Patent GB-955947-A (GB)
Title: Improvements in or relating to gas turbine plants
IPC: F02C7/08
Filed: 1960-06-24
Abstract: 955,947. Gas turbine plant; turbines; combustion chambers. C. C. HILL. June 24,1960 [June 26, 1959], No. 22123/60. Headings F1G, F1L and F1T. A gas turbine plant comprises a compressor and a turbine mounted co-axially, the plant having circumferentially thereof an exhaust passageway spaced radially outwardly of the turbine rotor, the turbine rotor being disposed between the compressor impeller and the combustion equipment, air from the compressor being caused to flow axially therefrom to the combustion equipment, and the combustion gases being caused to flow therefrom in the opposite axial direction to the turbine, means being provided to cause the gases leaving the turbine to reverse in direction in a path surrounding the turbine rotor, the gases thereafter being caused to flow radially outwardly to the exhaust passageway. The plant shown comprises a centrifugal compressor impeller 24 and an axial flow turbine rotor 25 mounted at opposite ends of a shaft 26 which is mounted in bearings 107, 108 in a bearing housing 44, air from the compressor flowing axially through the tubes 49 of a heat exchanger, the preheated air then entering the combustion equipment 80, the gases from which discharge in the opposite direction to the air flow in the heat exchanger, into the turbine 25, the gases from the turbine being reversed in direction by the wall 93 and then flowing radially outwardly across the tubes 49 of the heat exchanger. The air intake to the compressor is through the passage 29 which is formed in sound insulating material 35, 36 and the compressor casing is formed by the walls 33, 32, 31 also by the bearing housing 44, diffusing vanes 46 being disposed at the outlet from the impeller and an axially extending diffuser portion being provided at 47. Air from the diffuser 47 enters a manifold 48 from which it flows through a series of axially extending tubes 49 of rectangular form, corrugated elements 54 affording radial passages for flow of exhaust gases being disposed between adjacent tubes 49. The preheated air discharges from the tubes 49 into the space 22 around the flame tube 80, and air enters the flame tube through inlets 83, 84 in the flame tube, also through openings in the burner assembly 89 by means of which fuel is supplied to the flame tube. The gases discharge from the flame tube through nozzles formed between hollow vanes 68 on to the turbine rotor blades 25a, exhaust gases therefrom being reversed in direction by the curved wall 93 and then discharging radially outwardly through the passages formed by the corrugated members 54 of the heat exchanger. The turbine casing is a frustoconical member 61 which is supported from the outer casing 56 by means of a frusto-conical member 59. A portion of the pre-heated air from the space 22 flows between the wall of the flame tube 80 and the frusto-conical member 59 and thence through the hollow nozzle guide vanes 68 into the chamber 70 formed between the wall 71 which is disposed adjacent the upstream face of the turbine rotor disc 25, and the hemispherical wall 72. Air discharges from the chamber 70 through openings 74 in the wall 71 and flows radially outwardly across the adjacent face of the turbine rotor disc to cool it. Air also discharges from the chamber 70 through openings 75 in the hemispherical wall 72 and is guided by the baffle 76 to flow adjacent the roots of the turbine rotor blades 25a and periphery of the rotor disc. A portion of air flowing through the compressor outlet 47 is led through passages 78, 79 to the space adjacent the upstream face of the turbine rotor disc 25 for thrust balancing purposes. The fuel nozzle 174 is caused to rotate during operation by means of air flowing through openings in the shroud member 151. The nozzle is mounted within a cylindrical member 170 to which is secured a graphite bush 171, the bush being rotatably mounted on a fixed hollow shaft 154 through which fuel flows to the nozzle. Blades 169 are secured to the member 170 and air passing through the openings in the shroud 150 is directed by the fixed guide blades 168 secured to the stationary member 152 on to the blades 169 thus causing the nozzle 174 to rotate. The fuel passage 161 within the shaft member 154 is closed by a spring-loaded valve 162, the valve being openedupon starting of the plant by means of the solenoid 164. The fuel burner assembly is mounted in the combustion chamber 87 and projects into the frusto-conical end wall 85 of the flame tube. The flame tube is supported from the casing 56 by means of clips 91 which engage retainer loops 92 secured to the flame tube wall. Lubricating oil is supplied to an annular groove 135 in the member 109, oil flowing from the groove through passages 137, 139 to the bearings 108, 107 respectively, the oil being returned from the bearings through a common outlet. Specifications 955,948 and 955,949 are referred to.