基于DBT-DBN模型的气化炉超温动态风险分析

Dynamic risk analysis of gasifier overtemperature scenario based on DBT-DBN

为加强煤气化装置核心设备气化炉的安全风险管理,利用动态领结(DBT)模型和动态贝叶斯网络(DBN)相结合的风险分析方法,构建气化炉超温事故风险分析模型。首先,分析设备故障的时序性,建立超温事故的DBT模型,结合模糊评价确定设备故障的发生概率;然后,将DBT映射到DBN中,将故障维修的动态特征定义为转移概率,双向推理气化炉超温的风险因素;最后,预测气化炉发生超温及其后果的动态趋势,并依据诊断推理辨识导致气化炉超温的主要因素。研究结果表明:在考虑维修因素下气化炉运行一年后发生超温的概率为64.4%;气化炉超温的风险因素中,操作失误在生产周期内的影响较大,设备故障集中在磨煤制浆工段。

In order to strengthen safety risk management of gasifier in coal gasification units,a dynamic risk analysis approach based on DBT and DBN was applied to construct an analysis model of gasifiers’ overtemperature risks. Firstly,DBT model was established by analyzing sequential dependency of failure events,and their probability was determined considering fuzzy evaluation. Then,DBT model was mapped into DBN,linguistic variables were converted into prior probabilities,and risk factors were obtained through bidirectional reasoning. Finally,dynamic risk trend of gasifier overtemperature and consequences was predicted,and critical factors were identified by diagnosis reasoning. The results show that probability of gasifier overtemperature is about 64. 4% after one year with maintenance factor taken into consideration.Among all key factors,operation error in production cycle has a greater impact,and equipment faults mainly occur in coal grinding and pulping section.