Thermal management control method of afterprocessor based on intake and exhaust system

Abstract

The invention discloses a postprocessor heat management control method based on an air intake and exhaust system. The method comprises the steps that a work condition point of a steady state test for an original engine is determined through analysis on a test loop and the exhaust temperature, and the target temperature is determined according to the variation trend of the SCR temperature of the original engine in a WHTC test loop; the influence mechanism of the opening degree of a variable geometrical cross section turbocharger on the SCR temperature is determined on the basis of the WHTC test loop; the influence mechanism of a late intake valve switching-off mechanism on the SCR temperature is determined on the basis of the WHTC test loop; a WHTC cold start test is conducted, and meanwhile an optimal variable geometrical cross section turbocharger-late intake valve switching-off mechanism control strategy parameter is determined by changing the opening degree of the variable geometrical cross section turbocharger and the switching-off set time of the intake valve. According to the method, the exhaust temperature can be increased, so that the NOx conversion efficiency of a post-processing system is improved. The method is suitable for a diesel engine with the variable geometrical cross section turbocharger.

Description

technical field [0001] The present invention relates to diesel engine exhaust post-treatment technology, variable geometry cross-section turbocharging technology and Miller cycle technology that delays intake valve closing late, more specifically, relates to a post-processor thermal management based on intake and exhaust systems Control Method. Background technique [0002] With its outstanding high efficiency, low fuel consumption, low CO 2 Emissions and other characteristics are widely used in the field of commercial vehicles and passenger vehicles. However, oxygen-enriched combustion in the cylinder is usually accompanied by a large amount of nitrogen oxide emissions, mainly referring to nitrogen monoxide (NO) and nitrogen dioxide (NO 2 ), both collectively referred to as NO x . Normally, NO in the exhaust of diesel engines accounts for the vast majority, and it can reach 90% in some working conditions. Medical research has shown that NO and NO 2 It will have advers...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a post-processor thermal management control method based on the intake and exhaust system, aiming at low-load conditions of the diesel engine and the low conversion efficiency of the SCR system during the cold start process, which can increase the temperature of the exhaust gas and improve the efficiency of the after-treatment system. NO x Conversion efficiency

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