Fuzzy grey relational analysis for influencing factors of heat transfer in a blast furnace hearth

For a blast furnace, the hearth erosion profile is mainly determined by the temperature distribution in the refractory. Numerical simulation was conducted to simulate the heat transfer and flow in a blast furnace hearth. Based on the simulation results, a fuzzy grey relation analysis method combining the grey entropy analysis and Euclidean grey relation analysis was put forward for evaluating the effects of various factors on the temperature distribution of sample areas at the bottom and sidewall refractory. Impacts of four typical factors (porosity of deadzone, floating height of deadman, radius of deadzone and temperature of cooling water) were evaluated by grey entropy analysis and Euclidean grey relational analysis, respectively. Lastly, a fuzzy grey relational analysis was employed to make a comprehensive evaluation of the four factors. Results have shown that the floating height of deadman is the dominant factor affecting the temperature distribution both on the bottom and sidewall.