7L28/33D

This marine diesel engine employs a sequential turbocharging system to optimize performance across varying loads, a key feature in modern marine propulsion systems. The MAN Energy Solutions 7L28/33D is designed to deliver 2275 kW of power at 750 rpm, utilizing marine diesel oil (MDO) as its primary fuel. With a bore of 280 mm and a stroke of 330 mm, it comprises seven cylinders arranged in an L configuration, adhering to a four-stroke cycle. The engine's swept volume per cylinder is 20.3 dm³, and it boasts a compression ratio of 16.5:1. The engine is equipped with MAN TCA turbochargers, which automatically cut off the second turbocharger at part load to enhance efficiency. Common maintenance concerns include seawater cooling system strainer clogging and raw water pump impeller failure, necessitating weekly inspections and annual replacements. Additionally, turbocharger fouling from sodium and vanadium compounds can occur, requiring visual inspections and performance curve measurements. Fuel injector wear leading to poor atomization and carbon deposits in exhaust valves are also frequent issues, demanding regular monitoring and adjustments to fuel treatment additives. Cylinder liner wear due to abrasive particulate contamination and piston-liner misalignment is another critical area for routine borescope inspections.