以热损失最小为目标的焦炉工序分析与优化

基于焦炉工序的物料平衡和能量平衡,以工序热损失最小为目标,构建了焦炉工序的优化模型。以入炉煤配比、加热煤气配比、入炉煤含水量和推焦温度等9个参数为优化变量,考虑13个约束条件,利用焦化厂实际生产数据进行了优化,得到了最小热损失和最优变量值,并分析了优化变量对最小热损失的影响规律。研究表明:适当增加1/3焦煤和瘦煤的用量并减少气煤、肥煤和焦煤的用量可以降低焦炉工序的热损失;高炉煤气和焦炉煤气用量约为7∶1时,能够使焦炉工序的热损失达到最小值。提高脱硫工艺水平可提高硫分的约束上限,从而间接降低热损失。优化后,混合煤挥发分含量可降低3.3%,最小热损失可降低13.74%。实际生产过程中,应使各原料的用量处于使最小热损失变化较小的区间内,且应尽量接近最优配比,以保证焦炉工序连续平稳生产的同时降低热损失。

Analysis and optimization of coking process with minimum heat loss

Taking the heat loss minimization as the optimization objective,an optimization model of cokdng process was established based on the material balance and energy balance.Taking 9 parameters as optimal design variables (including coal charging ratio,heating gas ratio,water content of charging coal and coke pushing temperature,et al.) and considering 13 constraint conditions,a coking process was optimized with practical production data.The minimum heat loss and the optimal design variables were obtained.The influences of optimal design variables on minimum heat loss were studied.The results showed that increasing the dosages of 1/3 coking coal and lean coal and synchronously decreasing the dosages of gas coal,fat coal and coking coal could reduce the heat loss of the coking process.When the mixture ratio of blast furnace gas to coke oven gas was 7∶1,the minimum heat loss was obtained.Improving the desulfurization technology could relax the upper bound of sulfur constraint,which indirectly decreased the heat loss.After optimization,the volatile content of mixed coal could decrease by 3.3 ％ and the minimum heat loss decrease by 13.74 ％.In practical production,the dosages of raw materials should be kept in the range where the minimum heat loss changes relatively little to ensure continuous and stable production of coking process while reducing heat loss.