The global shift toward renewable fuels and the reduction in anthropogenic environmental impact have become increasingly critical. However, the current challenges in fully transitioning to environmentally friendly fuels necessitate the use of transitional fuel mixtures. While many alternatives have been explored, the combination of hydrogen and LPG appears to be the most practical under the conditions specific to Kazakhstan. This study presents experimental findings on a novel burner system that utilizes the airflow swirl and hydrogen enrichment of LPG. It evaluates the effects of hydrogen addition, fuel supply methods, and swirl intensity—achieved by adjusting the outlet vanes—on flame stabilization as well as NO_x and CO emissions. The results show that the minimum NO_x concentration achieved was 12.08 ppm, while the minimum CO concentration was 101 ppm. Flame stabilization studies indicate that supplying the fuel at the center of the burner, rather than at the base, improves stabilization by 23%. Additionally, increasing the proportion of hydrogen positively affects stabilization. However, the analysis also reveals that, as the hydrogen content in the fuel rises, NO_x concentrations increase. These findings highlight the importance of balancing the hydrogen enrichment, airflow swirl, and fuel supply methods to achieve optimal combustion performance. While hydrogen-enriched LPG offers enhanced flame stabilization, the associated rise in NO_x emissions presents a challenge that requires careful management to maintain both efficiency and environmental compliance.

This study investigates the emission characteristics and flame behavior of an air-staged swirl burner operating on LPG. The burner is equipped with a 45° vane swirler and an adjustable secondary-air section. Experiments were conducted at air velocities ranging from 20 to 43 m/s using a Testo 350 gas analyzer, while temperature measurements were obtained with thermocouples positioned 90 mm downstream of the burner exit. The results show that increasing the secondary-air opening leads to a monotonic decrease in the mean exit temperature and NO_x formation over the entire velocity range. In contrast, CO concentrations increase at higher air velocities and larger secondary-air fractions due to reduced residence time and partial quenching of the reaction zone. The fully staged configuration (100%) achieved the lowest NO_x levels (≤3 ppm) at 20 m/s, whereas the non-staged case resulted in the highest temperatures and NO emissions. Overall, the experimental results demonstrate that a moderate secondary-air opening provides the best compromise between low NO_x emissions and acceptable CO levels for compact LPG-fired swirl combustors.