Choose the right Anti-Icing Application

Protect your Gas Turbine from Ice Formation during High Humidity & Low Temperatures

Anti-icing mechanisms are generally used on gas turbine inlets when the air temperature is below 5 °C and the relative humidity is above 70%. Insufficient icing protection may result in inlet filter system issues and ice formation at the turbine inlet.

Inlet Filter system Issue

  • Snow and ice collect on the inlet filters and components:
    • High and long-term pressure drop reduces turbine efficiency and power output.
    • Degradation of filter media performance increases the risk of carry over since water will drag contaminants through the filter, resulting in engine degradation due to fouling or corrosion.

Ice Formation at the Turbine Inlet

  • Ice forms on the turbine inlet bell-mouth and inlet guide vanes:
    • Overall turbine performance is reduced since ice formation alters flow geometry.
    • Catastrophic failure may occur if ice is ingested by the turbine.

to mitigate these risks, there are various anti-icing options show in Table 1, where location, heat capacity, and functionality for each option is outlined.

Table 1

Anti-Icing Option  Location Heat Capacity Functionality
Pulse System Filter protection only None Cartridges pulse snow and thin ice off filters.
Heat Exchanger: Heating Coils Upstream or downstream Limited by heat source availability: Target is to heat the air by +/- 10°C Heating coils pump fluid such as steam of glycol with water to heat inlet components and can be operational even before starting the engine.
Hot Air: Ventilation Upstream or downstream Limited by heat radiated by the engine in the enclosure: Target is to heat the air by +/- 10°C Ventilation air from the enclosure is reused through a ducting system to warm the incoming air. Electrical heaters may be required to increase the temperature if the air is not warm enough.
Hot Air: Exhaust Upstream or downstream Unlimited: Target is to heat the air by +/- 10°C Ducts, dampers, and fans direct hot air flow from the exhaust, mixed with ambient air to the inlet.
Hot Air: Compressed Bleed Upstream or downstream Limited by the OEM spec. Target is to heat the air by +/- 10°C Hot air is sent through pipes from the gas compressor bleed, and is distributed through anti-icing rakes in the opposite direction of the airflow.
Heat Surface: Infrared Surface protection only Limited by electrical power availability. Heats only the surface to 20-30°C and does not heat the air Infrared heaters are installed in front of filters to prevent ice formation. They heat the surface by radiation and do not heat the air significantly.
Electrical Resistance Upstream or downstream Limited by electrical power availability. Target is to heat the air by +/- 10°C An electrical heater is used for anti-icing. They can also be installed on metal vanes.
Heated CamVanes Vane protection only Limited by electrical power availability. Target is to heat the vane surface - can heat the air by 1-3°C Vanes are heated by an electrical heating cable to prevent freezing and allows drainage of collected water.

Although summer is a few months away in some countries, you can prepare for next year by installing the right anti-icing system for your local site conditions.

Depending on your current filter solution and operational requirements, the anti-icing application may change. For recommendations on the optimal application for your site, contact your local representative.

Upstream: placed in front of the air inlet filter system
Downstream: placed behind the filters and protects only the bellmouth

Created Thursday, August 8, 2019