Annular arrangement of heat exchangers
A heat exchanger having: front and aft ends; heat exchanger cores in an annular loop that define circumferential gaps between adjacent pairs of the cores, the cores, individually or as axially aligned sets, extend from the front to aft ends and have facing inlet sides and circumferentially facing outlet sides configured such that the inlet sides and the outlet sides from the adjacent pairs of the cores face into the same circumferential gaps; and core guide vanes disposed in the circumferential gaps, the core guide vanes have an aft portion that extends from the front end to the aft end of the heat exchanger, wherein: at the front end the heat exchanger, the core guide vanes are closer to the outlet side of the cores; and at the aft end the heat exchanger, the core guide vanes are closer to the inlet sides of the cores.
1. A heat exchanger comprising:
a front end and an aft end spaced apart from each other;
heat exchanger cores that are circumferentially spaced apart from each other in an annular loop such that they define circumferential gaps between adjacent pairs of the cores;
wherein the cores, configured individually or as axially aligned sets, extend from the front end to the aft end and have circumferentially facing inlet sides and circumferentially facing outlet sides configured such that the inlet sides and the outlet sides from the adjacent pairs of the cores face into the same ones of the circumferential gaps; and
core guide vanes disposed in the circumferential gaps;
the core guide vanes have an aft portion that extends from the front end to the aft end of the heat exchanger;
wherein: at the front end the heat exchanger, the core guide vanes are closer to the outlet side of the cores; and at the aft end the heat exchanger, the core guide vanes are closer to the inlet sides of the cores;
whereby the core guide vanes are configured to turn a gas flow from an axial direction toward the inlet sides of the cores and from the outlet sides of the cores toward the axial direction.
2. The heat exchanger of claim 1 , wherein:
the cores are counter-flow or cross flow heat exchangers.
3. The heat exchanger of claim 1 , wherein:
the cores are rectangular shaped and have cases that include axial front surfaces;
the core guide vanes each include a forward portion that extends forward from the aft portion; and
the heat exchanger further comprises:
an annular inlet duct extending axially forward from the front end of the heat exchanger to a front end of the inlet duct, wherein the forward portion of the core guide vanes extends to the front end of the inlet duct; and
duct guide vanes that extend axially forward from the inlet sides of the cores to an adjacent one of the core guide vanes, and connect over the axial front surfaces of the cores, to thereby form a flow path around the front surfaces of the cores.
4. The heat exchanger of claim 3 , wherein the heat exchanger has a first outer diameter, the inlet duct tapers toward the front end of the inlet duct to a second outer diameter that is smaller than the first outer diameter.
5. The heat exchanger of claim 4 , wherein:
the heat exchanger has a radial center; and
the cases of the cores have radial outer surfaces located at the first outer diameter of the heat exchanger and radial inner surfaces that are spaced apart from the radial center of the heat exchanger, to thereby define a center flow passageway between the cores.
6. The heat exchanger of claim 1 , further comprising:
shroud sections extending between the cores, to define a radial flow boundary around the circumferential gaps.
7. A gas turbine engine comprising:
an engine inlet;
an engine core located aft of the inlet;
an exhaust duct located aft of the engine core; and
the heat exchanger of claim 1 disposed between the engine core and the exhaust duct.