基于V锥流量计压损比的湿气液相流量在线检测

Online measurement of liquid flow rate in wet gas based on pressure loss ratio of V-cone flowmeter

针对湿气中液相流量在线检测误差较大的问题,提出采用V锥流量计压损比实现湿气液相流量直接测量的思路。实验研究了节流比分别为0.45、0.55、0.65和0.75的4个V锥流量计压损比特性,结果表明,压损比较好的反映了湿气中含液量的变化,其随液体密度弗鲁德数增大而增加,并且受气液密度比的影响;对于节流比为0.55的V锥流量计,在本实验范围内,压损比基本不受气体密度弗鲁德数的影响。建立了该流量计基于压损比的湿气液相流量测量关联式,其预测的绝大部分工况点液相流量满度相对误差小于±5.0%;当体积含液率大于0.5%时,液相流量相对误差优于±20.0%。研究结果可为建立基于单节流装置双差压的湿气气、液分相流量在线测量方法提供技术支撑。

The online measurement result for the liquid flow rate of the wet gas flow has large error. In this study,a new method based on the pressure loss ratio of the V-Cone flowmeter is proposed to directly measure the liquid flow rate. Four V-Cone flowmeters with equivalent diameter ratios of 0. 45,0. 55,0. 65 and 0. 75 are experimentally investigated. The results show that the pressure loss ratio can reflect the variation of the liquid flow rate in the wet gas. The pressure loss increases with the liquid densiometric Froude number and is affected by the density ratio of gas-liquid. For the V-Cone flowmeter with the diameter ratio of 0. 55,the pressure loss ratio is fairly free from the effects of the gas densiometric Froude number in the present test cases. The correlation to predict the liquid flow rate is developed based on the pressure loss ratio. The full scale relative error of the liquid mass flow rate predicted by the correlations is within± 5. 0% under most operating conditions. The relative error is within ± 20. 0% when the liquid volume fraction is more than 0. 5%.Research results provide the technology support for the development of measuring the gas and liquid flow rate simultaneously based on two differential pressure of one throttle device.