METHOD OF CONTROLLING TURBOCHARGER SPEED OF A PISTON ENGINE AND A CONTROL SYSTEM FOR A TURBOCHARGED PISTON ENGINE

摘要

Invention relates to method of controlling turbocharger speed of a piston engine in which method the engine is operated below or at a predetermined load and combustion air is pressurised with the compressor part, the intake valve is controlled by a first intake valve lift profile and fuel is combusted in the engine (10), the exhaust valve is controlled by a first exhaust valve lift profile. The engine is run in a second mode of operation above the predetermined load during which the closing of the inlet valve is advanced compared to that of the first mode of operation and the air flow between an outlet of the compressor part and an inlet of the turbine part is increased allowing more combustion air to flow through the compressor part (25.1).