GB806611A - Improvements relating to steam turbine power plant - Google Patents

Abstract

806,611. Steam turbines. METROPOLITANVICKERS ELECTRICAL CO. Ltd. Feb. 7, 1957 [Feb. 17, 1956], No. 5024/56. Class 110 (3). A steam turbine power plant comprises four turbines each comprising two pressure sections coupled in tandem pairs on two shafts each of which drive a generator. The turbine I on the shaft X contains a high-pressure section 4 and a secondary intermediate pressure section 13, and the turbine II two low-pressure sections 15. The turbine III on the shaft 7 contains primary and secondary intermediate pressure sections 10, 16 and the turbine IV two low-pressure sections 18. Steam is supplied to the section 4 from a boiler B through a superheater 1 and controlled by the emergency and governor valves 2, 3. After expansion in the section 4, the steam is reheated in the heater 7 and passed through intercept emergency and governor valves 8, 9 to the primary intermediate pressure section 10 of the turbine III. After expansion in the section 10, the steam is divided. Half the quantity passes through a cross-over 11 and an energency valve 12 to the secondary intermediate pressure section 13 of the turbine I which discharges through the sections 15 of the double-flow low-pressure turbine II. The remaining half of the steam from section 10 expands through the secondary intermediate pressure section 16 of turbine III which discharges through the section 18 of the doubleflow low-pressure turbine IV. The pressure in the cross-over 11 can be adjusted to vary the distribution of the load between the two shafts. Additional turbines may be coupled to one or both shafts. These additional turbines may be located intermediate the machines I and II and III and IV.