【作者】 张星；

【导师】 闻建龙；

【作者基本信息】 江苏大学 ， 流体力学， 2010， 硕士

【摘要】 流固两相流动在国民经济的各个领域有着广泛的应用,其相关参数的测量对于设备的设计和运行都起着至关重要的作用。目前,对于流场透明度低、高浓度、固相颗粒大小分布不均匀的混合流体的测量,收获甚少。本文在已有研究的基础上,自行设计一套用于测量流固两相流相关参数的系统——直管密度计测量系统,并对其进行优化设计。在此基础上,对四种具有代表性的混合溶液进行测量,获得了一些基础性的数据。进行的主要工作及取得的成果如下：1、对目前两相流的研究和处理方法及两相流参数检测的现状和发展进行了简要介绍,阐述了流固两相流的流动理论,对流固两相流相关参数指标进行了分析。2、以流固两相流体力学为基础,研究直管密度计测量段中混合流体的运动,从而推导出混合流体在管道中运动的数学模型方程。3、根据现行的测量流固两相流相关参数存在的问题,设计并加工、组装了直管密度计测量系统,对其进行了初步测试。4、利用直管密度计测量系统的三种方案对清水介质进行了测量,通过试验结果得出：直管测量段采用内外管形式,并配有压力补偿程序的方案测量效果最理想。测量的密度基本不随时间和变频器的频率的变化而变化,误差和波动范围都能控制在1%以下。5、利用优化后的实验方案,对盐水溶液、高岭土溶液、锰矿浆溶液和泥沙溶液进行了实际测量。测量结果显示,系统在短时间内对混合流体的测量均可达到很好的效果。长时间测量时,混合流体的温度会因为浆体泵的不断做功而升高,使橡胶柔性接头有所膨胀,内管受到的浮力增大,称重传感器感受到的压力减小,密度随之减小。当采用温度补偿之后,可以有效地避免温度的变化对测量带来的影响。6、将优化后的实验方案应用到疏浚行业实际进行测量,并与钴60密度计和取样测量的值进行对比,结果表明：实际取样测得的泥浆平均密度与直管密度计采集的泥浆平均密度值基本接近,相对误差很小；直管密度计采集到的数据曲线与钴60密度计采集到的数据曲线变化趋势基本一致。测试结果完全符合工业生产的精度和稳定度要求,具有很好的推广应用价值。更多还原

【Abstract】 Liquid-solid two-phase flow has been widely applied to the field of national economics, and the relative parameters are playing a vital role in the design and operation of the equipment. At present, the measurement results on the mixed flow are limited for their low transparency, high concentration and non-uniform distribution of the solid-phase particle size. In this paper, based on the existing study, a straight pipe density meter measurement system was designed and optimized for measuring the relative parameters of liquid-solid two-phase flow. Acquiring some basic data, four representatie mixed fluids were measured. The main work and achievements are as follows:1、Made a brief introduction about the current research of two phase flow, as well as the research status and development of the parameters testing, expounding the fluid-solid two-phase flow theory and making an analysis about the related parameters index of fluid-solid two-phase flow.2、Based on the fluid mechanics, studied the movement of mixed liquid in measuring section of the straight density meter to deduce the mathematical model of the equation of the mixed fluid in the pipeline.3、According to the current problems in measuring the relative parameters of fluid-solid two-phase flow, designed, improved and assembled a straight density meter measure system to make a preliminary test.4、The water media in three schemes was tested by using straight pipe density meter measurement system. From the experiment result, it was concluded that the idealest measurement method is measuring section of pipe in inner-outer form, equipping with pressure compensation. The density is independent of time and frequency, and the error and fluctuating range can be controlled in less than 1 percent.5、Using the optimized measurement system to measure the Saline solution, gaolin solution, manganese ore pulp solution and the silt solution, it showed that the system of measuring the mixed flow could achieve good results in a short time. For a long time, the temperature of the mixed flow increased with the slurry pump constantly working that made the rubber flexible connection inflated and increased the buoyancy of tube and decreased the pressure which suffered by weighing transducer.6、The optimized experiment scheme was applied to measure the dredge industry. Comparing with the sample results measured by cobalt 60 density meter, the average density of mud is approximate to the result of straight pipe; the curve variation of the data collected by density meter is consistent with that of cobalt 60 density meter. Test results are fully satisfied with the requirement of accuracy and stability in industrial production, which is worth to apply.更多还原