修正的ISI法及其应用

Modified ISI and its application

针对本质安全指标(ISI)灵敏性不强,指标区间不连续,评价方式较片面等缺点,对ISI的指标取值方法和评价模式进行了修正。通过建立指标区间函数,提高了指标的灵敏性,实现了指标区间的连续化;根据事故演变情形,提出了改良的评价模式,并增加了危害指标、诱变指标和事故指标,分别反映过程潜在的危害因素、诱变因素和事故情形;分别用ISI和ISIM对EDC过程实例的2个路径,即直接氯化法和氧氯化法,进行了评价和比较,ISI的评价结果分别为29和32,MISI评价结果中,危害指标分别为1232.4和1745.8,诱因指标分别为5.83和7.45,事故指标分别为277.1和751.1,表明MISI法的评价结果更加符合实际过程信息,同时从危害、诱变和事故3个方面反映过程的安全特征。

Aimed to overcome the disadvantages of ISI（Inherent Safety Index） method,which are inferior sensitivity,discontinuous index intervals, unilateral evaluating mode,it is modified that index calculating and evaluating mode of ISI.By establishing function for index intervals,sensitivity of index is improved,realizing the continuity of index intervals simultaneously.According to the scenario of accident developing,a modified evaluating mode is provided,also proposing the hazard index,induction index,and accident index,which show respectively the potential hazards,inducement, and accident scenario of process.Through the evaluation and comparison of two different EDC processes,i.e.direct chlorination and oxychlorination, the result of ISI for each process is 29 and 32,yet for MISI,the value of hazard index is 1232.4 and 1745.8,the value of induction index is 5.83 and 7.45,the value of accident index is 277.1和751.1,which showed that the evaluating results of MISI（Modified Inherent Safety Index） accord to the process information much more,and reflect the safety characteristic of process in three aspects i.e.hazard,induction and accident.