Aircraft and method for pre-cooling an environmental control system

Abstract

An aircraft includes an environmental control system having a bleed air inlet, a gas turbine engine having at least one low pressure bleed air supply and at least one high pressure bleed air supply, and a turbo air cycle machine having a first turbine section, a second turbine section, a first compressor section, and second compressor section.

What is claimed is: 
     
         1 . An aircraft comprising:
 an environmental control system having a bleed air inlet;   a gas turbine engine having at least one low pressure bleed air supply and at least one high pressure bleed air supply;   a turbo air cycle machine having a rotationally coupled first turbine section, a second turbine section, and a first compressor section, and a selectively rotationally coupled second compressor section;   an upstream turbo-ejector selectively fluidly coupling the low and high pressure bleed air supplies to the first turbine section and at least one of the first compressor section or the second compressor section; and   a downstream turbo-ejector fluidly combining fluid outputs from at least one of the first turbine section or the second turbine section with fluid output from the at least one of the first compressor section or the second compressor section into a common flow that is supplied to the bleed air inlet of the environmental control systems.   
     
     
         2 . The aircraft of  claim 1 , wherein the first compressor section and the second compression section are in parallel. 
     
     
         3 . The aircraft of  claim 2 , wherein the first turbine section, the second turbine section, and the first compressor section are rotationally coupled to a common shaft. 
     
     
         4 . The aircraft of  claim 3 , further comprising at least one of a clutch assembly, a decoupling mechanism, or a mechanical fuse disconnect, configured to selectively couple the second compressor section to the common shaft. 
     
     
         5 . The aircraft of  claim 1 , further comprising a bypass conduit fluidly coupling the fluid output of the first turbine section to the downstream turbo-ejector. 
     
     
         6 . The aircraft of  claim 5 , further comprising a bypass valve configured to selectively control fluid flow through the bypass conduit. 
     
     
         7 . The aircraft of  claim 1 , further comprising a source valve fluidly coupling an ambient air supply to the low pressure bleed air supply in the upstream turbo-ejector. 
     
     
         8 . The aircraft of  claim 7 , wherein the source valve is configured to supply one of the ambient air supply or the low pressure bleed air supply to at least one of the first compressor section or the second compressor section. 
     
     
         9 . A method of providing air to the environmental control system of the aircraft of  claim 1 , the method comprising:
 selectively supplying at least some of ambient air, low pressure bleed air, or high pressure bleed air to the turbo air cycle machine to precondition the bleed air according to operational demands of the environmental control system;   wherein the selectively supplying comprises selectively supplying to at least one of the first compressor section or the second compressor section based on desired flow capacity; and   wherein the preconditioning comprises selectively providing a fluid output emitted from the first turbine section of the turbo air cycle machine to the second turbine section of the turbo air cycle machine for further cooling.   
     
     
         10 . The method of  claim 9 , further comprising selectively supplying a fluid output from the at least one of the first compressor section or the second compressor section of the turbo air cycle machine to a fluid output emitted from at least one of the first turbine section of the turbo air cycle machine or the second turbine section of the turbo air cycle machine. 
     
     
         11 . The method of  claim 10 , further comprising de-coupling the second compressor section. 
     
     
         12 . An aircraft comprising:
 an environmental control system having a bleed air inlet;   a gas turbine engine having a low pressure (LP) bleed air supply and a high pressure (HP) bleed air supply;   a turbo air cycle machine comprising a first turbine section, a second turbine section, a first compressor section, and a second compressor section;   a controllable valve assembly located upstream of the turbo air cycle machine and comprising:
 a first fluid coupling between the LP bleed air supply and the first turbine section; 
 a second fluid coupling between the HP bleed air supply and the first turbine section; and 
 a third fluid coupling between the LP bleed air supply and at least one of the first compressor section or the second compressor section; and 
   a turbo-ejector fluidly combining at least one turbine output flow from at least one of the first turbine section or the second turbine section with at least one compressor output flow from the at least one of the first compressor section or the second compressor section to form a common output flow that is supplied to the bleed air inlet.   
     
     
         13 . The aircraft of  claim 12 , further comprising a fourth fluid coupling from an outlet of the first turbine section to an inlet of the second turbine section, whereby a first turbine output flow is supplied to the second turbine section to form a second turbine output flow. 
     
     
         14 . The aircraft of  claim 13 , wherein the turbo-ejector fluidly combines the second turbine output flow from the second turbine section with the compressor output from the at least one of the first compressor section or the second compressor section to form the common output flow. 
     
     
         15 . The aircraft of  claim 13 , further comprising a bypass conduit fluidly coupling an outlet of the first turbine section to the turbo-ejector. 
     
     
         16 . The aircraft of  claim 15 , further comprising a bypass valve fluidly coupled to the outlet and configured to supply a first portion of the first turbine output flow to the second turbine section, and to supply a second portion of the first turbine output flow to the bypass conduit. 
     
     
         17 . The aircraft of  claim 16 , wherein the first portion is between 0-100% of the first turbine output flow. 
     
     
         18 . The aircraft of  claim 13 , wherein the turbo-ejector fluidly combines each of the first turbine output flow, the second turbine output flow, a first compressor output flow from the first compressor section, and a second compressor output flow from the second compressor section to form the common output flow. 
     
     
         19 . The aircraft of  claim 13 , further comprising an ambient air supply fluidly coupled to the controllable valve assembly. 
     
     
         20 . The aircraft of  claim 19 , wherein the controllable valve assembly is configured to supply one of the ambient air supply or the LP bleed air supply to at least one of the first compressor section or the second compressor section.