Abstract
Reducing the anthropogenic impact on the environment is an increasingly urgent challenge, particularly in the energy and heat generation sectors. This study presents the results of an experimental investigation into the combustion characteristics of four nozzle types in a burner system. The experiments focused on emissions of NOx and CO under varying equivalence ratios. This study presents an experimental investigation of combustion with one swirl-stabilized nozzle and two multihole plates under varying equivalence ratios (φ). The swirl-stabilized configuration produced the highest NOx, reaching 54.4 ppm at φ = 0.9, which we attribute to higher flame temperatures and longer effective residence. In contrast, the multihole plates—122 holes of 1.0 mm and 36 holes of 4.0 mm in a 100 mm insert—exhibited lower NOx and lower temperatures owing to more effective fuel–air mixing. CO showed a strong dependence on both geometry and φ; the lowest levels occurred near φ ≈ 0.9, consistent with optimal combustion. The findings underscore the importance of nozzle geometry and air–fuel ratio in optimizing combustion efficiency and minimizing harmful emissions, providing valuable insights for the development of low-emission combustion systems in modern energy applications.