Abstract: A method of operating a fuel system is provided. The method includes removing fuel from at least a portion of the fuel system using a gravity drain process. The method also includes channeling nitrogen into at least a portion of the fuel system to facilitate removing air and residual fuel from at least a portion of the fuel system, thereby mitigating a formation of carbonaceous precipitate particulates. The method further includes removing air and nitrogen from at least a portion of the fuel system during a fuel refilling process using a venting process such that at least a portion of the fuel system is substantially refilled with fuel and substantially evacuated of air and nitrogen. The method also includes removing air from at least a portion of the refilled fuel system using a venting process. The method further includes recirculating fuel within at least a portion of the fuel system, thereby removing heat from at least a portion of the fuel system and facilitating a transfer of operating fuel modes.

Abstract: A recirculation system for circulating distillate during gas fuel operation so as to reduce or eliminate distillate carbon formation. The recirculation system keeps the distillate's temperature below the carbon formation limit by circulating the distillate back to a storage tank to cool the distillate due to a volume of the storage tank compared to the volume of the recirculation system. The recirculating flow also exercises the flow dividers' gears without having to perform fuel transfers. Further, the system evacuates air from the liquid fuel lines to further decrease the likelihood of carbonaceous residue forming on any interior surfaces that are actually exposed to distillate.