Risk Analysis For Hydrocracking Cooler

Petrochemical industry is one of the most dangerous industries in modern manufacturing industry. As everyone know, hazards, such as fire, explosion, toxicity and so on, always lie in petrochemical industry potentially, which would cause accidents under certain conditions and even bring the loss of life and public property. So it is important and necessary to perform risk assessment for petrochemical equipment and to find weak points, which can be benefit for ensuring safety of equipment, reducing maintenance cost and prompting competition power of companies etc.The object in this paper is the reactor effluent trim cooler in high pressure hydrocracking unit. The corrosive mediums, which are contained in naphtha in tube side, such as the hydrogen sulfide(H2S), ammonia(NH3) and so forth, are easily to cause corrosion of the cooler for long-term service. According to the service condition and regular inspection, risk assessment for the cooler was executed. Furthermore, corresponding risk acceptable level was defined based on current practical situation of society and companies.Main research contents and conclusions are as follows:(1)The technique—qualitative, semi-quantitative and quantitative analysis methods of API 581 recommended by American Petroleum Institute, has been used for risk assessment of cooler, which includes calculating failure likelihood and failure consequence and determining risk value. The results show that the risk for tube side of the cooler is of middle-high risk, while low risk is assigned to shell side. In addition, the comparison between above-mentioned three methods has also been performed. Less information is needed and also the analysis process is relatively less precise and detailed in risk assessment by qualitative risk analysis method. Compared with the other two methods, the quantitative method is the most reasonable for the procedure is the relatively detailed and consequences considered is relatively comprehensive; Semi-quantitative method, which is between other two methods, can...