CFD modeling of thermal processes in the firebox and heat load distribution on the screen surface firebox

Abstract

Using ANSYS FLUENT numerical modeling and mathematical modeling, the main characteristics of combustion processes during the combustion of natural gas were determined. In this work, the combustion processes and NOx formation in the firebox were modeled at different loads of the GM- 50-14/250 boiler. The temperature distribution along the height of the firebox and the heat load on the screen panels were determined. The results of calculations by two types of models were compared with each other and with the data of measurements on the operating equipment. The environmental performance of the firebox, namely the formation of NOx at different heat loads, was determined. The maximum boiler capacity at which its operation meets European environmental standards was determined. The deviation of calculations on the formation of NOx in the GM-50-14/250 boiler at 40% of the rated power compared to the results of field tests using ANSYS FLUENT modeling was 8%, and using the mathematical model - 27%. When operating at rated power, the deviations of the results decreased to 2% and 8%, respectively. The deviation of the results of thermal calculations of the combustion in the firebox by different types of modeling in the active combustion zone and at the outlet of the firebox is up to 3% at different loads.