Cryogenic assisted bottoming cycle

A gas turbine engine comprising:

• a top cycle and a bottoming cycle;
• said top cycle including a top compressor having an associated shaft, and a top turbine driving the associated shaft to in turn drive the top compressor, a combustor positioned intermediate the top compressor and the top turbine, and the combustor receiving compressed air from the top compressor and receiving a fuel, the combustor being capable of igniting a mix of the fuel and the compressed air, and passing products of combustion downstream over the top turbine to drive the top turbine and the associated shaft, the products of combustion passing downstream of the top turbine through a first heat exchanger, and then to an exhaust nozzle;
• the bottoming cycle having a bottoming compressor and a bottoming turbine, the first heat exchanger exchanging heat between the products of combustion downstream of the top turbine and a fluid line with a bottoming cycle working fluid, the first heat exchanger receiving the bottoming cycle working fluid downstream of the bottoming compressor and upstream of the bottoming turbine such that the products of combustion heat the bottoming cycle working fluid, downstream of the bottoming turbine the bottoming cycle working fluid passing through a second heat exchanger, and then returning to the bottoming compressor, a bottoming shaft being driven by the bottoming turbine to drive the bottoming compressor, and power from rotation of the bottoming shaft being captured for further use;
• a source housing the fuel to be delivered to the combustor via the second heat exchanger, such that the bottoming cycle working fluid provides heat to the fuel being delivered to the combustor;
• wherein the source is configured to maintain the fuel at a temperature equal to or below 0° F.;
• wherein a third heat exchanger is positioned to exchange heat between the products of combustion downstream of the first heat exchanger, and the fuel downstream of the second heat exchanger, with the products of combustion passing through the third heat exchanger;
• and
• wherein an electric motor is positioned downstream of the third heat exchanger, and is configured to power an exhaust compressor which receives the products of combustion downstream of the third heat exchanger, and said exhaust compressor being upstream of the exhaust nozzle, said electric motor being provided with a control that controls the speed of the electric motor dependent on conditions of the gas turbine engine.