Abstract The pressure drop characteristics of negative pressure sampling drill pipe were studied experimentally in this work. The pressure drop was measured by a customized designed negative pressure sampling test system. The effects of the inner diameter of the drill pipe, the solid-gas rate and the inlet air velocity on the internal pressure drop of the drill pipe were analyzed. When the drill pipe is loaded under the same inner diameter and air velocity, the pressure drop of the drill pipe increases as the solid-gas rate increases. With the same inner diameter and solid-gas rate, the rate of gas phase pressure drop to solid phase pressure drop increases with the increase of air velocity. Through the experimental pressure drop data, the additional pressure drop coefficient model is established by dimension analysis method, which can accurately predict the pressure drop of the drill pipe. The maximum error between the modeled value and the measured value is –16.2%.

中文翻译：

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稀负压气力输送压降特性

摘要 本文对负压采样钻杆的压降特性进行了实验研究。通过定制设计的负压采样测试系统测量压降。分析了钻杆内径、固气速率和进气速度对钻杆内压降的影响。当钻杆在相同的内径和空气速度下加载时，随着固气速率的增加，钻杆的压降增加。在相同的内径和固气速率下，气相压降与固相压降的速率随着空气流速的增加而增大。通过实验压降数据，采用量纲分析方法建立附加压降系数模型，可准确预测钻杆压降。建模值和测量值之间的最大误差为 –16.2%。