陆上大型LNG薄膜型储罐日蒸发损失定量解析模型OA

Objective Membrane-type liquefied natural gas(LNG)storage tanks offer significant advantages over conventional tanks,including higher volumetric efficiency,shorter construction periods,and lower carbon emissions.However,the thermal insulation design of membrane-type tanks in China still relies mainly on conservative calculations,often neglecting key factors such as the specific heat transfer characteristics of the structure and interfacial thermal contact resistance.This leads to overestimation of the daily boil-off rate(BOR)and increased cost.This study aims to propose a quantitative analytical model for the daily BOR that accounts for interfacial thermal contact resistance,using the world's largest onshore membrane-type LNG storage tank(240,000 m3)in eastern Guangdong as a case study.Method Based on Fourier's law,a layer-by-layer heat transfer analysis method was developed on accounting for the structural features of the sidewall,bottom,and roof,as well as the interfacial thermal contact resistance.Subsequently,the Greenwood-Williamson contact theory and the Gaussian distribution were introduced to analyze the solid-gas coupled heat transfer mechanism at the layered interfaces,thus quantifying the thermal contact resistance.Result The predicted daily BOR under extreme weather conditions in eastern Guangdong was 0.0442%,which was lower than the design target.With the design requirements met,optimizing the thickness of the bottom polyurethane foam was identified as the most cost-effective approach,achieving material saving up to 23.24%.Additionally,the surface roughness of the insulation material had a significant effect on thermal contact resistance,and selecting materials with a surface roughness of approximately 40 μm improved the thermal insulation performance.Conclusion This study provides theoretical support for the optimal design of membrane-type LNG storage tanks and offers important engineering guidance for balancing thermal insulation performance with cost-effectiveness.