Inter-cooled preheat of steam injected turbine engine

A propulsion system for an aircraft comprising:

• a core engine including a core flow path where a core airflow is compressed in a compressor section, communicated to a combustor section, mixed with a hydrogen-based fuel and ignited to generate a gas flow that is expanded through a turbine section, wherein the compressor section includes a first compressor upstream of a second compressor;
• a hydrogen fuel system configured to supply hydrogen fuel to the combustor section through a fuel flow path;
• a condenser arranged along the core flow path and configured to extract a water flow from the gas flow;
• an evaporator arranged along the core flow path and configured to receive a portion of the water extracted by the condenser to generate a steam flow, wherein the steam flow is injected into the core flow path upstream of the turbine section;
• and
• an intercooling system comprising a preheater disposed within the compressor section, the preheater configured for transferring thermal energy from the core airflow into a portion of the water flow and communicating the resulting heated water flow to the evaporator and then into the core engine.

A method of intercooling a core airflow of a turbine engine comprising:

• communicating a portion of a water flow to an intercooling system disposed within a compressor section of the turbine engine;
• cooling the core airflow with the portion of the water flow by placing the core airflow and the portion of the water flow into thermal communication in the intercooling system resulting in a heated water flow;
• communicating h heated water flow from the intercooling system to an evaporator aft of a combustor of the turbine engine to generate a steam flow;
• and
• injecting the steam flow into the combustor.