Methodology and case study of quantitative preliminary hazard analysis based on cloud model

Preliminary hazard analysis (PHA) is an effective method to identify and evaluate hazards in a system. Then, prevention measures can be set according to assessment results. However, assessment results may not be detailed and reasonable enough due to the qualitative assessment by PHA. This paper proposes a quantitative PHA called cloud model-preliminary hazard analysis (CM-PHA). The cloud model (CM) is utilized to improve PHA. The cloud model-hazard grade (CM-HG) is proposed to classify hazards, and the algorithm of CM-HG is established. Then, steps to conduct quantitative assessments of hazards are provided. The process of CM-PHA to obtain the CM-PHA diagram is worked out accordingly. A case study of hazards in the biomass gasification station is developed based on CM-PHA. A qualitative PHA is introduced and compared with the proposed method. Comparison results show that the assessment results obtained by CM-PHA are more detailed and precise, and corresponding prevention measures for hazards are more reasonable.