Study on the Influence of Offshore Elevated Flare on the Layout of LNG Terminal

Abstract

In order to save land, the elevated flare of the LNG terminal is usually considered to be arranged on the sea. The thermal radiation and leakage evaporation diffusion of elevated flare are the key issues to be considered in the plane layout of the wharf. In this paper, the physical process of the flare thermal radiation and the evaporation and diffusion of the terminal sump are analyzed by using engineering knowledge. Combined with the theory of thermal radiation and vapor diffusion and the actual project scenario, the corresponding mathematical model is given and applied to the engineering practice for a large number of calculations. The following conclusions are drawn: (1) The thermal radiation received by the LNG terminal is weakly related to the flare height, that is, the effect of increasing the flare height to control the thermal radiation at the header is not obvious; There is a linear positive correlation with the flare treatment capacity; It is strongly inversely proportional to the distance from the wharf to the flare. It is preferred to reduce the thermal radiation intensity at the wharf by adjusting the distance between the wharf and the flare. When the distance between the wharf and the flare is greater than 100m, the thermal radiation value of the wharf is always less than the specified limit. (2) Within the scope of conventional design, the safe distance between the wharf working platform and the flare is about 20∼90m; The optimal safe distance between the wharf fire control room, bridge approach pipe gallery and the flare should be greater than 61m and 41m respectively. (3) The combustible vapor concentration at the flare is linearly and positively correlated with the flare height, so the flare height should be reduced as much as possible during design. (4) The combustible vapor concentration at the flare is negatively correlated with the distance from the flare to the terminal sump. It is found that the distance should not be less than 180m through calculation. When the distance is more than 300m, the combustible vapor concentration at the flare has little relationship with the flare height and the ambient wind speed. When the distance is more than 340m, the combustible vapor concentration at the flare is always less than the specified limit.