多相流管道输量突增的瞬态效应试验研究

在大型多相流环道上进行了液量增加的瞬态试验，讨论了试验中的瞬态效应。当液相流量快速增加后，压力波首先传播到管道各点，压力发生扰动，一般时间后空隙传播到各点，压力快速上升。压力快速变化向下游的传播速度等于空隙波的波速。在段塞流时，空隙波波速等于液塞运动速度，在分层流时，空隙波波速等于液体实际流速；在气团流时，空隙波波速等于气液混合物的速度。差压的变化较为复杂，在不同流型和液量下的变化不同。

Experimental Research on the Transient Characteristics of the Sudden Increase of the Liquid Flow Rate in Multiphase Pipelines

For the purposes of gaining an insight into the characteristics of trans ient flow, the experiments of upliquid transient flow are conducted on the large multiphase flow loop and the transient responses are presented. Following the a ccretion of liquid flow rate, pressure waves resulting from the fluctuation of t he fluid density propagate downstream quickly and pressure of various points und ergoes disturbances. After some time, voidage waves arrive various points, as a result, the pressure build up quickly. The results demonstrate that the transmis sion speed of pressure increase approximates the voidage wave traveling at a vel ocity equal to slug translation velocity in case of slug flow, liquid flow veloc ity under stratified flow and mixture velocity under plug flow. The evolution of the pressure drop varying with the flow pattern and the liquid flow rate is dif ferent with that of the pressure in most cases. The time for the pressure drop t o reach the steady value is shorter than the pressure. In the transients, the ga s holdup descends slowly and tends to steady state asymptotically with small mag nitude of void fraction decrease.