孔板流量计计量精度数值模拟研究
Research on Numerical Simulation of Orifice Flowmeter Measurement Accuracy
浏览(2471) 下载(5)
- 引用格式:
-
张兵强,高有兵,蒲鹤.孔板流量计计量精度数值模拟研究[J].天然气与石油,2014,32(4):0.doi:
Zhang Bingqiang, Gao Youbing, Pu He.Research on Numerical Simulation of Orifice Flowmeter Measurement Accuracy[J].Natural Gas and Oil,2014,32(4):0.doi:
- DOI:
- 作者:
- 张兵强1 高有兵1 蒲 鹤2
Zhang Bingqiang, Gao Youbing, Pu He
- 作者单位:
- 1.中国石油天然气集团公司西气东输管道分公司豫皖管理处,2.国家安全生产监督管理总局化学品安全登记中心
1.China National Petroleum Corporation West-East Gas Pipeline Company Henan and Anhui Management Office；2.State Administration of Work Safety Chemical Safety Registration Center
- 关键词:
- 计量精度；孔板；数值模拟；SST k-ω湍 流模型
Measuring accuracy; Orifice plate; Numerical simulation; SST k-w turbulence model
- 摘要:
- 孔板流量计使用过程中其计量误差会逐渐变大。为研究孔板流量计计量精度影响因素，选用SST k-ω 湍流模型对孔板流量计孔板前后流场变化情况进行了数值模拟分析，SST k-ω 湍流模型更适合对流减压区流场计算，通过模拟实验确定了孔板流量计最佳取压位置，并定性分析了取压孔位置对计量精度的影响。在实验条件下，孔板节流前后引起的温差使计量精度产生0.067 52‰ 的误差；孔板开孔直角入口边缘尖锐度变钝会导致孔板前后流场发生较大变化，节流前后压差降低，导致流量计计量值小于真实值，因此孔板流量计使用一段时间后必须测试孔板锐度，必要时应更换孔板，以免影响计量精度。
In operation of orifice flowmeter, measurement error will gradually get large. In order to identify factors affecting the measuring accuracy, selected is SST k-w turbulence model to conduct numerical simulation analysis on flow field changes upstream and downstream of orifice plate in orifice flowmeter. SST turbulence control equation is more suitable for flow field calculation in convection reduced pressure zone. Determined is the optimum pressure tapping point through simulation experiment and conducted is qualitative analysis on the effect of pressure tapping point location on the measuring accuracy. Under experimental conditions, temperature difference upstream and downstream of orifice plate throttling may result in error of 0.067 52%0 in measurement accuracy. Sharp degree drop of hole edge at opening rectangular entrance will lead to great changes of flow field upstream and downstream of orifice plate and pressure differential drop upstream and downstream of throttling, consequently, it leads to less measurement values than real ones. Therefore, sharp degree of orifice plate shall be test after orifice flowmeter operates for a period of time, and orifice plate is replaced if necessary so as to avoid affecting the measuring accuracy.
