Combining simulation and testing

the reduction was researched of exhaust temperature before turbine of a high-boosted marine diesel engine at low load with propeller curve. The simulation results show that the effect of the intake and exhaust valve timing optimization on the reduction of exhaust temperature before turbine is not obvious because the valve timing optimization is limited to the piston movement and valve lift. The exhaust temperature before turbine

however

can be greatly reduced with a cylinder bypass system and meanwhile the brake specific fuel consumption(BSFC) at low load also goes down. The cylinder bypass system was verified on the engine and the results show that the cylinder bypass system is able to greatly lower the exhaust temperature before turbine with the reduction up to 120 ℃.