Engine exhaust hydrocarbon injection system and control strategy thereof

Abstract

The invention discloses an engine exhaust hydrocarbon injection system. The engine exhaust hydrocarbon injection system comprises an engine exhaust pipe, an air supply assembly, an oil supply assembly, a mixing chamber, an injection pipe, an HC nozzle and a control unit, the air supply assembly and the oil supply assembly are connected with the mixing chamber, the HC nozzle is located on the downstream of the mixing chamber and communicates with the mixing chamber, the air supply assembly comprises a compressed air source and an air valve, the oil supply assembly comprises a low-pressure oil source, an oil cut-off valve and a metering pump, and the metering pump is a solenoid pulse type metering injection unit and used for accurately metering the amount of fuel oil entering the mixing chamber. The hydrocarbon injection system is high in injection precision, good in atomization effect, high in system reliability and low in cost.

Description

technical field [0001] The invention belongs to the field of engine emission control, and specifically relates to an engine exhaust hydrocarbon injection system, especially a hydrocarbon injection system used for heat management of exhaust post-treatment and regeneration system of a particle capture filter (DPF). Background technique [0002] In recent years, with the increasingly stringent emission regulations, the requirements for vehicle exhaust after-treatment technology have also been changed. Diesel Particulate Filter (DPF, Diesel Particulate Filter) technology in diesel engine systems is considered to be the most effective way to reduce carbon emissions in exhaust gas. The most effective post-treatment method for smoke particles, the PM capture efficiency can reach more than 90%. DPF filters the PM in the exhaust when the exhaust passes through the filter. Gas, so that the soot particles in it are burned to realize the regeneration of DPF, and prevent the DPF from bei...

AI Technical Summary

Problems solved by technology

[0005] However, for this system, there are still the following disadvantages: because the pressure fluctuation is still large, in order to obtain sufficient measurement accuracy, one or even more than two pressure sensors must be used, which will increase the cost of the system. On the other hand, using Larger size solenoid valves have a lower operating frequency, the dynamic adjustment range of oil supply flow is limited by the PWM duty ratio, and the adjustment accuracy is still low

Images