Equipment Preservation in Power Plants

Impact of Uncontrolled Humidity

 

Most power plants generate electricity by burning fossil fuels such as coal, oil, and natural gas. High moisture content can significantly affect the overall productivity of the power plant.

Consequences of High Humidity

 

In the power industry, expensive equipment like turbines, power generators, boilers, condensers, etc., can rust and corrode while in storage, during plant shutdowns, or even when in operation due to moisture in the air. Moisture accelerates the rate of corrosion, leading to:

● Deterioration of parts and components

● Malfunctioning of equipment

● Decreased lifespan of turbines and other machinery

Additional Effects

Operational Efficiency: Corroded equipment often leads to increased maintenance requirements and operational downtime.

● Cost Implications : Repairing or replacing corroded components can be very costly and time-consuming.

Causes of Uncontrolled Humidity

The rate of corrosion accelerates when relative humidity crosses the critical level of 40%. Above this level, industrial pollutants like sulfur dioxide further enhance the corrosion rate. Corrosion is faster when surfaces are exposed to polluted air in combination with high relative humidity.

Recommendation

 

During power plant standby, relative humidity should be maintained at 15%-30% RH at 24°C.

During operation, relative humidity should be kept below 35% RH at ambient temperature to minimize losses due to high humidity.

If the relative humidity of the storage area for expensive equipment is kept below 40%, all equipment like generators, turbines, and their components can be maintained in well-preserved condition for immediate activation when required.

Solution

Josem Solutions

Dehumidification involves drying the air by actually removing moisture from it. Removing moisture from the storage area lowers the relative humidity, effectively preventing corrosion and microbial growth. During turbine storage, proper dehumidification ensures minimal deterioration of all internal systems.

Idle power plants can be effectively protected from corrosion by blowing dehumidified air through the steam side as well as the generator winding. Dehumidified air keeps non-nuclear components like boilers, condensers, and turbines rust-free when the plant is shut down for refueling—a process that can take up to a year. In the case of fossil fuel power stations, layup can occur due to furnace or boiler repair or the availability of less expensive power from an alternate source. During such periods, a flow of dehumidified air in the facility prevents rusting and other harmful moisture-related problems.

Desiccant dehumidifiers provide the ideal low-humidity environment for the preservation and deactivation of power plants, as they are capable of maintaining RH as low as 1% or even lower at a constant level, regardless of ambient conditions.