With respect to the security issue of storage tanks’ seal ring fire, by taking 10×104 m3 crude oil tank as the research object, using Visual C++ 6.0 programming software to calculate the model domain of seal ring fire and FLUENT programming software, the thermal radiation of burning storage tank was simulated, which could get the thermal radiation in different distance from the burning storage tank and the damage to people and devices in different thermal radiation. The results showed that the burning storage tank radiated heat equably to all around under the condition of breezeless and steady pool fire. With the distance from the burning storage tank increasing, the thermal radiation decreased. When the thermal radiation decreased from 37.5 kW/m2 decreasing to 12.5 kW/m2, the damage to people and devices greatly decreased. Without considering the influence of wind speed and the adjoining storage tanks’ spraying, the safe distance of adjoining storage tank was 35.5 m.

According to different damage process of natural gas pipeline leakage diffusion problems, using FLUENT software, CFD simulation model was established, and studied the different leak diameter of the effects on gas leakage diffusion area and simulated the natural gas leak and diffusion process between mountain and city terrain. The situation of wind speed changing along with the height and mass discharge rates variable with the time were taken into account and UDFs were programmed into the FLUENT to amend them. It concluded that the bigger hold can achieve the higher range, the max lower explosive limit of the high from the ground and downwind horizontal distances of diameter of 6.35 , 25.40 mm and 101.60 mm were 92 m and 322 m,122 m and 770 m, 408 m and 1291 m. When diffuses on the surface and in the soil, the 101.60 mm leak diameter had the maximum diffusion range. The biggest downwind horizontal distances were up to 80 m and 105 m respectively. This was because the gas lost a lot of turbulent energy influenced by the soil above the pipeline.