Experimental Study of Shaftless Underground Gasification in Thin High-Angle Coal Seams
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- 作者：Lanhe Yang ; Shuqin Liu ; Li Yu ; Jie Liang
- 刊名：Energy & Fuels
- 出版年：2007
- 出版时间：July 2007
- 年：2007
- 卷：21
- 期：4
- 页码：2390 - 2397
- 全文大小：137K
- 年卷期：v.21,no.4(July 2007)
- ISSN：1520-5029
文摘
The purpose of this article is to study the feasibility of shaftless underground gasification in thin high-anglecoal seams and the reliability of a new two-stage technique for pushing-through gasification galleries withfirepower permeation. This paper first presents the theory, design, and technical details of a field experimentthat tests the new process, which consists of blind-hole electric ignition of an underground gasifier, a forwardand backward firepower seepage method, and gasification of a small shaftlike gasifier. The results of theexperiment are then analyzed. It is concluded that the bigger the blast intensity, the faster the moving speedof the fire source and the higher the average temperature of the gallery; however, if the blast intensity exceededa critical value, the moving speed of the fire source (pushing-through speed) and the average temperatureexhibited the drop tendency. Under the experimental conditions, the average leakage rate for the blasting was81.89%, with an average volume of discharge of 93.82 m3/h and an average gallery diameter of 0.40 m. Alongwith the progression of the firepower pushing-through process, the air blast leakage rate dramatically declined.In addition, the heating value of coal gas rose with the increase of gas flow and approached stabilization. Theexperiment showed that the heating value of underground water gas produced by two-phase gasification couldreach 12.00 MJ/m3, in which the content of H2 exceeded 48% and those of CO and CH4 were 13% and 7%,respectively.