Method and aircraft for providing bleed air to an environmental control system

Abstract

A method and aircraft for providing bleed air to environmental control systems of an aircraft using a gas turbine engine, including determining a bleed air demand for the environmental control systems, supplying low pressure and high pressure bleed air to the environmental control systems, wherein the proportional supplying is controlled such that the conditioned air stream meets the determined bleed air demand.

What is claimed is: 
     
         1 . A method of providing bleed air to environmental control systems (ECS) using a gas turbine engine, the method comprising:
 determining a bleed air demand for the ECS;   proportionally supplying low pressure and high pressure bleed air from a compressor of the gas turbine engine to a turbine section and compressor section of a turbo air cycle machine, with the turbine section emitting a cooled air stream and the compressor section emitting a compressed air stream; and   combining the cooled air stream and the compressed air stream to form a conditioned air stream;   wherein the proportional supplying is controlled such that the conditioned air stream meets the determined bleed air demand.   
     
     
         2 . The method of  claim 1  wherein the determining the bleed air demand comprises determining at least one of air pressure or air temperature demand for the ECS. 
     
     
         3 . The method of  claim 2  wherein the determining the bleed air demand comprises determining both the air pressure and the air temperature demand for the ECS. 
     
     
         4 . The method of  claim 1  wherein the bleed air demand is a function of at least one of number of aircraft passengers, aircraft flight phase, or operational subsystems of the ECS. 
     
     
         5 . The method of  claim 1  wherein proportionally supplying low pressure and high pressure bleed air comprises supplying 100% of one of the low pressure or high pressure bleed air and 0% of the other of the low pressure and high pressure bleed air. 
     
     
         6 . The method of  claim 1  wherein proportionally supplying low pressure and high pressure bleed air comprises step-wise proportionally supplying the low pressure and high pressure bleed air. 
     
     
         7 . The method of  claim 6  wherein the step-wise proportionally supplying the low pressure and high pressure bleed air is a function of the aircraft flight phase. 
     
     
         8 . The method of  claim 7  wherein the aircraft flight phase is one of ground idle, taxi, takeoff, climb, cruise, descent, hold, and landing. 
     
     
         9 . The method of  claim 6  wherein the step-wise proportionally supply the low pressure and high pressure bleed air is a function of the rotational speed of the gas turbine engine. 
     
     
         10 . The method of  claim 6  wherein the rotational speed of the gas turbine engine comprises predetermined speed ranges for the gas turbine engine. 
     
     
         11 . The method of  claim 1  wherein proportionally supplying low pressure and high pressure bleed air comprises continuously proportionally supplying the low pressure and high pressure bleed air. 
     
     
         12 . An aircraft comprising:
 an environmental control system (ECS) having a bleed air inlet;   a gas turbine engine having a low pressure bleed air supply and a high pressure bleed air supply;   a turbo air cycle machine having rotationally coupled turbine and compressor sections;   an upstream turbo-ejector fluidly coupling the low and high pressure bleed air supplies to the turbine and compressor sections; and   a downstream turbo-ejector fluidly combining fluid outputs from the turbine and compressor sections into a common flow that is supplied to the bleed air inlet of the ECS.   
     
     
         13 . The aircraft of  claim 12  wherein the environmental control system comprises an air-conditioning subsystem and a de-icing subsystem. 
     
     
         14 . The aircraft of  claim 12  wherein the upstream turbo-ejector comprises directly fluidly coupling the high pressure bleed air supply with the turbine section. 
     
     
         15 . The aircraft of  claim 14  wherein the upstream turbo-ejector comprises simultaneously supplying the low pressure bleed air supply to the compressor section and the high pressure bleed air supply. 
     
     
         16 . The aircraft of  claim 15  wherein the upstream turbo-ejector is configured to entrain at least a portion of the low pressure bleed air in the high pressure bleed air supply coupled with the turbine section. 
     
     
         17 . The aircraft of  claim 12  further comprising a controller module configured to controllably operate at least one of the upstream turbo-ejector or downstream turbo-ejector. 
     
     
         18 . A method of providing bleed air to an environmental control systems (ECS) of an aircraft using a gas turbine engine, the method comprising proportionally supplying low pressure and high pressure bleed air from a compressor of the gas turbine engine to a turbo air cycle machine to precondition the bleed air according to operational demands of the ECS. 
     
     
         19 . The method of  claim 18  further comprising determining the operational demands of the ECS by way of determining at least one of air pressure or air temperature demand for the ECS. 
     
     
         20 . The method of  claim 18  wherein proportionally supplying low pressure and high pressure bleed air comprises supplying 100% of one of the low pressure or high pressure bleed air and 0% of the other of the low pressure and high pressure bleed air.