Simulation and performance eva‎luation of national engine equipped with gasoline compression combustion (GCI) system with direct injection strategy

3/9/2023 12:00:00 AM

Direct injection compression gasoline combustion is a concept that uses gasoline instead of diesel fuel in compression ignition engines for higher efficiency and lower emissions. This research has implemented this new combustion concept in a spark-ignition engine. All simulations performed in this study were performed by CONVERGE CFD software. First, fuel injection in a constant volume was simulated to understand the concept of penetration length better, and the results of this section were compared with laboratory results. Then, the geometry of the EF7TC engine was modeled and simulated, and the results were examined with laboratory results. Then the conversion of the EF7TC engine to the EF7 GCI was investigated and the performance was performed under different conditions. The following comparison was made between EF7TC and EF7GCI modes. The results showed that the fuel consumption and emissions of the EF7GCI engine are much lower than the EF7TC. Also, the output power of this combustion concept is less than EF7TC. Then, the dual injection strategy on the new engine was examined, and a comparison was made between this mode and single injection. This section showed that in dual mode, the amount of fuel consumption decreases, and the output power also increases. The stagnation effect between two consecutive injections (Dwell Time) was also discussed. The results showed that the smaller the distance between two consecutive injections, the better the NOx emission. Also, by examining the effect of compression ratio on engine performance, it was observed that engine performance improves by increasing the compression ratio from 9.6:1 to 13:1. In other words, output power, IMEP increase and fuel consumption also decrease. It was also observed that low octane fuel (RON 70) instead of RON 95 leads to increased output power and thermal efficiency.

استراتژي تزريق دوگانه، آلاينده‌ها، اسپري، احتراق تراكمي بنزيني، نسبت تراكم، فشار تزريق

Dual injection strategy, Pollutants, Spray, Gasoline compression ignition Compression ratio, Injection pressure

Ehsan mirzaei

Dr. Mohammad Hassan Shojaeefard