Thermo-Stressed State of the DKVR-10-13 Boiler Drum when Replacement of the Standard Burner with a Jet-Niche One

This work is devoted to the analysis of the thermally stressed state of the drum-separator of the DKVR-10-13 boiler type using CFD modeling using the Ansys Fluent software package. The main attention in the study was paid to studying the influence of structural and operational factors on the strength and stability of the boiler drum equipped with jet-niche burners. The analysis was carried out for two boiler operating modes: nominal load and at 60% power. The technology of stabilized combustion without pre-mixing in the burner was used. Gas distribution was carried out through round holes, perpendicular to the oxidant flow, which contributed to more efficient mixing of fuel and air. The difference between the maximum and minimum temperature of the drum surface did not exceed 30 °C, which ensures the stability of the structure. Visualization of the fields of velocity, temperature and concentrations of reaction products (in particular NOx) showed that the jet-niche technology contributes to the reduction of emissions of harmful substances and more complete combustion of fuel. The absence of flame instability or displacement of its position confirms the reliability of the combustion mode. The influence of the temperature field, internal pressure and heat flow on the strength of the drum was studied, taking into account the weakening holes. The maximum equivalent stress according to the Mises criterion was 75 MPa, which is significantly lower than the ultimate strength of the material. The maximum deformation of the drum was 1.1 mm, which does not pose a threat of destruction. The passport thickness of the drum wall (10 mm) is sufficient to ensure strength in both studied modes. Replacing standard burners of the DKVR-10-13 boiler type with jet-niche ones contributes to: Improving the efficiency and uniformity of fuel combustion, increasing environmental performance due to reducing NOx emissions, while ensuring the thermal strength of the drum even in variable operating modes. The results of the study are a solid basis for improving burner devices in boilers of this type and increasing their energy efficiency.