Safety analysis of diesel hydrogenation unit based on a semi-quantitative risk assessment method

HAZOP analysis as a qualitative method can better identify the potential risks in the early design stage and in-service stage of the device. However, it is greatly influenced by the subjective factors of the appraisers during the assessment, which has a great impact on the accuracy and effectiveness of the risk assessment results. A semi quantitative compound risk assessment method (HALOPA method) is used to study the possible problems in the process flow and safety protection system of typical domestic diesel hydrogenation units. Taking the failure scenario of deoxygenated water pump as an example, the protective layer analysis method (HALOPA analysis) is adopted. On the basis of calculating the frequency of failure scenario and considering the acceptable risk standards of enterprises, the suggestions for improving the current independent safety protection layer and its safety integrity level (SIL) are put forward. The analysis results show that there are some shortcomings in existing process control, interlock protection, alarm setting and other protection measures of diesel hydro fining unit. The composite risk assessment method (HALOPA method) is of positive significance for effectively discovering and eliminating potential safety hazards in the operation process of the unit and ensuring safety in production.