小长径比垂直管气液两相流动特性分析

实验观察了小长径比垂直上流管内流型及特点,并对管入口处的压力波动特性和系统的压差波动特性进行了试验研究.结果表明:小长径比(L/D)垂直管内流型表现为泡状流、塞状流、乳沫状流、环状流和液束环状流;分别增加管线中的气量、液量,或者同时增加气液流量,均会造成垂直管入口处压力波动的均值和最大压力的增加;压力信号的概率密度(PDF)大部分呈双峰分布,也存在单峰和多峰分布;差压信号的概率密度符合正态分布,其功率谱密度同压力信号相比具有频率波动范围宽、幅值小的特点.

CHARACTERISTICS FOR GAS-LIQUID TWO-PHASE FLOW IN A UPWARD VERTICAL PIPE WITH SMALL LENGTH-DIAMETER RATIO

Many experiments about Characteristics for air/water two-phase Flow have been carried in 2.2m long,50 mm i.d.vertical stainless steel pipe.Flow patterns are obtained through watching. The results also show that the increase of gas flowrate or liquid flowrate will cause the increase of mean value and maximal value of pressure and differential pressure.Most distributions of probability density function(PDF)for pressure signal show dual-peak distributions.However,there are some single-peak and multi-peak distributions.Distributions of probability density function(PDF)for differential pressure signal obey normal distributions.By contrast with pressure signals,distributions of power spectral density(PSD)for differential pressure signal show wider frequency range and lower amplitude.