Research On The Law Of Fluid Accumulation In Fluctuating Wet Gas Pipeline Based On OLGA Software

In the process of natural gas gathering and transportation,the most commonly used process is wet gas transportation,but this process will lead to the generation of liquid accumulation,accompanied by complex terrain,serious safety accidents will occur.The generation of effusion is related to many factors,and the existence of effusion will have many adverse effects.Therefore,it is of great significance to study the law of liquid accumulation in undulating wet gas pipeline and explore the formation mechanism and influencing factors of liquid accumulation for the safe transportation of wet gas pipeline.Based on the theory of liquid holdup mechanism,transient flow mathematical model and unified flow pattern prediction of two-phase flow,this paper analyzed from the perspective of phase balance and force,and established two kinds of three-stage undulating pipelines by using the OLGA software.The variation law of dip Angle,inlet temperature,outlet pressure,gas-liquid ratio,pipeline diameter and flow rate along with the whole length of the pipeline,and the variation law of the midpoint liquid holdup of each section of the three sections and the average liquid holdup of the whole length of the pipeline with each of these factors were analyzed by single factor,and the range of suitable pipeline parameters was determined.The multi-factor optimization design can determine the size and change rule of each factor on the influencing index.Therefore,this paper constructs an orthogonal table with five factors and six levels,selects the data range commonly used in engineering,carries out the range and variance analysis,and determines the optimal level combination of two kinds of three-stage pipelines and the ordering of the primary and secondary factors affecting the change of pipeline liquid holdup respectively.It provides theoretical guidance for reducing the existence of effusion in the future.For the research of pressure drop,this paper uses the experimental data found in the simulation pipeline to analyze the error of the pressure drop between the existing seven mathematical models of two-phase flow and the mathematical model applied by OLGA,the transient simulation software of multiphase flow.The results showed that when the diameter of the pipe was between 300 and 400 mm,the simulation result of OLGA software was relatively uniform,about 18% to 20%.For pipelines with large diameter,BB and DEF mechanical model have better simulation results than other models.