Swirl reducing gas turbine engine recuperator

Abstract

A gas turbine engine recuperator recuperator including exhaust passages providing fluid flow communication between an exhaust inlet and an exhaust outlet, the exhaust inlet being oriented to receive exhaust flow from a turbine of the engine and the exhaust outlet being oriented to deliver the exhaust flow to atmosphere, the exhaust passages having an arcuate profile in a plane perpendicular to a central axis of the recuperator to reduce a swirl of the exhaust flow. Air passages are in heat exchange relationship with the exhaust passages and providing fluid flow communication between an air inlet and an air outlet, design to sealingly respective plenum of the gas turbine engine.

1 . A method of deswirling and cooling an exhaust flow in an exhaust duct of a gas turbine engine, comprising:
 circulating the exhaust flow from a turbine section of the gas turbine engine to a recuperator extending within the exhaust duct;   circulating air discharged from a compressor section to a combustor of the gas turbine engine through air passages of the recuperator; and   deswirling and diffusing the exhaust flow by circulating the exhaust flow through exhaust passages of the recuperator having an arcuate profile in a plane perpendicular to a central axis of the recuperator and in heat exchange relationship with the air passages.   
     
     
         2 . The method as defined in  claim 1 , wherein circulating the exhaust flow from the turbine section to the recuperator includes circulating the exhaust flow through passages defined by circumferential splitters located in the exhaust duct and supported by radially extending struts having an asymmetrical airfoil shape twisted to reduce the swirl of the exhaust flow. 
     
     
         3 . The method as defined in  claim 2 , further comprising reducing the swirl of the exhaust flow with the splitters being curved in the plane perpendicular to the central axis of the recuperator. 
     
     
         4 . The method as defined in  claim 2 , wherein the exhaust flow circulates through the passages defined by the circumferential splitters along a path oriented progressively from an axial or substantially axial direction to a radial or substantially radial direction. 
     
     
         5 . The method as defined in  claim 2 , wherein the splitters form part of the recuperator. 
     
     
         6 . The method as defined in  claim 1 , wherein circulating the exhaust flow through the exhaust passages of the recuperator includes circulating the flow from an exhaust inlet to an exhaust outlet of the exhaust passages, and wherein the arcuate profile defines a curve having a concave side facing a same circumferential direction from adjacent an exhaust inlet to adjacent the exhaust outlet, the arcuate profile directing the exhaust flow in an arcuate direction from the exhaust inlet to the exhaust outlet. 
     
     
         7 . The method as defined in  claim 1 , wherein the air and exhaust passages are relatively oriented such as to define a mixed counter flow and double pass cross flow heat exchanger. 
     
     
         8 . The method as defined in  claim 1 , wherein the recuperator comprises a plurality of identical and independent arcuate segments. 
     
     
         9 . The method as defined in  claim 1 , wherein the recuperator has a shape substantially conforming to that of the exhaust duct.