基于Chisholm模型的V锥流量计气液分层流测量新模型

New model for measuring stratified gas-liquid flow by Chisholm-model-based V-cone flowmeter

针对V锥流量计应用Chisholm模型测量气液分层流时误差较大的问题,采用节流比分别为0.55、0.65和0.75的三个V锥流量计,实验研究了高含气率(体积含气率>95%)气液分层流条件下,气、液相流量、压力以及节流比对Chisholm模型修正因子C的影响规律,并建立气液分层流测量模型。结果表明,修正因子C随LockhartMartinelli参数XLM的增大而单调递减,但基本不受压力和气体密度Froude数的影响,而节流比变化则对C有一定影响;建立了C随XLM变化的测量模型,获得了不同节流比的V锥流量计气液分层流测量新模型。对于节流比为0.55和0.65的V锥流量计,分别在94.6%和88.6%置信水平下,新模型预测的气相流量相对误差不超过±3.0%;节流比为0.75时,在91.7%置信水平下,预测的气相流量相对误差不超过±4.0%。

Large errors are usually observed when Chisholm model is used in V-cone flowmeter to measure stratified gas-liquid flow rate.Three V-cone flowmeters with throttle ratios of 0.55,0.65 and 0.75 were used to study stratified gas-liquid flow at gas volume fraction of more than 95%.The effects of gas and liquid flow rates,operating pressure and throttle ratio on correction factor C of the Chisholm model were analyzed and new model for measuring stratified gas-liquid flow was developed.Correction factor C was monotonically decreased with increase of Lockhart-Martinelli,XLM,but was hardly affected by pressure and the gas densiometric Froude number.However,C was somehow affected by throttle ratio.The relationship between C and XLM was obtained and new models for three V-cone flowmeters to measure stratified flow were developed.The relative standard error of the predicted gas flow rate was with±3.0%for V-cone flowmeters with throttle ratios of 0.55 and 0.65 under confidence level of 94.6%and 88.6%,respectively,while that was with±4.0%under 91.7%confidence level for V-cone flowmeter with throttle ratio of 0.75.