鄂庄烟煤地下气化反应区分布与工艺参数的关联特性

煤炭地下气化反应区分布受进口工艺参数的影响,同时也决定了出口煤气的有效组分和热值。通过鄂庄烟煤富氧地下气化模型试验,获得了6种不同氧气体积分数下反应区温度场和煤气组分,从而研究了氧化区、还原区和干馏干燥区分布状态及其与进出口工艺参数的关联特性。结果表明,在模型试验条件下合理的3区温度范围为:氧化区(1 200℃)、还原区(600~1 200℃)、干馏干燥区(200~600℃);在气化过程中,3区面积分布依次为:氧化区还原区干馏干燥区,当氧气体积分数在29.56%~44.07%时,3区比例(氧化区∶还原区∶干馏干燥区)平均为1∶1.5∶7.5,当氧气体积分数在49.07%~86.21%时,3区比例平均为1∶1.2∶2.8;随着氧气体积分数的增大,氧化区在3区中所占比例先增大后减小,还原区比例持续增大,干馏干燥区比例持续减小,其平均扩展速率分别为:当氧气体积分数增大1%时,氧化区和还原区比例分别增大0.26%和0.19%,干馏干燥区减小0.45%;出口煤气中CO2体积分数与α(氧化区面积/还原区面积)的增减趋势相反,当α=0.96时,CO2体积分数最低,为23.17%,CO随着还原区比例的增大而增大,CH4体积分数随干馏干燥区比例的减小而减小。

Correlation characteristics of reaction zone distribution and technical parameters during UCG of Ezhuang bituminous coal

In UCG process,the reaction zone distribution is impacted by the technical parameters of injection borehole,and the heat value and effective compositions of coal gas are decided by the reaction zone.The temperature field figures and gas composition were obtained by gasifying Ezhuang bituminous coal at six different concentrations of rich oxygen as gasification agents in pilot test system,then the correlation characteristics of reaction zone distribution and technical parameters were studied.The research results show that the effective temperature range of oxidation zone,reduction zone and dry distillation zone is more than 1 200 ℃,600-1 200 ℃ and 200-600 ℃,respectively.During the gasification,the ranking of the area value of three zones is oxidation zone