Impact of spark ignition timing and colorless distributed combustion on combustion and emissions of a natural gas-fueled heavy-duty converted engine

Aktaş F., Kethudaoglu G., Korkmaz Y., Karyeyen S.

Applied Thermal Engineering, cilt.279, 2025 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 279
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.applthermaleng.2025.127749
  • Dergi Adı: Applied Thermal Engineering
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, PASCAL, Aerospace Database, Business Source Elite, Business Source Premier, Communication Abstracts, Compendex, INSPEC, Metadex, DIALNET, Civil Engineering Abstracts
  • Anahtar Kelimeler: Colorless distributed combustion, Diesel engine conversion, Natural gas, NOX emissions, Spark ignition timing
  • Gazi Üniversitesi Adresli: Evet

Özet

This study investigates the effects of spark ignition timing (SIT) and Colorless Distributed Combustion (CDC) on the performance, in-cylinder combustion characteristics, and emissions of a natural gas-fueled heavy-duty converted engine. CDC refers to a combustion regime with highly uniform heat release and minimal visible flame, resulting in very low NOx emissions. The research explores various oxygen concentrations in the oxidizer (ranging from 23 % to 13 % by mass) to analyze the impact on combustion efficiency and pollutant emissions. This study demonstrates the combined effects of SIT and oxygen dilution on CDC formation in a converted heavy-duty engine. Advanced SIT (700 CAD) and delayed SIT (720 CAD) conditions were tested to assess their influence on combustion performance, heat release characteristics, and emission formation. The results indicate that advanced SIT improves power output and thermal efficiency but leads to higher NOX emissions, whereas delayed SIT reduces NOX emissions at the cost of decreased performance. Implementing CDC in the converted engine effectively suppressed NOX formation, achieving ultra-low emission levels below 1 ppm at reduced oxygen concentrations. While lower oxygen concentrations contributed to a more uniform combustion process, they also increased unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions. Overall, operating under CDC conditions demonstrated a promising strategy for optimizing engine efficiency while meeting stringent emission regulations.