Control method for reducing cold start emission based on hybrid electric vehicle

Abstract

The invention provides an electric heating type three-way catalytic converter structure and a control method for reducing cold start emission based on a hybrid electric vehicle. The control method comprises the steps that a whole vehicle controller detects whether an ECU controls an engine to start or not through a CAN bus, if the fact that the engine starts is detected, the whole vehicle controller reads the current temperature T of a three-way catalytic converter and a battery SOC, and the current temperature T is compared with the set initiation temperature T1; if the current temperature Tis larger than the initiation temperature T1, it is judged that the engine is in a hot start state, the three-way catalytic converter does not need electric heating, and electric heating is stopped; and if the current temperature T is less than the initiation temperature T1, the engine is in a cold start state, at this time, the state of the battery SOC is judged based on CAN bus communication. The further processing method is also disclosed. According to the electric heating type three-way catalytic converter structure and the control method for reducing cold start emission based on the hybrid electric vehicle, an external heat source is provided for the three-way catalytic converter by utilizing a large capacity battery and high-voltage equipment on the hybrid electric vehicle, under thepremise that the dynamic property is met, the purpose that whole vehicle emission at the cold start stage is reduced is achieved, and accordingly the low-pollution property superiority of the hybridelectric vehicle is further exerted.

Description

technical field [0001] The invention belongs to the technical field of hybrid vehicle emission optimization control, and specifically relates to a method for reducing the emission of a three-way catalytic converter in the cold start stage before ignition of a three-way catalytic converter during the cold start of the vehicle or the frequent start and stop of the urban working condition. A control method for electrically heating a three-way catalytic converter by using a large-capacity battery on a hybrid electric vehicle. Background technique [0002] With the increasingly stringent emission regulations, the emission problem of the engine cold start process is becoming more and more prominent. Research shows that the cold start process contributes 50% to 80% of the emissions of the whole test process to the HC and CO emission limits of the ignition engine vehicle operating condition method. At the same time, hybrid vehicles shut down the engine under idling and pure electri...

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Problems solved by technology

[0004] The traditional methods of reducing emissions during cold start by heating the three-way catalytic converter include: when the engine is started, measures such as increasing the cycle fuel injection volume and reducing the ignition advance angle are often taken to increase the exhaust temperature, but this will also increase the HC, CO Emissions; 12 / 24V battery is used for low-voltage heating, but the power consumption is too large, which may easily cause battery power feeding; by optimizing the structure and installation position of the three-way catalytic converter, the three-way catalytic converter should be as close as possible to the outlet of the exhaust manifold. Thereby increasing the exhaust gas temperature, but this method makes the three-way catalytic converter seriously affected by thermal shock, which is easy to cause catalyst aging

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