GB888828A - Steam turbine unit with steam turbine driven auxiliary engines on board ships - Google Patents

Abstract

888,828. Steam turbine plant. TURBIN AB DE LAVAL LJUNGSTOM. June 27, 1960, No. 22416/60. Class 110 (3). In a steam turbine plant for ships comprising a main steam turbine unit and steam turbinedriven auxiliaries, the auxiliary steam turbines are supplied from the main steam line and they exhaust to a primary exhaust system (distinct from the exhaust system of the main steam turbine unit) and steam is taken from the primary exhaust system at comparatively high pressure and led to heat-consuming apparatus. The primary exhaust system is connected by means of a pressure maintaining valve to a secondary exhaust system which is at a lower pressure than the primary system, the secondary system being also connected by means of a pipe line having a back-pressure valve with a low-pressure stage of the main turbine from which steam is obtained. The plant shown comprises a main steam turbine set comprising a high-pressure turbine 1 and a low-pressure turbine 2, the two turbines driving the propeller 4 through gearing 3. Steam is supplied through a pipe line 5 controlled by valve 6 and steam passes from the highpressure turbine to the low-pressure turbine through line 7. The exhaust outlet from the low-pressure turbine 2 is indicated at 2a. Auxiliary turbines 8 driving auxiliaries are supplied with steam from the line 5 through the branch 9, and the exhaust steam therefrom passes through valve-controlled lines 11 to the primary exhaust system 13. Steam is supplied from the latter through valve-controlled lines 15 and 18 to the combustion air preheater 14 and the deaerator preheater 17 respectively. The primary exhaust system 13 is connected by means of a pressure-maintaining valve 20 to the secondary exhaust system 21 from which steam is supplied through valve-controlled lines 22 to the feed water heater 24 and other heat-consuming apparatus 25. The secondary exhaust system 21 is also supplied with steam bled off from the low-pressure turbine 2 through a line 26 having a back-pressure valve 27. Surplus steam from the system 21 is led through a valve-controlled line 28 to a condenser. Steam is also bled off from the high-pressure turbine 1 through a valve-controlled line 31 to a second stage air preheater 30. The amount of exhaust steam in the primary exhaust system 13 may be supplemented by steam bled from the high-pressure turbine through lines 31 and 33 and pressure-reducing valve 34.