Document Type : Research Paper


Mechanical Engineering Dept., University of Technology-Iraq, Alsina’a street,10066 Baghdad, Iraq.


This study investigated the effect of exhaust gas re-circulation (EGR) on performance and exhaust emissions in a single-cylinder, air-cooled, and direct-injection diesel engine. The Iraqi diesel fuel (D100) and European diesel fuel (ED100) were utilized at different speeds from (2100 to 3300 in intervals of 300) using the recycling of exhaust gas by a ratio (0%, 5%, 10%, 15%, and 20%. The study showed that European diesel fuel positively impacts engine performance and emissions. Compared to Iraqi diesel fuel, European decreased diesel fuel the brake-specific fuel consumption by (10.96%), increased brake thermal efficiency by (8.67%), decreased exhaust gas temperature by (9.99%), and (NOX, UHC, and decreased (CO) emissions by (7.94%, 10.07%, and 36.98%) respectively. When using the EGR ratio, the highest percentage that can be used is (20%). If this percentage exceeds this, it will cause a flame loss because the recycled gases are inert. Furthermore, the results indicate that brake-specific fuel consumption increases by (15.395%) and brake thermal efficiency decreases by (13.44%) with increased EGR ratio. In contrast, exhausting gas temperature and NOX emissions decreases by (4.01% and 14.57%) respectively. Finaly, the UHC and CO emissions increased with the increase of EGR ratio.

Graphical Abstract


  • Iraqi diesel produces higher NOx emissions than European diesel.
  • Engine performance degrades with the EGR system.
  • NOx emissions are reduced with the increase of EGR.
  • CO and UHC emissions increased with the increase of EGR.


Main Subjects

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