煤炭地下气化时,井下高温高压气体携带大直径的煤粉颗粒对节流工具造成严重的冲蚀磨损.为此,设计了双节流孔结构的井下节流工具,并结合高温冲蚀磨损试验结果对 DNV(Det Norske Vertitas)冲蚀预测模型进行参数修正.开展了井下节流工具气固两相流冲蚀磨损数值模拟,研究高温条件下不同气体速度、不同颗粒质量流量及不同颗粒直径对节流工具的冲蚀磨损规律.研究结果表明:节流工具壁面冲蚀磨损区域随着气体流速的增大沿节流孔呈现环形分布;颗粒直径为5 mm,质量流量为7.5×10-4 kg/s,气体速度为 20m/s时,其对应的节流工具壁面冲蚀磨损速率最大.所得结论可为延长节流工具的安全服役年限、降低管线破损及爆炸的风险以及提高煤炭地下气化开采的经济性提供指导.
Erosional Wear of Throttling Tool for Underground Coal Gasification
During underground coal gasification,the downhole high-temperature and high-pressure(HTHP)gas carries large-diameter slack coal particles to cause severe erosional wear on the throttling tool.In this regard,a downhole throttling tool with dual orifice structure was designed.Combined with high-temperature erosional wear test results,parameter correction was conducted on the Det Norske Vertitas(DNV)erosion prediction model.Fi-nally,numerical simulation of gas-solid two-phase flow erosional wear of downhole throttling tool was performed to understand the erosional wear law of throttling tool at different gas velocities,particle mass flow rates and particle diameters under high-temperature conditions.The results show that the erosional wear area on the wall of the thrott-ling tool exhibits a ring distribution along the throttle orifice as the gas flow rate increases.When the particle diam-eter is 5 mm,the mass flow rate is 7.5×10-4 kg/s and the gas velocity is 20 m/s,the corresponding erosional wear rate of the throttling tool wall is the highest.The research conclusions have important guiding significance for extending the safe service life of throttling tools,reducing the risk of pipeline damage and explosion and improving the economic efficiency of underground coal gasification exploitation.
万方数据
维普
