GB599775A - Improvements in gas turbine plant for electric ship propulsion and the like - Google Patents

Abstract

599,775. Gas turbines. BRITISH THOMSON-HOUSTON CO., Ltd., and FORSLING, B. E. G. Oct. 22, 1945, No. 27749. [Class 110 (iii)] [Also in Group XXXV] A gas turbine plant comprises high- and lowpressure turbine rotors 10, 13 on independent shafts. The rotor 13 drives an alternator 14 for electric ship propulsion. The rotor 10 drives the air compressor 2 and, through gearing 11, the exciter 12 for the alternator. The compressed air is heated in an economizer 6, preferably as described in Specification 597,852, [Group XIII], and passes to two combustion chambers 8 formed in the lower head of the economizer. For starting, the exciter is used as a motor, air is blown off from an intermediate point in the compressor through a valve 17 and the useful power turbine 13 is byepassed by the open valve 16. When manoeuvring, the load taken by turbine 13 is controlled by the byepass valve 16. In a plant with three turbine rotors on independent shafts, the high-pressure turbine drives the high-pressure compressor and the exciter, the intermediate turbine drives a lowpressure compressor and the low-pressure turbine drives the alternator. The gases are re-heated in a combustion chamber 'between the high and intermediate turbines. For starting, the low-pressure compressor and the useful power turbine are byepassed. In another plant, two low-pressure turbines in parallel receive re-heated gases from the high-pressure turbine which drives the high-pressure compressor and the exciter. One of the lowpressure turbines drives the low-pressure compressor and the other, the alternator. For starting, the low-pressure compressor is byepassed and the inlet valve to the re-heating combustion chamber in front of the useful power turbine is closed or nearly closed.