Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
On the need for Total and Localized Exergy Disaggregation in Thermoeconomic Diagnosis based on Comprehensive Diagrams
Submission Author:
Pedro Rosseto de Faria , ES
Co-Authors:
Pedro Rosseto de Faria, Rodrigo Guedes dos Santos, Marcelo Aiolfi Barone, Raphael Amorim Lorenzoni, José Joaquim Conceição Soares Santos, Dimas Jose Rua Orozco
Presenter: Pedro Rosseto de Faria
doi://10.26678/ABCM.COBEM2021.COB2021-1489
Abstract
Thermoeconomics, the discipline that combines thermodynamic concepts with economic ones, can be divided into three main areas of application: cost allocation, diagnosis and optimization. Thermoeconomic diagnosis has been widely applied to find the causes of additional irreversibility and to assess its impact on energy consumption. The dissipative components and residues can be still considered a challenge in thermoeconomics due to the difficulties that some approaches have to deal with them. Most of the diagnosis works use the productive diagram and exergy disaggregation for dissipative component treatment and isolation. While the treatment of dissipative components means to define fuel and product (productive purpose) of them, the isolation means to define its input and output flows. Recently, an alternative possibility to deal with dissipative components and reduce the complexity of the model was presented through the localized physical exergy disaggregation in the productive diagram. This paper aims to implement a thermoeconomic diagnosis analysis through the comprehensive diagram, which combines the characteristics of the conventional physical and productive diagrams and avoids arbitrariness linked to the interconnections used in the productive ones. A Rankine cycle with different simulated anomalies is evaluated by two distinct thermoeconomic models (E and H&S) and also with the localized physical exergy disaggregation. The thermoeconomic diagnosis method called Fuel Impact Formula is used to quantify the effects of each malfunction and evaluate the complexity involved. The methods used are also evaluated regarding the capability to isolate and treat the dissipative equipment (condenser) of the plant and the complexity of the modeling. Results show that all models applied in the diagnosis analysis using comprehensive diagram present coherent results of additional fuel consumption due to the anomalies. Besides, the H&S Model and the localized disaggregation, which are able to isolate and treat the condenser, present similar results of malfunctions and dysfunctions. However, the E Model can only isolate the condenser presenting a different behavior of anomalies.
Keywords
Diagnosis, comprehensive diagram, Physical Exergy Disaggregation, thermoeconomics, localized disaggregation, dissipative components
