Design of Electric Supercharger for Reducing Black Smoke Emission from Diesel Engine

An additional electric supercharger(ES) system was developed to reduce the black smoke emission from diesel engine of bus.The ES system includes intake air system,a supercharger driven by high-speed electric motor,power supply system on board and an intelligent unit for recognizing operation condition.The ES system is powered by a 24-voltage bat-tery on board and does not consume too much power due to its short running time.The ES installed on diesel engine only works for several ten seconds during transient operation such as engine starting and rapid acceleration,it does not work in the steady state operation.The testing results on bench show that with the help of additional ES,the performances of engine are improved remarkably,e.g.the intake air flow and torque increase,the exhaust emission reduces,the smoke is eliminated dramatically at sharp acceleration particularly,and fuel consumption also decreases.Furthermore,the installation of the ES system is convenient and reliable,and the tests on road obtain the same results as those on bench while the ES system is mounted on a bus.