Hybrid pneumatic and electric secondary power integrated cabin energy system for a pressurized vehicle

Abstract

A system for providing compressed air to pneumatic loads in a vehicle such as an aircraft is disclosed. The system may include a gas turbine engine having; a) an engine compressor with an air inlet coupled to an interior of a cabin of the vehicle; and b) a load compressor coupled to the gas turbine engine having a compressed air outlet coupled to one or more pneumatic loads of the vehicle. One or more electrically-driven cabin air compressors (CACs) have compressed air outlets coupled to the one or more pneumatic loads.

What is claimed is: 
     
         1 . An environmental control system (ECS) for a vehicle comprising:
 a first pneumatically-driven pack;   a second pneumatically-driven pack; and   a controller;   wherein, during a first mode of operation of the vehicle, the controller is configured to pneumatically couple the first pack and the second pack to a load compressor of a gas turbine engine,   wherein, during a second mode of operation of the vehicle, the controller is configured to pneumatically de-couple the first pack from the load compressor, and   wherein, during the second mode of operation of the vehicle, the controller is configured to pneumatically couple the first pack to one or more cabin air compressors (CACs).   
     
     
         2 . The ECS of  claim 1 , wherein the gas turbine engine comprises a component of an auxiliary power unit (APU) of the vehicle. 
     
     
         3 . The ECS of  claim 1 , wherein at least one of the CACs is driven via electrical power from an electrical generator of the vehicle. 
     
     
         4 . The ECS of  claim 3 , wherein the controller is configured to, in the event of inoperability of the gas turbine engine or the electrical generator, or in the event of a failure of electrical-load management, pneumatically couple the second pneumatically-driven pack to at least one of the CACs during operation of an aircraft while in-flight. 
     
     
         5 . The ECS of  claim 1 :
 wherein the vehicle is an aircraft; and   wherein, during ground and in-flight operations, a pressure ratio of the load compressor comprises substantially a same pressure ratio as that of at least one of the CACs.   
     
     
         6 . A method for providing environmental control in a vehicle, the method comprising:
 driving, with compressed air from a first air source of the vehicle or from a second air source of the vehicle, a first pack of an environmental control system (ECS) of the vehicle, wherein the first air source is different than the second air source; and   driving, with compressed air from the second air source, a second pack of the ECS, the second air source comprising at least one cabin air compressor (CAC).   
     
     
         7 . The method of  claim 6 , wherein the first air source comprises a load compressor of a gas turbine engine. 
     
     
         8 . The method of  claim 6 , wherein driving the first pack and the second pack comprises, in the event of inoperability of an auxiliary power unit (APU) or an electrical-load-management failure:
 driving, with compressed air from the second air source, the first and second pack, wherein the second air source comprises at least one cabin air compressor (CAC).   
     
     
         9 . The method of  claim 8 , wherein the at least one CAC includes a first CAC and a second CAC, wherein driving the first pack and the second pack comprises, in the event of the inoperability of the APU or an electrical-load-management failure:
 driving, with compressed air from the first CAC, the first pack of the ECS; and   driving, with compressed air from the second CAC, the second pack of the ECS.   
     
     
         10 . The method of  claim 6 , further comprising:
 providing the second air source with electrical power from one or more electrical generators.   
     
     
         11 . The method of  claim 10 , wherein the first air source includes at least one of the one or more electrical generators. 
     
     
         12 . The method of  claim 6 , wherein the compressed air from the second air source comprises compressed air from a plurality of CACs, and wherein driving the first pack or the second pack comprises:
 driving at least one of the first pack or the second pack via least two CACs of the plurality of CACs;   driving the first pack via a first CAC of the plurality of CACs; or   driving the second pack via a second CAC of the plurality of CACs, wherein the first CAC differs from the second CAC.   
     
     
         13 . An environmental control system (ECS) comprising a controller, wherein the controller is configured to:
 pneumatically couple a first pneumatically-driven pack to a load compressor of a gas turbine engine;   pneumatically couple a second pneumatically-driven pack to a first set of one or more cabin air compressor (CACs);   pneumatically de-couple the second pneumatically-driven pack from the one or more CACs;   pneumatically couple the second pneumatically-driven pack to the load compressor of the gas turbine engine;   pneumatically de-couple the first pneumatically-driven pack from the load compressor of the gas turbine engine; and   pneumatically couple the first pneumatically-driven pack to the one or more CACs.   
     
     
         14 . The ECS of  claim 13 , wherein the CACs receive air via a pneumatic duct. 
     
     
         15 . The ECS of  claim 14 , wherein the gas turbine engine receives air from an interior of the vehicle and outputs air via the pneumatic duct. 
     
     
         16 . The ECS of  claim 13 , wherein the controller is configured to:
 cause the APU to provide electrical power to the one or more CACs.   
     
     
         17 . The ECS of  claim 13 , wherein the one or more CACs include a plurality of CACs, wherein the controller is further configured to:
 pneumatically couple and de-couple the first pneumatically-driven pack to and from at least two of CACs of the plurality of CACs.   
     
     
         18 . The ECS of  claim 17 , wherein to pneumatically couple and de-couple the first pneumatically-driven pack to and from the at least two CACs, the controller is configured to:
 de-couple the first pneumatically-driven pack from a first CAC of the at least two CACs; and   couple the second pneumatically-driven pack to the first CAC.   
     
     
         19 . The ECS of  claim 13 , wherein the controller is further configured to pneumatically couple at least one of the one or more CACs to one or more main engines. 
     
     
         20 . The ECS of  claim 19 , wherein to pneumatically couple the at least one CAC to the one or more main engines, the controller is configured to:
 cause the at least one CAC to provide compressed air to the one or more main engines; and   cause the at least one CAC to start the one or more main engines with the compressed air.