Flare gas utilization in a cogeneration plant is an attractive proposition considering its environmental and economic incentives. Evaluation of the operational risk of integrating flare gas with cogeneration is complex due to the uncertainty in flare gas quality and process conditions. The current study delves into the change in operational risk after modifying the existing cogeneration process with the addition of fuel from flare gas. Based on the process hazards evaluation, the current study identified two critical loss control events (or top events) - boiler gas temperature exceeding operating design temperature and rich fuel mixture in the boiler firebox. The underlying causes that may contribute and lead to these loss control events were identified using fault trees and were updated to the existing cogeneration scenarios. Similarly, different consequential events that may arise from the loss control events were analysed using event trees with existing system safeguards. A Bayesian network model with its explanatory power mapped all the identified dangerous scenarios from the fault trees and event trees to predict integrated systems reliability and diagnose causal factors. Bayesian Network analysis illustrates the dynamic cause-effect relationship and determines the risk escalation due to the changes in the composition of flare gas that is fed to the boiler. The presence of a higher percentage of hydrogen (above 40 mol%) in the flare gas escalates the risk of lean air to fuel ratio in the boiler firebox and increases boiler radiation zone duty. These conditions are detrimental to the boiler firebox operation and can result in critical scenarios such as flame impingement and tube rupture. Additionally, other consequences-a steam explosion and boiler stack explosion were also investigated. However, their probability of occurrence was relatively insignificant with the given frequency of flare gas utilization in the cogeneration system.

考虑到其环境和经济激励措施，在热电联产厂中利用火炬气是一个有吸引力的提议。由于火炬气质量和工艺条件的不确定性，火炬气与热电联产整合的操作风险评估很复杂。目前的研究深入探讨了在通过添加火炬气燃料修改现有热电联产工艺后运营风险的变化。基于过程危害评估，当前的研究确定了两个关键的损失控制事件（或顶部事件）——锅炉燃气温度超过运行设计温度和锅炉火箱中的燃料混合物丰富。使用故障树确定可能导致和导致这些损失控制事件的根本原因，并更新到现有的热电联产方案。相似地，使用事件树和现有系统保护措施分析了可能由损失控制事件引起的不同后果事件。具有解释力的贝叶斯网络模型从故障树和事件树中映射了所有已识别的危险场景，以预测集成系统的可靠性并诊断因果因素。贝叶斯网络分析说明了动态因果关系，并确定了由于供给锅炉的火炬气成分变化而导致的风险升级。火炬气中存在更高百分比的氢气（高于 40 mol%）会增加锅炉火箱中空燃比稀薄的风险，并增加锅炉辐射区的负荷。这些条件不利于锅炉火箱运行，并可能导致火焰冲击和管道破裂等关键情况。此外，还调查了其他后果——蒸汽爆炸和锅炉烟囱爆炸。然而，在热电联产系统中火炬气使用频率给定的情况下，它们的发生概率相对较小。