Main steam inlet structure for steam turbine

摘要

A main steam inlet structure of a steam turbine has two inlet tubes which are separable from an inner casing and an outer casing of the turbine and are arranged concentrically with a spacing therebetween to constitute an inflow passage for main steam are connected at one end to the outer casing and at the other end to the inner casing, by seal rings. Cooling steam extracted from turbine stage midway is supplied to a cooling steam passage of the spacing formed between the two inlet tubes, thereby cooling the inner inlet tube.