摘要
電石乙炔製程在國內外氣體業界曾發生多起火災爆炸事故，造成人員傷亡及設備不同程度之損傷。國內電石乙炔廠計有八家，為避免重蹈覆轍，本研究利用危害與可操作分析（Hazard and Operability Studies, HAZOP）及失誤樹分析（Fault Tree Analysis, FTA）風險分析技術，以國內某乙炔廠之電石乙炔製程為分析對象，系統化找出潛在危害因子，並分析出其可能發生原因與機率，提升電石乙炔廠設備運轉及人員操作面之安全性，以供緊急應變時救災參考。鑒於台灣電石乙炔廠事故統計數據不足，且其製程設備與日本相近，因此本研究事故統計數據主要引用日本關東乙炔工業株式會社發行之「溶解乙炔之安全」，針對1946年至2002年間日本溶解乙炔製造工廠發生之事故之統計數據。失誤樹分析（FTA）採用國內核能所開發之故障樹分析套裝軟體INERFT。結果發現，HAZOP分析後未發現有高危害等級(1或2)的潛在危害，顯示製程相關安全措施於設計之初均已詳加考慮。FTA結果顯示，失誤率超過可接受風險標準值1.0E-006(次/年)之重要失效組合為(1)氮氣噴熄火花故障與投入電石撞及金屬為5.240E-005(次/年）；(2)人員未依安全作業標準程序定時測定純度與洗淨器W故障無法淨化為2.120E-005(次/年）。
關鍵字：乙炔、電石乙炔、危害與可操作分析 (HAZOP)、失誤樹分析 (FTA)
ABSTRACT
Fire and explosion occurred at acetylene gas processing factories are often reported. There are eight calcium carbide based acetylene plants in Taiwan. To avoid occurring accidents to these plants, we applied Hazard and Operability Study ( HAZOP) and Fault Tree Analysis (FTA) to systematically identify hazard sources and assess the associating risks. The assessed results will be used as a reference for their emergency and response training. Since the processing equipments at these plants are similar to those in Japan and the data about the accidents in acetylene plants in Taiwan are insufficient for this FTA study, we utilized the statistical data from the “Safety Manual for Dissolved Acetylene” which covered the accidents occurred between 1946 and 2002 in Japan. A FTA program developed by Institute of Nuclear Energy Research Taiwan has been used to calculate the probability of accidents.
The results in this study showed that no high hazard rating of 1 or 2 were found by HAZOP, possibly due to the adoption of proper safety measures at the process design stage. FTA results showed the failure frequency of combination of the breakdown of the nitrogen spurt and calcium carbide hit the metal wall when it added in is 5.240E-005 and the failure frequency of combination of people failed to follow the Standard Operation Procedure (SOP) to measure the purity of calcium carbide and the breakdown of scrubber is 2.120E-005.
Keywords: Calcium carbide; Acetylene; Hazard and Operability Study (HAZOP);Fault Tree Analysis ( FTA)
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