Chemical Industrial Park Accident Risk Assessment Method and Its Application
Author:Hu Zuo Sheng
Supervisor:wu zong zhi
In recent years,a large number of chemical industry parks have been built in China with a rapid trend,which achieves a rational allocation of resources and promotes the sustainable development of the chemical industry.However,the issues related to the unreasonable layout and the inadequate risk control measures put potential pressures on the development of chemical industry parks.There exist various kinds of hazards in chemical industry parks,which would lead to accidents with severe consequences if they cannot be effectively controlled.In order to ensure chemical industry parks could operate safely and extraordinary accidents could be prevented effectively,it is essential to assess the risks faced by chemical industry parks and take specific control measures in advance.Therefore,the studies focusing on risk assessment methods for chemical industry parks have practical significance,which could provide theoretical guidance for accident prevention in chemical industry parks.Firstly,this paper first analyzes the risk characteristics of the chemical industry based on historical chemical engineering accident data and typical accident cases and then classifies 3 accident risk assessment units of chemical industry park and 12 risk assessment objects.On this basis,the risk assessment methods applicable to the three risk assessment units and the chemical industry park are studied.Then ArcGIS software is used to realize the risk visualization of different units and whole parks.Finally,chemical industry parks in a certain city is selected to verify the above methods.The main research contents and specific conclusions are as follows:(1)Based on the data analysis of chemical accidents and the case study of typical accident,three risk assessment units in the chemical industry park including the chemical production unit,the personnel-intensive site unit,and the oil and gas facilities units have been classified.The chemical production unit contains enterprises involved in hazardous chemicals production,storage,and usage and enterprises whose processes involved in ammonia or chlorine;the personnel-intensive site unit contains offices buildings,staff dormitories,and canteens;the oil and gas facilities unit contains oil and gas pipelines,gas stations,and gasoline stations.The analysis results of the number and fatalities of chemical accidents between 2011 to 2015 indicate that: 1)in the context that the gross output value of petrochemical industry is increasing yearly,the number and fatalities of chemical accidents are decreasing;2)accidents frequently occur in seasons with high and low temperature,and in places along the southeast coast;3)poisoning and asphyxia,explosion,and falling accidents are the most common accident types in chemical enterprises,and accidents occur frequently in enterprises involved in the chemical raw material industry,the coal chemical industry,and the fine chemistry industry;4)the unreasonable layout,the inadequate financial input,and the belated emergency response are the common causes of chemical accidents.(2)A multilevel flow modelling(MFM)method for calculating the initiating events frequency is proposed for chemical production unit;a fire risk assessment method that combines the probability and severity of fire is proposed for personnel-intensive site unit;research on injury patterns of accident consequences,calculation models,and injury criteria for oil pipelines and natural gas pipelines for oil and gas facility unit.The individual,societal risk acceptance criteria in U.K.,U.S.,the Netherlands,and China are compared and analysed.Divide the risk grades of chemical production unit,as well as oil and gas facility unit according to China’s individual risk acceptance criteria;according to the situation of building fire protection facilities,a risk grading method for personnel-intensive site unit is proposed.(3)Based on the establishment of the overall risk assessment process for the chemical industry park,the overall risk assessment method for the chemical park is constructed,and the accident risk assessment software for the chemical industry park is developed.Chemical industry park accident risk assessment method based on potential life loss and AHP-based fuzzy comprehensive chemical industry park accident risk assessment method are developed to calculate the overall risk value and risk ranking value for the chemical industry park,respectively.The PLL risk assessment method selects the potential life loss as the overall risk quantification index of the chemical industry park.Through the individual risks of the three risk assessment units,the potential life loss of each unit is obtained,and then the overall risk value of chemical industry park is obtained.The AHP fuzzy comprehensive risk assessment method first establishes a chemical industry park accident risk assessment index system based on the three risk assessment units and the risk assessment objects they include,and then uses the analytic hierarchy process to obtain the weight values of the index system.Finally,the risk rankings of different assessment objects are calculated based on the risk grades of the three risk assessment units,and their contribution to the risk of major accidents in the chemical industry park is analyzed.(4)A GIS risk map for the chemical industry park is established to visualize the risk calculation results of the above unit risk assessment and overall risk assessment.ArcGIS software is used to establish three layers of chemical industry park accident risk maps in points,lines,and planes,which correspond to the risks of companies,risk assessment units,and chemical industry park.The overall structure of the risk map,the evaluation unit identification,the risk level identification,and the layer information list are designed,and layer overlays with different risk assessment units and different risk levels were implemented.Combining the company’s spatial geographic information and risk information,intuitively presents the basic situation of the company’s geographical location,coordinates,risk level,and name.(5)Case application study.Seven chemical industry parks of different district in City A is selected to verify the chemical industry park accident risk assessment method.The results show that the method of chemical industry park accident risk assessment proposed in this paper can realize the risk assessment of typical facilities and personnel-intensive site in the park,and provide the technical basis for accident prevention in the chemical industry park.The innovation points are:(1)a multilevel flow modelling(MFM)method for calculating the initiating events frequency is proposed;(2)a chemical industry park risk value assessment method based on potential life loss is proposed;(3)a AHP-based fuzzy comprehensive chemical industry park risk ranking assessment method are proposed.