Heat exchanger assembly for aircraft ecs

Abstract

An aircraft environmental conditioning system is disclosed that includes an air cycle system for conditioning a flow of hot compressed air by reducing its temperature and pressure. The air cycle system includes a heat exchanger having a heat rejection side in fluid communication with the airflow and a heat absorption side in fluid communication with external unconditioned air. The system also includes an airflow path from an external air inlet to the heat absorption side of the heat exchanger. A centrifugal separator is disposed in the airflow path, and includes a tubular body portion having an inlet that receives airflow, a deflector in the tubular body portion that imparts a vortex motion to airflow in the tubular body portion, and an outlet portion that includes a clean air outlet in fluid communication with the heat absorption side of the heat exchanger and a scavenge air outlet for removing particulate matter.

1 . An aircraft environmental conditioning system, comprising
 an air cycle conditioning system for conditioning an airflow comprising hot compressed air by reducing its temperature and pressure, the air cycle conditioning system including a heat exchanger having a heat rejection side in fluid communication with said airflow and a heat absorption side in fluid communication with external unconditioned air;   a heat exchanger assembly comprising an external air inlet and a first flow path from the external air inlet to the heat absorption side of the heat exchanger and from the heat absorption side of the heat exchanger to an external air exhaust outlet;   a particulate separator disposed along the first flow path between the external air inlet and the heat exchanger, the particulate separator being movable between a deployed position in the first flow path and a stand-by position not in the first flow path.   
     
     
         2 . The aircraft environmental conditioning system of  claim 1 , wherein the heat exchanger assembly further comprises a fan disposed in the first flow path. 
     
     
         3 . The aircraft environmental conditioning system of  claim 1 , wherein the particulate separator is a screen or mesh. 
     
     
         4 . The aircraft environmental conditioning system of  claim 1 , wherein the particulate separator is a centrifugal separator comprising a tubular body portion having an inlet that receives external air from the external air inlet, a deflector in the tubular body portion that imparts a vortex motion to air flow in the tubular body portion, and an outlet portion that comprises a clean air outlet in fluid communication with the heat absorption side of the heat exchanger and a scavenge air outlet for removing particulate matter. 
     
     
         5 . The aircraft environmental conditioning system of  claim 4 , comprising a plurality of said centrifugal separators disposed along the first flow path. 
     
     
         6 . The aircraft environmental conditioning system of  claim 1 , wherein the particulate separator is configured to, or is disposed in a housing configured to align and seal with a conduit along the first flow path, thereby directing the external air flow along the first path into the tubular body inlet. 
     
     
         7 . The aircraft environmental conditioning system of  claim 1 , further comprising a controller configured to direct the particulate separator to move between the deployed position and the stand-by position. 
     
     
         8 . The aircraft environmental conditioning system of  claim 7 , wherein the external air inlet comprises a ram external air inlet and a secondary external air inlet, and the controller is configured to direct air from the ram air inlet along the first flow path when the centrifugal separator is in the stand-by position, and is configured to deploy the particulate separator when the secondary external air inlet is open. 
     
     
         9 . The aircraft environmental conditioning system of  claim 7 , wherein the controller is configured to deploy the particulate separator if the aircraft is on or within proximity to the ground or if the fan is operating. 
     
     
         10 . The aircraft environmental conditioning system of  claim 1 , wherein the heat exchanger assembly further comprises a second flow path, without a particulate separator disposed therein, connecting the external air inlet to the heat absorption side of the heat exchanger. 
     
     
         11 . The aircraft environmental conditioning system of  claim 10 , wherein the external air inlet comprises a ram external air inlet and a secondary external air inlet, the first flow path is along a path from the secondary external air inlet to the particulate separator to the heat absorption side of the heat exchanger, and the second flow path is along a path from the ram external air inlet to the heat absorption side of the heat exchanger. 
     
     
         12 . The aircraft environmental conditioning system of  claim 10 , further comprising a controller configured to direct air from the external air inlet between the first flow path and the second flow path. 
     
     
         13 . The aircraft environmental conditioning system of  claim 12 , wherein the controller is configured to direct air from the external air inlet to the first flow path when the aircraft is on or proximate to the ground or the fan is operating, and is configured to direct air from the external air inlet to the second flow path when the aircraft is in flying at altitude or the fan is not operating. 
     
     
         14 . The aircraft environmental conditioning system of any of  claims 1 - 13 , wherein the particulate separation device is configured to separate particles of 4 μm to 3 mm from air in the first flow path.