Patent Publication Number: US-11389677-B2

Title: Fire-fighting system for an aircraft, having a double-chamber reservoir

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of the French patent application No. 1903914 filed on Apr. 12, 2019, the entire disclosures of which are incorporated herein by way of reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a fire-fighting system for an aircraft, the fire-fighting system having a reservoir with a double chamber, and to an aircraft having at least one such fire-fighting system. 
     BACKGROUND OF THE INVENTION 
     An aircraft conventionally has at least one nacelle inside which an engine, for example of the turbojet type, is disposed. The nacelle and the engine are fixed to the structure of the aircraft by means of a pylon fixed beneath the wing of the aircraft. 
     In order to avoid the structure of the aircraft becoming damaged when the engine catches fire, the aircraft is fitted with a fire-fighting system. 
     The fire-fighting system has two reservoirs which are installed in the pylon and which contain an extinguishing fluid. For each reservoir, the fire-fighting system also has a network of pipes which extends between the reservoir and the engine. 
     Each reservoir is closed by a disc and is fitted with an explosive cartridge which destroys the disc when it is activated. This destruction allows the extinguishing fluid to be released and then to flow into the pipes. 
     Although such a fire-fighting system gives good results, the two-reservoir architecture is bulky. 
     Indeed, the diameter of the engines is tending to increase and this then leads to the nacelle being brought closer to the wing and correspondingly reduces the space available in the pylon for accommodating the two reservoirs and the two networks of pipes. 
     It is therefore desirable to find a fire-fighting system having a novel architecture which allows space to be saved in the pylon. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to propose a fire-fighting system having a two-chamber reservoir thus allowing space to be saved, resulting in better integration into the pylon of an aircraft. 
     To that end, a fire-fighting system for an aircraft is proposed, the fire-fighting system having:
         a reservoir having an exterior envelope which delimits an interior volume of the reservoir and an interior wall which extends inside the exterior envelope and separates the interior volume into a first chamber and a second chamber which are separate from one another and are each filled with an extinguishing fluid,   a network of pipes, and   a valve system which is arranged so as to allow, in succession, the extinguishing fluid to flow from the first chamber to the network of pipes, and then the extinguishing fluid to flow from the second chamber to the network of pipes.       

     Such a fire-fighting system allows simpler installation in the aircraft, the fitting of a single network of pipes and hence a saving in terms of weight and volume. 
     Advantageously, the valve system has:
         a duct which has a first orifice opening into the first chamber, a second orifice opening into the second chamber, and a third orifice opening onto the network of pipes, the duct also having a first seat downstream of the second orifice and a second seat downstream of the first orifice,   a shut-off member able to move between a first position in which the shut-off member is positioned on the first seat and a second position in which the shut-off member is positioned on the second seat,   a first disc which shuts off the passage between the first orifice and the third orifice,   a second disc which shuts off the passage between the second orifice and the shut-off member, and   for each disc, an opening system intended to destroy the disc when it is activated.       

