Final-stage moving blade of wet cooling steam turbine

Abstract

The invention relates to a final-stage moving blade of a wet cooling steam turbine, which is characterized in that the effective height of the blade is 736.6mm, the relative value of the height H of a blade body is monotonously increased to 1.0 from 0.0, an installation angle c is independently reduced to 14.78 degrees from 72.06 degrees, an area A from a root section to a top section has the change rule that A is more than and equal to 1.0 and less than or equal to 4.511, an axial width Xa from the root section to the top section has the change rule that Xa is more than or equal to 1.0 and less than or equal to 4.093, a chord length b1 from the root section to the top section has the change rule that b1 is more than or equal to 1.0 and less than or equal to 1.324, and the maximum thickness W1 from the root section to the top section has the change rule that W1 is more than or equal to 1.0 and less than or equal to 3.587. Especially, the final-stage moving blade is suitable for a subcritical wet cooling steam turbine with the back pressure of 6-10kPa, the power of 150-250MW and the rotating speed of 3000rpm.

Description

technical field [0001] The invention relates to moving blades of wet-cooled steam turbines, especially suitable for subcritical wet-cooled steam turbines with a back pressure of 6-10kPa, a power of 150MW-250MW, and a rotational speed of 3000rpm. Background technique [0002] With the development of thermal power generation technology, high-parameter, large-capacity units have become the mainstream of the current market due to their advantages such as high efficiency, environmental protection and energy saving. At present, the domestic steam turbine market is mainly dominated by units of 300MW, 600MW and 1000MW, and units of lower power levels are rarely used by power plants. But in some domestic power plants and some developing countries abroad, there is still a certain market for 200MW units. [0003] At present, most of the 200MW steam turbines in China are designed around the 1980s. Although they were improved in the early 1990s, their design indicators and adopted techn...

AI Technical Summary

Problems solved by technology

The frequency of this blade structure is difficult to calculate accurately, and it is necessary to rely on multiple tests to determine the installation position of the tie bars

And in the actual operation process, due to the errors in manufacturing and assembly and the large torsional recovery angle of the long blades, the arched shrouds have problems such as uneven force and cracks, which seriously affect the safe and normal operation of the steam turbine.

[0007] In summary, the 200MW final blades designed in the 1990s can no longer meet the high requirements for steam turbine economy and safety in the new era

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