EFFECTS OF INLET FLOW RATE CHANGES ON TWO-PHASE STRATIFIED FLOW IN HORIZONTAL PIPELINES

摘要

An experimental program was carried out to investigate the effects of flow rate changes on two-phase stratified flow. An existing 420-m long, 77.9-mm diameter horizontal test facility was modified for this study, and a new generation of capacitance sensors was developed to measure liquid holdup. Experimental runs consisted of gas and liquid flow rate changes, pipeline start-up with different initial conditions, and liquid blow out tests. The initial and final steady-state flow patterns for these transient tests were stratified flow. Measured parameters included inlet gas and liquid flow rates, outlet liquid flow rate, absolute pressure and differential pressures, temperature, and liquid holdup. An analysis of the experimental data revealed some of the propagation characteristics of the transients caused by flow rate changes. One may utilize these characteristics in the gas transport line control systems such as SCADA. The experimental data also showed that a change in inlet gas flow rate could create fast transients, inducing a temporary intense slugging at the pipeline outlet, while transients induced by a liquid flow rate change at the pipe inlet were comparatively slow.