Studying on the pore size distribution of coal is vital for determining reasonable coalbed methane development strategies.The coalbed methane project is in progress in the southern Junggar Basin of northwestern China,...Studying on the pore size distribution of coal is vital for determining reasonable coalbed methane development strategies.The coalbed methane project is in progress in the southern Junggar Basin of northwestern China,where high volatile bituminous coal is reserved.In this study,with the purpose of accurately characterizing the full-scale pore size distribution of the high volatile bituminous coal of the southern Junggar Basin,two grouped coal samples were applied for mercury intrusion porosimetry,low-temperature nitrogen adsorption,low-field nuclear magnetic resonance,rate-controlled mercury penetration,scanning electron microscopy,and nano-CT measurements.A comprehensive pore size distribution was proposed by combining the corrected mercury intrusion porosimetry data and low-temperature nitrogen adsorption data.The relationship between transverse relaxation time(T2,ms)and the pore diameter was determined by comparing the T2 spectrum with the comprehensive pore size distribution.The macro-pore and throat size distributions derived from nano-CT and rate-controlled mercury penetration were distinguishingly analyzed.The results showed that:1)comprehensive pore size distribution analysis can be regarded as an accurate method to characterize the pore size distribution of high volatile bituminous coal;2)for the high volatile bituminous coal of the southern Junggar Basin,the meso-pore volume was the greatest,followed by the transition pore volume or macro-pore volume,and the micro-pore volume was the lowest;3)the relationship between T2 and the pore diameter varied for different samples,even for samples with close maturities;4)the throat size distribution derived from nano-CT was close to that derived from rate-controlled mercury penetration,while the macro-pore size distributions derived from those two methods were very different.This work can deepen the knowledge of the pore size distribution characterization techniques of coal and provide new insight for accurate pore size distribution characterization of high volatile bituminous coal.展开更多
基金supported by the Opening Fund of Key Laboratory of Continental Shale Accumulation and Development(North-east Petroleum University),Ministry of Educationthe National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2016ZX05043-004-001)the National Natural Science Foundation of China(Grant No.41772158).
文摘Studying on the pore size distribution of coal is vital for determining reasonable coalbed methane development strategies.The coalbed methane project is in progress in the southern Junggar Basin of northwestern China,where high volatile bituminous coal is reserved.In this study,with the purpose of accurately characterizing the full-scale pore size distribution of the high volatile bituminous coal of the southern Junggar Basin,two grouped coal samples were applied for mercury intrusion porosimetry,low-temperature nitrogen adsorption,low-field nuclear magnetic resonance,rate-controlled mercury penetration,scanning electron microscopy,and nano-CT measurements.A comprehensive pore size distribution was proposed by combining the corrected mercury intrusion porosimetry data and low-temperature nitrogen adsorption data.The relationship between transverse relaxation time(T2,ms)and the pore diameter was determined by comparing the T2 spectrum with the comprehensive pore size distribution.The macro-pore and throat size distributions derived from nano-CT and rate-controlled mercury penetration were distinguishingly analyzed.The results showed that:1)comprehensive pore size distribution analysis can be regarded as an accurate method to characterize the pore size distribution of high volatile bituminous coal;2)for the high volatile bituminous coal of the southern Junggar Basin,the meso-pore volume was the greatest,followed by the transition pore volume or macro-pore volume,and the micro-pore volume was the lowest;3)the relationship between T2 and the pore diameter varied for different samples,even for samples with close maturities;4)the throat size distribution derived from nano-CT was close to that derived from rate-controlled mercury penetration,while the macro-pore size distributions derived from those two methods were very different.This work can deepen the knowledge of the pore size distribution characterization techniques of coal and provide new insight for accurate pore size distribution characterization of high volatile bituminous coal.
文摘通过试验研究的方法得到了2种低挥发份煤种等离子点火时的喷枪功率、煤粉浓度和一次风速等运行参数。航天大功率可调节等离子点火试验台以660 MW四角切圆煤粉锅炉单只燃烧器为原型,按照1∶1比例搭建。试验结果表明,为实现成功点火,对于Vdaf（干燥无灰基挥发份含量）为22.14%的贫瘦煤,等离子点火喷枪输出功率不低于386 k W,点火煤粉浓度不低于0.24 kg/kg,点火初期一次风速控制在18.2-19.2 m/s为宜;对于Vdaf为16.4%的贫煤,等离子喷枪输出功率不低于435 k W,点火煤粉浓度不低于0.27 kg/kg,一次风速应控制在18.2-19.2 m/s范围之内。
