Energy recovery evaluation and temperature field research of underground coal gasification under different oxygen concentrations
Energy recovery evaluation and temperature field research of underground coal gasification under different oxygen concentrations
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DOI：
10.1016/j.fuel.2022.125389
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发表时间：
2022
期刊：
影响因子：
7.4
通讯作者：
F. Su;Zhang Tao;Junwen Wu;Q. Deng;A. Hamanaka;Yi-he Yu;Meng-jia Dai;Xiao-long He;Jun-nan Yang
中科院分区：
文献类型：
--
作者：
F. Su;Zhang Tao;Junwen Wu;Q. Deng;A. Hamanaka;Yi-he Yu;Meng-jia Dai;Xiao-long He;Jun-nan Yang
通过对选定的煤样进行UCG模拟实验，研究了不同氧气浓度下，气化剂配比对产品煤气成分和热值的影响。在此基础上，基于化学计量理论，建立了基于生成气中碳（C）平衡的能量回收评价方法，并对地下气化工艺的能量回收率和煤耗进行了评价。根据煤气成分和热力学守恒定律，建立了煤炭地下气化温度场评价模型。通过计算反应热和显热，确定了各阶段气化室温度。实验研究结果表明，当气化剂中氧气体积分数为40- 70%时，产气热值由10.48 MJ/m3提高到12.48 MJ/m3。所产生的气体的热值随着氧气浓度的增加而增加。此外，能量回收率从69.63%提高到83.88%，表明随着氧气浓度的增加，UCG实验的气化效率可以显着提高。煤耗理论值与实际监测值的误差在10%以内，有效地评价了气化过程的煤耗。理论计算温度与实验监测温度结果一致，反应热与气化温度也呈线性相关。因此，该方法可以有效地确定气化室温度。这些监测和评价方法有望指导地下现场实验的分析。
In this paper, UCG simulation experiments were carried out on selected coal samples to study the effects of the gasification agent ratio on the product gas composition and calorific value under different oxygen concentrations. Moreover, an energy recovery evaluation method based on stoichiometric theory was established based on the carbon (C) balance in the generated gas content, and the energy recovery rate and coal consumption of the underground gasification process were evaluated. Based on the composition of the produced gas and the thermodynamic law of conservation, an evaluation model of the underground coal gasification temperature field was established. The gasification chamber temperature in each stage was evaluated by calculating the reaction heat and sensible heat. The experimental and research results showed that when the volume fraction of oxygen in a gasification agent was in the range 40–70 % and the calorific value of the produced gas increased from 10.48 MJ/m3to 12.48 MJ/m3. The calorific value of the produced gas increased with an increasing oxygen concentration. Furthermore, the energy recovery rate increased from 69.63 % to 83.88 %, indicating that the gasification efficiency of the UCG experiment can be significantly improved with an increasing oxygen concentration. The error between the theoretical value of the coal consumption and the actual monitoring value was within 10 %, which effectively evaluates the coal consumption in the gasification process. The theoretical calculation temperature was consistent with the experimental monitoring temperature results, and the reaction heat was found to also be linearly correlated with the gasification temperature. Therefore, this method can effectively determine the gasification chamber temperature. These monitoring and evaluation methods are expected to guide the analysis of subsurface field experiments.