Patent GB-907992-A (GB)
Title: Heat exchange apparatus, e.g. for use in gas turbine engines
Inventor: KENT NELSON HECTOR
IPC: F02C7/047
Filed: 1960-03-14
Abstract: 907,992. Gas turbine plant. ROLLS-ROYCE Ltd. March 7, 1961 [March 14, 1960], No. 8957/60. Class 110 (3). A gas turbine engine comprising an engine casing and an internal wall mounted within the casing by a plurality of substantially radial struts to define an annular intake, has the casing or internal wall provided with an arcuate fluid supply manifold and an arcuate fluid exhaust manifold both of which communicate in succession with ducts extending along the struts, a fluid inlet conduit communicating with the fluid supply manifold and with a supply of heated fluid under pressure and at a temperature higher than that of the struts, the supply and exhaust manifolds having a wall separating the incoming and outgoing fluids so formed that the cross-sectional area of the supply and exhaust manifolds respectively diminish and increase in the direction of fluid flow, the arrangement being such that the total pressure heads at the inlets to the ducts are substantially equal and the fluid heats the struts so that they expand by substantially equal amounts. The gas turbine annular intake 11 defined between the engine casing 10 and a nose cone 16 supporting a compressor bearing, has the nose cone supported by a number of struts 17 which extend tangentially of the nose cone to diminish the buckling effect of differential expansion and contraction of the struts. Mounted about and adjacent the forward end of the engine casing is an annular air exhaust manifold 19 communicating with the interior of the hollow struts 17 and an exhaust port 20. A chamber 21 is mounted in the manifold 19 and connected by a pipe 22 to the outlet of the compressor. The chamber 21 supplies hot air to pipes 23, 24, Fig. 4, which are connected in turn to pipes 26 which extend into the hollow struts 17. The ends of the pipes 26 are spaced from the nose cone 16 so that the heated air may flow through the spaces 27 to heat the struts and then into the manifold 19. To maintain the total pressure heads at the inlets to the pipes 16 substantially equal, seven of the twelve pipes 26 communicate with the pipes 23 and the remaining five pipes communicate with the pipe 24. The pipes 23, 24 are spaced from the engine casing by heat-insulating blocks 25. The pressure drop along the pipes 23, 24 which causes unequal heating of the struts 17 is reduced by making each of the pipes of a series of portions of progressively reduced internal crosssectional area. The bores of the pipes 26 where they join the pipes 23, 24 may be progressively increased with distance from the chamber 21. If desired, the inner ends of the pipes 26 may be constricted. Each of the pipes 23, 24 may be formed of inner and outer skins with an annular layer of heat insulating material between them. The passages 27 may be connected together around the nose cone so as to equalize the pressures in these passages. Since the pipes 24 extend beyond the pipes 23, the space occupied by these pipes adjacent the exhaust port 20 is less than that adjacent the chamber 21. Thus the exhaust manifold 19 is formed so that no substantial change of total pressure occurs in it towards the exhaust port 20. The hot air from the struts 17 may be used to heat the nose cone 16 and the leading edge of the air intake 11 before being exhausted to atmosphere. Specification 879,621 is referred to.