高浓度黏稠膏体体积弹性模量预测模型

Prediction model for bulk elastic modulus of highly concentrated viscous pastes

  • 摘要: 高浓度黏稠膏体管道输送正朝着高压力、大浓度、长距离、大口径方向发展,但随着输送距离与泵送压力提高,输送系统会出现物料严重返流和管道剧烈振动。上述问题均受长输系统中高浓度黏稠膏体受压后弹性恢复影响,与高浓度黏稠膏体体积弹性模量有关。为建立高浓度黏稠膏体体积弹性模量的预测模型,以煤泥膏体为例,采用定义法设计煤泥膏体体积弹性模量的实验装置,并对实验装置进行误差分析,研究了压力、环境温度、含气量对体积弹性模量单因素影响规律。研究发现相同压力下,煤泥膏体体积弹性模量随环境温度、含气量的增大而减小,随压力呈非线性变化,当压力较小时,体积弹性模量随着压力上升而急剧增大;当压力超过一定值,体积弹性模量趋于稳定;当压力继续增大,超过一定界限,其值会继续增大。通过回归分析,在煤泥膏体压缩阶段,体积弹性模量与环境温度的变化规律与压力无关,体积弹性模量随环境温度、含气量的升高而减小。基于上述理论分析,提出了适用于压缩阶段任意压力煤泥膏体体积弹性模量的修正系数,给出任意压力和不同环境温度、含气量的体积弹性模量模型;对煤泥膏体预测值与实验值进行偏差计算,在压缩阶段绝大部分偏差都在3%以下,可实现对体积弹性模量准确预测。

     

    Abstract: High concentration viscous paste pipeline conveying is developing towards high pressure, large concentration, long distance, and large diameter. However, as the conveying distance and pumping pressure increase, the conveying system will have serious material reflux and the violent vibration of pipeline. All the above problems are affected by the elastic recovery of high-concentration viscous paste in the long-distance conveying system after pressure, which is related to the bulk elastic modulus of high-concentration viscous paste. In order to establish the prediction model of the bulk elastic modulus of highly concentrated viscous paste, the experimental device of bulk elastic modulus of coal slurry paste was designed by definition method. Also the error analysis of the experimental device was carried out to study the single-factor influence law of pressure, ambient temperature and gas content on bulk elastic modulus. It was found that the bulk elastic modulus of coal slurry paste decreases with the increase of ambient tem perature and gas content under the same pressure, and it changes nonlinearly with the pressure. When the pressure is low, the bulk elastic modulus increases sharply with the rise of pressure. When the pressure exceeds a certain value, the bulk elastic modulus tends to be stable. When the pressure continues to increase beyond a certain limit, its value will continue to increase. Through regression analysis, in the compression stage of coal slurry paste based on the above theoretical analysis, the correction coefficients for the bulk elastic modulus of coal slurry paste at any pressure in the compression stage are proposed, and the bulk elastic modulus model is given for any pressure and different ambient temperatures and gas contents. The deviation between the predicted and experimental values of coal slurry paste was calculated, and the deviation is below 3% in most of the compression stages, which can realize the accurate prediction of the bulk elastic modulus.

     

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