89690 20210902121706.0 doi 10.3390/en13082024 sideral 117822 ART-2020-117822 eng Valero, Antonio Universidad de Zaragoza (orcid)0000-0003-0702-733X Relative free energy function and structural theory of thermoeconomics 2020 Access copy available to the general public Unrestricted This paper explores the advantages of using relative free energy instead of exergy to build a mathematical theory of thermodynamic costs to diagnose malfunctions in thermal systems. This theory is based on the definition of a linearized characteristic equation that represents the physical behavior of each component. The physical structure of the system described by its energy interrelationships is called “primal”, and its derivatives are the costs and consumptions. The obtained costing structure is the mathematical “dual” of its primal. The theory explains why the F and P cost assessment rules and any other suggestion may (or may not be) rational under a given disaggregation scheme. A result of the theory is a new thermodynamic function, called the relative free energy, and a new parameter called deterioration temperature due to a component''s deterioration cause, characterized by a h-s thermodynamic trajectory describing the effects on the exiting stream. The relative free energy function allows for an exact relationship between the amount of used resources and the increase in entropy generation caused by the deterioration path of the component. This function allows the obtaining of, for the first time, an appropriate characteristic equation for a turbine and a new definition of efficiency that does not depend on the environment temperature but on its deterioration temperature. Also, costing with relative free energy instead of exergy may open a new path for more precise and straightforward assessments of component deteriorations. info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 3.004 2020 ENERGY & FUELS 70 / 114 = 0.614 2020 Q3 T2 0.597 2020 Control and Optimization 2020 Q2 Electrical and Electronic Engineering 2020 Q2 Renewable Energy, Sustainability and the Environment 2020 Q2 Energy Engineering and Power Technology 2020 Q2 Fuel Technology 2020 Q2 Energy (miscellaneous) 2020 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Torres, César Universidad de Zaragoza (orcid)0000-0002-6360-1159 5004 590 Universidad de Zaragoza Dpto. Ingeniería Mecánica Área Máquinas y Motores Térmi. 13, 8 (2020), 2024 [21 pp.] ENERGIES Energies 1996-1073 310040 http://zaguan.unizar.es/record/89690/files/texto_completo.pdf Versión publicada 517555 http://zaguan.unizar.es/record/89690/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:89690 articulos driver 2021-09-02-09:17:29 ARTICLE