Process Hazard Analysis Of Diesel Hydrogenation Unit Based On HALOPA Method And SIL Rating Of Safety Protection System

Since entering the 21 st century,economy has developed further well in China,among them,the petrochemical industry,as one of the country’s pillar industries,is also facing production hazards while creating substantial benefits for the country.Most of the production processes in the petrochemical industry have risks such as high temperature,high pressure,flammability,explosiveness,poisoning,and corrosion.If an accident occurs,the consequences will be more serious and will cause a lot of losses.Therefore,certain protective measures should be taken to ensure safe production.This paper will take the diesel hydrogenation unit of a petrochemical company in Liaoning as the research object,aiming at the possible problems of the process and its safety protection system,based on the hazard and operability analysis(HAZOP analysis)to carry out the process hazard analysis,and give it according to the risk level Related recommended measures.A total of 23 nodes were analyzed and 122 suggestions for improvement were put forward.At the same time,the protection layer analysis method(LOPA analysis)is used to calculate the occurrence frequency of failure scenarios.In order to solve the problems in the multi-scenario protection layer analysis(LOPA)analysis,the risk vector map is established to integrate the accident scene and the independent protection layer.Systematic analysis of factors such as the frequency of occurrence of accidents,correction factors,and accident consequences,respectively,using the maximum method and the sum method to calculate the frequency of consequences,discussing the optimal calculation method for the frequency of accidents caused by multiple initial events;explaining the ignition source,exposure factor and lethality Probability and other correction factors are used and suggestions for improvement are put forward to avoid the problem of excessively high probability of death under conventional LOPA analysis.After completing the HAZOP and LOPA analysis,the safety integrity level(SIL)of the newly added protection layer device is rated,and the residual risk after the improvement is determined.The analysis results show that the existing process control,interlock protection,alarm settings and other protective measures of the diesel hydrofining unit analyzed in this analysis have certain shortcomings.The correct use of risk vector maps and correction factors can effectively improve the analysis quality of LOPA;different If the scene failure frequency value caused by the initial event is very different or there is a shared protection layer,the maximum value method can be used,and the sum method can be used in other cases;if multiple scenes simultaneously apply the maximum value method and the legal value,the comprehensive calculation method is used;The summation method is too conservative,the maximum value method is too optimistic,and the comprehensive calculation method is more accurate.The compound risk assessment method(HALOPA method)given in this article is of positive significance for effectively discovering and eliminating safety hazards during the operation of the device and ensuring safe production.