Hazard and emission standards for vehicle exhaust

2019-6-5 21:51:35

Hazard and emission standards for vehicle exhaust

Automobile emissions refer to harmful gases such as CO (carbon monoxide), HC + NOx (hydrocarbons and nitrogen oxides), and PM (fine particles, soot) emitted from exhaust gas. In order to curb the generation of these harmful gases, and to encourage automobile manufacturers to improve their products to reduce the source of these harmful gases, China has borrowed from European automobile emission standards, and domestically produced new cars will indicate the European standards for engine exhaust emissions.

Harm of automobile exhaust

Car exhaust contains carbon monoxide, nitrogen oxides and other solid particles that adversely affect the human body, causing great harm to human health. The following is a detailed analysis of the harmful substances in the car exhaust:

1, carbon monoxide

Carbon monoxide binds hemoglobin in the blood 250 times faster than oxygen. Carbon monoxide enters the blood circulation through the respiratory tract and forms a carboxyhemoglobin after affinity with hemoglobin, thereby weakening the function of blood to transport oxygen to tissues, damaging the central nervous system, causing human sensation, reaction, understanding, memory and other dysfunctions. The blood circulation system causes life-threatening.

2. Nitrogen oxides

Nitrogen oxides mainly refer to nitrogen monoxide and nitrogen dioxide, which are harmful gases to the human body, especially to the respiratory system. Exposure to air for 10 minutes in air with a nitrogen dioxide concentration of 9.4 mg/m3 can cause human respiratory dysfunction.

3. Hydrocarbons

It is still unclear about its direct harm to human health. However, when nitrogen oxides and hydrocarbons act under the action of the sun's ultraviolet rays, they produce an irritating light blue smoke containing various complex compounds such as ozone, aldehydes, and nitrates. The most prominent hazard to the human body is irritating the eye and upper respiratory tract mucosa, causing redness and sore throat.

4, solid suspended particles

The composition of solid suspended particles is complex and has a strong adsorption capacity. Solid suspended particles enter the lungs of the human body with breathing, and are trapped in different parts of the respiratory tract by collision, diffusion, deposition, etc., causing respiratory diseases. When the suspended particles accumulate to a critical concentration, they will stimulate the formation of malignant tumors. In addition, suspended particulates can also directly contact the skin and eyes, block the hair follicles and sweat glands of the skin, cause dermatitis and conjunctivitis, and even cause corneal damage.

5, lead

Lead is a toxic heavy metal element. Most automotive oils are blended with an anti-explosive agent such as tetraethyl lead or methyl lead. The lead and its compounds produced after combustion are toxic substances. More than 60% of the lead in the urban atmosphere comes from the burning of leaded gasoline in automobiles. Excessive levels of lead in the human body can cause cardiovascular diseases and affect the function and nervous system of important organs such as liver and kidney. Because the lead dust ratio is large, it usually accumulates in the air at a height of about 1 meter, so it poses the greatest threat to children.

European automobile exhaust emission standards

The European automobile exhaust emission standard is a vehicle exhaust emission standard jointly adopted by the European Union countries to limit the environmental damage caused by automobile exhaust pollutants.

European automotive emission standards are implemented by the European Economic Commission's vehicle emissions regulations and the European Union's vehicle emissions directives. In Europe, standards for vehicle emissions are generally tightened every four years. In 1992, the Euro 1 standard was implemented. Since 1996, the Euro II standard has been implemented. Since 2000, the Euro III standard has been implemented. Since 2005, the Euro IV standard has been implemented. Since 2009, the Euro 5 standard has been implemented. Since 2014, the Euro 6 standard has been implemented.

Compared with the US and Japan's automobile emission standards, European testing requirements are relatively broad. Therefore, European standards are also the automobile exhaust systems that are mostly used in developing countries.