Mud Density Detection System Based On Dynamic Weighing Method

The role of mud density is very important in the use of shield machine for underground construction works and oil drilling works.It is a very important data indicator for tunneling and discovering new oil layers.The main role of the mud shield machine is to use the dynamic balance of the inlet and outlet mud density to ensure the progress of mining.Oil drilling is mainly based on the density of the outflow mud to determine whether there is underground oil layer.Therefore,the study of the on-line detection system for mud density is very meaningful.For the problem of mud density detection,this paper studies a method of on-line detection of mud density using the dynamic weighing.The volume of the known flow of the pipeline as a measurement pipeline,the application of load cells to the mud into the pipeline for the instantaneous weight and time to measure,according to the volume,mass flow and density of the relationship between the measurement of the average pipe slurry density.In this paper,the mud density detection system of dynamic weighing method is studied from four parts: theoretical research,simulation analysis,experimental platform construction,experimental data processing and result analysis.Firstly,the theory of weighing and the hydrodynamic characteristics of mud are studied,and the mud is used as an incompressible non-Newtonian fluid.There is a certain sediment in the process of flow.The particle diameter,velocity and volume fraction of mud are analyzed.And the influence of the instantaneous weighing results in the pipeline,and provide the theoretical basis for the analysis of the experimental results.In this paper,the correlation method is used to measure the flow time of the fluid.The mass density and the calculated flow time are obtained by dynamic weighing.Secondly,ANSYS finite element analysis software is used to simulate the flow of mud,the process of sensor force,the stability and vibration of experimental system.The flow rate of the mud in the horizontal pipeline is analyzed,and the relationship between the flow rate,the volume fraction and the poor quality of the inlet and outlet is analyzed.The force of the sensor is simulated and the linearity of the instrument is verified.The vibration condition and mode of the experimental system are simulated,and a more stable restraint mode is found.The first six modes of the pipeline are obtained and the stability of the experimental device is improved.Finally,in the course of the experiment,the industrial waste soil and slag and the water were mixed with a certain proportion as the fluid to be measured.The data were collected by the acquisition card and Lab VIEW software.After pretreatment with MATLAB software,the correlation method was used to obtain the two data relevance.The time difference is calculated and the weight of the mud in the current pipe is obtained by the discrete integral method.The realm density of the mud is calculated by the volume of the known measuring pipe.The experimental results show that the mud quality and density obtained by the correlation method and integral method are basically consistent with the two-phase flow density used in the experiment,and the feasibility of using the dynamic weighing method to obtain the mud density is proved.The dynamic weighing method studied in this paper is suitable for underground engineering such as drilling and shield.