Compressor cooling for turbine engines

Abstract

Systems, apparatuses and methods (“utilities”) for use in “internally” cooling the compressor of a gas turbine engine so as to approximate isothermal compression and thereby increase the power and/or efficiency of the engine. In one arrangement, a “cooling jacket” or heat exchanger having coolant circulating or passing therethrough may be mounted around an outer surface of the compressor to absorb heat or thermal energy generated from the compressor. In another arrangement, the stator blades of the compressor may include passages through which a coolant may be circulated or passed to absorb heat from air passing through the compressor.

1 . A stator structure for a compressor, comprising:
 a stator casing comprising inside and outside surfaces, and inlet and outlet ends, wherein air generally moves in an air flow direction from the inlet towards the outlet end;   a plurality of spaced stator sections extending from the inside surface of the stator casing, wherein each stator section comprises a plurality of stator blades, and wherein each stator blade comprises:
 an intake passage extending along a length of the stator blade for receiving a flow of coolant into the stator blade; and 
 a return passage, fluidly interconnected to the intake passage, and extending along the length of the stator blade for passing the flow of coolant out of the stator blade, wherein the coolant is operable to absorb thermal energy from the stator blade and transfer thermal energy away from the stator blade. 
   
     
     
         2 . The stator structure of  claim 1 , wherein each stator section comprises a stator ring that is secured to the inside surface of the stator casing, wherein the plurality of stator blades extend away from the stator ring. 
     
     
         3 . The stator structure of  claim 1 , wherein each stator blade comprises first and second opposing ends, wherein the first end is interconnected to the inside surface of the stator casing, and wherein the second ends of the stator blades in a stator section are interconnected by a shroud cover. 
     
     
         4 . The stator structure of  claim 1 , wherein each stator blade comprises first and second generally opposing blade surfaces, wherein at least one of the first and second generally opposing blade surfaces comprises at least one fin extending therefrom. 
     
     
         5 . The stator structure of  claim 4 , wherein the at least one fin extends between and interconnects at least first and second adjacent stator blades. 
     
     
         6 . The stator structure of  claim 1 , wherein the inside surface of the stator casing comprises a plurality of pairs of ports, each pair comprising a first port that is fluidly interconnected to the intake passage of a stator blade and a second port that is fluidly interconnected to the return passage of the stator blade. 
     
     
         7 . The stator structure of  claim 6 , further comprising a fluid jacket attached to the outside surface of the stator casing that provides coolant to the first port and receives coolant from the second port of each of said pair of ports of the stator casing. 
     
     
         8 . The stator structure of  claim 7 , wherein the fluid jacket comprises a first cavity that provides coolant to the first ports and a second cavity that receives coolant from the second ports. 
     
     
         9 . The stator structure of  claim 8 , wherein the first cavity includes at least one port that receives coolant from a heat exchanger, and wherein the second cavity includes at least one port that passes coolant to the heat exchanger. 
     
     
         10 . An apparatus for use with a gas turbine engine, comprising:
 an annular housing including inside and outside surfaces, and inlet and outlet ends, wherein air generally moves in an air flow direction from the inlet end towards the outlet end; and   a plurality of spaced sets of stators extending from the inside surface of the housing, wherein each set of stators comprises a plurality of stator blades; and   a first heat exchanger extending around at least a portion of the outside surface of the housing, wherein the first heat exchanger is operable to absorb thermal energy from the housing and transfer thermal energy away from the stator blades.   
     
     
         11 . The apparatus of  claim 10 , wherein the first heat exchanger comprises:
 at least one coolant fluid path.   
     
     
         12 . The apparatus of  claim 11 , wherein the coolant fluid path comprises:
 an outer wall spaced from the outer surface of the housing to form a fluid tight cavity between the outer wall and the outer surface of the housing;   an inlet port for introducing coolant into the cavity; and   an outlet port for removing coolant from the cavity, wherein coolant is operable to flow through the cavity between the inlet and outlet ports.   
     
