Patent Publication Number: US-10330261-B2

Title: System and method for a heated gas cylinder assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of, claims priority to and the benefit of, U.S. Ser. No. 15/363,997 filed Nov. 29, 2016 entitled “SYSTEM AND METHOD FOR A HEATED GAS CYLINDER ASSEMBLY,” which is incorporated herein its entirety by reference for all purposes. 
    
    
     FIELD 
     The present disclosure relates to compressed gas cylinder assemblies, and more specifically, to systems and methods for a heated gas cylinder assembly. 
     BACKGROUND 
     Various industries, such as automotive, marine, aircraft, medical, sporting equipment, food and beverage, plumbing and electrical industries, may use compressed gas tank assemblies or high-pressure gas cylinders for storage and delivery of pressurized fluid. For example, compressed gas cylinder assemblies (or inflation assemblies) may be used with aircraft evacuation systems. In that respect, the compressed gas cylinder may supply gas to inflate life rafts, evacuation slides, and/or other floats to be used in evacuation situations. The amount of gas needed to provide inflation may vary as the operating temperature changes (e.g., heated gas is capable of doing more work than cold gas). Typically, an external propellant system, such as a solid propellant gas generator, may mix hot gas with the gas supplied from the compressed gas cylinder to account for cold operating temperatures. 
     SUMMARY 
     In various embodiments, a gas cylinder assembly is disclosed. The gas cylinder assembly may comprise an outer shell defining an interior chamber. The gas cylinder assembly may comprise a heat exchanger disposed within the interior chamber. The heat exchanger may comprise an inner bore. A pyrotechnic composition may be disposed within the inner bore. 
     In various embodiments, the pyrotechnic composition may comprise a metal oxide aluminum thermite. In various embodiments, the heat exchanger may comprise a heat exchanger spoke extending radially outward from the heat exchanger. In various embodiments, the gas cylinder assembly may further comprise an igniter disposed within the pyrotechnic composition and configured to ignite the pyrotechnic composition. In various embodiments, the gas cylinder assembly may further comprise an inner shell coupled to a radially outer surface of the heat exchanger. The inner shell may be configured to at least partially cover the heat exchanger. A first end of the inner shell may be coupled to an outlet of the outer shell to allow for a flow of a gas between the heat exchanger and the inner shell and through the outlet. In various embodiments, the heat exchanger may be aluminum. 
     In various embodiments, a gas cylinder assembly may comprise a gas cylinder and an outlet assembly fluidly coupled to an outlet of the gas cylinder. The gas cylinder assembly may comprise a heat exchanger disposed within the gas cylinder. The heat exchanger may comprise an inner bore. The heat exchanger and the gas cylinder may define an interior chamber. A pyrotechnic composition may be disposed within the inner bore. 
     In various embodiments, the gas cylinder assembly may further comprise an igniter disposed within the pyrotechnic composition and configured to ignite the pyrotechnic composition. In various embodiments, the gas cylinder assembly may further comprise an igniter control configured to transmit an ignition signal to the igniter to control ignition of the pyrotechnic composition. The heat exchanger may comprise a heat exchanger spoke extending radially outward from the heat exchanger. In various embodiments, the gas cylinder assembly may further comprise an inner shell coupled to a radially outer surface of the heat exchanger spoke. The inner shell may be configured to at least partially cover the heat exchanger. A first end of the inner shell may be coupled to the outlet of the gas cylinder to allow for a flow of a gas between the heat exchanger and the inner shell and through the outlet. In various embodiments, an inflatable device may be in fluid connection with the outlet assembly. In various embodiments, the pyrotechnic composition may comprise a metal oxide aluminum thermite. 
     In various embodiments, a method of releasing a heated gas mixture is disclosed. The method may comprise igniting a pyrotechnic composition. The pyrotechnic composition may be dispersed within an inner bore of a heat exchanger, the heat exchanger may be disposed within a gas cylinder, and the gas cylinder and the heat exchanger may define an interior chamber comprising a gas mixture. The method may comprise heating, by the heat exchanger, the gas mixture to create the heated gas mixture. The method may comprise releasing the heated gas mixture from an outlet of the gas cylinder. 
     In various embodiments, the gas mixture may be heated for a predetermined time prior to releasing the heated gas mixture. In various embodiments, the gas cylinder may comprise an inner shell coupled to the outlet and configured to at least partially cover the heat exchanger. The inner shell may be configured to enable a flow of the heated gas mixture between the heat exchanger and the inner shell through the outlet. In various embodiments, the heated gas mixture may be heated and released simultaneously. In various embodiments, the method may further comprise transmitting, by an igniter control, an ignition signal to an igniter disposed within the pyrotechnic composition. The igniter may be configured to ignite the pyrotechnic composition in response to receiving the ignition signal. 
