Effect of the Shapes of Diversion Umbrellas on Temperature Field in a Large Spherical Tank During Heat Treatment Processes

Internal combustion method is widely used to reduce residual stress of large spherical tanks in China, when post weld heat treatment of the spherical tanks is required. During the heat treatment processes diversion umbrellas set in the spherical tanks can be utilized to drop the maximal difference of wall temperatures of the spherical tanks. Numerical simulation based on Fluent software was carried out to study the effect of an A-shaped diversion umbrella and three V-shaped diversion umbrellas with different angles on internal flow and wall temperatures of a 10000 m³ spherical tank. The results show that the V-shaped diversion umbrellas have better performance than the A-shaped one, but the angles of the V-shaped diversion umbrellas from 100° to 140° have little effect on maximum wall temperature differences of the spherical tank during the heat preservation stage of the heat treatment processes.