GB607884A - Improvements in the starting and manoeuvring of gas turbine plants for electric ship propulsion and the like - Google Patents

Abstract

607,884. Gas turbines. BRITISH THOMSON-HOUSTON CO., Ltd., and FORSLING, B. E. G. Oct. 22, 1945, No. 27750. [Class 110 (iii)) In a gas turbine including high- and lowpressure turbines on separate shafts, the highpressure turbine driving an air-compressor and the low-pressure turbine providing useful power and in which the output of the useful power turbine is controlled by a valve in a byepass conduit, no control devices are inserted in the flow path of the useful power turbine. The turbine rotor 13 drives an alternator 14 for electric ship propulsion. The turbine 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 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 or low-pressure turbine 'drives a low-pressure compressor and the remaining 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 same high-pressure turbine which drives the highpressure compressor and the exciter. One of the low-pressure turbines drives the lowpressure compressor and the other the alternator.