Abstract:
A thermal pneumatic deicing system for deicing a RAM air heat exchanger includes an environmental control system (ECS) including a RAM air heat exchanger and an outlet, an electronics housing including a plurality of electronic components, and a duct fluidically connecting the RAM air heat exchanger and the electronics housing. The duct includes a valve. A controller is operatively connected to the valve. The controller is configured and disposed to selectively fluidically connect the RAM air heat exchanger and the electronics housing to facilitate deicing of the heat exchanger.

Description:
BACKGROUND OF THE INVENTION 
     Exemplary embodiments pertain to the art of aircraft systems and, more particularly, to a thermal pneumatic deicing system for an aircraft RAM air heat exchanger. 
     Aircraft include environmental control systems (ECS) that provide air supply, thermal control, and cabin pressurization for aircrew and passengers. Many ECS include a RAM air system including primary, and often times secondary, heat exchangers. In some cases, the primary and secondary heat exchangers are integrated into a single system. The RAM air system also generally includes a scoop that delivers a cooling airflow to the heat exchanger(s). As a consequence of using external air, the heat exchanger(s) often times experience ice build-up. The ice build-up reduces airflow through the heat exchanger(s) lowering system efficiency and increasing risk of Air Cycle Machine (ACM) surge. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Disclosed is a thermal pneumatic deicing system for deicing a RAM air heat exchanger including an environmental control system (ECS) including a RAM air heat exchanger and an outlet, an electronics housing including a plurality of electronic units, and a duct fluidically connecting the RAM air heat exchanger and the electronics housing. The duct includes a valve. A controller is operatively connected to the valve. The controller is configured and disposed to selectively fluidically connect the RAM air heat exchanger and the electronics housing to facilitate deicing of the heat exchanger. 
     Also disclosed is an aircraft including a fuselage extending from a nose portion to a tail portion through a body portion. The fuselage includes an aircraft cabin, first and second wings projecting from the body portion, and a thermal pneumatic deicing system including an environmental control system (ECS) including a RAM air heat exchanger having a heat exchanger face and an outlet, an electronics housing including a plurality of electronic units, and a duct fluidically connecting the RAM air heat exchanger and the electronics housing. The duct includes a valve. A controller is operatively connected to the valve. The controller is configured and disposed to selectively fluidically connect the RAM air heat exchanger and the electronics housing to facilitate deicing of the heat exchanger. 
     Further disclosed is a method of deicing a RAM air heat exchanger in an aircraft. The method includes directing a cooling airflow into an electronics housing, exchanging heat between electronics in the electronics housing and the cooling airflow forming a heated airflow, and selectively guiding the heated airflow to the RAM air heat exchanger. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  is a perspective view of an aircraft having a thermal pneumatic deicing system for a RAM air heat exchanger in accordance with an exemplary embodiment; and 
         FIG. 2  is a block diagram illustrating the thermal pneumatic deicing system of  FIG. 1   
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     An aircraft, in accordance with an exemplary embodiment, is indicated generally at  2  in  FIG. 1 . Aircraft  2  includes a fuselage  4  extending from a nose portion  6  to a tail portion  8  through a body portion  10 . Body portion  10  houses an aircraft cabin  14  that includes a crew compartment  15  and a passenger compartment  16 . Body portion  10  supports a first wing  17  and a second wing  18 . First wing  17  extends from a first root portion  20  to a first tip portion  21  through a first airfoil portion  23 . First airfoil portion  23  includes a leading edge  25  and a trailing edge  26 . Second wing  18  extends from a second root portion (not shown) to a second tip portion  31  through a second airfoil portion  33 . Second airfoil portion  33  includes a leading edge  35  and a trailing edge  36 . Tail portion  8  includes a stabilizer  38 . In the exemplary embodiment shown, aircraft  2  includes a thermal pneumatic deicing system  40 . The term “deicing system” should be understood to describe a system that prevents ice build-up from surfaces and also may remove ice already built up on a surface. The term “thermal pneumatic deicing system” should be understood to describe a system that prevents and/or removes ice using conditioned air. 
