Rapid Prediction of Hot-Air Temperature of Kalugin Top Combustion Hot Blast Stove by Means of Computational Fluid Dynamics Numerical Simulation

Abstract

Based on the three-dimensional (3D) steady-state CFD numerical simulations conducted previously on an industrial Kalugin top combustion hot blast stove, a two-dimensional (2D) transient CFD numerical model for a single channel (hole) of a column of checker bricks in the regenerator of the same hot stove was established in the present work. The average mass flowrate and temperature of the flue gas flowing into the checker brick holes during the combustion period predicted by the 3D model were used as the inlet boundary conditions of the 2D model. Inside the hole of the checker bricks, processes of fluid flow and heat transfer of the flue gas during the combustion period and those of cold air during the hot-air-supply period were simulated using the 2D model for multiple operation cycles (combustion and hot-air-supply periods) of the hot stove, enabling rapid predictions of hot-air temperature under different operating conditions. The simulation results show that when the fuel gas flowrate and air consumption coefficient during the combustion period are controlled within the range of 80,000–100,000 Nm3/h and 1.02–1.28, respectively, a hot-air temperature in the range from 1273 °C to 1295 °C can be obtained during the hot-air-supply period. Applying this optimized operating condition to the industrial hot stove investigated in this study can achieve significant effects of reducing fuel gas flowrate by 8.6% and increasing hot-air temperature by 32 °C. In addition, a regression analysis on the numerical simulation results and the data measured from the industrial hot stove yields a roughly linear relationship between the dome temperature during the combustion period and the hot-air temperature during the hot-air-supply period, that is, the hot-air temperature would be increased by about 16 °C for every increment of 10 °C in the dome temperature, for instance. Therefore, the influences of the operating parameters on heat transfer characteristics in the regenerator and on hot-air temperature obtained in the present work provide a useful reference for guiding the hot stove operation optimization to achieve significant energy saving and emission reduction through facilitating more efficient combustion to minimize fuel gas consumption in steel plants.

Numerical Simulation Study on the Thermal Efficiency of Hot Blast Stoves

“…The aim of the present work is to explore a method to calculate the thermal efficiency of hot blast stoves through simulation results without relying on on-site test data, making it possible to evaluate the energy efficiency of the hot blast stove in operation and design. In recent years, numerical studies have been widely used to simulate the performance of specific components of hot blast stoves, such as burners and combustion chambers [14][15][16][17], regenerators [18][19][20], and even entire hot blast stoves [21][22][23][24][25][26][27]. These studies have mainly focused on the influence of the structure of hot blast stoves on the combustion, heat transfer, and turbulent processes.…”