Second-last-stage moving blades for half-speed large-capacity nuclear power steam turbines

Abstract

The invention provides a penultimate-stage moving blade for a half-speed high-capacity nuclear turbine. The penultimate-stage moving blade comprises shrouding strips, a blade working part, an intermediate body and a blade root. The height of the blade working part is 1286 mm. The molded line of the blade working part is a variable cross-section twisted blade. The sectional area of the variable cross-section twisted blade gradually decreases along with increasing of the height of the cross section of the blade. Relative twist exists between every two adjacent cross sections. The shrouding strips are located at the top of the blade working part. The blade root is located at the bottom of the blade working part and is a side-mounted first-tree-shaped blade root with a large round angle and low stress concentration. The intermediate body is located between the blade working part and the blade root. The width of the intermediate body is equal to the axial width of the blade root. The shrouding strips, the blade working part, the intermediate body and the blade root are integrally formed. When the blade is in a static state, a gap between the working faces of the two adjacent shrouding strips is zero. The adjacent shrouding strips are coupled to each other at a working rotation speed, so that the whole circle of the penultimate-stage moving blades are connected into a group. The penultimate-stage moving blade is applicable to AP1000 nuclear turbine power generation units and future CAP1400 / CAP1700 nuclear turbine power generation units and can well meet the requirements for pneumatic performance and strength of half-speed high-capacity nuclear turbines.

Description

technical field [0001] The invention relates to a moving blade of a steam turbine, in particular to a second-last stage moving blade used for a half-speed large-capacity nuclear power steam turbine. Background technique [0002] Long blades are key components of large-capacity nuclear power steam turbines, and their performance determines the efficiency and safety of steam turbines. Usually, the design and development of the last two or three blades of low pressure are collectively referred to as the development of long blades of steam turbines. Each low-pressure last-stage long blade and its matching next-to-last-stage moving blades and next-to-last-stage moving blades are called a series of long blades. [0003] At present, the low-pressure last-stage moving blades used for million-level nuclear power steam turbines on the market mainly include about 20m2 for matching exhaust area. 2 The 900mm height level second-end moving blades designed for low-pressure last-stage lon...

AI Technical Summary

Problems solved by technology

In addition to the requirements of low cooling water temperature in the coastal and central and northern regions, the exhaust area of ​​the original 900mm and 1100mm height grades of the second-end long blades is too small, which can no longer meet the existing needs

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