     The forgoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated herein otherwise. These features and elements as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the following illustrative figures. In the following figures, like reference numbers refer to similar elements and steps throughout the figures. 
         FIG. 1  illustrates an exemplary aircraft with an evacuation system, in accordance with various embodiments; 
         FIG. 2  illustrates a side perspective view of a heated gas cylinder assembly, in accordance with various embodiments; 
         FIG. 3  illustrates a side perspective view of a heated gas cylinder assembly comprising an inner shell, in accordance with various embodiments; and 
         FIG. 4  illustrates a method of releasing a heated gas mixture. 
     
    
    
     Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present disclosure. 
     DETAILED DESCRIPTION 
     The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosures, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. 
     The scope of the disclosure is defined by the appended claims and their legal equivalents rather than by merely the examples described. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, coupled, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. Surface shading lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials. 
     In various embodiments, and with reference to  FIG. 1 , an exemplary aircraft  100  is depicted. The present disclosure describes gas cylinders and heated gas cylinder assemblies with respect to inflatable evacuation systems of an aircraft  100 , however, it will be understood the systems and methods of the present disclosure may be suitable for use in other systems having compressed gas systems. Aircraft  100  may comprise a fuselage  102  with wings  104  fixed to fuselage  102 . Emergency exit door  106  may be disposed on fuselage  102  and an evacuation system  108  may be stored, for example, in an undeployed condition in a packboard (container) housing inside the fuselage of aircraft  100 . A panel  110  may cover evacuation system  108  when installed within aircraft  100 . Evacuation system  108  may jettison panel  110  and deploy an inflatable device, such as an inflatable slide, in response to emergency exit door  106  opening. Evacuation system  108  may include a heated gas cylinder assembly  112  coupled to an inflatable device  114  and configured to inflate the inflatable device  114  (see  FIG. 2 ). 
     In various embodiments, and with reference to  FIG. 2 , a heated gas cylinder assembly  112  is depicted. Heated gas cylinder assembly  112  may include a cylinder shell  120  (e.g., a gas cylinder) configured to contain a gas mixture  126  that is under pressure. Cylinder shell  120  may comprise an outer surface  121  opposite an inner surface  122 . Inner surface  122  may define an interior chamber  125  (along with an outer surface  141  of a heat exchanger  140 , as discussed below). Inner surface  122  may comprise a metal liner, such as, for example, aluminum and/or aluminum alloy. Outer surface  121  may comprise one or more composite shells made of carbon fiber and/or other types of materials including composites (such as fiber reinforced polymers), metal, nano-fabrics, and/or nano-materials. In various embodiments, outer surface  121  may also include a fiberglass shell disposed on an outer surface of a carbon fiber shell. 
     In various embodiments, cylinder shell  120  may be configured to contain any desired gas mixture  126 , such as, for example carbon dioxide, a carbon dioxide and nitrogen mix, and/or any other suitable gas mixture, and/or a compressed liquid. In various embodiments, gas mixture  126  within cylinder shell  120  may be configured to be pressurized to about 2,300 pounds per square inch gauge (psig) (15,858 kPa) or greater (wherein the term “about” in this context only means +/−1,000 psig (6,895 kPa)). In various embodiments, the pressure of gas mixture  126  within cylinder shell  120  may be based on various factors, such as, for example, gas mixture  126  composition, gas mixture  126  temperature, and/or the like. Cylinder shell  120  may be in fluid communication with an inflatable device  114  (depicted schematically). In that regard, cylinder shell  120  may comprise an outlet  123  configured to allow the flow of gas mixture  126  out cylinder shell  120 , and to inflatable device  114 . Although heated gas cylinder assembly  112  is depicted as an inflation cylinder for inflatable device  114 , it should be understood that the concepts described herein are not limited to use with inflatable devices, as the teachings may be applied to other gas cylinders for use in non-aircraft systems as well. 
     In various embodiments, heated gas cylinder assembly  112  may comprise an outlet assembly  130 . Outlet assembly  130  may be coupled to cylinder shell  120  at outlet  123  and may be configured to maintain and control a release pressure of gas mixture  126  exiting from cylinder shell  120 . Outlet assembly  130  may provide gas mixture  126  to inflatable device  114  through outlet  123  and an assembly opening  133  (e.g., a valve and/or the like) of outlet assembly  130 . In various embodiments, outlet assembly  130  may also comprise a pressure gauge  135  configured to monitor the pressure of gas mixture  126  in cylinder shell  120 . In various embodiments, additional components (not depicted) may be disposed between outlet assembly  130  and inflatable device  114 , such as, for example, tubing, an aspirator, and/or other elements. Inflatable device  114  can be, for example, a slide, a raft, a slide/raft combination, and/or any other inflatable device or system configured to receive compressed fluid (e.g., gas mixture  126 ). 
