[Editor's note] As EGR engines and high-pressure common-rail engines are far apart in price, the EGR diesel engines that were recently certified by the environment have caused a panic in the sales market. This is also the fuse of this technical route. With the implementation of the National III emission standards, the battle for the technical route of the National III diesel engine has also been quietly spreading in the commercial vehicle market. Since the price of EGR engines is much lower than that of high-pressure common-rail engines, this has triggered panic in the sales market and pushed the technological battle to new heights.
On July 23, the relevant national ministries, colleges and universities, industry associations, and 17 commercial vehicle and key spare parts companies held fierce discussions at the 2008 China Commercial Vehicles State III Technology Summit Forum. After several hours of technical criticism, experts present generally believe that whether it is high-pressure common rail or EGR, in the technical route of diesel engines, China should fully learn from international successful experience.
Tang Dagang, director of the motor vehicle emission monitoring center of the Ministry of Environmental Protection, told reporters that as a national environmental protection agency, the view of the automaker’s technical route is: Regardless of the technology used, as long as it can meet emission standards, it is reasonable, but as a new The technology that has been researched and developed must ensure that it is reliable.
High pressure common rail and EGR confrontation
Due to the implementation of State III emission standards, diesel engines need to be upgraded technically.
“The EGR engine emitted by a country III is 10,000 to 20,000 yuan lower than the state-III diesel engine of high-pressure common-rail. Take the Cummins engine as an example, the price of a Cummins III engine is about 15,000 higher than that of the national II standard. ~ 2 million; and a Taiwan III EGR engine price is only about 10,000 yuan higher than the price of the National II." A domestic commercial vehicle company related personnel told reporters.
"More than 10,000 yuan, for the price of a commercial vehicle vehicle, accounted for about 5%, this cost is very concerned about the user." Said Liu Bin, director of R & D center of Shanghai Huizhong Automobile Manufacturing Co., Ltd.
As EGR engines and high-pressure common-rail engines are far apart in terms of price, the EGR diesel engines that have just recently been certified as environmentally friendly have caused a panic in the sales market. This is also the fuse of this technical route.
Many in the industry pointed out that the price difference of about 1 million, EGR engine may have an advantage in the sales market. However, they believe that the current domestic EGR technology has yet to be examined in terms of stability, reliability, environmental consistency and further technical upgrading.
There are also industry insiders questioned: In foreign countries, the cost of EGR engine and high pressure common rail engine is almost the same, why is there such a big price difference in China?
Li Yunqiang, deputy director of Weichai Power Technology Center, told reporters that from the user's point of view, due to the introduction of exhaust gas into the working principle of EGR, it is easy to cause poor combustion of the engine. In the long run, the economy is poor. “The economics of high-pressure common-rail engines can reduce the user's cost of use. In terms of practicality, high-pressure common rails are more advanced. Moreover, upgrading of high-pressure common-rail engines to China IV is easier in terms of technical upgrading.â€
Yang Fuyuan, a professor at Tsinghua University and a diesel emission expert, said that the problem with EGR is the deposition of particulates in the pipeline. "After a few hundred hours of operation, there will be particulate matter deposits in the pipeline, which will reduce the effect of EGR. In addition, it is a problem of the tightness and reliability of the EGR valve, and it is also prone to the deposition of particles, which is also when new concepts are burned. Try to reduce the reliance on EGR."
According to report, the current domestic automobile manufacturers using EGR technology are only China National Heavy Duty Trucks, and China National Heavy Duty Truck Co., Ltd. will naturally be drawn into the whirlpool of this technological dispute.
Regarding various doubts in the market, China National Heavy-Weapon Organization Promotion Department Minister Ni Guixiang said in an interview with this reporter that he can only rely on the use of EGR in the market in the future to prove one by one.
However, he also explained to the reporter that if only from the material cost point of view, the cost of the EGR engine and high pressure common rail engine is similar. “The current price difference is mainly reflected in the technical R&D expenses. Since China National Heavy Duty Truck's EGR engine technology is independently developed by China National Heavy Duty Truck, so in terms of core technology, it is owned by China National Tsinghua University; and domestic use. The core part of the high pressure common rail engine is imported from abroad, so the price will be higher."
Regarding stability and reliability issues, Ni Guixiang said that the heavy-duty EGR engine of China National Heavy Duty Truck was in charge of the two-year experiment by the Tianjin China Steam Weaving Research Center before it was introduced to the market. At present, the possible problems with the engine are only speculations. Also depends on the future use. However, he also told reporters: "Since the quality of domestic oil products is uneven, some oil products do not meet the National III standards. This is an obstacle that may be encountered during the use of EGR engines."
International experience is worth learning
In terms of motor vehicle emission standards, "China is following some developed countries, so we can take some detours." Tang Dagang said.
The technical dispute or so, in the United States and Europe and other countries have emerged the same problem, but also through the same discussion and practice, many experience is China can learn from, and some failed cases are also worthy of Chinese auto makers take warning.
As the largest independent engine manufacturer in the world, Cummins currently uses high pressure common rail and EGR technology in Europe and the United States at the same time, but the premise is to select the technical route according to the different requirements of European and American markets for emissions.
According to Cummins (China) General Technology Advisor, the choice is made because Europe and the United States require different emission standards. “In the United States, the emission standards paid more attention to the control of nitrogen oxides at the initial stage, and less emphasis was placed on particulate matter. European emission standards are more important for particulate matter from the very beginning.â€
EGR is very effective for reducing nitrogen oxides. "According to a test we did, we can reduce nitrogen oxides by more than 90%," according to Yang Fuyuan.
"So, Cummins has been using EGR technology in the United States and will continue to use it in 2007. By 2010, Cummins will continue to use EGR technology in the United States."
However, as the demand for particulate emissions from the United States has gradually increased, the demand for high pressure common rail engines using SCR aftertreatment systems is high. "Because EGR alone can't reduce particulate emissions," he said.
“In Europe, Cummins has been insisting on the use of SCR's high-pressure common-rail engines because of the high demand for particulate emissions.†He said.
At the same time, he also mentioned Ni Guixiang's above-mentioned concerns. He said that the selection of technical routes must also take into account the quality of oil products. "The EGR engine requires less than 500ppm of sulfur in the fuel. In the early US, the sulfur content in diesel was relatively high. The sulfur dioxide produced after the combustion of the fuel combined with the water, corroded the EGR channel, resulting in a lot of EGR damage." He reminded Chinese auto makers to also pay attention to this issue: Since the sulfur content of fuel oil varies from place to place in China, it is necessary to consider how to ensure that the engine can meet emission standards during use.
In addition, Yang Fuyuan pointed out that the selection of technical solutions must also consider the technical capabilities of key component companies. "Only domestic companies can support the requirements of the State III regulations, so as to meet the needs of the National IV and National V."
According to Ni Guixiang, China National Heavy Duty Truck is developing a national IV engine and a national V engine. He told reporters: "The engines of China IV emission will use EGR and high pressure common rail technology together."
Moreover, Tang Dagang said that the current national III emission standards are only transitional. It is expected that after the introduction of the National IV emission standard as soon as possible, using the engine with OBD, the above-mentioned problems of reliability and consistency may be controlled and resolved.
It can be seen that both the high-pressure common-rail technology and the EGR technology are at the moment, and both will eventually reach the same goal, all just to be able to meet higher emission standards.