The invention discloses an engine and a supercharging
system thereof. The supercharging
system of the engine comprises an air inlet pipeline, an exhaust pipeline, a bypass pipeline and a
bypass valve,wherein the air inlet pipeline is connected with an
air compressor and an engine body; the exhaust pipeline is connected with the engine body and a
turbine; an air inlet end of the bypass pipeline isconnected with the air inlet pipeline, and an air outlet end is connected with the exhaust pipeline; and the
bypass valve is arranged on the bypass pipeline and controls the ventilation capacity of the bypass pipeline. According to the engine and the supercharging
system thereof, the
bypass valve is properly opened at a certain opening according to requirements under the appropriate working condition, supercharged intake air is bypassed to an exhaust side under the action of
differential pressure, and the flow and energy of exhausted air are increased after being bypassed, so that the outputpower of the
turbine is increased; and due to increase of surge margin of the engine and increase of the air-fuel ratio, the
fuel injection quantity can be increased by the engine to obtain higher torque output, the surge problem of a
supercharger cannot be caused, and the reliability of the
supercharger is improved.