Gas–liquid two-phase flow sampling measurement using a swirl sampler

• The principle of two-phase flow sampling and metering method was proposed.
• The liquid and gas extraction ratio determination equations were inferred.
• The extraction ratio influencing factors were studied.
• The flow rate measurement accuracy is independent of flow patterns.

A very small portion of total flow was sampled using a specially designed swirl type sampler for gas–liquid two-phase flow metering. The sampling holes were evenly placed around the circumference of the pipe wall and a swirl vane was mounted upstream to change the asymmetry flow pattern into uniform annular flow. The total flow rate of each phase was determined according to the flow rate of sample flow and the extraction ratio. The liquid extraction ratio is mainly controlled by the number and diameter of the sampling holes and the gas extraction ratio can be obtained based on the resistance relationship between the main loop and the sample loop. Experiments were conducted in an air–water two-phase flow loop, flow patterns such as wavy flow, slug flow and annular flow were observed. The experimental results demonstrated that the error of flow rate measurement was less than 6.0% and independent of flow patterns.

A very small portion of total flow was sampled using a specially designed swirl type sampler for gas-liquid two-phase flow metering. The sampling holes of the swirl sampler were evenly placed around the circumference of the pipe and a swirl vane was mounted upstream to change the asymmetry flow pattern into uniform annular flow. The sampled fluid was separated and metered by a compact separator and flow back into the main stream finally. The total flow rate of each phase was determined according the flow rate of sample flow and the extraction ratio.Figure optionsDownload as PowerPoint slide