COMBINED STEAM TURBINE, STEAM- OR GAS- AND STEAM-TURBINE POWER PLANT, METHOD OF OPERATING A COMBINED STEAM TURBINE

摘要

Combined steam turbines have a high-pressure module (1, 45) and an intermediate-pressure module (3, 47) in a casing (5) common to both modules, wherein the casing (5) has an inner casing (9, 43) enclosing an expansion section (7) and an outer casing (11, 41) enclosing the inner casing (9, 43), and wherein the inner casing (9, 43) is formed by parts (9A, 43A) joined together by joining means. Combined steam turbines are normally designed for subcritical steam states. In order to be able to also use a combined steam turbine (10, 20, 30, 40) for supercritical steam states, a casing (5) having a reliable and lasting closing effect is provided, in contrast to conventional combined steam turbines. To this end, according to the novel concept, the high-pressure module (1, 45) is designed for the admission of steam to an expansion section (7A) at supercritical steam states, and the high-pressure module (1, 45) and/or the intermediate-pressure module (3, 47), for assisting the joining means, has a pressure medium for pressing the parts (9A, 43A) of the inner casing (9, 43) together.