Atomization characteristics of different water/heavy fuel oil emulsions in a pressure-swirl injector

In the present study, different water in heavy fuel oil (HFO) emulsion fuels containing 5, 10, 15% water content have been prepared under ultrasound irradiation without surfactant. The stability of the prepared emulsion fuels has been investigated. The best stability was observed for the emulsion fuel containing 5% water (E5) due to its more uniform water droplet size distribution. Then, the atomization behavior and spray characteristics of the emulsion fuels have been investigated in a pressure-swirl injector using a high speed camera. The examined ranges for temperature and pressure were (60-110 degrees C), and (10-25 bar), respectively. The breakup length for each fuel sample in each operating condition was calculated through the image processing analysis. It was found that the micro explosion phenomena associated with the evaporation of the water droplets in the fuels has the most impact on the emulsion fuel spray characteristics. The best atomization performance was observed for E5 considering all examined fuel samples. A 68% decrease in the breakup length was observed for E5 compared to the neat HFO at 90 degrees C and 15 bar.

Automated summary

In this study, water-in-heavy fuel oil (HFO) emulsion fuels with different water content (5%, 10%, 15%) were prepared using ultrasound irradiation without surfactant. The stability of the emulsion fuels was investigated and it was found that the emulsion fuel with 5% water content had the best stability. The atomization behavior and spray characteristics of the emulsion fuels were then examined in a pressure-swirl injector, and it was observed that the micro explosion phenomena caused by the evaporation of water droplets had the most significant impact on the spray characteristics. The emulsion fuel with 5% water content showed the best atomization performance compared to the other fuel samples.