油水两相流弯管处安全分析

针对油水两相流经过弯管时的流向改变会导致流体速度和压力发生突变，造成发生静电事故和腐蚀事故风险上升 的不利影响，提出了RSM模型和Mixture模型相结合的安全分析方法。该方法对不同入口速度和含水率的油水两相流进行 数值模拟，并用Origin软件拟合了进口最大允许流速与管径及含水率的经验关系。结果表明，在含水率和入口速度一定 时，随着管径的增加，弯管处的最大速度呈现逐渐减小的趋势:当管径和入口速度一定时，随着含水率的增加，弯管处 的最大速度也逐渐减小。最大压力出现在弯管外拱壁处，最小压力出现在弯管内侧拱壁处。在实际生产中，增加弯管下 游直管段内侧壁的壁厚，可有效防止空化腐蚀所造成的危害；通过含水率来确定安全流速，可有效降低静电事故的风险 。

Safety analysis on oil-water two-phase flow in curved pipe

The flow direction change of oil-water two-phase flow passing through the curved pipe will cause the sudden change of fluid velocity and pressure, which leads to the rise of risk about electrostatic accident and corrosion accident. The method combining RSM model with Mixture model was proposed. The numerical simulation of oil-water two-phase flow with different inlet velocity and water cut was carried out, and the empirical relationship among maximum allowable inlet flow velocity, pipe diameter and water cut was fitted by using Origin software. The results showed that when the water cut and inlet velocity are constant, the maximum velocity in the curved pipe gradually decreases with the increase of pipe diameter. When the pipe diameter and inlet velocity are constant, the maximum velocity in the curved pipe decreases gradually with the increase of water cut also. The maximum pressure occurs at the external arch wall of curved pipe, and the minimum pressure occurs at the internal arch wall of curved pipe. In practical production, increasing the wall thickness of internal wall in the straight pipe at the downstream of curved pipe can effectively prevent the hazard caused by cavitation corrosion. The safety flow velocity can be determined by water cut, which can effectively reduce the risk of electrostatic accidents.