US Patent 9752728 Cryogenic tank assembly

A cryogenic tank assembly includes a cryogenic tank having an internal volume that is configured to contain liquefied natural gas (LNG). The cryogenic tank includes an inlet and an outlet that are each fluidly connected to the internal volume. The assembly includes a recirculation conduit coupled in fluid communication between the inlet and the outlet. The recirculation conduit extends along a path between the inlet and outlet external to the internal volume of the cryogenic tank such that the path is configured to be exposed to an ambient environment of the cryogenic tank. The recirculation conduit is configured to: receive a flow of LNG from the internal volume through the outlet; transfer heat from the ambient environment to the LNG flow to change the LNG flow to a flow of natural gas; and inject the natural gas flow into the internal volume of the cryogenic tank through the inlet.