     
         13 . The apparatus of  claim 12 , wherein the first heat exchanger comprises:
 a plurality of fluid paths, wherein a different one of the fluid paths is aligned with a different one of the sets of stators.   
     
     
         14 . The apparatus of  claim 13 , wherein the first heat exchanger comprises:
 an inlet header including a plurality of inlet ports interconnected to at least one of the plurality of fluid paths; and   an outlet header including a plurality of outlet ports interconnected to at least one of the plurality of fluid paths.   
     
     
         15 . The apparatus of  claim 12 , further comprising:
 a second heat exchanger interconnected to said inlet and outlet ports for removing heat from coolant upon said coolant exiting said first heat exchanger.   
     
     
         16 . The apparatus of  claim 15 , wherein said second heat exchanger comprises a radiator. 
     
     
         17 . The apparatus of  claim 11 , wherein the first heat exchanger comprises:
 first and second sections, wherein the first and second sections are adapted to extend about a respective half of the annular housing and be secured together.   
     
     
         18 . The apparatus of  claim 11 , wherein the first heat exchanger comprises:
 a dividing wall extending between the outer wall of the first heat exchanger and the outer surface of the housing to form first and second cavities, wherein each of the first and second cavities comprises:   an inlet port for receiving coolant and passing the coolant into the respective first or second cavity; and   an outlet port for removing coolant from the respective first or second cavity   
     
     
         19 . The apparatus of  claim 10 , wherein at least a portion of the stator blades comprise:
 an intake passage extending along a portion of a length of the stator blade for receiving a flow of coolant into the stator blade; and   a return passage, fluidly interconnected to the intake passage, and extending along a portion of the length of the stator blade for passing the flow of coolant out of the stator blade.   
     
     
         20 . The apparatus of  claim 10 , wherein each stator blade comprises first and second generally opposing blade surfaces, wherein at least one of the first and second generally opposing blade surfaces comprises at least one fin extending therefrom. 
     
     
         21 . The apparatus of  claim 20 , wherein the at least one fin extends between and interconnects with an adjacent stator blade. 
     
     
         22 . The apparatus of  claim 20 , wherein said at least one fin further comprises at least one ridge on its surface, where the at least one ridge is oriented at least partially transverse to the air flow direction. 
     
     
         23 . A gas turbine engine, comprising:
 a turbine section;   a combustion chamber that is fluidly interconnected to the turbine section;   a compressor that is fluidly interconnected to the combustion chamber, wherein the compressor comprises a housing having an inside surface and an outside surface; and   a fluid jacket extending around at least a portion of the outside surface of the housing, wherein the first fluid jacket is operable to circulate coolant over the outside surface of the housing to absorb thermal energy from the compressor and transfer thermal energy away from the compressor.   
     
     
         24 . The engine of  claim 23 , wherein the fluid jacket comprises:
 an outer wall spaced from the outside surface of the housing to form a cavity between the outer wall and the outer housing;   an inlet port for receiving coolant and passing the coolant into the cavity; and   an outlet port for receiving coolant from the cavity, wherein coolant is operable to flow through the cavity as the coolant flows between the inlet and outlet ports.   
     
     
         25 . The engine of  claim 24 , wherein the fluid jacket comprises a dividing wall extending between the outer wall of the fluid jacket and the outer housing to form first and second cavities, wherein each of the first and second cavities comprises:
 an inlet port for passing the coolant into the respective first or second cavity; and   an outlet port for removing coolant from the respective first or second cavity, wherein coolant is operable to flow through the respective first or second cavity as the coolant flows between the inlet and outlet ports.   
     
     
         26 . The engine of  claim 24 , wherein the fluid jacket comprises first and second sections, wherein the first and second sections are adapted to extend about the outside surface of the compressor and be secured together. 
     
