Method and apparatus for active clearance control

A method of controlling a clearance between a tip of at least one compressor blade and an inner annular casing, said method comprising:

• defining a first cavity, a second cavity, and a third cavity between the inner annular casing and an outer annular casing;
• channeling at least one flow of cooling fluid from the first cavity to a manifold system including at least one conduit disposed within the second and third cavities;
• and
• channeling the at least one flow of cooling fluid from the manifold system to an impingement system disposed within the third cavity and positioned on a radially outer surface of the inner annular casing.

A turbomachine comprising:

• a compressor defining an axis of rotation, said compressor comprising:
• an inner annular casing comprising a radially outer surface;
• and
• an outer annular casing extending over at least a portion of the inner annular casing, said inner annular casing and said outer annular casing defining a plurality of cavities therebetween;
• and
• a clearance control system comprising:
• a manifold system comprising a plurality of conduits disposed within said plurality of cavities, said plurality of conduits extending axially along the inner annular casing, said plurality of conduits configured to channel a flow of cooling fluid between said plurality of cavities;
• an impingement system comprising a header and a plurality of plenums configured to channel said flow of cooling fluid to the radially outer surface of the inner annular casing and disposed within said plurality of cavities, said impingement system extending circumferentially about the inner annular casing, said plurality of conduits configured to channel said flow of cooling fluid to said impingement system;
• and
• a channel system comprising a plurality of channels disposed on the radially outer surface of the inner annular casing and configured to channel said flow of cooling fluid to the turbomachine, wherein said plurality of channels is configured to control said flow of cooling fluid to said manifold system.