     As shown in  FIG. 2 , thermal pneumatic deicing system  40  includes an environmental control system (ECS)  50  mounted in body portion  10  of aircraft  2 . ECS  50  includes an inlet  52  which, in the exemplary embodiment shown, is positioned near leading edge  25  of first wing  17  ( FIG. 1 ). It should however be understood that inlet  52  may be arranged in other locations. Inlet  52  is fluidically connected with a RAM air system  53  having a RAM air heat exchanger  54 . RAM air heat exchanger  54  includes a RAM air heat exchanger face  56  that receives an airflow from inlet  52 . RAM air system  53  also includes an outlet  60  that delivers conditioned air to aircraft cabin  14  through a cabin air duct  64 . More specifically, cabin air duct  64  extends from a first end  67 , fluidically connected to outlet  60 , to a second end  68  through an intermediate portion  70 . Second end  68  is fluidically connected with, and delivers conditioned air to, aircraft cabin  14  (represented schematically as a box in  FIG. 2 ). A recirculation duct  71  extends from a first end  72  to a second end  73  through an intermediate portion  74  having a fan  75 . Fan  75  draws a portion of the conditioned air from aircraft cabin  14  back to intermediate portion  70  of cabin air duct  64 . 
     An electronics housing cooling duct  76  extends between aircraft cabin  14  and an electronics housing  78 . Electronics housing  78  includes a fan  80  that draws cooling air from aircraft cabin  14  to provide convection cooling for electronic components, indicated generally at  82 . More specifically, electronics housing cooling duct  76  extends from a first end  85 , fluidically connected to aircraft cabin  14 , to a second end  86  fluidically connected with electronics housing  78 . Cooling air from aircraft cabin  14  is passed in a heat exchange relationship with electronic components  82  forming a heated airflow. RAM air system  53  delivers ambient air to aircraft cabin  14 . The ambient air is conditioned, or heated, prior to entering aircraft cabin  14 . During flight, RAM air heat exchanger  54  may experience an icing condition that reduces airflow efficiency. In particular, ice may form at RAM air heat exchanger face  56  reducing airflow into RAM air system  53 . 
     In accordance with the exemplary embodiment, thermal pneumatic deicing system  40  includes a deicing duct  90  that selectively delivers the heated airflow from electronics housing  78  to RAM air heat exchanger  54 . More specifically, deicing duct  90  extends from a first end section  92 , fluidically connected with electronics housing  78 , to a second end section  93  through an intermediate section  95 . Second end section  93  is positioned to deliver the heated airflow onto RAM air heat exchanger face  56  and into RAM air heat exchanger  54 . The heated airflow thaws any ice than may have formed on RAM air heat exchanger  54 . A valve  99  is arranged along intermediate section  95 . Valve  99  selectively delivers the heated airflow to RAM air heat exchanger  54  and an outlet duct  110  that leads to ambient. Outlet duct  110  is provided in body portion  10  of fuselage  4  (as shown in  FIG. 1 ). A controller  120  is operatively connected to valve  99 . Controller  120  may include sensors (not shown) that indicate an ice build up on RAM air heat exchanger face  56  or may selectively command valve  99  to open and divert the heated airflow from passing to ambient and, instead, flow to RAM air heat exchanger  54  during flight conditions known to produce ice. 
     At this point it should be understood that the exemplary embodiment describes a system that selectively delivers heated airflow from an electronics housing to a RAM air heat exchanger for deicing. The thermal pneumatic deicing system includes a controller that operates a valve to deliver a deicing airflow to the RAM air heat exchanger or releases the heated airflow to ambient. The controller may use sensors to detect an icing condition or may deliver the deicing airflow under flight conditions known to produce icing. Further, it should be understood that the type, number, and location of the electronic components may vary. It should also be understood that additional components, accessories, ducts and the like may be fluidically connected to the deicing system. 
     While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.