Analysis of Fuel Heat Loss via Exhaust Gas in Marine Diesel Engines Using Turbochargers on MV Tonasa Line XVI

Abstract

Energy efficiency in the maritime transport sector has become a top priority due to stricter international regulations regarding carbon emissions and fuel efficiency. This study aims to analyze the amount of waste heat energy lost through the exhaust system of the main diesel engine on MV Tonasa Line XVI and evaluate the effectiveness of a turbocharger in recovering a portion of this energy to enhance operational performance. The methodology used is quantitative experimental observation by collecting engine parameters at load variations of 50%, 75%, and 100% of the Maximum Continuous Rating (MCR), including exhaust gas temperatures before and after the turbine, scavenge air pressure, and specific fuel consumption. The results show that at 50% load, the exhaust gas temperature entering the turbocharger reaches 340°C and exits at 270°C, with a system heat recovery efficiency of 63.1%. Increasing the load to 75% raises the exhaust gas temperature to 390°C, with system efficiency reaching 71.0%, while under full load (100%), the temperature peaks at 440°C with an effective thermal efficiency of 72.4%. The findings demonstrate that the turbocharger effectively reduces specific fuel consumption (SFC) from 230.7 g/kWh at low load to 221.1 g/kWh at full load, confirming its vital role in converting exhaust enthalpy into mechanical work for combustion air compression to directly support compliance with Energy Efficiency Existing Ship Index (EEXI) standards. Furthermore, the residual exhaust gas energy remaining at 350°C under high loads presents a significant opportunity for additional waste heat recovery systems, such as an economizer, to achieve further energy optimization.