关键词: 排气系统；排气背压；柴油机；燃油经济性；台架试验

Abstract: Exhaust system is an important part of engine accessories, the size of exhaust backpressure directly affects the pump gas loss and thermal efficiency of diesel engine, thus affecting the vehicle fuel economy performance. In this paper, the variation trend of engine power and fuel consumption rate with the increase of exhaust backpressure was measured under rated working conditions through diesel engine bench test. The simulation model of truck was built in AVL CRUISE software, through the influence curve of exhaust backpressure on vehicle economy, the optimization direction of exhaust system is given.

Key words: Exhaust system; Exhaust backpressure; The diesel engine; Fuel economy; Bench test