Análisis de la producción de entropía en una máquina térmica operada con un sistema químico no–lineal

Analysis of entropy production in a thermal engine powered by a nonlinear chemical system

J. Villanueva–Marroquín y D. Barragán*

Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia Cra 30 # 45–03, Bogotá, Colombia. * Autor para la correspondencia. E–mail: dabarraganra@bt.unal.edu.co, dabarraganra@gmail.com Fax (+57–1) 3165220

Resumen

Con el propósito de minimizar la velocidad de producción de entropía –disipación termodinámica– durante un proceso químico, la segunda ley de la termodinámica se aplica al estudio de una máquina térmica sujeta a procesos isotérmicos de expansión–compresión. Se determina la magnitud del coeficiente global de transferencia de calor (W m^–2 K^–1) del pistón que minimiza la disipación termodinámica cuando éste es conducido por la reacción química AB, representada en régimen oscilatorio por el modelo termocinético de Sal'nikov.

Palabras clave: optimización basada en la segunda ley la termodinámica, velocidad de producción de entropía, disipación termodinámica, modelo de Sal'nikov, oscilador termocinético.

Abstract

Second law optimization is applied to study a thermal engine driven by a thermokinetic oscillator. The Sal'nikov model is used to modeling the net process AB, which for given values of the control parameters exhibits nonlinear behavior like oscillations in temperature and concentrations. Constant of global heat transfer in W m^–2 K^–1for the engine which minimizes the rate of entropy production during transformation is obtained after numerical evaluation.

Keywords: second law optimization, rate of entropy production, thermodynamic dissipation, Sal'nikov model, thermokinetic oscillator.

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Agradecimientos

A la Universidad Nacional de Colombia por la financiación de los proyectos DIB–803770, DIB–803734 y DINAIN 20601002443. Agradecemos a Miguel A. Montero–Páez por el diseño de las figuras.

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