     
         27 . The engine of  claim 24 , wherein the fluid jacket comprises:
 an inlet header including the inlet port, and an outlet header including the outlet port.   
     
     
         28 . The engine of  claim 27 , wherein the inlet header comprises:
 a plurality of inlet ports and the outlet header comprises a plurality of outlet ports.   
     
     
         29 . The engine of  claim 23 , wherein the fluid jacket further comprises:
 a plurality of fluid paths extending around separate portions of the outside surface of the housing.   
     
     
         30 . The engine of  claim 29 , wherein a different one of the fluid paths is aligned with a different stator section connected to the inside surface of the housing. 
     
     
         31 . The engine of  claim 23 , further comprising a recuperator that is fluidly interconnected to an outlet of the compressor and an inlet to the combustion chamber, wherein the recuperator uses exhaust gases from the turbine section to heat compressed air exiting the compressor prior to entry into the combustion chamber. 
     
     
         32 . A compressor, comprising:
 a stator structure, comprising:
 a stator casing including inside and outside surfaces, inlet and outlet ends, and a central axis running through a center of the stator casing, wherein air generally moves in an air flow direction from the inlet towards the outlet end; 
 a plurality of spaced stator sections extending from the inside surface of the stator casing, wherein each stator section comprises a plurality of stator blades; and 
 a plurality of coolant passages extending through the stator sections, wherein the coolant passages receive coolant that is operable to absorb thermal energy from the stator sections and transfer the thermal energy away from the stator sections; and 
   a rotor structure, comprising:
 a rotatable shaft having a longitudinal axis that is coincident with the central axis of the stator casing; and 
 a plurality of rotor sections attached to and extending from the rotatable shaft, wherein each rotor section includes a plurality of rotor blades, wherein the rotor sections are disposable between the spaced stator sections. 
   
     
     
         33 . The compressor of  claim 32 , further comprising a heat exchanger extending around the outside surface of the stator casing, wherein the first heat exchanger is operable to absorb thermal energy from the compressor and transfer thermal energy away from the compressor. 
     
     
         34 . A method for use in cooling a compressor in a gas turbine engine, comprising:
 establishing a coolant fluid path that extends at least partially over an outside surface of a housing of the compressor;   first passing a coolant along the coolant fluid path over the outside surface of the housing;   absorbing, using the coolant, thermal energy from the compressor; and   second passing the coolant along the coolant fluid path away from the outside surface of the compressor housing.   
     
     
         35 . The method of  claim 34 , wherein the establishing step comprises establishing the coolant fluid path through passages within a plurality of stator blades of the compressor. 
     
     
         36 . The method of  claim 35 , wherein the first passing step comprises, after passing the coolant over the outside surface of the compressor housing, passing the coolant along the coolant path through the passages in the plurality of stator blades. 
     
     
         37 . The method of  claim 36 , wherein the second passing step comprises, after passing the coolant through the passages in the plurality of stator blades, passing the coolant to an external heat exchanger. 
     
     
         38 . The method of  claim 34 , wherein the releasing step comprises circulating the fluid through a heat exchanger. 
     
     
         39 . The method of  claim 34 , further comprising passing the coolant through a cooling jacket disposed about an outside surface of the compressor. 
     
     
         40 . A process for use in a gas turbine engine, comprising:
 using a compressor having a housing, compressing air at a substantially constant temperature;   in conjunction with the compressing step, circulating a cooling fluid over an outside surface of the compressor housing or through stator blades in the compressor, wherein the cooling fluid removes heat from the air to allow the compressing step to operate at the substantially constant temperature;   using a combustion chamber, heating the compressed air at a substantially constant pressure;   expanding the heated, compressed air through a turbine stage to drive the turbine stage and the compressor; and   exhausting the air to the atmosphere.   
     
     
         41 . The thermodynamic cycle of  claim 40 , further comprising:
 passing the compressed air through a recuperator disposed within the exhaust flow of the engine to increase the temperature of air exiting the compressor.