Secondary air control system for vehicle engine

Abstract

The auxiliary air control system on the engines comprises an auxiliary air supply channel between the air inlet end and the waste exhaust end of the engine. Concatenated on the channel and driven by negative pressure, there exists a front control valve and a backward control valve, both of which opens when the engine is going to produce carbon monoxide or hydrocarbon, guiding the auxiliary air tothe exhaust end to foster with oxidization of waste with catalysis. The control valve can produce big negative pressure to close the valve when the engine returns oil instantly, stopping the release of auxiliary air from the exhaust end to avoid the combustion at the end of the emission and promote deacidizing the nitrogen oxide with catalysis.

Description

technical field [0001] The invention relates to a secondary air control system for a locomotive engine, in particular to a front and rear control valve connected in series on a secondary air supply pipeline between the engine intake end and the exhaust gas discharge end to control the secondary air Secondary air to the technology of the timing of the exhaust gas discharge side. Background technique [0002] In order to reduce harmful gases in the exhaust gas of traditional locomotive engines, a catalytic converter (Catalytic Converter) is installed in the exhaust pipe, and precious metal components such as platinum (Pt), palladium (Pd) and rhodium (Rh) contained in the catalyst are used to convert Harmful carbon monoxide (CO) and hydrocarbons (HC) are oxidized to harmless carbon dioxide (CO 2 ) and water (H 2 O); and reduce harmful nitrogen oxides (NOx) to harmless nitrogen (N 2 ) and oxygen (O 2 ). [0003] And know, in order to be beneficial to carry out oxidation and...

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Problems solved by technology

[0004] However, the above method is not conducive to catalytic reduction of nitrogen oxides (NOx) in the exhaust gas, because when the engine is running at a medium or high speed, a large amount of nitrogen oxides is easily generated in the exhaust gas emitted by the engine. The valve 420 can only close the valve briefly and intermittently at the moment of oil return from the engine. It is difficult to keep the valve closed continuously so as to block the secondary air from entering the exhaust pipe, resulting in the phenomenon that the catalyst cannot effectively reduce nitrogen oxides. As a result, the discharge into the outside atmosphere is the main cause of acid rain and the destruction of the ozone layer, which has a huge impact on the natural environment and needs to be improved urgently

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