王文, 王恒, 李东印, 李化敏, 李怀宾, 张益民. 低浓度弱涡流场瓦斯富集新方法及试验研究[J]. 煤炭学报, 2018, (3): 751-758. DOI: 10.13225/j.cnki.jccs.2017.0744
引用本文: 王文, 王恒, 李东印, 李化敏, 李怀宾, 张益民. 低浓度弱涡流场瓦斯富集新方法及试验研究[J]. 煤炭学报, 2018, (3): 751-758. DOI: 10.13225/j.cnki.jccs.2017.0744
WANG Wen, WANG Heng, LI Dongyin, LI Huamin, LI Huaibin, ZHANG Yimin. New method and experiment of methane enrichment under low concentration and weak vortex field[J]. Journal of China Coal Society, 2018, (3): 751-758. DOI: 10.13225/j.cnki.jccs.2017.0744
Citation: WANG Wen, WANG Heng, LI Dongyin, LI Huamin, LI Huaibin, ZHANG Yimin. New method and experiment of methane enrichment under low concentration and weak vortex field[J]. Journal of China Coal Society, 2018, (3): 751-758. DOI: 10.13225/j.cnki.jccs.2017.0744

低浓度弱涡流场瓦斯富集新方法及试验研究

New method and experiment of methane enrichment under low concentration and weak vortex field

  • 摘要: 针对煤矿回风巷大量低浓度瓦斯排入大气层,造成资源浪费及环境污染现状,设计及制造了低浓度瓦斯富集涡流塔,并进行了离析态和非离析态试验,同时采用数值模拟与物理试验结果进行对比。结果表明:离析态时涡流塔内稳定瓦斯体积分数从下至中(上)逐渐升高(从0.50%增至0.70%),表明弱涡流场离析状态下瓦斯富集效果较为明显;非离析态时涡流塔中(上)部瓦斯体积分数增幅不明显(从0.50%增至0.55%);两种状态下涡流塔底部瓦斯体积分数均是先升高后逐渐降低至稳定(<0.50%);离析态涡流塔上(中)部的瓦斯体积分数稳定时间比非离析态时长,底部瓦斯体积分数稳定时间基本一致;弱涡流场下叶片转速对瓦斯体积分数稳定所需时间影响较大,而对最终瓦斯体积分数高低影响不明显;最后,利用改进的Richardson数阐述了混合气体的速度及瓦斯层厚度等对涡流场强弱控制作用,解释了弱涡流场下离析态低浓度瓦斯富集特征明显,非离析态瓦斯富集效果差的原因。

     

    Abstract: The massive emission of low concentration methane from the ventilation roadway results in the waste of re- sources and environmental pollution. For this serious situation,the vortex tower for methane enrichment with low con- centration was designed and the segregation and non-segregation experiments were carried out as well as the compari- son with numerical simulation results. The results reveal that the stable concentration of methane under segregation state in the vortex tower gradually increases from bottom to top (0. 50% -0. 70% ),which demonstrates that the meth- ane enrichment effect is significant in the weak vortex field under segregation state. However,the increase of the meth- ane concentration under non-segregation state in the upper part of the vortex tower is not obvious (0. 50% -0. 55% ). In both cases,the methane concentration at the bottom of the vortex firstly grows and then gradually reduces to stable state (less than 0. 50% ). The stability time of methane concentration in the upper (middle) part of the vortex tower under segregation state is longer than that under the non-segregation state while the stability time at the bottom of the vortex shows similar discipline. The stability time of the methane concentration is significantly affected by the speed of the blade in the weak vortex field while insensitive to the impact of the final gas concentration. Finally,the improved Richardson Numbers were used to discuss the strength and weak control of vortex field in terms of the speed of the mixing methane and the thickness of methane layer. The reasons for the methane enrichment in the prominent segrega- tion state with low concentration whereas that on the weak condition in non-segregation state under the weak vortex field were revealed.

     

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