Air inlet device for controlling exhaust gas temperature by waste gas drainage

Abstract

The invention discloses an air inlet device for controlling exhaust gas temperature by waste gas drainage. The air inlet device comprises an intercooler (1), a turbocharger (2), a selective catalytic reduction (SCR) postprocessing device (3) and a drainage pipeline (6); a compressor outlet of the turbocharger (2) is communicated with an air inlet tube of an engine (2) through the intercooler (1); a turbine outlet of the turbocharger (2) is communicated with the SCR postprocessing device (3); an exhaust port of the SCR postprocessing device (3) is provided with a temperature sensor (5); one end of the drainage pipeline (6) is communicated with a turbine inlet of the turbocharger (2); the other end of the drainage pipeline (6) is communicated with the outlet of the intercooler (1); the drainage pipeline (6) is provided with a controlled valve (7); the temperature sensor (5) and the controlled valve (7) are respectively and electrically connected with an engine electronic control unit (ECU) (8). By the air inlet device, the conversion efficiency of a catalyst in the SCR postprocessing device (3) of the engine is improved.

Description

technical field [0001] The invention relates to an engine intake device, in particular to an intake device which utilizes waste gas diversion to control exhaust temperature. Background technique [0002] The main harmful substances emitted by the combustion of automobile engines are nitrogen oxides (NOx) and various particulates (PM). With the increasing national automobile exhaust emission standards, the engine exhaust after-treatment system has become an indispensable system for the engine; At present, domestic manufacturers of large-scale supercharged diesel engines for vehicles generally use SCR after-treatment devices to reduce NOx emissions. The catalyst conversion efficiency of the SCR after-treatment device depends on the exhaust gas temperature. Generally, when the temperature of the catalyst in the SCR after-treatment device is higher than 280°C, the sulfate will decompose and be discharged with the exhaust gas, so that the conversion efficiency of the catalyst rea...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide an air intake device that uses exhaust gas diversion to control the exhaust temperature in view of the low exhaust temperature of the existing engine and the low catalyst conversion efficiency of the SCR after-treatment device.

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