Heat Transfer And Fatigue Study Of LNG Spherical Tank

With the structure regulating of energy sources and more attention paying to environment protection,the using of nature gas is increasing.contrast with gas,the volume of the liguefied natural gas(LNG)is only its 1/625.So it's better for remote transportation,reclaim and peak shaving in application.There are lots of advantages with the spherical tank compare with other ones.Withimproving of manufacture technics,Now spherical tank has used in shipping storageand soon.Warm keeping is one of important aspect for LNG storage.For large-scale LNG tank,Hydronitrogen(N₂)is used extensively in insulating layer at present.For its high cost and complicated manufacture technics,the BOG(boil off gas)is used for substitute. which is better by heat transfer process analysis,model establishing and heat leakage and evaporation rate calculation.comparing to N₂,It's obvious for simpler technics and lower cost.Equator tangent pillar supporting is used extensively for connection between spherical tank and its sphere.Which could induce high local stress at low-water mark"a" in connection part.In which two-oriented stress condition combining shearing and latitudinal stress is established by simplified analysis according to state standard.The manner mentioned above is not accurate enough.Because the affection of loads is ill-considered induced by wind.earthquake and so on.To solve this problem,finite element modeling is used.As an important aspect of design by analysis,analysis of fatigue is used here by the date come from finite element analysis.Contrast with the conclusion caculated by state stardard,the stress and strain analysis for the spherical pressure vessele is more precise.