Pressurized closed cooling system

Abstract

An aircraft air conditioning system includes an air supply system (engine bleed or cabin air compressor taking ambient air and pressurizing it at or above cabin pressure) and a cooling system (air cycle or vapor cycle cooling packs to reject heat outside the vessel). These systems can exist as independent systems or combined into a single unit. Air supply and cooling are powered from either engine bleed air or electric power. In order to increase the airflow through the cabin, some cabin air is re-circulated and mixed with fresh air from the air supply system.

1 . A pressurized cooling system for a vehicle, comprising:
 a recirculation air flow coming from the vehicle;   a fresh air flow being delivered to a cooling subsystem; and   at least one injection location for mixing at least a portion of the recirculation air flow with the fresh air flow, wherein the portion of the recirculation air flow is either cooled prior to mixing with the fresh air flow or the portion of the recirculation air flow is mixed with the fresh air flow at a location upstream of a conditioned air flow being delivered from the cooling subsystem.   
   
   
       2 . The pressurized cooling system according to  claim 1 , further comprising:
 at least another injection location, in addition to the at least one injection location, the at least another injection location mixing at least a second portion of the recirculation air flow with the fresh air flow after the fresh air flow passes through a compressor of an air cycle machine.   
   
   
       3 . The pressurized cooling system according to  claim 1 , wherein the cooling subsystem includes an environmental control system (ECS) pack having an air cycle machine. 
   
   
       4 . The pressurized cooling system according to  claim 3 , further comprising a water extractor disposed downstream of the air cycle machine. 
   
   
       5 . The pressurized cooling system according to  claim 3 , wherein:
 the air cycle machine includes a compressor and a turbine; and   the at least one injection location includes a first injection location mixing the portion of the recirculation air flow with the fresh air flow after the fresh air flow passes through the compressor.   
   
   
       6 . The pressurized cooling system according to  claim 1 , further comprising at least one cabin air compressor for receiving and pressurizing the fresh air flow. 
   
   
       7 . The pressurized cooling system according to  claim 6 , wherein the at least one injection location includes a second injection location mixing the portion of the recirculation air flow with the fresh air flow before the fresh air flow is delivered to the at least one cabin air compressor. 
   
   
       8 . The pressurized cooling system according to  claim 1 , wherein the at least one injection location includes a third injection location mixing the portion of the recirculation air flow with the fresh air flow before the fresh air flow is delivered to the cooling subsystem. 
   
   
       9 . The pressurized cooling system according to  claim 1 , further comprising a recirculation flow heat exchanger wherein the at least one injection location includes a fourth injection location mixing the portion of the recirculation air flow after the portion of the recirculation air flow has passed through the recirculation flow heat exchanger with the fresh air flow after the fresh air flow has passed through a cooling subsystem. 
   
   
       10 . The pressurized cooling system according to  claim 9 , further comprising at least one of a fifth injection location and a sixth injection location, wherein:
 the fifth injection location mixing the portion of the recirculation air flow with the fresh air flow before the fresh air flow is delivered to the cooling subsystem; and   the sixth injection location mixing the portion of the recirculation air flow with the fresh air flow after the fresh air flow passes through a compressor.   
   
   
       11 . A pressurized cooling system for an aircraft comprising:
 a recirculation air flow coming from the aircraft;   a fresh air flow being delivered to a cooling subsystem;   a cabin air compressor for pressurizing the fresh air flow into a pressurized fresh air flow;   a first injection location for providing a fluid connection between the recirculation flow and the fresh air flow prior to the fresh air flow reaching the cabin air compressor; and   at least one injection location for mixing at least a portion of the recirculation air flow with the fresh air flow, wherein the portion of the recirculation air flow is either cooled prior to mixing with the fresh air flow or the portion of the recirculation air flow is mixed with the fresh air flow at a location upstream of a conditioned air flow being delivered from the cooling subsystem.   
   
   
       12 . The pressurized cooling system according to  claim 11 , wherein the at least one injection location includes a second injection location for mixing the portion of the recirculation air flow with the pressurized fresh air flow before the pressurized fresh air flow is delivered to the cooling subsystem. 
   
   
       13 . The pressurized cooling system according to  claim 11 , wherein the at least one injection location includes a third injection location mixing the portion of the recirculation air flow with the pressurized fresh air flow after the pressurized fresh air flow passes through a compressor of an air cycle machine. 
   
   
       14 . The pressurized cooling system according to  claim 11 , further comprising a recirculation flow heat exchanger, wherein the at least one additional injection location includes a fourth injection location mixing the portion of the recirculation air flow after the portion of the recirculation air flow has passed through the recirculation flow heat exchanger with the pressurized fresh air flow after the pressurized fresh air flow has passed through the cooling subsystem. 
   
   
       15 . A method for providing cooling to an aircraft cabin, the method comprising:
 providing a fresh air flow through a cooling subsystem;   providing a recirculation air flow from the aircraft cabin;   cooling the recirculation air flow;   mixing the recirculation air flow with the fresh air flow to provide a mixed recirculation air flow; and   delivering the mixed recirculation air flow and fresh air flow to the aircraft cabin.   
   
   
       16 . The method according to  claim 14 , wherein the step of cooling the recirculation air flow occurs before the step of mixing the recirculation air flow with the fresh air flow. 
   
   
       17 . The method according to  claim 14 , wherein the step of cooling the recirculation air flow occurs after the step of mixing the recirculation air flow with the fresh air flow. 
   
   
       18 . The method according to  claim 17 , wherein the step of mixing the recirculation air flow with the fresh air flow occurs before the fresh air flow passes through the cooling subsystem. 
   
   
       19 . The method according to  claim 17 , wherein the step of mixing the recirculation air flow with the fresh air flow occurs after the fresh air flow is compressed by a compressor of an air cycle machine in the cooling subsystem. 
   
   
       20 . The method according to  claim 15 , further comprising:
 pressurizing the fresh air flow with a cabin air compressor; and   mixing at least a portion of the recirculation air flow with the fresh air flow prior to the step of pressurizing the fresh air flow with a cabin air compressor.