Methodology for Energy Efficiency Analysis and Optimization of Ship Systems using Exergy Modeling

• DOI: https://doi.org/10.22533/at.ed.3174212406086

• Palavras-chave: Emissões de Navios; Eficiência Energética, Eficiência Exergética, Índice de Eficiência Energética de Navios Existentes

• Keywords: Ship Emissions; Energy Efficiency, Exergetic Efficiency, Energy Efficiency Existing Ship Index

• Abstract: In January 2023, the International Maritime Organization (IMO) through Resolution 333 (76), required ships of 400 GT or more engaged in international voyages to comply with the Energy Efficiency Existing Ship Index (EEXI). This study aims to develop a tool for selecting existing technologies that have the greatest impact on CO₂ reduction, aligning vessels with environmental indicators. It is common for ships, even of the same design, to exhibit different performances due to various operations and maintenance. Therefore, it is essential to consider the unique characteristics of each vessel. This paper presents a methodology developed through exergy modeling to identify primary inefficiencies and assess the potential for residual heat recovery in the main combustion engines of an oil tanker that did not meet the EEXI criteria and operates off the Brazilian coast relieving FPSOs. Exergy modeling allows identifying areas of significant energy waste and applying suitable technology. The study concludes that applying the proposed methodology enables a genuine reduction in CO₂ emissions, aligning vessels with IMO's environmental indicators. Despite the longstanding use of exergy in the maritime domain, the method presented here uses exergy as a tool for selecting emission reduction technology, an unexplored territory.