In recent years, the emissions upgrade has become China's automotive technology with the development of an important issue. Olympics approaching, Beijing has taken the lead in the implementation of the country ¢ô standards. Although the emissions upgrade is more light for gasoline and diesel vehicles be limited to public transportation, postal and other special industries, but sooner or later, this must be the full implementation of the new standard is like a sword hanging in mid-air, enterprises must constantly remind as soon as possible Prepared.

¢ô country road diesel engine technology enterprises reached a consensus

For diesel engines, because of their major pollutants in the exhaust particulates and nitrogen oxides in the formation conditions on the reverse of care, resulting in a diesel engine emissions upgrade, especially over the ¢ó phase of the emissions upgrade technology in a different line. One group through the purification of particles of catalytic reduction of nitrogen oxides, the SCR (selective catalytic reduction) technology. The other is through the purification machines to reduce nitrogen oxides, particulate machine, through the capture of particulate filters for the EGR (exhaust gas recirculation) technology. Both technologies can achieve the emission standards ¢ô States, but because the technology used in very different, from the engine itself to the performance of oil and related facilities are dependent on a big difference.

This is rich foreign enterprises technical reserves, many enterprises of the two routes has conducted in-depth technical study and do a good job in preparing a comprehensive. Chinese enterprises can not afford, but the conditions do not allow them to select two technical routes. Whether to make the right choice, will directly determine the future survival of enterprises.

"We take the country ¢ô engine technology strategy, through the reduction of urea nitrogen oxides solution to the SCR route." Weichai power products Sun Jian, vice minister of planning, told reporters.

China launched the first of the Yuchai ¢ô diesel engines, but also the use of SCR as a post-processing techniques to achieve the ¢ô emissions.

In domestic sales have been a lot of the Cummins Engine ¢ô said, although they also mastered the two technologies, but in their view, SCR technology more suitable for the Chinese market.

The technical routes, the domestic mainstream diesel engine manufacturing enterprises have basically reached a consensus, SCR will be the future of domestic diesel engine emissions continue to upgrade the main technical direction.

SCR technology more in line with the national conditions of China

Cummins in a research report that the use of SCR technology in Europe compared with the same engine displacement ¢ô the Euro ¢ó engine, the maximum torque and maximum power in the past about 10 percent of the upgrade, and use the same technology EGR ¢ô engine of the EU and the EU was broadly unchanged ¢ó engine. At the same time, the use of SCR technology in Europe ¢ô engine fuel consumption level than the same engine displacement of the Euro ¢ó lower 5 percent to 7 percent, the use of EGR engine technology will have higher than about 3 percent. In other words, the same engine displacement of Europe ¢ô using SCR technology EGR technology can fuel economy compared to nearly 10 percent, more dynamic and strong.

With fuel economy and a strong driving force for these two main advantages, SCR engines need to add fuel when the defect on the urea solution is not so important. Chinese consumers, especially on fuel consumption rate of sensitivity is very high, fuel economy means that the product will have a vast market. At the same time, China as a big agricultural country has a very powerful fertilizer production capacity, as the necessary technical SCR urea solution in China is very easy to produce and manufacture of this point for China to promote the SCR technology to create convenient conditions.

From the weight of the impact, although the use of SCR technology engines need to carry a certain weight of the urea solution and the corresponding catalytic reduction systems, but the use of EGR system will increase the weight of many. As the use of EGR technical requirements for a stronger engine cooling capacity, so will lead to additional weight of radiators, supporting the use of variable cross-section of the supercharger and particulate after treatment plants will also increase the weight.

"At present, the consensus reached by China and the European market is basically the same, medium and large diesel engines, SCR technology more appropriate, and in the small engines EGR more appropriate." Automotive Engineering Institute of Jilin University Professor Liu Zhongchang told reporters, "This is mainly Is because the engines used SCR system, regardless of their size, are required to install a set of quantitative control and urea injection system, with the cost of emission no big change. EGR technology and the use of particulate traps, will have a tremendous difference in emission costs Differences. Therefore, the use of small diesel EGR technology, the manufacturing cost is far lower than the large diesel engines. "

In addition, SCR technology only to a certain temperature range of the work can be effective, therefore more suitable for a long time the work load of heavy diesel engines. Conditions in the city's car diesel engine, long-term work in low-load region, the temperature of exhaust gas can not meet the requirement, so only suitable for use EGR technology.