基于动态称重法的泥浆密度检测系统研究

发布时间：2018-03-15 09:56

本文选题：泥浆密度　切入点：动态称重　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：在利用泥水盾构设备进行地下施工工程和石油钻井工程中,泥浆密度的作用非常重要,是隧道挖掘和发现新的石油层的一个非常重要的数据指标。泥水盾构机是利用进出口泥浆密度的动态平衡来保证挖掘进度,石油钻井主要是根据出浆密度判断地下是否存在石油层。研究实时的泥浆密度检测系统对地下工程是非常有意义的。对于泥浆密度检测的问题,本文研究一种利用动态称重的原理在线检测泥浆密度的方法,利用已知体积的输流管道作为测量管道,并使用称重传感器对流入该管道的泥浆进行瞬时的重量及流过管道的时间进行测量,根据体积、质量流量和密度的关系,得到测量管道中浆体的瞬时平均密度。本课题主要从理论研究、仿真分析、实验平台搭建、实验数据处理及结果分析四个部分对动态称重法的泥浆密度检测系统进行研究。首先对称重理论和泥浆的流体力学特性进行研究,得出泥浆作为一种不可压缩的非牛顿流体,在流动过程中会有一定沉积;理论分析泥浆的粒子直径,流速和体积分数对泥浆在输流管道中流动情况及瞬时称重结果的影响,为实验结果分析提供理论依据;本课题研究相关性法测量流体流动时间的理论,通过动态称重得到的质量流量及计算出的流动时间得出泥浆密度。其次应用ANSYS有限元分析软件对泥浆的流动情况、传感器受力过程、实验系统的稳定性和振动进行仿真。分析在不同流速、粒径和体积分数时,泥浆在水平管道中的流动情况,找出流速、体积分数与出入口质量差之间的关系;仿真传感器受力过程,验证该仪器的线性度;对实验系统的振动情况及模态进行仿真,找到一种较稳定的约束方式,得到管道的前六阶振型,提高实验装置的稳定性。最后在实验过程中,利用工业废土和渣石与清水按一定比例混合作为待测流体,通过采集卡和LabVIEW软件采集数据,使用MATLAB软件预处理后利用相关性法求出出入口两个传感器测得的数据的相关性,计算出时间差,再通过离散积分取均值的方法得到当前管道中的泥浆重量,利用已知测量管道的体积计算出泥浆实时密度。实验结果证明:利用相关性法和积分的方法得到的泥浆质量和密度与实验所用两相流密度基本一致,证明利用动态称重的测量方法间接得到泥浆密度的可行性。本课题研究的动态称重方法测量泥浆密度的系统适用于钻井及盾构等地下工程。
[Abstract]:Mud density plays a very important role in underground construction and oil drilling by using mud shield equipment. Is a very important data index for tunnel excavation and discovery of new oil layers. The mud shield machine uses the dynamic balance of the density of the inlet and outlet mud to ensure the progress of the excavation. Oil drilling is mainly based on the slurry density to determine the existence of oil layers underground. It is very meaningful to study the real time mud density detection system for underground engineering. In this paper, a method of on-line measuring mud density using the principle of dynamic weighing is studied. The flow pipeline with known volume is used as the measuring pipe. The instantaneous weight of the mud flowing into the pipeline and the time of passing through the pipeline are measured by using a weighing sensor, according to the relationship between volume, mass flow rate and density. The instantaneous average density of slurry in pipeline is obtained. Four parts of the experiment data processing and result analysis are used to study the mud density measurement system of dynamic weighing method. Firstly, the symmetrical weight theory and the fluid dynamics characteristics of the mud are studied, and it is concluded that the mud is an incompressible non-Newtonian fluid. The influence of particle diameter, velocity and volume fraction of mud on the flow and instantaneous weighing results of slurry in the pipeline is analyzed theoretically, which provides a theoretical basis for the analysis of experimental results. In this paper, the theory of measuring fluid flow time by correlation method is studied, and the mud density is obtained by the mass flow rate obtained by dynamic weighing and the calculated flow time. Secondly, the flow of mud is analyzed by ANSYS finite element analysis software. The stability and vibration of the experimental system are simulated. The flow of mud in horizontal pipeline is analyzed at different velocity, particle size and volume fraction, and the relationship between velocity, volume fraction and mass difference between inlet and outlet is found out. The linearity of the instrument is verified by simulating the force process of the sensor, and the vibration and mode of the experimental system are simulated, a more stable constraint mode is found, and the first six modes of the pipeline are obtained. Finally, in the process of the experiment, the industrial waste soil and slag stone are mixed with clear water in a certain proportion as the fluid to be tested, and the data are collected by the acquisition card and LabVIEW software. After preprocessing with MATLAB software, the correlation method is used to calculate the correlation of the data measured by the two sensors at the inlet and outlet, and the time difference is calculated, and then the mud weight in the current pipeline is obtained by the method of taking the mean value of the discrete integral. The real time density of mud is calculated by measuring the volume of pipeline. The experimental results show that the mud quality and density obtained by the method of correlation and integration are basically consistent with the density of two-phase flow used in the experiment. It is proved that it is feasible to obtain mud density indirectly by using dynamic weighing method. The system of measuring mud density by dynamic weighing method studied in this paper is suitable for underground engineering such as drilling and shield tunneling.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE311

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