Design and Engine Performance Simulation of a Turbo-Cooling System

With the purpose of further lowering the intake temperature of diesel engine, a turbo-cooling system was developed, which was matched with a diesel engine. The system consists of two turbochargers and an intercooler: one turbocharger is the traditional exhaust driven turbo, and the other is an air turbocharger, which consists of a low expansion ratio radial air turbine coupled with a low pressure ratio centrifugal compressor. The 1-D preliminary design and the 3-D simulation of the air turbine and the low pressure ratio compressor were carried out. The new designed air turbine and compressor were manufactured and tested to get the performance maps. Further, the computational model of the diesel engine matched with this turbo-cooling system was set up. The simulated result shows that the turbo-cooling system can lower the intake temperature effectively and potential of reducing NO_x exhaust. It is also can be expected that exhaust gas recirculation could be realized more easily.