Exhaust postprocessing device and method used for engine

Abstract

The invention provides an exhaust postprocessing device and method used for an engine. The exhaust postprocessing device comprises a postprocessing part used for conducting postprocessing on exhaust of the engine and arranged in an exhaust pipeline, a bypass branch and a bypass valve, wherein an inlet and an outlet of the bypass branch communicate to the exhaust pipeline located at the inlet end and the outlet end of the postprocessing part correspondingly; and the bypass valve is arranged in the bypass branch and used for enabling exhausted gas from the engine to wholly or at least partially bypass the postprocessing part according to commands of an electronic control unit of the engine.

Description

technical field [0001] The invention relates to an exhaust aftertreatment technology, in particular to an exhaust aftertreatment device and an exhaust aftertreatment method for an engine. Background technique [0002] With the development of automobile technology, the requirements for automobile emission levels are getting higher and higher. In order to protect the environment and reduce automobile exhaust pollution, different countries have formulated different emission regulations or standards. With the upgrading of emission regulations, exhaust post-treatment has gradually become an indispensable part of the engine. However, since the exhaust post-treatment has certain requirements for temperature, in order to meet the emission results of the engine in normal operating conditions that meet the requirements of the regulations, usually It is necessary to increase the exhaust gas temperature (also called exhaust temperature) under lower load conditions during the calibration...

AI Technical Summary

Problems solved by technology

With the upgrading of emission regulations, exhaust post-treatment has gradually become an indispensable part of the engine. However, since the exhaust post-treatment has certain requirements for temperature, in order to meet the emission results of the engine in normal operating conditions that meet the requirements of the regulations, usually It is necessary to increase the exhaust temperature (also called exhaust temperature) under lower load conditions during the calibration process, and the negative effect is to worsen fuel consumption

[0003] One way to reduce the demand for exhaust temperature is to reduce the cooling of the after-treatment components by the low-temperature exhaust gas under the condition of idling speed (with a small amount of fuel injection) and the throttle is zero. The usual method is to set an air intake throttle valve in the intake pipe. And under the working conditions of idling speed and zero throttle, the opening of the air intake throttle valve is reduced, thereby reducing the intake air volume and thus reducing the cooling of the aftertreatment, but this method is due to the valve response of the air intake throttle valve. It takes time. Correspondingly, it takes time to increase the speed of the supercharger, which often affects the subsequent acceleration, which in turn affects the dynamic performance of the engine.

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