CFD Modeling of Heat Exchange Processes in a GM-50 Fuel Boiler

This scientific paper delves into the analysis of the feasibility of replacing the standard burners of the GM-50 boiler (E-50-3.9-440GM) with jet-niche technology-based burners (JNT). The study was conducted using the ANSYS Student software package. Numerical modeling allowed us to analyze in detail the process of fuel combustion in a steam boiler, assess its efficiency and determine the impact on environmental factors. The object of the study is the processes that occur during the combustion of gaseous fuel and their impact on the performance of the GM-50 power boiler. The subject of the study is the CFD-model of the GM-50 fuel boiler, the standard burners of which are capable of operating on both liquid and gaseous fuel. Methane was used as fuel for the given model, and standard axial burners were also compared with modern jet-niche burners that are more environmentally friendly. The verification of the CFD-model that was carried out using the data obtained by the Energy Resources Service of PJSC “Kyivenergo”, Ukraine [9] during their experimental studies and the model calculations showed that the discrepancy does not exceed 10 %. The parameters used for comparison were the temperature at the center of the fuel and the average NOx value over the cross-sectional area of the fuel in front of the festoon. The average temperature of flue gases in the “festoon window” was also determined using the Normative method, and in this case the discrepancy between the calculation data does not exceed 6.7 %. It was established that the standard burners of the GM-50 boiler fail to meet the standards for nitrogen oxide emissions and it was recommended to replace them with the burners of a jet-niche type. The developed CFD-model shows a 20% reduction in the average NOx value at the fuel outlet when replacing standard burners with JNT burners. The obtained result can be explained by the fact that the temperature in the active combustion area of a fuel boiler equipped with JNT burners reaches 1400 °C, and not up to 1800 °C as in the case of using standard burners.