Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
AN EVALUATION OF THERMOECONOMIC DIAGNOSIS THROUGH THE LOCALIZED DISAGGREGATION IN A REFRIGERATION SYSTEM
Submission Author:
Rodrigo Guedes dos Santos , ES
Co-Authors:
Rodrigo Guedes dos Santos, Pedro Rosseto de Faria, Marcelo Aiolfi Barone, Raphael Amorim Lorenzoni, Dimas Jose Rua Orozco, José Joaquim Conceição Soares Santos
Presenter: Administrador ABCM
doi://10.26678/ABCM.COBEM2021.COB2021-1538
Abstract
Thermoeconomics can be defined as the energetic efficiency science that joins concepts of the Second Law of Thermodynamics with ones from economic analysis, being mainly applied to solve problems in complex systems where the exclusive use of the First Law of Thermodynamics (mass and energy balances) in conventional analysis methods would not be enough. With this new approach, issues related to local optimization, to operational diagnosis, and to rational cost assessment of the plant final products could now be addressed. It is worth mentioning, that the thermoeconomic diagnosis is applied to identify the source of extra fuel consumption in each system element due to the presence of anomalies. Exergy is the most adequate thermodynamic magnitude used in thermoeconomics. The physical exergy disaggregation (Et&EM, H&S and UFS Models) has been introduced as an alternative for the isolation and treatment of dissipative components, and as well for residues cost allocation and improvement of the accuracy of the results. However, it increases the complexity of the model. For plants with dissipative equipment, such as the condenser or valve, the productive diagram, based on total exergy (E Model), need to join this dissipative equipment with other productive equipment. In this work, a refrigeration system with different simulated anomalies is evaluated by combining four different methodologies (E, Et&EM, H&S and UFS Models) in order to perform a localized physical disaggregation only in the dissipative components (condenser and valve). It is worth mentioning that E and H&S Models are unable to isolate and treat the condenser and / or valve, so this study combines at least two methodologies that are capable of doing it. The fuel impact formula is used as a thermoeconomic diagnosis methodology to quantify the effects of each malfunction and evaluate the complexity involved. The results show that the diagnosis analysis using localized physical disaggregation is able to isolate and treat the condenser and valve. Furthermore, the E Model with localized UFS Model, the E Model with localized H&S and UFS Models and E Model with localized Et&EM Model, which are able to isolate and treat the condenser, present similar results of malfunctions and dysfunctions. However, the separate calculation of mechanical and thermal exergies may be arbitrary.
Keywords
Diagnosis, productive diagram, Physical Exergy Disaggregation, localized disaggregation, thermoeconomics
