기관사고 예방을 위한 선박 냉각수 계통 부식 관리의 중요성: 해양사고 재결서 분석과 실험적 검증 = Importance of Corrosion Management in Marine Engine Cooling Water Systems for the Prevention of Engine-Related Accidents: Analysis of Maritime Accident Written Verdicts and Experimental Verification

다국어 초록 (Multilingual Abstract)

This study examines corrosion behavior in marine engine cooling water systems (CWS) with focus on maritime accident prevention. Key causes of cooling system related incidents were identified through the analysis of maritime accident written verdicts, and the influence of corrosion inhibitor concentration on corrosion was experimentally evaluated. A total of 950 written verdicts from the Korea Marine Safety Tribunal were analyzed using text mining and a large language model. The results indicated that CWS related incidents accounted for the highest proportion of engine incidents, with the primary causes identified as human errors such as poor maintenance and inadequate inspection. Based on this, the effect of dosing a corrosion inhibitor and controlling its concentration, a key factor in cooling water management, was evaluated for spheroidal graphite cast iron (FCD-500). A nitrite-based inhibitor was applied at concentrations ranging from 0 to 19,000 ppm, and corrosion characteristics were evaluated through immersion tests and electrochemical techniques. At the recommended concentration of 13,000 ppm, both uniform and localized corrosion were effectively suppressed, whereas in the low-concentration range of 3,000–7,000 ppm, localized corrosion increased the risk of equipment damage.