GB493174A - Method of operation and operating device for gas turbine prime movers, in particularfor ships - Google Patents

Abstract

493,174. Gas - turbine plant. COMPAGNIE ELECTRO-MECANIQUE. Nov. 1, 1937, No. 29799. Convention date, Oct. 30, 1936. [Class 110 (iii)] The manoeuvring of a ship, fitted with gas turbines and a combustion air compressor driven by a separate gas turbine with its own combustion chamber, is carried out by means of compressed air expanding in a turbine, which may be a separate machine or part of the main prime mover. The divided main propelling turbine T1, Fig. 1, receives hot gases from the combustion chambers D<1>1 and D<11>1 which are supplied with fuel at R<1>1 and R<11>1 respectively. Combustion air, supplied by the compressor C driven by a separate gas turbine T3 with its own combustion chamber D3, is heated in the heatexchanger E1 by the exhaust gases of the turbine T1. The air supply to the combustion chamber D3 is heated in the heatexchanger E3 by the exhaust gases of the turbine T3. The ship may be manoeuvred by shutting off both of the fuel supplies R<1>1, R<11>1 and driving the machine Tl with compressed air controlled by one of the valves V<1>1, V<11>1. An astern turbine T2 is supplied with compressed air controlled by a valve V2. A combustion chamber may be fitted in front of turbine T2 if continuous operation of this machine is required. The turbines T1, T2 may be replaced by (1) a special manoeuvring turbine, (2) parts of the main turbine, or (3) part of a group of main turbines. The starting of the plant is effected by means of a small auxiliary motor adapted to drive one of the compressor units at low speed until its burners can be ignited, and the other machines may be started with air supplied by this compressor. A device, Fig. 2, for maintaining the gas temperature at the inlet of the main machines constant and as high as possible consists of a two circuits (1), (3) controlling the fuel supply to the compressor and main turbines. Oil under pressure is supplied at J and passes through the diaphragms dl, d3 to the servomotors P1, P3, operated by the pressure in the circuits (1), (3). These circuit pressures are controlled by the leak-off orifices A1, A3. If the lever Q is operated to open or close the orifice A3, the compressor turbine T3 speeds up or slows down and the quantity and pressure of the air supplied to the combustion chambers of the main machines are altered. This in turn causes the diaphragm Y, connected to a Venturi tube in the air supply line, to open or close the orifice Al which controls the amount of fuel supplied to the main machines. The diaphragm X, connected to a Venturi tube in the fuel supply line to the main machines, will then operate to reestablish equilibrium of the orifice Al. A temporary increase or decrease in temperature during acceleration or deceleration is allowed by a device consisting of an auxiliary orifice in circuit (1) operated by the lever Q together with a time delay device attached to the rod R1 connecting diaphragms X, Y.