저온 LCO2 저장탱크의 열-구조해석을 통한 안전성 평가와 최적설계에 관한 연구

Abstract

This study evaluates the structural safety of low-temperature liquefied carbon dioxide(LCO₂) storage tanks and proposes optimal design solutions. As a critical component of carbon capture, utilization, and storage(CCUS) technology aimed at reducing greenhouse gas emissions, LCO₂ requires robust and reliable storage and transportation solutions. This research focuses on Type-C independent storage tanks, as defined by the International Maritime Organization(IMO), analyzing the combined effects of thermal and mechanical loads through a thermal-structural coupled analysis. Using the finite element analysis(FEA) tool ANSYS, thermal and structural analyses were conducted under conditions of an internal temperature of -50°C and a design pressure of 19 bar. The study identified significant thermal stress and stress concentrations in critical areas, including the inner tank and brackets. To address these vulnerabilities, several design modifications were proposed, including adjustments to the diameters of the brackets and GRP, aimed at minimizing heat ingress and enhancing structural stability. The results demonstrated that the optimized design maintained structural integrity under low-temperature and high-pressure conditions, meeting the allowable stress criteria specified in the IGC Code. Among the proposed modifications, the optimized design(Model B) effectively reduced equivalent stress in the brackets, mitigated heat ingress, and ensured mechanical stability. This study provides a quantitative evaluation of the thermal-structural interactions in LCO₂ storage tank design and offers practical optimization strategies to improve both structural safety and thermal performance. These findings contribute to advancements in CCUS technology and low-temperature storage systems and have potential applicability to other low-temperature storage tanks, such as LNG tanks. The results serve as a foundational guideline for designing and evaluating storage tanks operating under high-pressure and low-temperature conditions.