【作者】 郭海涛；

【导师】 李一博； 曹玉芬；

【作者基本信息】 天津大学 ， 工程（专业学位）， 2021， 硕士

【摘要】 水体运动时会携带大量泥沙,在流速变缓区域往往会造成泥沙淤积。这给河道整治、港口运输以及水库淤积治理等带来重要影响,因此需要利用高精度含沙量测量仪对水体含沙量进行测量。然而目前没有含沙量测量仪计量标准装置,无法对这些仪器进行有效标定,使得仪器数据可靠性差,在使用中造成了巨大经济损失。因此,搭建含沙量测量仪计量标准装置可以填补国内含沙量测量仪计量领域的空白,有效减少水运工程领域的经济损失,带来巨大的社会效益和经济效益。目前高精度含沙量测量仪依赖进口,受制于国内研究水平,无法选择研制更高精度含沙量测量仪作为计量器具的方案。因此,本课题提出了通过配置高精度水体悬沙场,利用悬沙场作为标准器计量含沙量测量仪的方案。为此搭建了含沙量测量仪计量标准装置,设计了多点同步采样装置并完成了对装置所构建悬沙场的不确定度评定工作。搭建含沙量测量仪计量标准装置时,首先对提出的螺旋桨和格栅组两种搅拌结构进行了详细比较,依据仿真结果选择了格栅组搅拌方案。选定方案后进行了机械结构设计,具体包括格栅组、动力传输装置、自动进料装置以及其他配套机械结构等。对装置机械结构的实验验证结果表明:所设计的机械结构具有良好的搅拌能力和稳定性。其次,为了使机械结构能够正常工作,设计了控制系统。依据所需的控制器件设计了相应的硬件电路,编写了软件程序,主要包括人机交互界面、自动进料模块、搅拌模块以及三种传感器通讯模块等。控制系统设计完成后,对整个装置的实验验证结果表明:机械结构与控制系统配合可以使含沙量测量仪计量标准装置具有准确添加原料以及变频搅拌的功能,具有构建均匀稳定悬沙场的能力。在含沙量测量仪计量标准装置搭建完成后,需要对装置的不确定度进行评定。由于现有的采样器具均不满足多点、同步和快速的采样需求,因此设计了多点同步采样装置,依据上下分层的采样方法对计量装置所构建的悬沙场进行了采样。在全量程范围内对装置的相对标准不确定度进行了检测,实验结果表明:本装置在0.1kg/m~3到30kg/m~3的量程范围内所构建的悬沙场的相对标准不确定度小于1%,性能指标符合设计要求。更多还原

【Abstract】 When the water body moves,it will carry a lot of sediment,and it will often cause sedimentation in the area where the flow velocity slows down.This has an important impact on river improvement,port transportation,and reservoir siltation management.Therefore,it is necessary to use a high-precision suspended sediment concentrations measuring instrument to measure the suspended sediment concentrations of the water body.However,there is currently no metrology standard device for suspended sediment concentrations measuring instruments,and it is impossible to effectively calibrate these instruments,which makes the reliability of the instrument data poor and causes huge economic losses in use.Therefore,the establishment of the metrology standard device for the suspended sediment concentrations measuring instrument can fill the gap in the measurement field of the domestic suspended sediment concentrations measuring instrument,effectively reduce the economic loss in the field of water transportation engineering,and bring huge social and economic benefits.At present,the high-precision suspended sediment concentrations measuring instrument relies on imports and restricted by the level of domestic research,it is impossible to choose the solution that developing a higher-precision suspended sediment concentrations measuring instrument as metrology standard instrument.This project proposes a solution for measuring suspended sediment concentrations by configuring high-precision water suspended sand fields and using the suspended sediment field as a standard instrument.To this end,a metrology standard device for a suspended sediment concentrations measuring instrument was built,a multi-point synchronous sampling device was designed,and the uncertainty assessment of the suspended sediment field constructed by the device was completed.When building the standard measurement device for the suspended sediment concentrations measuring instrument,the two proposed mixing structures of the propeller and the grid group were first compared in detail,and the grid group mixing scheme was selected based on the simulation results.After selecting the plan,the mechanical structure design was carried out including the grid group,power transmission device,automatic feeding device and other supporting mechanical structures.The experimental verification results of the mechanical structure of the device show that the designed mechanical structure has good stirring ability and stability.Secondly,in order to make the mechanical structure work normally,a control system is also designed.Corresponding hardware circuits are designed according to the required control devices,and software programs are written,including human-computer interaction interface,automatic raw material feeding module,stirring module,and three sensor communication modules.After the design of the control system is completed,the entire device is verified by experiments.After the design of the control system is completed,the experimental verification results of the entire device show that the mechanical structure and the control system can make the standard device of the suspended sediment concentrations measuring instrument have the functions of accurately adding raw materials and frequency mixing,and have the ability to build a uniform and stable suspended sediment field.After the construction of the metering standard measurement device for the suspended sediment concentrations measuring instrument is completed,the uncertainty of the device needs to be evaluated.Since none of the existing sampling instruments can meet the requirements of multiple-locations,synchronous and fast sampling,a multiple-locations synchronous sampling device is designed,and the suspended sediment field constructed by the metering device is sampled according to the sampling method of upper and lower layers.After testing the relative standard uncertainty of the device within the full range,the experimental results proved that in the range of 0.1kg/m~3to 30kg/m~3,the standard uncertainty of the suspended sediment field is less than 1%,and the performance indicators meet the design requirements.更多还原