Buffer system for a gas turbine engine

Abstract

A buffer system for a gas turbine engine includes a heat exchanger having a first inlet and outlet and a second inlet and outlet. The first outlet is configured to provide a cooled pressurized fluid. First and second air sources are selectively fluidly coupled to the first inlet. A third air source is fluidly coupled to the second inlet. Multiple fluid-supplied areas are located remotely from one another and are fluidly coupled to the first outlet. The multiple fluid-supplied areas include multiple bearing compartments. A method of providing pressurized air in a gas turbine engine includes selectively providing pressurized air from multiple air sources to a heat exchanger to cool the pressurized air. The cooled pressurized air is distributed to multiple fluid-supplied areas within the gas turbine engine.

1 . A buffer system for a gas turbine engine comprising:
 a heat exchanger having a first inlet and outlet and a second inlet and outlet, the first outlet configured to provide a cooled pressurized fluid;   first and second air sources selectively fluidly coupled to the first inlet;   a third air source fluidly coupled to the second inlet; and   multiple fluid-supplied areas located remotely from one another and fluidly coupled to the first outlet, the multiple fluid-supplied areas including multiple bearing compartments.   
     
     
         2 . The buffer system according to  claim 3 , wherein the first, second and third air sources are different than one another. 
     
     
         3 . The buffer system according to  claim 1 , comprising low and high pressure compressors, the second air source is provided by the high pressure compressor, and the third air source provided by the low pressure compressor. 
     
     
         4 . The buffer system according to  claim 3 , wherein a valve is fluidly coupled to at least one of the first and second air sources, the valve configured to regulate fluid flow from the first and second air sources to the heat exchanger. 
     
     
         5 . The buffer system according to  claim 3 , wherein a mid-stage is provided fluidly between the low and high pressure compressors, the first air source provided by the mid-stage. 
     
     
         6 . The buffer system according to  claim 1 , comprising a high pressure compressor including a rotor, and the multiple fluid-supplied areas including the rotor. 
     
     
         7 . The buffer system according to  claim 1 , comprising a low pressure turbine including a shaft, and the multiple fluid-supplied areas including the shaft. 
     
     
         8 . The buffer system according to  claim 1 , comprising a component, and the multiple fluid-supplied areas including the component, which is configured to be cooled by the cooled pressurized fluid. 
     
     
         9 . The buffer system according to  claim 1 , comprising a bypass flow path arranged between core and fan nacelles, the second outlet fluidly coupled to the bypass flow path. 
     
     
         10 . The buffer system according to  claim 9 , comprising a low pressure compressor fluidly coupled to the second inlet. 
     
     
         11 .- 15 . (canceled) 
     
     
         16 . A gas turbine engine comprising:
 a fan;   a compressor section fluidly connected to the fan;   a combustor fluidly connected to the compressor section;   a turbine section fluidly connected to the combustor; and   a buffer system comprising:
 a heat exchanger having a first inlet and outlet and a second inlet and outlet, the first outlet configured to provide a cooled pressurized fluid; 
 first and second air sources selectively fluidly coupled to the first inlet; 
 a third air source fluidly coupled to the second inlet; and 
 multiple fluid-supplied areas located remotely from one another and are fluidly coupled to the first outlet, the multiple fluid-supplied areas including multiple bearing compartments. 
   
     
     
         17 . The gas turbine engine according to  claim 16 , wherein the gas turbine engine is a high bypass geared aircraft engine having a bypass ratio of &eater than about six (6). 
     
     
         18 . The gas turbine engine according to  claim 16 , wherein the gas turbine engine includes a low Fan Pressure Ratio of less than about 1.45. 
     
     
         19 . The gas turbine engine according to  claim 16 , wherein the low pressure turbine has a pressure ratio that is greater than about 5. 
     
     
         20 . The gas turbine engine according to  claim 16 , wherein the first, second and third air sources are different than one another. 
     
     
         21 . The buffer system according to  claim 1 , wherein the first inlet is fluidly connected to the first outlet, and the second inlet is fluidly connected to the second outlet. 
     
     
         22 . The gas turbine engine according to  claim 16 , wherein the first inlet is fluidly connected to the first outlet, and the second inlet is fluidly connected to the second outlet.