基于单V锥节流装置的湿气气液流量在线测量

提出采用两相质量流量系数对V锥节流装置湿气测量误差进行修正,试验研究洛克哈特-马蒂内利参数、气体密度弗鲁德数以及气液密度比对V锥节流装置两相质量流量系数的影响规律。V锥节流装置的节流比为0.55,试验介质为压缩空气和水,气液密度比为0.002 445~0.006 083,气体密度弗鲁德数为0.3~2.0,洛克哈特-马蒂内利参数为0.01~0.34。结果表明,两相流量系数随洛克哈特-马蒂内利参数增加而线性增大,同时还受气体密度弗鲁德数和气液密度比的影响。获得了两相质量流量系数与洛克哈特-马蒂内利参数、气体密度弗鲁德数和气液密度比的定量关系,建立湿气流量测量的半经验关联式。利用V锥节流装置前后锥体对湿气具有不同的差压响应特性,获得了其差异性的影响规律,建立单节流元件双差压的湿气气液流量双参数测量方程。在试验范围内,测得的气相质量流量相对误差小于±5.0%,平均误差为2.2%;液相质量流量相对误差小于±20.0%,平均误差为9.8%。该方法具有系统简单、成本低廉、精度较高的特点。

Online Measurement of Gas and Liquid Flow Rate in Wet Gas Base on Single V-cone Throttle

The two-phase mass flow coefficient is proposed to correct the deviation of the V-Cone meter when it is used to measure the wet gas. The effects of the Lockhart-Martinelli parameter, the gas densiometric Froude number and the gas to liquid density ratio on the two-phase flow coefficient are experimentally investigated. The diameter ratio of the V-Cone meter is 0.55. The experimental fluids are air and tap water. The gas to liquid density ratio, the gas densiometric Froude number and the Lockhart-Martinelli parameter range from 0.002 445 to 0.006 083, from 0.3 to 2.0 and from 0.01 to 0.34, respectively. The results show that the two-phase mass flow coefficient linearly increases with the Lockhart-Martinelli parameter and is affected by the gas densiometric Froude number and the gas to liquid density ratio. Then the quantitative relationship between the two-phase mass flow coefficient and the Lockhart-Martinelli parameter, the gas densiometric Froude number and the gas to liquid density ratio is obtained, based on which the correlation for the wet gas flow measurement is developed. The differential pressure response of the front and back cone of the V-Cone to the wet gas is investigated and the parameters affecting the different responses are also discussed, and finally the wet gas correlation to meter the gas and liquid mass flow rate is concluded. In the present cases, the relative error of the gas mass flow rate predicted by the correlation is within ±5.0% and the average relative error is 2.2%; the relative error of the liquid mass flow rate predicted by the correlation is within ±20.0% and the average relative error is 9.8%. The method proposed in this study possesses some remarkable performances, including simple structure, low cost and high accuracy.