     In various embodiments, heated gas cylinder assembly  112  may comprise a heat exchanger  140 . Heat exchanger  140  may be configured to provide thermal conduction to gas mixture  126 . In that respect, heat exchanger  140  may heat gas mixture  126  to any suitable temperature, such as, for example, about 50° F. (10° C.) to about 60° F. (16° C.), about 60° F. (16° C.) to about 80° F. (27° C.), about 80° F. (27° C.) to about 150° F. (66° C.), and/or about 150° F. (66° C.) to about 200° F. (93° C.) (wherein “about” in this context refers only to +/−5° F. (−12° C.)). Heat exchanger  140  may comprise any suitable thermally conductive material, such as, for example, aluminum, silver, and/or the like. Heat exchanger  140  may be substantially aligned with longitudinal axis A-A′, and may comprise a first end  142  axially opposite a second end  146 . In various embodiments, first end  142  may be fluidly coupled to and substantially aligned with outlet assembly  130  such that gas mixture  126  may pass through heat exchanger  140  before exiting cylinder shell  120 . In various embodiments, heat exchanger  140  may comprise one or more heat exchanger spokes  145  configured to provide additional thermal conduction to gas mixture  126 . Heat exchanger spokes  145  may extend in a radial direction away from longitudinal axis A-A′ and towards inner surface  122  of cylinder shell  120 . 
     In various embodiments, heat exchanger  140  may comprise an inner bore  150 . Inner bore inlet  153  may define a void on first end  142  of heat exchanger  140 , extending axially through heat exchanger  140 . Inner bore  150  may be substantially aligned with longitudinal axis A-A′. Inner bore  150  may be configured to store a pyrotechnic composition. Inner bore  150  may comprise an inner bore inlet  153  axially opposite an inner bore end  155 . In various embodiments, inner bore  150  may be filled, via inner bore inlet  153 , with a pyrotechnic composition configured to provide thermal conduction to heat exchanger  140  in response to ignition. In that respect, inner bore  150  may comprise any desired amount of pyrotechnic composition. For example, inner bore  150  may be filled with the pyrotechnic composition from inner bore end  155  to inner bore inlet  153 . In various embodiments, the amount of pyrotechnic composition may also be based on a desired final gas temperature, an energy requirement (e.g., temperature change, gas mixture  126  enthalpy, heat exchanger  140  mass, etc.), a desired heat of reaction, a pyrotechnic composition material, a gas mixture, and/or any other suitable operational variable. 
     In various embodiments, inner bore  150  may comprise any suitable pyrotechnic composition. In various embodiments, inner bore  150  may comprise a pyrotechnic composition that produces no gas during a chemical reaction. In various embodiments, the pyrotechnic composition may comprise a thermite powder. In that regard, the pyrotechnic composition may comprise any suitable thermite powder, such as, for example, a metal oxide aluminum thermite (e.g., a copper oxide aluminum thermite, an iron oxide aluminum thermite, etc.), and/or the like. In various embodiments, in response to the ignition of the pyrotechnic composition in inner bore  150 , the pyrotechnic composition may provide thermal conduction to heat exchanger  140 , allowing heat exchanger  140  to heat gas mixture  126 . 
     In various embodiments, and with reference to  FIG. 3 , heated gas cylinder assembly  112  may also comprise an inner shell  160 . Inner shell  160  may be configured to direct the flow of gas mixture  126  over heat exchanger  140 , before gas mixture  126  can exit cylinder shell  120 . In that respect, a second end  163  of inner shell  160  may be fluidly coupled to outlet assembly  130  to enable gas mixture  126  to flow through inner shell  160  and out outlet assembly  130 . In various embodiments, inner shell  160  may also be coupled to outer surface  141  of heat exchanger  140  (e.g., inner shell  160  may be coupled to outer surface  141  of heat exchanger spokes  145 ). In that regard, gas mixture  126  may flow between inner shell  160  and heat exchanger spokes  145  of heat exchanger  140  before exiting cylinder shell  120 . Inner shell  160  may comprise any suitable material, such as, for example aluminum, an aluminum alloy, and/or the like. 
     In various embodiments, inner shell  160  may at least partially cover heat exchanger  140 . In that respect, a first end  165  of heat exchanger  140  may extend axially along longitudinal axis A-A′ towards second end  146  of heat exchanger  140 . For example, and as depicted in  FIG. 3 , inner shell  160  may only partially cover heat exchanger  140  such that a portion of heat exchanger  140  is exposed to gas mixture  126 . In various embodiments, first end  165  of heat exchanger  140  may also align with second end  146  of heat exchanger  140  such that substantially all heat exchanger  140  is covered by inner shell  160 . 
