上下游闸阀对内锥流量计性能影响的实验研究

旨在认识恶劣流场对内锥流量计性能的影响,利用上下游闸阀实现对流场的扰动,设计内径为100 mm的实验样机一台.实验介质为常温水,雷诺数范围0.1×10~5～4.5×10~5.实验分基线实验与闸阀开度实验2种形式,累计65组,上游闸阀开度分别为75%/50%/25%.下游闸阀开度分别为100%/50%,安装形式13种,等效直径比分别为0.45/0.55/0.65/0.75/0.85.提出平均流出系数相对误差、不确定度和附加不确定度作为安装条件恰当与否的主要评价标准.实验结果给出了12种不同安装形式的直管段建议长度,并与国外研究结论进行了比较.等效直径比为0.45/0.55时,前直管段均为3D;等效直径比为0.65/0.75/0.85时前直管段均为5D.

Experimental research on the impact of upstream and downstream gate valves on the performance characteristics of a V-cone flow meter

In order to acquire a deep knowledge of installation requirements and application conditions, experi-ment investigation have been carried out here with a v-cone flowmeter prototype of 100 millimeter interior di-ameter with the β ratio of 0.45/0.55/0.65/0.75/0.85 respectively. The experiment medium is water of normal tem-perature and Reynolds number range of 0.1×10~5～4.5×10~5. There are two types of experiments which include the baseline experiments and the experiments of upstream& downstream gate valves with different opening ratios.There are 65 groups' experiments in all for the 13 installation scheme. The relative error of the averaged discharge coefficient and uncertainty and the additional uncertainty are the main evaluating criteria. Comparing with the foreign study conclusions, suggestions on installation requirements are given here for the 12 types of opening ra-tios of gate valves. For V-Cone flowmeters with the equivalent diameter ratio of 0.45/0.55/0.65/0.75/0.85, the proposed installation length of upstream pipes is 3D/3D/5D/5D/5D respectively.