气液两相流持液率及压降特性的试验研究

Study on the Characteristics Parameters of Gas-liquid Two-phase Flow

研究了不同流型下压力降与持液率的特点,以及压降脉动信号的方差与持液率、气、液相流量之间的关系。试验结果表明,分层流动的持液率值最高,平均压降最低;环状流动持液率值最低,平均压降值最高;段塞流动位于两者之间。分层流压降脉动信号的方差很小,随气、液量和持液率的变化小;段塞流压降脉动信号的方差最大,随气相流量和持液率的变化而变化较大,在相同气量下,方差随持液率的增大而增大,在相同持液率下,方差也随气量的增大而增大;环状流的方差在分层流和段塞流之间,气相流量的变化对压降脉动信号的方差的影响小,但液相流量的变化对其影响较大,随着液相流量和持液率的增大,压降脉动信号的方差会增大。

The main parameters of gas-liquid two-phase flow, such as flow patterns, pressure drop and liquid hold-up,are investigated in this paper. The flow patterns are closely related with pressure drop and liquid hold-up. The characteristics of pressure drop and liquid hold-up in different flow patterns are studied. According to the experiments under given flow rate of liquid, in stratified flow, the liquid hold-up is the highest and the average pressure drop is the lowest, while in annular flow, the result is opposite, in slug flow,the result is intermediate. The effect of liquid hold-up on dynamic feature of pressure signal is studied experimentally and theoretically. The Mean-Square Deviation (MSD) of pressure drop fluctuation signal in stratified flow is small,and it is hardly influenced by the flow rate of liquid and gas and liquid hold-up. The MSD of pressure drop fluctuation signal in slug flow is the biggest and is greatly influenced by the flow rate of liquid and gas and liquid hold-up, the MSD will be increased as hold-up and the flow rate of gas increase. The MSD of pressure drop fluctuation signal in annular flow is between the two patterns mentioned above,and it is little changed with the flow rate of gas,but is greatly influenced by the flow rate of liquid. The MSD will be increased as hold-up and the flow rate of liquid increase.