Controlling method and controlling device of vehicle emission controlling system and controlling system

Abstract

The embodiment of the invention discloses a controlling method and controlling device of a vehicle emission controlling system and the controlling system. The controlling system comprises an engine and an electronic controlling unit; the engine comprises a nitric oxide concentration sensor and an SCR device, and an original machine emission model is stored in the electronic controlling unit. The controlling method includes that the nitrogen oxide concentration sensor obtains the original concentration of nitrogen oxides emitted by the engine, the correction factor of the original emission model is calculated according to the original concentration of nitrogen oxides and the original emission model, and the original emission model is modified according to the correction factor so as to control the reduction agent injection quantity of the SCR device. By means of the technical scheme of the controlling system and the controlling method, the reducing agent precise injection control of thereducing agent of the SCR device is achieved, the excessive emission due to less injection of the reducing agent or the crystallization of the reducing agent due to more injection of the reducing agent is avoided, and the adaptability of the vehicle emission is improved.

Description

technical field [0001] Embodiments of the present invention relate to exhaust gas treatment technologies, and in particular to a control method, control device and control system for a vehicle emission control system. Background technique [0002] As the air pollution problem becomes more and more prominent, the regulations on automobile exhaust emission standards become more and more stringent, and the Selective Catalytic Reduction (SCR) technology has become a mainstream exhaust gas after-treatment technology. The tail gas treatment system with SCR injects reducing agent (such as urea) into the SCR device to achieve the purpose of reducing nitrogen oxides (NOx) in the tail gas, thereby reducing emissions and meeting the requirements of emission regulations. [0003] In the prior art, before the engine is assembled into the vehicle, the engine test bench simulates each working condition of the engine, calibrates and records the NOx production of the engine under various wor...

AI Technical Summary

Problems solved by technology

At present, the operating environment of the whole vehicle is very complicated, and the ambient temperature and humidity in different regions vary greatly. Even in the same region, the daily changes may be very large.

It will eventually affect the intake air humidity in the engine cylinder, which will lead to a very large change in the combustion temperature in the engine cylinder, which will eventually affect the output of engine NOx emissions

[0004] If the original machine emission model cannot identify the changes brought about by environmental factors, there will be under-spraying or over-spraying of the reducing agent

If the real engine outlet emissions become larger, under-injection will occur and the emissions will exceed the standard; if the engine outlet emissions become smaller, urea over-spray will occur, resulting in reductant crystallization, which will affect the power and emissions of the engine.

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