Interpretation of Entropy Calculations in Energy Conversion Systems

Often, second law-based studies present merely entropy calculations without demonstrating how and whether such calculations may be beneficial. Entropy generation is commonly viewed as lost work or sometimes a source of thermodynamic losses. Recent literature reveals that minimizing the irreversibili...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autor principal:	Yousef Haseli
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	performance improvement energy system irreversibility torrefaction cogeneration air separation Technology T
Acceso en línea:	https://doaj.org/article/96f79a94866f4fefb0e75d578d669649
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:96f79a94866f4fefb0e75d578d669649
record_format	dspace
spelling	oai:doaj.org-article:96f79a94866f4fefb0e75d578d6696492021-11-11T15:50:33ZInterpretation of Entropy Calculations in Energy Conversion Systems10.3390/en142170221996-1073https://doaj.org/article/96f79a94866f4fefb0e75d578d6696492021-10-01T00:00:00Zhttps://www.mdpi.com/1996-1073/14/21/7022https://doaj.org/toc/1996-1073Often, second law-based studies present merely entropy calculations without demonstrating how and whether such calculations may be beneficial. Entropy generation is commonly viewed as lost work or sometimes a source of thermodynamic losses. Recent literature reveals that minimizing the irreversibility of a heat engine may correspond to maximizing thermal efficiency subject to certain design constraints. The objective of this article is to show how entropy calculations need to be interpreted in thermal processes, specifically, where heat-to-work conversion is not a primary goal. We will study four exemplary energy conversion processes: (1) a biomass torrefaction process where torrefied solid fuel is produced by first drying and then torrefying raw feedstock, (2) a cryogenic air separation system that splits ambient air into oxygen and nitrogen while consuming electrical energy, (3) a cogeneration process whose desirable outcome is to produce both electrical and thermal energy, and (4) a thermochemical hydrogen production system. These systems are thermodynamically analyzed by applying the first and second laws. In each case, the relation between the total entropy production and the performance indicator is examined, and the conditions at which minimization of irreversibility leads to improved performance are identified. The discussion and analyses presented here are expected to provide clear guidelines on the correct application of entropy-based analyses and accurate interpretation of entropy calculations.Yousef HaseliMDPI AGarticleperformance improvementenergy systemirreversibilitytorrefactioncogenerationair separationTechnologyTENEnergies, Vol 14, Iss 7022, p 7022 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	performance improvement energy system irreversibility torrefaction cogeneration air separation Technology T
spellingShingle	performance improvement energy system irreversibility torrefaction cogeneration air separation Technology T Yousef Haseli Interpretation of Entropy Calculations in Energy Conversion Systems
description	Often, second law-based studies present merely entropy calculations without demonstrating how and whether such calculations may be beneficial. Entropy generation is commonly viewed as lost work or sometimes a source of thermodynamic losses. Recent literature reveals that minimizing the irreversibility of a heat engine may correspond to maximizing thermal efficiency subject to certain design constraints. The objective of this article is to show how entropy calculations need to be interpreted in thermal processes, specifically, where heat-to-work conversion is not a primary goal. We will study four exemplary energy conversion processes: (1) a biomass torrefaction process where torrefied solid fuel is produced by first drying and then torrefying raw feedstock, (2) a cryogenic air separation system that splits ambient air into oxygen and nitrogen while consuming electrical energy, (3) a cogeneration process whose desirable outcome is to produce both electrical and thermal energy, and (4) a thermochemical hydrogen production system. These systems are thermodynamically analyzed by applying the first and second laws. In each case, the relation between the total entropy production and the performance indicator is examined, and the conditions at which minimization of irreversibility leads to improved performance are identified. The discussion and analyses presented here are expected to provide clear guidelines on the correct application of entropy-based analyses and accurate interpretation of entropy calculations.
format	article
author	Yousef Haseli
author_facet	Yousef Haseli
author_sort	Yousef Haseli
title	Interpretation of Entropy Calculations in Energy Conversion Systems
title_short	Interpretation of Entropy Calculations in Energy Conversion Systems
title_full	Interpretation of Entropy Calculations in Energy Conversion Systems
title_fullStr	Interpretation of Entropy Calculations in Energy Conversion Systems
title_full_unstemmed	Interpretation of Entropy Calculations in Energy Conversion Systems
title_sort	interpretation of entropy calculations in energy conversion systems
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/96f79a94866f4fefb0e75d578d669649
work_keys_str_mv	AT yousefhaseli interpretationofentropycalculationsinenergyconversionsystems
_version_	1718433589209595904

Interpretation of Entropy Calculations in Energy Conversion Systems

Ejemplares similares