Fuel oxygen reduction unit control system

A method of operating a fuel oxygen reduction unit for a vehicle or a gas turbine engine of the vehicle,

• the fuel oxygen reduction unit comprising a catalyst, a contactor, and a fuel gas separator,
• and further defining a stripping gas flowpath in flow communication with the catalyst, a stripping gas inlet of the contactor, and a stripping gas outlet of the fuel gas separator,
• the method comprising:
• receiving data indicative of a parameter of a stripping gas flow through the stripping gas flowpath or of a component in flow communication with the stripping gas flow through the stripping gas flowpath;
• and
• determining an operability condition of the fuel oxygen reduction unit based on the data received indicative of the parameter of the stripping gas flow,
• wherein the operability condition is defined as an operational efficiency of the fuel oxygen reduction unit,
• wherein the receiving data indicative of the parameter of the stripping gas flow comprises receiving a first set of data indicative of the parameter at a first location along the stripping gas flowpath and receiving a second set of data indicative of the parameter at a second location along the stripping gas flowpath,
• wherein the first location is upstream of the catalyst, and
• wherein the second location is downstream of the catalyst.