RELAXATION SYSTEM FOR TEMPERATURE DIFFERENCE IN AXIAL DIRECTION OF TURBINE CASING

PURPOSE:To keep thermal stress low and reduce heat deterioration of a turbine casing by providing a partition plate at a suitable position in a bleeding chamber, forming a relaxation chamber for temperature difference, and introducing steam for relaxation of temperature difference from an adequate stage. CONSTITUTION:A partition plate 10 is projectionally provided on the way of axial direction of a bleeding chamber 3 formed between an external wheel casing 1 and an internal wheel casing 2, and a portion of the bleeding chamber 3 is partitioned as a relaxation chamber 11 for temperature difference. Bleeding steam is introduced from a bleeding hole 8 provided on an adequate stage to the bleeding chamber 3. Besides, bleeding steam for relaxation of temperature difference is introduced from a bleeding hole 12 provided on an adequate stage to the relaxation chamber 11 for temperature difference. Thus, temperature gradient in the axial direction of a turbine and thermal stress applied to the partition plate can be kept low.