Technical paper on automobile exhaust treatment 1 Overview of automobile exhaust treatment technology and methods
Abstract: At present, the number of cars in the world is increasing on a large scale, and automobile exhaust has become one of the main sources of air pollution, so the treatment of automobile exhaust has naturally become a concern of the whole society. Automobile exhaust contains a lot of harmful substances, which seriously damages the atmospheric environment, and the exhaust treatment is also facing great pressure. In order to reduce the pollution of automobile exhaust, effective countermeasures must be taken. This paper mainly expounds and analyzes the treatment technology of automobile exhaust.
Keywords: automobile exhaust; Governance technology; pollute
The development of automobile industry has provided people with a lot of convenience, and has gradually become a common public transport. However, controlling automobile exhaust emissions has always been a key issue in environmental protection, mainly because automobile exhaust contains a lot of harmful substances, which destroys the atmospheric environment. Therefore, effective control measures and efficient exhaust purification technology are needed to minimize automobile exhaust pollution and maintain our green home.
A, automobile exhaust pollution analysis
Automobile exhaust is very harmful to the environment. If automobile exhaust is directly discharged without treatment, it will seriously harm the environment and people's physical and mental health. The pollution in automobile exhaust mainly includes: (1) nitrogen oxides, which are toxic, and ultraviolet decomposition directly leads to secondary pollution. In areas with serious nitrogen oxide emissions, photochemical smog will appear, which not only destroys the atmospheric environment, but also harms human health; (2)CO and HC are extremely harmful gases, which will cause human poisoning if they are mixed in the air for a long time, and it is difficult to remove such pollutants in a free state; (3) Carbon dioxide, which is the main product of automobile exhaust, causes serious greenhouse effect and directly destroys the protective layer of the atmosphere.
Second, the control technology of automobile exhaust
The key of automobile exhaust control is mainly concentrated in the engine part of the automobile, and the control technology can be divided into two parts: combustion purification technology and exhaust purification technology.
(1) combustion purification technology. The object of combustion purification technology is the interior of automobile engine, mainly to reduce the content of harmful substances in exhaust gas. Combustion purification technology can be divided into the following three categories:
1. 1 Application of electronic control ignition system. In the internal control of automobile engine, the electronic control ignition system provides sufficient ignition energy to ensure accurate ignition and avoid automobile pollution caused by ignition problems. The electronically controlled ignition system really improves the quality of the mixture, can realize accurate ignition under different ignition conditions, and prevents the automobile from polluting the combustion due to insufficient ignition. The electronic ignition system of some cars has been improved. By controlling ignition, the application of electronic control ignition system in engine is improved, the best ignition state is provided, and the emission of CO and HC is really reduced.
1.2 variable intake pipe. Improving the gas supply efficiency of the intake pipe can promote complete combustion, and the variable intake pipe can control the intake pipe moderately, and optimize the working state of the intake pipe by using the fluctuation conditions in the variable intake process. The length of the intake pipe is variable and can be changed according to the state of the engine. When the engine speed decreases, long-distance gas supply can be selected, and when the engine speed increases, it can be changed to short-distance gas supply, so that the engine can get the best gas supply in any state and realize full combustion.
1.3 electronically controlled fuel injection. Electronic fuel injection control can ensure that the air-fuel ratio is in the best state, promote the fuel to have sufficient combustion conditions, and avoid the generation of harmful substances inside the engine. The electronically controlled fuel injection system has many functions, which is beneficial to combustion purification. Under the action of electronically controlled fuel injection, automobile engine can improve the quality of fuel injection, and can constantly adjust the fuel supply system according to the requirements of automobile starting to provide accurate fuel supply. Therefore, electronically controlled fuel injection can reduce the pollution of automobile exhaust by controlling combustion conditions, and the most important thing is to ensure full combustion and avoid toxic gases and soot particles in exhaust.
(2) tail gas purification technology. Exhaust gas purification technology acts on the exhaust part of automobile engine, and uses purification technology to control automobile exhaust gas to realize safe emission and reduce the harm of automobile exhaust gas to the atmospheric environment.
2. 1 filtration and regeneration. Filtration regeneration is the basic part of exhaust gas purification technology, which consists of filtration and regeneration devices and mainly purifies particulate matter in automobile exhaust gas. The filter device in tail gas purification can remove specific particles in tail gas, adsorb smoke containing toxic substances and prevent it from being discharged into the atmosphere. The adsorption efficiency of the filtration device is as high as 80%. At the same time, the filter regeneration device also has the function of reuse, which can send the available gas back to the automobile engine system, which embodies the technical advantages of energy saving and environmental protection.
