管道入口段雾化加注天然气减阻剂的数值模拟

采用数值模拟的方法研究天然气管道减阻剂的雾化加注过程，首先对气体管道入口段的稳态流场进行模拟，得到收敛的气流场，再将减阻剂作为一系列离散相雾滴从入口喷嘴注入后进行耦合计算，分析各雾化条件对雾滴索泰尔平均直径（SMD）及其在入口段管壁上吸附特性的影响。模拟结果表明：喷雾压差、喷雾流量、喷嘴直径和喷射角度是影响天然气管道减阻剂减阻效果和减阻距离的关键因素。喷雾压差越大，喷雾流量越小，雾滴的SMD越小，越容易吸附在入口段的管壁上；喷嘴直径和喷射角度对雾滴的SMD影响不大，但喷射角度较小时，雾滴能被气流携带更长距离。研究成果可为天然气减阻剂的工程应用提供一定的理论指导。（图6，表5，参17）。

Numerical simulation of atomized DRA at gas pipeline inlet

In order to investigate the effect of different factors in injecting atomized DRA on pipe wall adsorption at the pipeline inlet, the atomized adding process of gas DRA is numerically simulated. The simulation includes simulating the steady state flow field at pipeline inlet to obtain a convergent gas flow field, then calculating the DRA as a series of dispersed phase droplets which are injected into inlet nozzle, and finally analyzing the effects of atomization conditions on droplets＇ Sauter Mean Diameter （SMD） and the performance of adsorption on the inlet pipe wall. Results show that atomizing differential pressure, atomizing flowrate, nozzle diameter and nozzle angle play a crucial role in reduction effect and drag distance of gas pipeline DRA. The bigger the atomizing differential pressure is, the smaller atomizing flowrate and smaller SMD of droplets are, and the easier for the DRA to adsorb on pipe wall is. Nozzle diameter and nozzle angle have little impact on SMD of droplets. However, when the nozzle angle gets smaller, the distance the droplets can be carried by gas flow will be longer. The research results are able to provide the theoretical basis to the engineering application of the gas DRA. （6 Figures, 5 Tables, 17 References）