Authors: Q. Ma, Y. Du, Z. Peng, L. Ma, X. Chen, Q. Fang
Year: 2025
Industry: Fossil Fuel Power Generation
Keywords: Mention FSE, Dynamic, Boiler
ABSTRACT
To accommodate rapidly growing but highly variable renewable power in the grid, coal-fired power plants must operate flexibly through wide load changes. This leads to issues such as uneven heat load distribution and working fluid maldistribution, increasing rupture risks. In this study, a hydrodynamic model is developed to predict steam mass flux distribution among tubes and heat transfer processes within them, to ensure boiler stable operation. This model is then coupled with the combustion-side model via user-defined functions (UDFs) within the Fluent framework, using heating surfaces as data exchange boundaries for accurate temperature calculations. On the basis of the established models and coupling methods, a 1000 MW dual tangential-fired boiler is comprehensively simulated to analyze hydrodynamic parameter distributions under varying loads. Results show simulated values align with measurements, with relative errors below 10 %, validating reliability under 1000 MW supercritical and 400 MW subcritical conditions. Additionally, the lower water wall exhibits negative flow characteristics under supercritical conditions but positive characteristics under subcritical, while the upper wall consistently displays negative characteristics. Furthermore, the steam temperature continues to rise under supercritical conditions. The convective heat transfer coefficient initially increases and subsequently decreases. The tube temperature has an overall increasing trend reaching its maximum at 47 m. Under subcritical conditions, the steam temperature initially increases, then stabilizes at 629 K (500 MW) and 615 K (400 MW), finally increases again. The convection heat transfer coefficient initially increases. When heat transfer deterioration occurs at 36 m, the heat transfer coefficient decreases sharply and the tube temperature soars.