Development Of CNG Engine For Meeting China Stage Ⅴ Emission Regulations

Due to the more and more strictly emission legislation for the on road engines and the less and less uncycled crude oil resource situation the on road engines manufacturers are facing the big challenge now which means the engine should have the best dynamic performance and fuel economy under the strict emission requirements. Nearly all the countries in the world are focusing on the energy structure adjustment in the Auto industry and making the positive development of any new type of clean energy to decrease the pollution from the Auto industry. The CNG (compressed natural gas) is belived as an important resource due to the rich storage and competive cost and low emission. Basing on the advanced CNG engine technology and application both from the domestic and overseas this paper shows the study of a new Euro V CNG engine development through the optimized design and calibration on the phaser 210Ti desel engine which is the original product of Lovol Engines Company.The paper introduces the background and significance of this Euro V CNG engine project firstly. And then the Euro V CNG engine's design strategy is pointed out basing on the fully analysis of the CNG fuel property and the demestic & overseas CNG engine's charactics and the CNG engine's emission formation process & control strategy. The author redesigned the engine's combustion system, fuel supply system, ignition system and intake & exhaust system in the Phaser 210Ti desel. The new CNG engine's dynamic, economic and emission performances were greatly improved not only by the redesigned systems but also by the lean-burn firing strategy and oxidation aftertreatment components. Furthermore the Euro VI emission technology route was also beeen discussed basing on the Euro V achievement.The paper shows that an electronic controlled single fuel CNG engine was designed through the original basic engine structure optimization and the matching of main combustion concerned components. The engine's performance achieved to the development target and Euro V emission legislation after the electronic control system calibration, catalyst matching and emission development work finished. The OBD calibration was also performed and confirmed basing on the above working finished. The CNG technology route is discussed in this paper for the higher emission legislation requirement which will be regarded as the preparation of the engine emission promotion in the future.