Low-pressure stage moving blade for variable-speed mass-flow industrial steam turbine

Abstract

The invention designs a low-pressure stage moving blade for a variable-speed mass-flow industrial steam turbine. The low-pressure stage moving blade for the variable-speed mass-flow industrial steam turbine is taken as a tail three-stage blade of a low-pressure stage and comprises a blade body, a surrounding belt and a blade root. The low-pressure stage moving blade is characterized in that the blade body, the surrounding belt and the blade root are stamped into a whole from top to bottom, wherein a molded line of the blade body is a variable section twisted blade, the sectional area of the twisted blade gradually decrease from the root to the top, and two adjacent cross sections are relatively twisted. The structure has the characteristics that the molded line of the blade body is a variable section twisted molded line and is formed by a plurality of characteristic sections according to a characteristic rule, and the two adjacent cross sections are relatively twisted. The low-pressurestage moving blade can safely work at a backpressure of 5kPa-40kPa and a rotation speed of 2400rpm-4000rmp, has the characteristics of high variable-speed and variable-load efficiencies, good strength vibration performance, high mass flow, stable structure, convenience in machining and assembling and can be widely applied to heavy-load variable-speed industrial steam turbines.

Description

technical field [0001] The invention relates to a driving blade of an industrial steam turbine, in particular to a low-pressure stage moving blade of an industrial steam turbine with variable speed and large flow. Background technique [0002] In the field of industrial drives, especially in key fields such as large-scale ethylene and large-scale air separation, the demand for variable-speed, high-flow, and high-power industrial steam turbines continues to increase, and its high-efficiency and safety design has gradually become more important. The operating condition of the blades of the low-pressure stage group is harsh, and it must be able to operate from the blocking condition to the blowing condition. Therefore, the reliability of the blades of the low-pressure stage group directly affects the safe operation of the unit. The design technology of low-pressure stage moving blades has become the core technology in the design of steam turbines because of its wide range of te...

AI Technical Summary

Problems solved by technology

[0003] Previously, most variable-speed industrial steam turbines had low profile efficiency of the final third-stage moving blades, and most of them had no shrouds, which increased the loss of steam leakage

In order to increase the vibration and damping effect of the blades, most variable speed industrial steam turbines adopt the structure of loose ties, so that the blades are grouped. The loose ties structure increases the collision loss of water vapor and reduces the efficiency of the blades.

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