     In various embodiments, heated gas cylinder assembly  112  may comprise an igniter  157  configured to ignite the pyrotechnic composition in inner bore  150 . Igniter  157  may be located in any suitable location capable of igniting the pyrotechnic composition. For example, igniter  157  may be disposed in inner bore inlet  153  in contact with the pyrotechnic composition. Igniter  157  may comprise any suitable device capable of igniting the pyrotechnic composition, such as, for example, a pressure cartridge. In various embodiments, igniter  157  may be configured to ignite the pyrotechnic composition in response to receiving an ignition signal. 
     In that respect, and in various embodiments, igniter  157  may be in logical and/or electronic communication with an igniter control  158 . Igniter control  158  may be configured to transmit an ignition signal to igniter  157  to control ignition of the pyrotechnic composition. Igniter control  158  may comprise any suitable device, processor, and/or the like capable of transmitting the ignition signal to igniter  157  to cause igniter  157  to ignite the pyrotechnic composition. For example, and in various embodiments, igniter control  158  may be configured to transmit the ignition signal to igniter  157  in response to activation of an evacuation system. For example, and with brief reference to  FIG. 1 , igniter control  158  may transmit the ignition signal in response to the jettison of panel  110 , the deployment of inflatable device  114 , and/or at any other suitable event. In that respect, igniter control  158  may comprise a switch, and/or the like, positioned to trigger igniter control  158  in response to the jettison of panel  110  and/or the deployment of inflatable device  114 . In various embodiments, igniter control  158  may also be in logical and/or electronic communication with a processor. In that respect, igniter control  158  may be commanded via the processor to transmit ignition signal. For example, the processor may command ignitor control  158  in response to an aircraft emergency, pilot control, and/or the like. 
     In various embodiments, and with reference to  FIG. 4 , a method  400  of releasing a heated gas mixture is disclosed. Method  400  may allow for the simultaneous, or near simultaneous, heating and releasing of a gas mixture, or may also allow for the preheating of a gas mixture prior to release. In various embodiments, method  400  may comprise receiving an ignition signal (step  410 ). With brief reference to  FIGS. 2 and 3 , the ignition signal may be transmitted by igniter control  158  and received by igniter  157 . The ignition signal may be transmitted in response to an evacuation system deploying, and/or in response to any other suitable event. In various embodiments, method  400  may comprise igniting a pyrotechnic composition (step  420 ). With brief reference to  FIGS. 2 and 3 , igniter  157  may ignite the pyrotechnic composition in response to receiving the ignition signal from igniter control  158 . In response to ignition, the pyrotechnic composition may provide thermal conduction to heat exchanger  140 , enabling heat exchanger  140  to provide thermal conduction to heat gas mixture  126 . In various embodiments, method  400  may comprise releasing the heated gas mixture (step  430 ). With brief reference to  FIGS. 2 and 3 , the heated gas mixture  126  may be released from cylinder shell  120  via outlet  123  and assembly opening  133  of outlet assembly  130 . In that regard, the heated gas mixture  126  may be provided to inflatable device  114 . 
     In various embodiments, step  420  and step  430  may occur simultaneously, or near simultaneously. In that respect, gas mixture  126  may be heated by heat exchanger  140  and released via outlet assembly  130 . For example, and with brief reference to  FIG. 3 , heated gas cylinder assembly  112  may ignite the pyrotechnic composition and open assembly opening  133  of outlet assembly  130 . Gas mixture  126  may flow between heat exchanger  140  and first end  165  of inner shell  160 , before flowing through inner shell  160  and out outlet assembly  130 . In that respect, inner shell  160  may force gas mixture  126  to flow between heat exchanger  140  and inner shell  160 , thus enabling gas mixture  126  to be heated by heat exchanger  140  prior to exiting outlet assembly  130 . 
     In various embodiments, step  420  may also occur prior to step  430 , such that gas mixture  126  is preheated before it is released. For example, and with brief reference to  FIG. 2 , heated gas cylinder assembly  112  may ignite the pyrotechnic composition to provide thermal conduction to gas mixture  126 . Outlet assembly  130  may be configured to delay the flow of gas for a predetermined time (e.g., 5 seconds, 30 seconds, 1 minute, etc.), to allow gas mixture  126  to preheat prior to release. After the predetermined time, outlet assembly  130  may open to allow the flow of the heated gas mixture  126 . 
     Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosures. The scope of the disclosures is accordingly to be limited by nothing other than the appended claims and their legal equivalents, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. 
     Systems, methods and apparatus are provided herein. In the detailed description herein, references to “various embodiments”, “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
     Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element is intended to invoke 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.