浮式液化天然气生产储卸装置重气泄漏扩散模拟分析

Simulation and Analysis of Dispersion of Heavy Gas Leakage from FLNG Installation

为了研究浮式液化天然气(FLNG)生产储卸装置的甲板上部区域储罐发生泄漏后的扩散后果,建立了FLNG装置甲板上部区域的泄漏扩散模型,并利用计算流体力学(CFD)技术对其进行了液化天然气(LNG)重气泄漏的扩散模拟,得到了扩散后的区域影响结果,模拟结果满足重气扩散过程的堆积理论和低压卷吸理论.结果表明:该模型和模拟方法能够在一定程度上反映LNG泄漏扩散的真实物理情况,当离生活区最远储罐的前表面发生泄漏后,其泄漏范围不会扩散到生活区,对生活区没有影响;而当位于FLNG中部附近的储罐前表面发生泄漏后,在动力区建筑物的影响下,生活区背风处会形成低压空腔区,且该区域的LNG浓度较高.

The dispersion model of the upper deck area of the floating liquefied natural gas （FLNG） production stor- age and offioading unit was established in order to study the dispersion consequences after the leakage of upper deck storage tanks. By using the computational fluid dynamics （CFD） technique, the heavy gas dispersion after the leakage of LNG was stimulated and the effects of heavy gas dispersion were studied. The simulated result was in good agree- ment with the theories of heavy gas accumulation and low pressure entrainment. The analysis of simulated results shows that the CFD model and the simulation method can reflect the real physical situation of LNG leakage and dis- persion to some extent. When the leakage occurs on the front surface of the storage tank farthest away from the living area, the LNG heavy gas cannot spread to the living area, so it has no impact on the living area; however, when the leakage occurs on the front surface of the storage tank located near the middle of the FLNQ under the influence of the buildings in the power supply area, a low-pressure cavity area will form on the leeward side of the living area, where there is higher LNG concentration.