Intercooled combustor nozzle guide vane and secondary air configuration

A gas turbine engine having an axial centerline, comprising:

• a compressor section;
• an outer casing;
• a combustor section having an annular combustor disposed radially inward of the outer casing, the annular combustor having a combustion chamber disposed radially between a combustor outer radial wall structure and a combustor inner radial wall structure;
• wherein the outer casing and the combustor outer radial wall structure define a diffuser outer diameter flow path;
• an annular diffuser disposed between the compressor section and the annular combustor, wherein the annular diffuser is configured to direct diffuser gas towards the combustor section;
• an inner diffuser casing disposed radially inward of the annular combustor and spaced apart from the combustor inner radial wall structure;
• an inner casing disposed radially inward of and spaced apart from the inner diffuser casing, wherein the inner diffuser casing and the inner casing define an intercooler fluid passage (ICF passage);
• a heat exchanger configured to selectively cool a portion of the diffuser gas to provide intercooler gas;
• a first high-pressure turbine (HPT) stator vane stage, having a plurality of first HPT stator vanes;
• and
• a tangential onboard injector (TOBI) extending circumferentially around the engine axial centerline, the TOBI including a plurality of nozzles, an inner radial side, and an outer radial side;
• wherein a first portion of the intercooler gas is directed through the ICF passage and into the HPT stator vanes;
• wherein a second portion of the intercooler gas is directed through the TOBI nozzles;
• and
• wherein the TOBI includes a plurality of second TOBI outer radial cavities disposed radially outside of the TOBI nozzles, and a plurality of second TOBI entry passages, each respective second TOBI entry passage configured to provide fluid communication from the inner radial side of the TOBI to a respective second TOBI outer radial cavity.