US Patent 11161622 Fuel oxygen reduction unit

An engine includes a combustion section and a fuel delivery system in fluid communication with the combustion section for providing fuel to the combustion section. The fuel delivery system includes a fuel oxygen reduction unit defining a circulation gas flowpath. The fuel oxygen reduction unit includes a gas oxygen reduction unit positioned in the circulation gas flowpath for reducing an oxygen content of a flow of stripping gas through the circulation gas flowpath and a pre-heater positioned in thermal communication with the circulation gas flowpath upstream of the gas oxygen reduction unit.