Abstract: The invention provides a gas turbine intake air filter unit, wherein flow resistance of intake air passing through a tertiary filter layer does not become unreasonably great despite the filter layers are increased from two stages to three stages, and a balance of collecting efficiency of the filter layers and the intake air flow resistance is optimized. A weather louver 10, a primary filter layer 11, a secondary filter layer 12, and a tertiary filter layer 13 are sequentially disposed from an upstream side in the filter unit 1 installed at an upstream side end portion of an intake duct 2 communicating with a gas turbine 3, at least a recess 13e is formed toward a downstream side of the intake air flow A′ on an end face filter layer portion 13a that is a constituent of the tertiary filter layer 13 and is disposed orthogonally to the intake air flow A′ inside the intake duct 2.

Abstract: The invention provides a gas turbine intake air filter selecting system that works in accordance with density or nature of dust around a location of an individual gas turbine and with capacity and characteristics of the gas turbine.

Abstract: The invention provides a gas turbine intake air filter unit, wherein flow resistance of intake air passing through a tertiary filter layer does not become unreasonably great despite the filter layers are increased from two stages to three stages, and a balance of collecting efficiency of the filter layers and the intake air flow resistance is optimized.