油气泄漏火灾下FPSO热-结构耦合分析

针对FPSO油气泄漏引发的火灾风险,建立热-结构耦合分析模型,采用ANSYS Workbench软件对工艺区设备泄漏、火灾事故及灾害下结构响应进行数值模拟,重点分析工艺处理模块Ⅰ区设备温度分布及热变形情况。通过对比不同油气泄漏速率和环境风速下火灾发展、危害范围和结构受损程度,探讨油气泄漏孔孔径和风速对火灾后果的影响。结果表明:稳定发展火灾下工艺处理模块Ⅰ区设备周围环境维持高温状态;泄漏孔附近结构受损最严重,原油热处理器受火灾损害发生大的变形;随泄漏孔孔径增大,火灾危害范围扩大,结构发生大变形的区域增大,d=40 mm时原油热处理器受损最严重,d=60mm时结构受损区域最大,大部分结构受损程度加剧;来风风速的变大使得火灾更加剧烈,设备受损区域扩大,受损程度加剧,结构火灾风险加大。

Thermal-structure coupling analysis of FPSO under the fire accident caused by the oil-gas leakage

Given the hazardous nature of FPSO to be caused by the oil & gas leakage,the paper is aimed to introduce its study on the structural response of FPSO equipment and installation in case of a fire accident.In hoping to grasp the regularity of the fire spreading,we have established a model for predicting and assessing the consequence of such a fire by joining the CFD software Fluent with the Workbench as a software.By using the aforementioned thermal-structure coupling model,we have emphatically analyzed the thermal deformation of the equipment and facilities through Module Direct Ⅰ and compared the impacts that the gas leakage hole and the wind velocity to push the fire spreading,in addition to studying the range of the damaged equipment and deformed degree of the structure.And,therefore,the simulation resuits show that it won't take a few seconds for the fire to spread over most of the areas topside of the main deck of FPSO.And,later,it can be found that the main influential areas of the burning are mainly located at the crude oil thermal theater,the electric desalter and the sea water cooler.What is more,the high-temperature fire tends to being severe damage to the material properties,such as the steel and equipment with its continuous exposure to other things.And,then,the crude oil thermal processor will be subjected to the most serious damage while going to generate large plastic deformation and rigid displacement.What is more,the bigger the leakage aperture is,the more equipment and facilities tend to get inflamed with the gas cloud covering.Furthermore,the more the oil & gas leaks,the greater the equivalent stress,and the more serious the displacement as well as the plastic deformation of the structure in the same area.And,simultaneously,the broader the regional distribution with the large stress and displacement has become,the greater the damage of the equipment concerned would be.For example,when the leakage aperture is 40 mm,the crude oil thermal processor may suffer the most serious damage.While the fire is over 60 mm,the worst damage it is likely to be involved with.As the wind speed increases,the fire intensity and the spreading range will be going up to the totally destructible severity.Thus,it can be seen that the present study is expected to be helpful in assessing the hazardous degree of the fire incident to be caused by the oil & gas leakage on FPSO,which is of great value in the science research and engineering practice.