Investigations on premixed charge compression ignition engine with external mixture formation and exhaust gas recirculation technique

In present scenario it is need for automobile sector to develop clean technology which will result in less fuel consumption and green house gas. The Premixed charge compression ignition (PCCI) is one of the effective technologies that give efficiency close to conventional CI engine and eliminates generation of high NOx and PM simultaneously. In the present investigation twin cylinder four stroke water cooled CI engine is used for experimentation. One of the two cylinders of CI engine is modified to run on PCCI mode. An external mixture formation technique is used to achieve PCCI operation. For this purpose a device known as diesel vaporizer is designed and fabricated. The port fuel injector operates at 3 bar injection pressure is used to inject the fuel into the heated vaporizer where it vaporizes and mixes with air in the intake port to form a premixed charge. To control auto ignition of diesel vapor and air mixture, Exhaust gas recirculation (EGR) technique is used. In the present investigation 10 %, 20 % and 30 % EGR is used for PCCI mode of operation and the results were compared with CI mode of operation. The main objective of the present experimental study is to reduce exhaust emission percentage while maintaining thermal efficiency as close to CI engine. The brake thermal efficiency in PCCI mode little decreases comparing to CI mode but NOx and Smoke emissions decreases drastically in PCCI mode comparing to CI mode of operation.