基于管壁取样的气液两相流量测量

为克服传统取样式多相流量测量方法取样口易堵塞的缺点,提出了通过管壁取样测量气液两相流体流量的新方法.管壁四周均匀布置4个直径为2.5 mm的取样孔,并在上游采用旋流叶片将来流整改成液膜厚度均匀分布的环状流型,从而增强了取样的代表性.分析表明,取样流体中的液相质量流量与主流体液相质量流量的比值主要取决于取样孔的数目和大小,而取样流体中的气相质量流量与主流体气相质量流量的比值则与主管路液相流量有关.在管径为0.04 m的气液两相流实验回路进行的实验表明,在实验范围内液相取样比为0.049,基本不受主管气液相流量波动的影响,能够在宽广的流动范围内维持恒定.液相流量最大测量误差为6.8%,气相流量最大测量误差为8.9%.

Gas-Liquid Two-Phase Flow Metering with Pipe Wall Sampler

The fluid extracted from the holes of the pipe wall is adopted for gas-liquid two-phase flow rate metering to avoid the blockage in the traditional sampling method. The pipe wall with four 2. 5 mm diameter sampling holes and a spin generating element mounted upstream for modifying the inlet flow pattern are set up to improve the representative of the sampled fluid. The stratified flow, slug flow and asymmetry annular flow upstream become symmetry annular flow with uniform film thickness after the spin generating element. The liquid extraction ratio is only determined by the diameter and number of the sampling holes and independent of gas and liquid flow rate of the main pipe, and the gas extraction ratio is mainly controlled by the liquid flow rate of the main flow loop. The experiments have been carried out at a 40 mm diameter air-water two- phase flow loop, and the results indicate the liquid extraction ratio near 0. 049. The maximum errors of the liquid and gas flow rate measurement approach to 6.8% and 8. 9%, respectively.