What are high pressure common rail engines and EGR engines？

From the European two emission standards to the European three emission standards, in fact, is mainly the upgrade of the engine, at present in foreign countries, there are many places have adopted the national four emission standards, the main technology is high pressure common rail and EGR, as follows: With the implementation of the national three emission standards, the national three diesel engines have been technically upgraded。At present, diesel engines use high pressure common rail and EGR technology (EGR is the abbreviation of the English Exhaust Gas Recirculation three words, meaning exhaust gas recirculation system。It is an exhaust purification device for nitrogen oxide compound NOx, one of the harmful gases in the engine exhaust.。 At present, the domestic high pressure common rail engine with Ⅲ emission is about 10,000 to 20,000 yuan more expensive than the EGR engine with Ⅲ emission。Taking Cummins engine as an example, the price of a national III standard Cummins engine is about 1 higher than that of the national II standard.50,000 ~ 20,000 yuan;The price of a national Ⅲ standard EGR engine is only about 10,000 yuan higher than that of the national Ⅱ standard。 Due to the high pressure common rail engine and EGR engine in the price difference，Many in the industry point out，EGR engines may have an edge in the sales market，But they also point out，At present, the domestic EGR technology remains to be investigated in terms of stability, reliability, environmental consistency and further technical upgrading。 Relevant people also pointed out，In terms of user usage，The working principle of EGR is to send part of the exhaust gas produced by the diesel engine back to the cylinder，Form a cycle，Delaying the combustion process causes the pressure formation process in the combustion chamber to slow down，This is the main reason for the reduction of nitrogen oxides，But it can easily lead to poor engine combustion，The economy is bad in the long run。The high pressure common rail engine has better economy, which can reduce the user's use cost in the long run, and the high pressure common rail engine is also more advanced in terms of practical performance。And in terms of technological upgrading, it is easier to upgrade the high-pressure common rail engine to the national IV。 Some experts also pointed out that the problem of EGR is the deposition of particles in the pipeline, and after the EGR engine runs for several hundred hours, there will be the deposition of particles in the pipeline, which will reduce the effect of EGR。And the tightness and reliability of EGR valves, which can also cause particulate deposition。This is also the reason to minimize reliance on EGR when developing new concepts。 Some people in the industry questioned that in foreign countries, the cost of EGR engine and high pressure common rail engine is almost the same, why there will be a large price difference in China？ According to the survey, at present, the only car manufacturer using EGR technology in China is SinotruK。For the various doubts in the market, the relevant people of China National Heavy truck pointed out that it can only rely on the effect of EGR in the market in the future to prove one by one。Sinotruk related people also explained that if you look at the cost of materials alone, the cost of EGR engine and high pressure common rail engine is similar。The current price difference is mainly reflected in the cost of technology research and development。Since the EGR engine technology used by China National Heavy Duty Truck is independently developed by China National Heavy Duty Truck, it is mastered by China National Heavy Duty Truck in terms of core technology, and the core part of the high-pressure common rail engine used in China is imported from abroad, so the price will be relatively high。About stability and reliability，China National heavy duty truck relevant person said，Sinotruk's EGR engine was put on the market after two years of testing by the China Automotive Research Center in Tianjin，At present, the possible problems with the engine are only speculation，It also depends on the future use，However, SinotruK relevant people also pointed out that the quality of domestic oil products is uneven at present，Some oil products do not meet the national III standard，It is possible that the EGR engine will encounter obstacles during use，EGR engines require fuel with a sulphur content of less than 500ppm，But the sulphur content of fuel varies widely across China，This can compromise the performance of EGR。 To sum up, high pressure common rail engines have technical advantages over EGR engines, but are at a disadvantage in price。Whether the engine is using high-pressure common rail technology or EGR technology, the two will eventually reach the same destination, just to meet higher emission standards and reduce environmental pollution。