Gas Turbine Overview Brochure
Inlet heating systems for cold climates are designed to protect gas turbines and large compressors from damage due to icing and to keep the machine running with minimum effect on performance. Icing can block inlet filtration equipment, increasing pressure drop and potentially causing the gas turbine to shut down. Ice can also build up on the inlet bell-mouth, leading to risk of foreign-object damage and potential compressor surge.
It is the water content of air that allows ice to form. However, by altering the inlet temperature by means of an AAF inlet heating solution it results in a rise in the inlet temperature and prevents the formation of ice. AAF has several inlet heating solutions available, but it is worth noting that if the engine needs to start with a frozen inlet or frozen filters then heating coils would be the best option in this scenario.
Maintain a low pressure drop
Avoid an unexpected shutdown
AAF’s high pressure bleed air system diverts a percentage of warm and dry compressed air from one of the gas turbine compression stages. This is fed via a control valve through heavy duty piping into a manifold at the entry point to the filters.
AAF has implemented this system across many projects around the world, and this includes silencing the high velocity hot air to an acceptable level and dispersing the air uniformly across the intake. The high-pressure bleed air system can only be utilised when the gas turbine is operational.
The low pressure bleed air system is similar in approach to the high pressure bleed air system but this time the warm, dry air is injected from the hot air outlet from the gas turbine enclosure via a pressure reducing valve. It can also be taken from one of the gas turbine compression stages.
The system comprises of two components; the horizontal header duct and several vertical dispersion ducts to ensure the hot air is evenly distributed across the inlet. Unlike the high pressure bleed air system the low pressure bleed air system usually requires no additional silencer.
A gas turbine heating coil, also known as a steam and hot water heat exchanger, is the ideal heating solution. It prevents ice formation during operation and allows operators to de-ice a frozen filter system when the gas turbine is shut down. AAF heating coils require an independent source of hot water which is fed through coils to provide radiant heat to the frozen filter elements.
AAF heating coils are suitably spaced with a helical fin to prevent dirt build up and to allow for easier cleaning. This solution can be customised for any gas turbine inlet, speak to AAF to understand more about the technical specification.