2.2 closed-loop control. Closed-loop control is responsible for controlling the conversion and sensing parts in waste gas purification, and constitutes a waste gas purification device. A typical example is the three-way catalytic converter, which converts toxic nitrogen oxides into harmless nitrogen and oxygen through catalytic reduction, and then transports the oxygen to the oxygen-consuming part of the engine again by using the conduit. According to the experimental analysis, in the closed-loop control of three-way catalytic converter, when the air-fuel ratio is controlled in the range of 14.6: 1, the catalytic conversion efficiency can be improved to 90%, which greatly improves the level of tail gas purification.
2.3 air system. Air system is beneficial to the application of waste gas purification technology, which can improve the efficiency of waste gas purification and play a high-quality auxiliary role. Air-assisted closed-loop control exhaust purification technology can deeply purify automobile exhaust. The air system cooperates with the three-way catalytic converter to consume harmful gases such as HC and CO in the exhaust gas through combustion, and such harmful substances will be discharged into the air in the form of water and carbon dioxide to strengthen the control of automobile exhaust gas.
Third, the treatment method of automobile exhaust
With the development of science and technology, automobile exhaust treatment has a good development prospect. At present, high-end treatment methods have been put into the application of automobile exhaust treatment. Typical treatment methods include magnetization purification and plasma treatment.
(1) magnetization purification method. The treatment method of magnetization purification can change the composition of automobile fuel, promote the fuel to have sufficient combustion conditions, improve the combustion efficiency of the engine and reduce the emission of pollutants in exhaust gas. A large number of polluted gases contained in automobile exhaust can be obviously improved by magnetization purification, and the effective combustion of gases can be adjusted to varying degrees, which meets the requirements of automobile exhaust treatment.
(2) plasma treatment method. Plasma treatment method has high efficiency in automobile exhaust treatment and has the advantage of comprehensive purification. The activity of plasma is high. The pollutants in automobile exhaust can be treated, and the exhaust pollution can be avoided through secondary treatment. Plasma treatment can treat the air before it enters the automobile engine, ensure that the air contains enough combustible oxygen, and use oxygen in different States to improve the combustion efficiency of the engine, thus oxidizing CO and HC in the exhaust gas and improving the level of exhaust gas treatment. The application value of plasma treatment method in tail gas treatment is very high, which can not only reduce pollutants in tail gas, but also play a reducing role. The key point is to reduce nitrogen oxides in tail gas and transform them into pollution-free gases, thus reducing the harm of automobile tail gas to the environment and human health.
Four. Concluding remarks
The atmospheric environment is a valuable resource for our survival, so ensuring air cleanliness is an important subject of environmental protection. Due to the harm of automobile exhaust to the atmospheric environment, we must adopt scientific and reliable treatment methods, give full play to the filtration and purification function of treatment technology, strictly deal with toxic substances in automobile exhaust, and explore more advanced and effective ways and means from the technical level to realize zero pollution emission of automobile exhaust as soon as possible, so as to ensure the harmonious development of automobile industry and environmental protection.
References:
Gong Daguo, Yuan Zongxuan, Xie, Zhao, He Kebin. Plasma automobile exhaust treatment technology [J]. Chongqing Environmental Science, 2003, 02: 28-32+60.
[2] Zhang Shengyu, Zhang Pedestrian. Treatment technology of harmful substances in automobile exhaust [J]. Environmental Science and Management, 2012,07: 81-84.
Liu Minghai, Wu Qinchong, Yu, Liang, Ren Zhaoxing, Hu Xiwei. Development trend of low-temperature plasma technology in automobile exhaust treatment [J]. Trends of environmental science,1999,03:18-20.
Yu Shao, Li Guoxiang, Ai Ping. New progress of automobile exhaust pollution control technology [J]. Yunnan Chemical Industry, 2005, 06: 68-70+59.
About the author: Li Gang (1977-), male, from Xi, Shaanxi, bachelor degree, research direction: environmental protection.
Zhang Ruijun (1983-), male, from Yulin, Shaanxi, bachelor degree, research direction: environmental engineering.
Click the next page for details >>& gt Technical Paper on Automobile Exhaust Treatment