EGR (exhaust gas recirculation) and intake humidification based supercharged diesel engine environment protection device

The invention aims to provide an EGR (exhaust gas recirculation) and intake humidification based supercharged diesel engine environment protection device. The device comprises a diesel engine, a turbo-supercharger, an intake pipe and an exhaust pipe, the intake pipe is communicated with the diesel engine and a compressor of the turbo-supercharger, and the exhaust pipe is connected with the diesel engine and a turbine of the turbo-supercharger. The device further comprises a steam generator, a gas storage tank, a condenser, an EGR cooler and a steam ejector, the steam ejector is mounted on the intake pipe, the EGR cooler is mounted between the steam ejector and the exhaust pipe, a cooling water outlet of the EGR cooler and the turbine are communicated with the steam generator respectively, the steam generator is communicated with the gas storage tank and the atmosphere, the gas storage tank is communicated with the steam injector and a cooling water inlet of the EGR cooler, and the condenser is arranged on a pipeline between the gas storage tank and the cooling water inlet of the EGR cooler. Energy is saved, combustion and emission performance of a supercharged diesel engine can be improved, and the complete device is simple in structure and is applicable to marine diesel engine systems and the like.