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为了建立管道非连续流体(PNF)输送时管内层流压降数值模型,基于牛顿流体和宾汉流体管内层流压降模型,考虑实际工程中气体在管道中低速运动的阻力对PNF输送阻力的影响,对PNF压降模型进行简化。结合工程实践详细分析了PNF管内层流压降近似表达式和相对精确表达式,并分析了二者之间的偏差。结合对工程数据的分析,验证了PNF管内层流压降模型的有效性。结果表明:当PNF流量增大或输送管管径减小时,使用压降近似公式与压降相对精确公式计算出的压降值之间的偏差会减小。通过与实测值对比表明,本文模型较好地描述了PNF输送时的压降。其中压降近似模型的精度更优(计算值与实测值的偏差率为1.16%~8.33%),且求解更方便。
In order to establish a numerical model of laminar flow pressure drop in the pipe when conveying non-continuous fluid (PNF), based on the model of laminar flow pressure drop in Newtonian fluid and Bingham fluid pipe, considering the resistance of low- Influence, simplify the PNF pressure drop model. Combined with engineering practice, the approximate expression and relative exact expression of pressure drop in the inner layer of PNF tube were analyzed in detail, and the deviation between them was analyzed. Combined with the analysis of engineering data, the validity of laminar flow pressure drop model in PNF tube is verified. The results show that when the PNF flow rate increases or the pipe diameter decreases, the deviation between the pressure drop calculated by using the approximate formula of pressure drop and the accurate formula of pressure drop will decrease. Compared with the measured value, the model of this paper better describes the pressure drop of PNF. Among them, the pressure drop approximation model is more accurate (the deviation of the calculated value from the measured value is 1.16% ~ 8.33%), and the solution is more convenient.