Study Of Liquid Loading Characteristics In Wet Natural Gas Pipeline

With the increasing demand for nature gas,the safety of the gas transmission becomes an important issue.Since some liquid condensate is generated during the transmission,natural gas pipe flow is a typical low liquid loading gas-liquid two-phase flow.Low liquid loading has large effect of capacity and efficiency of gas transport system,however,only accurately predict the flow pressure drop and liquid loading can we design the pipeline size and downstream equipments. Gas-liquid interface will be different under different operating condition.The pressure drop pridiction calculated with different mechanistic model based on different gas-liquid interface has great discrepancy.Thus study on geomitrical characters of gas-liquid interface has significant theoretical value and important meaning for the safety and efficiency of pipeline transmission.Based on literature research this thesis has introduced the formation of and how to differentiate concave configuration in the wet gas pipeline.Theoretical analysis on the different configration mechanistic models by programming calculation,compared the results and the experimental data. For low gas velocity(<10m/s),FLAT model is recommended;for medium gas velocity(10-20m/s),ARS model and MARS model are recommended; for high gas velocity(10-20m/s),Double-Circle model is recommended.On the basis of study the theory and analysis of data,the wetted fraction corelation in the FLAT mechanistic model for low gas velocity is developed. The wetted fraction corelations in ARS model and MARS model are introduced into FLAT model.A new plat form model with wetted fraction corelation included weber number and froude number is estabilshed and pressure drop relationship is used to simplify the process else well.The performance of the model in this thesis shows better results with experiment data relative to FLAT model.