Study On Two-Phase Gas-Liquid Flow Technology In Pipeline

By researching of the two-phase gas-liquid flow technology in the pipeline, this paper has obtained the following findings:Based on the judgment formulas of flow pattern of Baker, Mandhane, Brill, Weisman, Taitel, the research in the paper integrates of the nth power Langrange interpolation polynomial and empirical formula to decide the flow pattern and judge conversion of the flow pattern conveniently.For gas-liquid two-phase flow techniques calculation in pipeline, the author takes the three flow models as the basis, including homogeneous phase flow model, drift flux model and combination model. Which are used to calculate the property parameters and the pressure drop, temperature drop, holdup in pipeline. And, by means of the calculation of examples and the comparisons are presented on above all models.Based on the relationships among the mass conservation, momentum conservation, and conservation of energy, the steady and transient calculated model of the wet natural gas pipeline are established. By considering the relationships between pressure, gas-liquid phase flow velocity, temperature and holdup, the steady calculation in the steady model is carried out by Adams predication revised formula & Runge-Kutta formula at the same time, which guarantees the accuracy of the results and convergence of the solution.In the process of analyzing the transient state of wet nature gas pipeline, the analytic and numerical methods are adopted to solve the equations. According to the character of slow transient of the wet nature gas pipeline, the analytic solution of pressure and mixed flow rate are worked out by means of neglecting the inertial item and adopting linear coefficient. In the course of the transient numerical analysis of the wet nature gas pipeline and on the base of the partial differential equations, the weighted implicit difference method is used for getting numerical solution.The present paper studies the hydraulic transient of the oil transportation pipeline including gas. Because the gas content affects the transient change greatly, so this paper establishes the bubble discrete layout model and the bubble average distribution model according to the proportion of gas in the pipeline. Based on the character of the bubble discrete layout model and considering the variable wave velocity, the characteristic method is adopted to solute the model. In the course of calculation on the buddle average distribution model and considering the column separation, because the solution and disposing boundaries condition of characteristic method are simple, meanwhile the Lax-Wendroff method analyses shock wave phenomenon easily. So the integrated method of characteristic method and Lax-Wendroff is used in the paper.By the analysis of experimental research and example of two-phase gas-liquid flow technology in pipeline, the results show that the theories and methods mentioned in the paper are available.In the end, the analysis software (MPPLA) on two-phase gas-liquid flow in pipeline is developed with the features of the wide application, simply operation, which can be used in the pipeline design and management of the two-phase gas-liquid flow pipeline.