Mitigation of rotating stall in turbine exhaust section using inner flow control vanes

A system, comprising:

• a turbine exhaust section comprising:
• an exhaust flow path;
• an inner exhaust wall radially disposed along the exhaust flow path;
• an outer exhaust wall disposed along the exhaust flow path and radially outward from the inner exhaust wall;
• an inner flow control vane configured to selectively extend radially outward from the inner exhaust wall, wherein a radial extent of the inner flow control vane, when extended, is less than a radial distance between the inner exhaust wall and the outer exhaust wall;
• and wherein the inner flow control vane is disposed downstream of a last stage blade of a turbine and upstream of an exhaust diffuser strut of the turbine exhaust section;
• and
• an actuation assembly configured to actuate the inner flow control vane to cause the inner flow control vane to radially extend outward;
• and
• a controller having one or more processors, the controller configured to:
• instruct the actuation assembly to actuate the inner flow control vane to cause the inner flow control vane to extend radially outward based on one or more operating conditions of the system;
• control the inner flow control vane to extend outward from the inner exhaust wall in response to a first operating condition susceptible to a rotating stall condition in the turbine;
• control the inner flow control vane to retract into the inner the inner exhaust wall in response to an absence of the first operating condition;
• or
• a combination thereof.

A system, comprising:

• a turbine exhaust section comprising:
• an exhaust flow path;
• an inner exhaust wall radially disposed along the exhaust flow path;
• an outer exhaust wall disposed along the exhaust flow path and radially outward from the inner exhaust wall;
• an inner flow control vane configured to selectively extend radially outward from the inner exhaust wall, wherein the inner flow control vane is disposed downstream of a last stage blade of the turbine exhaust section and upstream of an exhaust strut of the turbine exhaust section;
• and
• an outer flow control vane configured to selectively extend radially inward from the outer exhaust wall, wherein an outer radial extent of the outer flow control vane, when extended, is less than a radial distance between the inner exhaust wall and the outer exhaust wall;
• and wherein the outer flow control vane is disposed downstream of the last stage blade and upstream of the exhaust strut.

A system, comprising:

• a turbine exhaust section comprising:
• an exhaust flow path;
• an inner exhaust wall radially disposed along the exhaust flow path;
• an outer exhaust wall disposed along the exhaust flow path and radially outward from the inner exhaust wall;
• and
• an inner flow control vane configured to selectively extend radially outward from the inner exhaust wall, wherein an inner radial extent of the inner flow control vane, when extended, is less than a radial distance between the inner exhaust wall and the outer exhaust wall;
• and wherein the inner flow control vane is disposed downstream of a last stage blade of a turbine and upstream of an exhaust diffuser strut of the turbine exhaust section;
• wherein the inner flow control vane is configured to linearly extend from a recess disposed in the inner exhaust wall.