Discuss the corrosive hazards of turbine blades

Thread Content

The steam turbine is one of the three main components in a thermal power plant – the boiler, the steam turbine, and the generator – and its structure consists of rotating parts and fixed parts. The rotating part consists of an impeller, a main shaft, a coupling, and blades ； The fixed part consists of a nozzle, cylinder, steam seal, partition, fasteners, bearings, etc. In the process of thermal power generation, it is the steam turbine that converts thermal energy into mechanical energy; the efficiency of the power plant and the safety of its units are directly affected by the steam turbine. When a steam turbine generator set is in operation, steam entering the turbine carries various impurities, which leads to scale formation and corrosion. In particular, the final-stage blades operate under extremely harsh conditions, subjected to high temperatures, high pressures, centrifugal forces, steam forces, steam-induced vibrations, corrosion, vibrations, as well as the erosion caused by water droplets in the wet steam area, which exposes them to an even greater risk of damage. Moreover, as the load increases, corrosion and salt deposition on the turbine blades become more severe, which in turn has a more significant impact on the safe operation and efficiency of the unit. When the turbine is started, if the mass of superheated steam supplied does not meet the specified requirements, operating it under such conditions will allow salts to enter the turbine through dissolution and suspension in the steam. These salts gradually accumulate on the blades of the turbine, increasing their mass and thus affecting the turbine’s output ； An imbalance in salt accumulation can also lead to uneven mass, which is likely to cause vibrations ； Corrosion of the blades due to scale buildup can severely damage the material and strength of the blades, potentially leading to serious accidents during the operation of the turbine.