Finite-time thermodynamic analysis of a radiative heat engine with internal irreversibility

In the present paper, the thermoeconomic optimization of an irreversible solar-driven heat engine model has been carried out by using finite-time/finite-size thermodynamic theory. In our study we take into account losses due to heat transfer across finite time temperature differences, heat leakage between thermal reservoirs and internal irreversibilities in terms of a parameter which comes from the Clausius inequality. In the considered heat engine model, the heat transfer from the hot reservoir to the working fluid is assumed to be Dulong-Petit type and the heat transfer to the cold reservoir is assumed of the Newtonian type. In this work, the optimum performance and two design parameters have been investigated under two objective functions: the power output per unit total cost and the ecological function per unit total cost. The effects of the technical and economical parameters on the thermoeconomic performance have been also discussed under the aforementioned two criteria of performance.

“…where R is the so-called non-endoreversibility parameter [32,33]. Substituting Equations (2) and (3) into Equation (8), a relationship between T Y and T X is obtained as,…”

Section: Theoretical Modelmentioning

confidence: 99%

Finite-Time Thermoeconomic Optimization of a Solar-Driven Heat Engine Model

Barranco-Jiménez¹,

Sánchez-Salas²,

Angulo‐Brown³

2011

“…where τ = T L /T H , θ = T 3 /T H and the parameter R = ∆S 1 /|∆S 2 | is the non-endoreversibility parameter [37,38] (which characterizes the degree of internal irreversibility that comes from the Clausius inequality), ∆S 1 being the change of the internal entropy along the hot isothermal branch and ∆S 2 the entropy change corresponding to the cold isothermal compression. This parameter in principle is within the interval 0 < R ≤ 1 (R = 1 for the endoreversible limit).…”

Section: Thermoeconomic Analysismentioning

confidence: 99%

Thermoeconomic Optimization of an Irreversible Novikov Plant Model under Different Regimes of Performance

Pacheco-Paez

Angulo‐Brown

Barranco-Jiménez

2017

Abstract:The so-called Novikov power plant model has been widely used to represent some actual power plants, such as nuclear electric power generators. In the present work, a thermo-economic study of a Novikov power plant model is presented under three different regimes of performance: maximum power (MP), maximum ecological function (ME) and maximum efficient power (EP). In this study, different heat transfer laws are used: The Newton's law of cooling, the Stefan-Boltzmann radiation law, the Dulong-Petit's law and another phenomenological heat transfer law. For the thermoeconomic optimization of power plant models, a benefit function defined as the quotient of an objective function and the total economical costs is commonly employed. Usually, the total costs take into account two contributions: a cost related to the investment and another stemming from the fuel consumption. In this work, a new cost associated to the maintenance of the power plant is also considered. With these new total costs, it is shown that under the maximum ecological function regime the plant improves its economic and energetic performance in comparison with the other two regimes. The methodology used in this paper is within the context of finite-time thermodynamics.

“…This expression can be transformed into an equality by introducing a parameter R leading to [21,22], Figure 1. Schematic representation of a non-endoreversible Curzon-Ahlborn engine.…”

Section: Steady-state Characteristics Of a Curzon-ahlborn Engine Modementioning

confidence: 99%

Global Stability Analysis of a Curzon–Ahlborn Heat Engine under Different Regimes of Performance

Reyes-Ramírez

Barranco-Jiménez

Rojas-Pacheco

et al. 2014

We present a global stability analysis of a Curzon-Ahlborn heat engine considering different regimes of performance. The stability theory is used to construct the Lyapunov functions to prove the asymptotic stability behavior around the steady state of internal temperatures. We provide a general analytic procedure for the description of the global stability by considering internal irreversibilities and a linear heat transfer law at the thermal couplings. The conditions of the global stability are explored for three regimes of performance: maximum power (M P ), efficient power (EP ) and the so-called ecological function (EF ). Moreover, the analytical results were corroborated by means of numerical integrations, which fully validate the properties of the global asymptotic stability.