The Influence of Composition on Calorific Value and the Adiabatic Flame Temperature of Coal

Abstract

A quantitative analysis was conducted on the factors influencing the calorific value and adiabatic combustion temperature of coal. The analysis revealed that the rank correlation coefficients between the calorific value and the carbon, hydrogen, and sulfur contents in coal were 0.886, 0.214, and 0.27, respectively. To reduce dimensionality, the Car, Har, and Sar components of coal were integrated into a single variable, resulting in a regression model for the calorific value and the integrated variable. The model's coefficient of determination was R² = 0.8619, the adjusted coefficient of determination A.R² = 0.8587, explaining 85.87% of the variation in the calorific value. Based on combustion principles, a nonlinear regression was performed for the adiabatic combustion temperature. The standard errors of the model parameters were 0.002564 and 0.1655, respectively. The mean relative deviation between the measured and predicted values was 7.79%, with a standard deviation of 19.74°C for the coal samples. The average relative residual was 7.79, with a median of 6.66. The residual distribution exhibited right skewness, indicating potential for further improvement.