双向内外管差压流量计的数值仿真与实验研究

发布时间：2018-05-20 12:53

本文选题：双向内外管差压式流量计 + 等效直径比　；参考：《中北大学》2016年硕士论文

【摘要】：流量计量是流量控制的基础,差压式流量计是工业生产中应用广泛的一种流量计,V锥流量计出现为差压式流量计的发展打开了一个新的领域。但是V锥流量计由于其本身结构的原因还存在着一些不足,针对其结构上的缺陷,有人提出了双锥流量计和内外管差压流量计。本文结合了这两种流量计的优点,提出了一种新的差压式流量计——双向内外管差压流量计。本文从理论分析出发,借用流体仿真软件FLUENT对双向内外管差压流量计在DN32管径下的工作流场进行了模拟,研究了双向内外管差压流量计的一些特性;结合实验,对比分析了双向内外管差压流量计、双锥流量计和内外管差压流量计的各项性能。本文的主要完成的工作如下:1)分析双向内外管差压流量计的测量原理,建立理论模型;参照其他差压流量计,定义双向内外管差压流量计的等效直径比;分析流量计的工作流场特点,定义了分流比,确定了影响双向内外管差压流量计性能的三个主要因素为:扩散角θ、节流比β和分流比α。2)利用FLUENT对扩散角进行了优化,并以优化的扩散角建立不同等效直径比和分流比的模型进行仿真计算,得出等效直径比和分流比对双向内外管差压流量计性能的影响规律:流量计的压力损失和差压信号随着等效直径比的增大而减小、随着雷诺数的增大而增大,压损比随着雷诺数的增大而增大;而在等效直径比确定时,压损比随着分流比的增大先增大后减小,而且等效直径比越大,压损比最大的模型的分流比越小;分流比小的模型在低雷诺数下流出系数更稳定,分流比大的模型在高雷诺数下流出系数更稳定。3)在相同的等效直径比下,对比三种流量计的性能发现:双向内外管差压流量计的节能性、准确性最好,灵敏度稍逊于内外管差压流量计;经实验验证,结果基本一致,流出系数的误差在2%左右。
[Abstract]:Flow meter is the basis of flow control. Differential pressure Flowmeter is a kind of Flowmeter widely used in industrial production. The appearance of V-cone Flowmeter opens a new field for the development of differential pressure Flowmeter. However, there are still some shortcomings in V-cone Flowmeter because of its own structure. In view of its structural defects, two cone Flowmeter and inner and outer tube differential pressure Flowmeter are proposed. Combining the advantages of these two kinds of Flowmeters, a new differential pressure Flowmeter, a bidirectional differential pressure Flowmeter with internal and external tubes, is proposed. Based on the theoretical analysis and the fluid simulation software FLUENT, this paper simulates the workflow field of the two-way inner and outer tube differential pressure Flowmeter under the diameter of the DN32 tube, studies some characteristics of the two-way inner and outer tube differential pressure Flowmeter, and combines the experiment with the experiment. The performances of bidirectional differential pressure Flowmeter, double cone Flowmeter and Internal and external Tube differential pressure Flowmeter are compared and analyzed. The main work of this paper is as follows: (1) analyzing the measuring principle of bidirectional internal and external tube differential pressure Flowmeter, establishing the theoretical model, defining the equivalent diameter ratio of two-way inner and outer tube differential pressure Flowmeter with reference to other differential pressure Flowmeters. The characteristics of workflow field of Flowmeter are analyzed, the diffuser ratio is defined, and the three main factors that affect the performance of bidirectional internal and external tube differential pressure Flowmeter are determined: diffusion angle 胃, throttle ratio 尾 and shunt ratio 伪. 2) the diffusion angle is optimized by FLUENT. The models of different equivalent diameters ratio and shunt ratio are established by using the optimized diffusion angle. The influence law of the equivalent diameter ratio and the shunt ratio on the performance of the differential pressure Flowmeter is obtained: the pressure loss and the differential pressure signal of the Flowmeter decrease with the increase of the equivalent diameter ratio, and increase with the increase of Reynolds number. The pressure loss ratio increases with the increase of Reynolds number, and when the equivalent diameter ratio is determined, the pressure loss ratio increases first and then decreases with the increase of the shunt ratio, and the larger the equivalent diameter ratio, the smaller the shunt ratio of the model with the maximum pressure loss ratio. The outflow coefficient of the model with small shunt ratio is more stable at low Reynolds number, and the outflow coefficient with large shunt ratio is more stable at high Reynolds number. 3) at the same equivalent diameter ratio, Compared with the three kinds of Flowmeter, it is found that the bidirectional tube differential pressure Flowmeter is energy saving, the accuracy is the best, the sensitivity is slightly lower than that of the inner and outer tube differential pressure Flowmeter, and the result is basically the same after the experiment, the error of the outflow coefficient is about 2%.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH814

【参考文献】