While investigating the status quo of the state-of-the- art technology line of light trucks, the reporter also conducted an investigation on the fourth technology line of heavy trucks. Also in the Xi'an Chengbei Motor City, Hebei Tongli Automobile Trade City, Beijing Jingliang Road and other truck markets, the reporter found that, contrary to the situation of light trucks, the technical route for heavy truck four upgrades basically uses SCR. In fact, from a worldwide perspective, the technical route for upgrading the heavy-duty truck country is both SCR and EGR. Our heavy-duty truck companies mainly use the SCR technology route, starting from China's national conditions.
â— China's national quadruple truck technology line is more uniform
Reporters surveyed in multiple truck markets found that it was basically impossible to find a national quadruple truck using the EGR technology route because there was basically no enterprise producing the EGR state quadruple truck. This situation is not the same as the three countries in the second national escalation country, the three cars have both SCR and EGR. China National Heavy Duty Truck once produced a large number of national triple-cards using the EGR technology route. Prior to this, most truck companies such as Liberation, Dongfeng, and Shaanxi Automobile selected the high pressure common rail technology route that has become mainstream in Europe and made sufficient Technical reserves.
Heavy truck four products
However, Sinotruk and some enterprises have adopted EGR technology, and only installing a post-processing system on the Guoer's engine can easily meet the National III standard, which will result in a cost savings of 20,000 yuan compared to those using the electronically-controlled high-pressure common rail technology. Increased market share. At that time, the industry had also launched quite fierce debates on the merits of the two different technical routes appearing on the market. However, when the country’s third national standard was upgraded, there was no disagreement on the technical route. The mainstream heavy truck companies basically adopted the SCR technology line. Although, there have been previous reports that the liberation of FAW may use EGR, but the reporter did not see it in the market.
â— The national foreign quadruple card technology route is not uniform
In Europe, most truck companies have chosen SCR as the mainstream technology upgrade for the country’s four countries; in the United States, they have chosen the EGR+DOC+DPF technology route. Most European manufacturers chose SCR to meet Euro IV and Euro V emission standards, mainly due to cost considerations. European fuel prices are higher, and better fuel economy of SCR makes this technology the first choice. Of course, E-GR+DOC+DPF technology is still used in some areas, because in some places it is still stipulated that vehicles without particulate filters must not enter the urban area.
At present, the United States mainly adopts active regeneration E-GR+DOC+DPF technology to meet US2007 emission regulations. The reason is that fuel prices in the United States are relatively low, and the construction of urea supply systems and related infrastructure is not yet sound; at the same time, the US2007HDD standard put forward requirements for maintenance of new vehicles of 240000km, which also prevents the application of SCR technology in the United States to some extent. Because urea is added once every 5000km using SCR technology. Therefore, if you want to use SCR technology, you need to apply for a special permit.
For the more demanding Euro VI and US EPA 2010 emission standards, simply relying on SCR or EGR + DOC + DPF technology is difficult to meet the requirements, the two must be combined to meet the requirements. Recently, Daimler announced that its BlueTec system will use SCR technology to meet the US EPA 2010 standards; Cummins has also announced the use of SCR technology in its diesel engine to meet EPA2010.
â— Our company adopts SCR is based on national conditions
In general, the SCR has small changes to the engine, good engine durability, good fuel economy, lower fuel oil and oil quality requirements, no risk of catalyst blockage, good continuity of technology upgrades, no need for fuel injection regeneration The control device has lower costs for the use and maintenance of the engine. However, the SCR system needs to increase the urea injection system, and the requirements for packaging are also relatively high.
The SCR system needs to solve the urea supply problem first. EGR+DOC+DPF For the passive regeneration system, the fuel consumption is high, the E-GR and its cooling system need to be increased, the fuel with ultra-low sulfur content and high-quality lubricating oil are required, and the maintenance requirements for the engine itself and the post-processing are more High, otherwise it will affect the life of the engine and may cause the risk of catalyst clogging, and the continuous upgrading of technology is poor. However, the passive regeneration system does not require an additional urea injection system, and the package requirements are also lower.
For the active regeneration system, in addition to meeting the requirements of the above-mentioned passive regeneration system, it is also necessary to increase the fuel injection regeneration device and perform more complicated calibration, which increases the development cost and the difficulty of calibration. The EGR+DOC+DPF system must first address the nationwide supply of low-sulfur diesel and complex system calibration issues. The adoption of the SCR technology route by mainstream heavy truck companies in China is mainly based on the actual national conditions such as technological capabilities and current status of oil products.
A commercial vehicle expert at the Jianghuai Automotive Technology Center pointed out that SCR technology is more suitable for medium to long distance tractors. EGR+DPF technology is more appropriate for medium and short distance vehicles and lighter and lighter cards with smaller displacements. This is mainly due to the fact that engines with SCR systems need to be equipped with a urea dosing control and injection system regardless of their size. The cost does not change much with the displacement.
The particle trap system used by EGR technology can cause huge cost differences due to different displacements. Therefore, the use of EGR technology for small diesel engines, the manufacturing cost is much lower than that of large-scale diesel engines; because SCR technology can only be effective within a certain operating temperature range, it is more suitable for heavy-duty diesel engines that work long hours and heavy loads.
The EGR+DPF cost increase is relatively small, so it is more suitable for complex and price-sensitive dump trucks and medium and short-distance trucks. From the perspective of cost, fuel economy is the most critical factor for long-distance logistics. The fuel consumption will make the user willing to overcome the unfavorable factors caused by the addition of urea and thus select the SCR technology. The DPF requires regular cleaning, and it is difficult to guarantee long-distance logistics.
Fish Deboning Machine,Fish Meat Separator,Fish Meat Bone Separator,Fish Meat Extractor Machine
Henan Gems Machinery Co.,Ltd , http://www.gemsmachine.com