What are the hazards of low steam temperature at the turbine inlet?
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For back-pressure steam turbines, what are the hazards and risks associated with a decrease in the temperature of the medium-pressure steam at the inlet? What is the minimum it generally cannot be below? What is the appropriate temperature?
Be careful of water in the steam when the temperature is low; generally, the temperature of medium-pressure superheated steam should be maintained between 400 and 430 degrees
A lower temperature means that the energy of the steam is relatively low, resulting in increased energy consumption for the unit! Moreover, it can easily lead to the presence of water, which can cause fatal damage to the machinery!
Steam carries water, which exacerbates blade corrosion; water erosion on the final stage blades worsens, and increased axial thrust may damage the bearings
The steam in a turbine needs to be at a certain degree of superheating to ensure that it remains in a superheated state throughout the operation of the turbine. Otherwise, the steam will become supersaturated due to cooling, resulting in the formation of water, which can damage the turbine.
Low temperatures can cause steam to contain water droplets. When the impeller is operating at high speeds, one can imagine the consequences of the presence of such water droplets. Generally, the temperature should not be lower than 180°C; a range of 200–280°C is appropriate!
I’m sorry, I misread it; back-pressure type air compressors require high steam pressure, while what I was referring to is the condensing type!
Our medium-pressure steam is at around 370 degrees
A low temperature of the medium-pressure steam can lead to severe erosion caused by water on the blades in the latter stages; in severe cases, this can damage the blades. It is necessary to ensure that the temperature of the medium-pressure steam remains above 385 degrees
The output remains unchanged, the displacement increases, the enthalpy drop in the last stages rises, the axial force increases, more steam is consumed, efficiency declines, and the stress on the blades in the last stage increases.