淹没条件对连续射流破碎含瓦斯煤效率影响研究

为研究淹没条件对射流破煤效率的削弱程度，基于ALE算法，借助Ansys/Ls dyna模拟软件，建立围压状态下非淹没及淹没射流破碎含瓦斯煤体流固耦合模型，通过动态追踪破碎坑体单元失效演化过程及内部应力分布等瞬时信息，探讨2种射流状态下破煤成坑过程及破煤效率的差异。研究结果表明:淹没射流与非淹没射流两者破煤坑体形态差异显著，非淹没射流条件下射流破煤坑体断面较窄，深度较深，破煤效率前后阶段差别不大；淹没射流条件下射流破煤坑体断面较宽，深度较浅，在初始阶段形成漏斗状的破碎坑体，而后逐渐向下延伸，在0～100 μs内破煤效率最高；相同工况、同一时间内，淹没射流平均破煤深度是非淹没射流平均破煤深度的41.46%。研究结果可为水射流技术的现场应用提供参考依据。

Study on influence of submerged conditions on efficiency of breaking coal containing gas by continuous jet

In order to study the weakening degree of submerged conditions on the efficiency of breaking coal by jet, a fluid structure coupling model of breaking the coal containing gas by the non submerged and submerged jet under the confining pressure was established based on the ALE algorithm by using the Ansys/Ls dyna simulation software. The difference in pit formation process and efficiency of breaking coal under two types of jet status was discussed through dynamically tracking the failure evolution process of the broken pit body units and the instantaneous information such as the internal stress distribution, etc. The results showed that the difference in the pit body shape of breaking coal by the submerged jet and non submerged jet was significant. The section of pit body of breaking coal by the non submerged jet was narrower, the depth was larger, and the efficiency of breaking coal had little difference in the previous and later period. The section of pit body of breaking coal by the submerged jet was wider, the depth was smaller, and the funnel shaped breaking pit body formed in the initial period, then it extended downward gradually, while the efficiency of breaking coal was the highest at 0~100 μs. Under the same conditions and time, the average depth of breaking coal by the submerged jet was 41.46% of that by the non submerged jet. The results can provide the reference for the field application of water jet technology.