1. Pre-purification of pollutants emitted by gasoline engines
Pre-purification is to improve the quality of fuel, that is, to implement lead-free fuel and greatly reduce the sulfur content in fuel, improve the composition properties of benzene, aromatic hydrocarbons and olefins in gasoline, improve combustion efficiency, make fuel burn fully and reduce the emission of harmful substances.
2. Internal purification of pollutants emitted by gasoline engines
In-engine purification refers to reducing the emission of pollutants from gasoline engines from the perspective of improving engine performance. Scientific papers. That is, the electronic control system of gasoline injection, low emission combustion technology, exhaust gas recirculation technology, turbocharging and intercooling technology and multi-valve technology are adopted to improve the working performance of the engine, thus reducing the emission of harmful substances.
(1) electronic control system for gasoline injection
The electronic control system of gasoline injection uses various sensors to detect the various states of the engine, and then controls the injection time, injection quantity and ignition advance angle of the engine under different working conditions through microcomputer judgment and calculation, so that the engine can obtain a suitable air-fuel ratio mixture under different working conditions, improve the fuel combustion efficiency, and thus achieve the purpose of reducing the pollutant emission of the gasoline engine.
(2) Low emission combustion technology
Low emission combustion technology mainly relies on lean combustion technology, stratified combustion technology and gasoline direct injection technology to improve the formation and combustion conditions of combustible mixture, thus greatly reducing the emissions of CO, HC and nitrogen oxides.
(3) Exhaust gas recirculation technology
Exhaust gas recirculation technology is to send part of the exhaust gas discharged by the engine back to the intake pipe under the premise of ensuring that the engine power is not reduced, and then mix it with fresh air or fresh mixed gas, and then enter the cylinder again to participate in combustion. This reduces the oxygen concentration in the mixture, thus slowing down the combustion reaction, effectively controlling the generation of nitrogen oxides in the combustion process and reducing the emission of nitrogen oxides.
(4) Turbocharging and intercooling technology
Turbocharging intercooling technology is to use turbocharger to increase the air intake into the combustion chamber and cool the mixture before it enters the combustion chamber, so that the mixture burns more thoroughly and the exhaust gas is cleaner, thus reducing the emissions of CO and HC and improving the adaptability of engine power and gasoline engine in plateau areas.