The turbocharger match plays a key role for a successfully developed engine. Properly matched turbochargers ensure a good gas exchange, the right air flow rates, and air-fuel ratios as required for the combustion fine tuning.
AVL LIST GmbH in Graz, Austria, starting from a blank computer display, designed, developed and tested a medium speed diesel engine to cover three applications: power generation, marine propulsion and drilling rig drive. The 12 cylinder vee engine has 2370 HP rated power at 1500 rpm rated engine speed. For the drilling rig drive application 8% torque backup at low engine speed is available.
The turbocharging challenge was to specify a turbocharger to suit all three applications. Thus, the turbocharger operation ranged from the constant engine speed operation for power generation, to variable engine speed operation for marine propulsion and with torque backup for the drilling rig drive application.
The paper reports test results which demonstrate that AVL could match the engine over a wide application range. The engine performance and system layout calculations performed prior to testing were validated by tests. The engine performance software used is presented. A special emphasis is placed on the implementation, operation and impact of a bypass and waste-gate system as an aid to match the turbocharger for the engine operation with torque back-up.