| As the crude oil around the world keeps being drilled,the quantity of high quality and light oil is becoming less and less.Meanwhile,the exploitation and import quantity of heavy oil is increasing,which is the inevitable choice to fulfill the energy demand and lower the cost.Especially,the proportion of high sulfur crude oil processing is becoming larger in the oil processing industry of China.In order to face the challenge result from the variation of crude oil quality,the risk of more and more sulfur and sulfide must be seriously considered.Hydrogen sulfide generated during oil processing is the primary risk and threatening the life of workers in refinery enterprise.To prevent and control hydrogen sulfide poisoning event during heavy oil processing,research has been done in this paper as followed:（1）Based on Computational Fluid Dynamics,DNV Flacs software is chosen to establish a large-size ideal simulation scenario.Hydrogen sulfide diffusion is simulated in different parameters,such as leak hole size,leak height,leak direction and wind speed,to analyze the impact of these parameters on diffusion range,diffusion speed and concentration distribution.Simulation parameters are determined combining the unit manual and local weather conditions.Based on simulation results,the most dangerous scenario is determined.（2）Domestic and overseas laws and regulations concerning toxic gas detection setting are introduced by details.Small-size simulation scenario is established to research on the initial stage of hydrogen sulfide diffusion so as to determine when and where toxic gas cloud firstly falling down on the ground.Leak height and leak direction are main factors,which are considered to analyze the height and horizontal distance of toxic gas detector in different scenario.According to optimization results,advice is given to current laws and regulations.（3）Based on information from Google Earth and plane graph,3D simulation scenario of refinery plant is built by Flacs software to simulate hydrogen sulfide diffusion in the real plant.Dynamic and static methods are combined to study the severity of hydrogen sulfide leak accident in different wind speeds and leak directions.In concentration field,concentration of H2S is analyzed in different locations and times to describe the instant poisoning risk of H2S leak accident.In dosage field,worker death rates around different buildings and units are studied to describe cumulative poisoning risk of H2S leak accident,especially densely populated area. |
