| Blade is the important part of turbine. Thermal energy to mechanical energy transformation is implemented by blade. Blade fracture or damage will cause large economic loss of power plant. Fracture analysis of blade occurred in #2 unit of Thermal Power Plant is researched in detail in the paper. Technical improvement methods to solve the problem of the unit are presented and realized in the field with great success.Blade stress is analyzed in the paper first. Dynamic stress during operation and static strength of last stage blade are assessed comprehensively. Force activating on the last stage blade is determined. Blade dynamic frequency is calculated. Blade static frequency measurement instrument is developed and is tested in the field.Fracture analysis of blade is the key of the paper. It is confirmed by material, metallography, mechanics, macroscopic and microcosmic section analysis and test that the main reason is due to fatigue crack. It is ensured that blade design problem exists in the unit.Corresponding technical improvement methods are determined and realized in the field during the overhaul of the unit with great success based on the above analysis.
|
PDF Full Text Request