An Experimental Study of the Flowrate Transients in Slug Flow

Abstract

Abstract: An investigation of the characteristics of flowrate transients within slug flow was
conducted in a largescale outdoor testing facility. The test section consisted of a 378 m
long, 7.62 cm diameter stainless steel pipe.Air and water were used as the test fluids. The
response to a change of flowrate of either phase or two phases was measured using a series
of pressure transducers and differential pressure transducers. An increase or decrease in
gas flowrate caused a pressure overshoot above the value at new steady state or led to a
pressure undershoot to form a temporary stratified flow. Pressure waves existed in the
pipeline, spreading from the entrance to the exit. The magnitude of pressure overshoot in
"up-gas" transient or of pressure undershoot and period of the temporary stratified flow in
"Down-gas" transient are related to the change of gas flowrate and the distance away from
the entrance. In contrast, the change in liquid flowrate was accommodated by smooth
transitions between the corresponding steady states, and only one obvious change was found
in the slug frequency. According to experimental results, the pressure overshoot, pressure
undershoot and the pressure wave propagation were analyzed,and the phenomena were explained
reasonably. Some correlations for the calculation of the pressure overshoot and undershoot
were proposed.

Key words: slug flow, flowrate transient, pressure overshoot, pressure undershoot

摘要： An investigation of the characteristics of flowrate transients within slug flow was
conducted in a largescale outdoor testing facility. The test section consisted of a 378 m
long, 7.62 cm diameter stainless steel pipe.Air and water were used as the test fluids. The
response to a change of flowrate of either phase or two phases was measured using a series
of pressure transducers and differential pressure transducers. An increase or decrease in
gas flowrate caused a pressure overshoot above the value at new steady state or led to a
pressure undershoot to form a temporary stratified flow. Pressure waves existed in the
pipeline, spreading from the entrance to the exit. The magnitude of pressure overshoot in
"up-gas" transient or of pressure undershoot and period of the temporary stratified flow in
"Down-gas" transient are related to the change of gas flowrate and the distance away from
the entrance. In contrast, the change in liquid flowrate was accommodated by smooth
transitions between the corresponding steady states, and only one obvious change was found
in the slug frequency. According to experimental results, the pressure overshoot, pressure
undershoot and the pressure wave propagation were analyzed,and the phenomena were explained
reasonably. Some correlations for the calculation of the pressure overshoot and undershoot
were proposed.

关键词: slug flow;flowrate transient;pressure overshoot;pressure undershoot

HE Limin, GUO Liejin, CHEN Xuejun, CHEN Zhenyu, KOU Jie. An Experimental Study of the Flowrate Transients in Slug Flow[J]. .

何利民, 郭烈锦, 陈学俊, 陈振瑜, 寇杰. 段塞流的流量瞬变特性试验研究[J]. CIESC Journal.

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