The Evolution Of Liquid Ammonia Leakage And Its Impacts On Area Of Refugee

Based on the frequent occurrence of liquid ammonia leakage inside factory,it will evolve into a person poisoning、fire、 explosion accident.This paper focus on the liquid ammonia cylinder in Shanghai pharmaceutical co.,LTD.,as the main research object,simulate and calculate 5 possible types of accident after liquid ammonia leakage of accident by ALOHA,analyze the influence factors and law of each accident.According to the type of accident and laws,to find out the critical condition of the emergency set point and the nearest safety point under th most unfavorable situations,which has a practical guiding significance in liquid ammonia leakage accident in factory.This paper compares and analysises the 5 types of accidents liquid after liquid ammonia leakage occurred,including proliferation of the poisoning,flash fire,jet fire and vapor cloud explosion and boiling liquid expanding vapor explosion,compares the ammonia diffusion AEGLs area,fire thermal radiation region,explosion shock wave area,and the change of the ammonia concentration at various points,the change of the fire thermal radiation.It is concluded that under the same conditions,the diffusion poisoning accident after liquid ammonia leakage has the largest influence range,the BLEVE accident influence area is the second,the region of spray fiery radiation,the potential area of flash fire and the threat zone of vapor cloud explosion are relatively small.Liquid ammonia leakage and diffusion range,flashover occurred areas and steam cloud explosion threat area will increase with the increase of atmospheric stability,the decrease of wind speed,the increase of temperature,the increase of leakage aperture,the decrease of leakage hole height,the increase of liquid ammonia storage.The effects of atmospheric stability,wind speed,wind direction,leakage aperture,leakage hole height and liquid ammonia storage on the diffusion range are obvious,while the temperature has little effect on the diffusion range.The area of jet fire heat radiation will increase with the increase of temperature,the increase of leakage aperture,the increase of mass,and the wind speed and direction affect the position of the heat radiation area of the jet fire,which has almost no effect on the size of the area.The boiling liquid expands to steam The area affected by an explosion increases with increasing storage.After simulation calculation,it is concluded that when the wind direction is SE/NW and the specific building conditions of the plant are not considered,it is found that if meet one of the conditions: wind speed is greater than or equal to 4.0m/s,leakage aperture is less than or equal to 0.20 cm,storage is less than or equal to 10 kg,the emergency combination point will be in a safe range.By selecting the most unfavorable conditions,the nearest safety position of the emergency rendezvous will be at 115 meters north of the doorman on the highway.