Time Thermodynamics ◽  
Applied Physics ◽  
Real Power ◽  
Heat Engines ◽  
Ecological Optimization

AbstractThis paper presents a general property of endoreversible thermal engines known as the Semisum property previously studied in a finite-time thermodynamics context for a Curzon–Ahlborn (CA) engine but now extended to a simplified version of the CA engine studied by Agrawal in 2009 (A simplified version of the Curzon–Ahlborn engine, European Journal of Physics30 (2009), 1173). By building the Ecological function, proposed by Angulo-Brown (An ecological optimization criterion for finite-time heat engines, Journal of Applied Physics69 (1991), 7465–7469) in 1991, and considering two heat transfer laws an analytical expression is obtained for efficiency and power output which depends only on the heat reservoirs’ temperature. When comparing the existing efficiency values of real power plants and the theoretical efficiencies obtained in this work, it is observed that the Semisum property is satisfied. Moreover, for the Newton and the Dulong–Petit heat transfer laws the existence of the g function is demonstrated and we confirm that in a Carnot-type thermal engine there is a general property independent of the heat transfer law used between the thermal reservoirs and the working substance.

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.

Finite-Time Thermodynamics and Endoreversible Heat Engines

1993 ◽  
Vol 21 (4) ◽  
pp. 337-346 ◽  
Author(s):  
C. Wu ◽  
R. L. Kiang ◽  
V. J. Lopardo ◽  
G. N. Karpouzian
Keyword(s):  
Heat Transfer ◽  
Finite Time ◽  
Heat Engine ◽  
Power Production ◽  
Maximum Power ◽  
The Other ◽  
Finite Time Thermodynamics ◽  
Equilibrium Time ◽  
Heat Engines ◽  
Maximum Value

An endoreversible heat engine is an internally reversible and externally irreversible cyclic device which exchanges heat and power with its surroundings. Classical engineering thermodynamics is based on the concept of equilibrium. Time is not considered in the energy interactions between the heat engine and its environment. On the other hand, although rate of energy transfer is taught in heat transfer, the course does not cover heat engines. The finite-time thermodynamics is a newly developing field to fill in the gap between thermodynamics and heat transfer. Two types of engines are modelled in this paper—a reciprocating and a steady flow—with results obtained for maximum power output and efficiency at maximum power. It is shown that the latter is the same for both types of engines but that the maximum value of power production is different.

Optimization Analysis of Ship Steam Power System with Finite-Time Thermodynamics Theory

2012 ◽  
Vol 271-272 ◽  
pp. 1062-1066
Author(s):  
Zhi Guo Wei ◽  
Hai Kun Tao ◽  
Yong Li
Keyword(s):  
Heat Transfer ◽  
Power System ◽  
Finite Time ◽  
Influence Factors ◽  
Design Parameters ◽  
Carnot Cycle ◽  
Finite Time Thermodynamics ◽  
Steam Power ◽  
Cycle System ◽  
Steam Power System

A basic model with both property of thermodynamic and heat transfer is obtained by simplifying the prime process of ship Steam Power System (SPS), which is converted into endoreversible Carnot Cycle by the introduction of mean temperature in the cycle process. The design parameters is analyzed and optimized in the view point of finite time thermodynamics (FTT) and entropy generation minimization. Results show that, the temperature ratio (α) and the heat transfer parameter ratio (β) of heat source and heat sink are two important influence factors of cycle system performance, and the increase of α and decrease of β will redound to the reduction of irreversible loss and enhancement of power output.

Analysis on the Flow Process of Hot Oil in the Organic Heat Transfer Material Heater Based on Finite Time Thermodynamics

2011 ◽  
Vol 250-253 ◽  
pp. 2979-2983 ◽  
Author(s):  
Wei Li Gu ◽  
Yuan Quan Liu
Keyword(s):  
Heat Transfer ◽  
Entropy Production ◽  
Production Rate ◽  
Finite Time ◽  
Entropy Production Rate ◽  
Physical Parameters ◽  
Finite Time Thermodynamics ◽  
Flow Process ◽  
Dissipation Effect ◽  
Rate Of Dissipation

Analyses the flow process of hot oil in the organic heat transfer material heater based on finite time thermodynamics for the first time, obtains the entropy production rate which includes entropy production rate of dissipation effect and entropy production rate of potential difference, analyses the influence of flow pattern, physical parameters, structure and operation of the organic heat transfer material heater on the entropy production rate of dissipation effect, illustrates the influence of related parameters including Renold number, velocity, viscosity and pipe diameter on the entropy production rate of dissipation effect, and points out the type of hot oil must be considered to decrease the entropy production rate of dissipation effect and the velocity must be control under the premise of avoiding overheat.

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.

Finite Time Thermodynamics: Realizability Domain of Heat to Work Converters

2019 ◽  
Vol 44 (2) ◽  
pp. 181-191 ◽  
Author(s):  
M. A. Zaeva ◽  
A. M. Tsirlin ◽  
O. V. Didina
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Finite Time ◽  
Heat Engine ◽  
Energy Conversion Efficiency ◽  
Maximum Power ◽  
Working Fluid ◽  
Finite Time Thermodynamics

Abstract From the point of view of finite time thermodynamics, the performance boundaries of thermal machines are considered, taking into account the irreversibility of the heat exchange processes of the working fluid with hot and cold sources. It is shown how the kinetics of heat exchange affects the shape of the optimal cycle of a heat engine and its performance, with a focus on the energy conversion efficiency in the maximum power mode. This energy conversion efficiency can depend only on the ratio of the heat transfer coefficients to the sources or not depend on them at all. A class of kinetic functions corresponding to “natural” requirements is introduced and it is shown that for any kinetics from this class the optimal cycle consists of two isotherms and two adiabats, not only for the maximum power problem, but also for the problem of maximum energy conversion efficiency at a given power. Examples are given for calculating the parameters of the optimal cycle for the case when the heat transfer coefficient to the cold source is arbitrarily large and for kinetics in the form of a Fourier law.

scholarly journals Kinetic model for the finite-time thermodynamics of small heat engines

2015 ◽  
Vol 91 (3) ◽  
Author(s):  
Luca Cerino ◽  
Andrea Puglisi ◽  
Angelo Vulpiani
Keyword(s):  
Kinetic Model ◽  
Finite Time ◽  
Finite Time Thermodynamics ◽  
Heat Engines

On Some Nonendoreversible Engine Models with Nonlinear Heat Transfer Laws

2003 ◽  
Vol 10 (04) ◽  
pp. 351-375 ◽  
Author(s):  
L. A. Arias-Hernández ◽  
G. Ares de Parga ◽  
F. Angulo-Brown
Keyword(s):  
Heat Transfer ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Maximum Power ◽  
Working Fluid ◽  
Real Power ◽  
Optimization Criteria ◽  
Engine Model ◽  
Nonlinear Heat Transfer

In this work, we analyze a nonendoreversible thermal engine model with a nonlinear heat transfer law between the heat reservoirs and the working fluid under two optimization criteria: the maximum power regime and the so-called ecological criterion. We find that this nonendoreversible model has a similar behaviour to that shown by De Vos (Am. J. Phys. 53, 570 (1985)) for endoreversible models with two thermal conductances with only one superior conductance and with only one inferior conductance, respectively. The model is compared with two sets of real power plants, the first one containing power plants of old design (before 1960's) and the second one being formed by modern nuclear power plants. Our results suggest that the first group was designed under conditions which are reminiscent of a maximum power regime and the second one under an ecological-like criterion. We also study some general properties of nonendoreversible thermal engine models.

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