浮式生产系统泄漏天然气扩散规律与危险区域

考虑到浮式生产系统(FPSO)作业过程中存在的油气泄漏及火灾、爆炸等连锁风险,为了科学评估FPSO天然气泄漏风险,基于计算流体动力学理论,采用通用CFD软件Fluent建立FPSO关键系统泄漏天然气的扩散行为预测与评估模型,分析、判断可燃气体运动特点及危险区域的分布规律。根据仿真结果和对比分析,研究了泄漏可燃气体的扩散过程、行为特点以及风向、风速和泄漏速率等关键因素对可燃气体扩散危险区域的影响规律,综合考虑仿真结果与相关标准的要求,合理确定FPSO上部模块的一级2区IIA组危险区。结合FPSO油气泄漏风险特点,从工程应用角度提出应对措施与建议。

Combustible gas diffusion law and hazardous area of FPSO

Given the high risk of FPSO operation subjected to oil & gas leakage and subsequent chain effects (e.g. fire and explosion), the paper is aimed to introduce our study on the diffusion behavior of flammable gas in leakage and corresponding hazardous area on FPSO. Concerning the actual operating parameters of the two important equipments respectively belong to crude oil treatment system and flare stack system, the gas leakage rate with different hole diameters was calculated as source term based on an appropriate leak source model. A CFD-based evaluation model which had been proved to be useful in predicting the diffusion behavior and distribution law of gas was developed, the diffusion characteristics of gas diffusion are summarized, and the influence of wind direction, wind velocity, and leakage rate on the gas diffusion behavior was analyzed in details with Fluent. Based on the hazardous area of gas and relative recommended standards, the hazardous location classified as Class I Zone 2 Group IIA on FPSO topside is divided. Finally some improvement recommendations for engineering application are proposed.