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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

A STUDY OF ESTIMATION METHOD OF FLOW PATTERN OF GASLIQUID TWO-PHASE BY USING FLOW SOUND IN VERTICAL PIPE

Get access (open in a dialog) DOI: 10.1615/IHTC16.mpf.023082
pages 6263-6270

Аннотация

The gas-liquid two-phase flow is a flow state seen in thermal plant or chemical plant, etc. It is difficult to know gas-liquid ratio in thermal plant, but the difference in flow pattern mainly caused by gas-liquid ratio influences pressure loss of flow and heat transfer performance. For this reason, detection methods of various flow pattern are being examined, but methods mainly involving visualization in tube and methods requiring processing on tube are mainly used. If gas and liquid flow rate are known, we can use effective equations for calculating transition of flow pattern, we can also use the maps of flow pattern proposed by some researchers, but both flow rate could not know in running plant. In this research, we try to know flow patterns in pipe from detecting and analyzing flow sound. We analyzed sound pressure collected by penetrating an acrylic tube of φ12 mm through an anechoic box and flowing water / air two-phase flow. Effective sound pressure was correlated with two-phase flow velocity considering slip by flow pattern rather than homogeneous velocity. When changing air flow rate with constant water flow rate, effective sound pressure peaked at churn flow, then decreased and increased in annular flow. In the frequency analysis, each feature was seen in three groups of bubble flow, slug flow / churn flow, and annular flow. Finally, we could separate characteristics of slug flow and churn flow by fluctuating sound analysis.