Purge and cooling air for an exhaust section of a gas turbine assembly

A turbine assembly in a turbine engine, the turbine assembly having an outer casing, an inner casing, an annular exhaust gas path defined between outer and inner flow path walls, and a turbine exhaust casing cavity located radially outward and radially inward from the gas path, and further comprising:

• a plurality of struts extending between the inner casing and the outer casing;
• a first purge air path extending radially inward through at least one of the struts conducting purge air to the inner casing for supplying purge air to at least one component radially inward from the inner casing;
• and
• a second purge air path having an inlet located at the inner casing and extending radially outward through the at least one of the struts for further conducting the purge cooling air radially outward to provide a flow of purge air to an outer location of the exhaust casing cavity radially outward from the outer flow path wall;
• wherein the at least one of the struts includes opposing axially extending side walls, the opposing side walls defining a cavity forming the second purge air path therebetween, and including strut orifices defined through the side walls for flow of the purge air out of the at least one of the struts.

A turbine assembly in a turbine engine, the turbine assembly having an outer casing, an inner casing, an annular exhaust gas path defined between outer and inner flow path walls, and a turbine exhaust casing cavity located radially outward and radially inward from the gas path, and further comprising:

• a plurality of struts extending between the inner casing and the outer casing;
• a first purge air path extending radially inward through at least one of the struts conducting purge air to the inner casing for supplying purge air to at least one component radially inward from the inner casing;
• a second purge air path having an inlet located at the inner casing and extending radially outward through the at least one of the struts for further conducting the purge cooling air radially outward to provide a flow of purge air to an outer location of the exhaust casing cavity radially outward from the outer flow path wall;
• and
• including a passage extending axially forward in the turbine engine conducting the purge air exiting from the first purge air path to a location adjacent a turbine stage cooling cavity, where the purge air mixes with air from the turbine stage cooling cavity, and including a chamber conducting purge air axially rearward to an inlet to the second purge air path.