A Signed Digraphs Based Method for Detecting Inherently Unsafe Factors of Chemical Process at Conceptual Design Stage

• Published in: Chinese journal of chemical engineering Vol. 16; no. 1; pp. 52 - 56
• Main Author: 王杭州 陈丙珍 何小荣 邱彤 章龙江
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2008
• Subjects: conceptual design; inherent safety; SDG图; signed digraphs; 初步设计方案; 化工过程; 错误侦破方法; conceptual design; signed digraphs; inherent safety
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(08)60036-1

Digraph-based causal models have been widely used to model the cause and effect behavior of process systems. Signed digraphs （SDG） capture the direction of the effect. It should be mentioned that there are loops in SDG generated from chemical process. From the point of the inherent operability, the worst unsafe factor is the SDG having positive loops that means any disturbance occurring within the loop will propagate through the nodes one by one and are amplified gradually, so the system may lose control, which may lead to an accident. So finding the positive loops in a SDG and treating these unsafe factors in a proper manner can improve the inherent safety of a chemical process. This article proposed a method that can detect the above-mentioned unsafe factors in the proc- ess conceptual design stage automatically through the analysis of the SDG generated from the chemical process. A case study is illustrated to show the working of the algorithm, and then a complicated case from industry is studied to depict the effectiveness of the proposed algorithm.