     Advantageously, each chamber is fitted with a sensor suitable for monitoring the pressure of the extinguishing fluid in the chamber, and the two sensors are connected to one and the same interface. 
     The invention also proposes an aircraft having an engine, a pylon which bears the engine, and a fire-fighting system according to one of the preceding variants, wherein the reservoir is fixed in the pylon, and wherein the network of pipes extends between the reservoir and the engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned features of the invention, along with others, will become more clearly apparent on reading the following description of one exemplary embodiment, the description being given with reference to the appended drawings, in which: 
         FIG. 1  is a side view of an aircraft according to the invention, and 
         FIG. 2  is a schematic representation in cross-sectional view of a fire-fighting system according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows an aircraft  10  which has a fuselage  11  to each side of which is fixed a wing  13  which bears an engine  14  such as a turbofan. 
     For each engine  14 , the aircraft  10  also has a pylon  12  which fixes the engine  14  beneath the wing  13 . 
     For each engine  14 , the aircraft  10  has a fire-fighting system  100 .  FIG. 2  shows the fire-fighting system  100 . 
     The fire-fighting system  100  has a reservoir  102  which is fixed in the pylon  12  and a network of pipes  104  which extends between the reservoir  102  and the engine  14 . 
     The reservoir  102  has an exterior envelope  202  which delimits the interior volume of the reservoir  102  and an interior wall  204  which extends inside the exterior envelope  202  and separates the interior volume of the reservoir  102  into a first chamber  206   a  and a second chamber  206   b  which are separate from one another. 
     Each chamber  206   a - b  is filled with an extinguishing fluid. 
     The fire-fighting system  100  also has a valve system  250  which is arranged so as to allow, in succession, the extinguishing fluid to flow from the first chamber  206   a  to the network of pipes  104 , and then the extinguishing fluid to flow from the second chamber  206   b  to the network of pipes  104 . 
     The valve system  250  and the interior wall  204  establish sealing between the two chambers  206   a - b , meaning that the extinguishing fluid from one chamber  206   a - b  cannot flow to the other chamber  206   b - a.    
     Such a fire-fighting system  100  thus allows simpler installation in the aircraft  10 , the fitting of a single network of pipes  104  between the reservoir  102  and the engine  14  and hence a single interface between the valve system  250  and the network of pipes  104 . 
     Such an installation also allows compliance with legislation requiring two separate volumes of extinguishing fluid to be present per engine  14 . 
     The valve system  250  has a duct  252  which in this case is T-shaped and which has a first orifice  254   a  which opens into the first chamber  206   a , a second orifice  254   b  which opens into the second chamber  206   b , and a third orifice  254   c  which opens onto the network of pipes  104 . 
     In other words, the first orifice  254   a  is in fluidic communication with the first chamber  206   a , the second orifice  254   b  is in fluidic communication with the second chamber  206   b , and the third orifice  254   c  is in fluidic communication with the network of pipes  104 . 
     Thus, the first chamber  206   a  is in fluidic communication with the network of pipes  104  via the first orifice  254   a  and the third orifice  254   c , and the second chamber  206   b  is in fluidic communication with the network of pipes  104  via the second orifice  254   b  and the third orifice  254   c.    
     The valve system  250  also has a shut-off member  256  which is able to move between a first position (shown in solid line in  FIG. 2 ) and a second position (shown in dashed line in  FIG. 2 ). In the embodiment of the invention shown in  FIG. 2 , the shut-off member  256  takes the form of a ball. 
     In the first position, the shut-off member  256  is positioned on a first seat  258   a  made in the duct  252  downstream of the second orifice  254   b  relative to a flow of extinguishing fluid from the second chamber  206   b  to the third orifice  254   c . This positioning shuts off the passage between the second orifice  254   b  and the third orifice  254   c  while leaving the passage between the first orifice  254   a  and the third orifice  254   c  clear, thus allowing the extinguishing fluid to flow from the first chamber  206   a  to the network of pipes  104 . 
     In the second position, the shut-off member  256  is positioned on a second seat  258   b  made in the duct  252  downstream of the first orifice  254   a  relative to a flow of extinguishing fluid from the first chamber  206   a  to the third orifice  254   c . This positioning shuts off the passage between the first orifice  254   a  and the third orifice  254   c  while leaving the passage between the second orifice  254   b  and the third orifice  254   c  clear, thus allowing the extinguishing fluid to flow from the second chamber  206   b  to the network of pipes  104 . 
     The shut-off member  256  and the seats  258   a - b  form a valve. 
     The valve system  250  also has a first disc  260   a  which shuts off the passage between the first orifice  254   a  and the third orifice  254   c . In the embodiment of the invention shown in  FIG. 2 , the first disc  260   a  is disposed between the shut-off member  256  and the third orifice  254   c , but it could be disposed between the first orifice  254   a  and the shut-off member  256 . 
     The valve system  250  also has a second disc  260   b  which shuts off the passage between the second orifice  254   b  and the shut-off member  256 , i.e., the first seat  258   a  in this case. 
     For each disc  260   a - b , the valve system  250  has an opening system  262   a - b , typically an explosive cartridge, which is intended to destroy the disc  260   a - b  when it is activated. 
     The aircraft  10  conventionally has fire sensors distributed in the engine  14  and connected to a control unit which also controls each opening system  262   a - b.    
     The operating principle of the fire-fighting system  100  is then as follows. When the control unit detects a fire in the engine  14 , it commands the activation of the opening system  262   a  associated with the first disc  260   a  which opens. Under the pressure of the extinguishing fluid present in the first chamber  206   a , the shut-off member  256  is pressed against the first seat  258   a  and the extinguishing fluid is then prevented from going to the second chamber  206   b  and flows to the third orifice  254   c  and the network of pipes  104 . 
     If the quantity of extinguishing fluid thus released is not sufficient to put out the fire, the control unit commands the activation of the opening system  262   b  associated with the second disc  260   b  which opens. Under the pressure of the extinguishing fluid present in the second chamber  206   b , the shut-off member  256  is pressed against the second seat  258   b  and the extinguishing fluid is then prevented from going to the first chamber  206   a  and flows to the third orifice  254   c  and the network of pipes  104 . 
     The pressure in each chamber  206   a - b  is monitored by a suitable sensor  208   a - b  such as a pressure sensor, for example. The architecture of the reservoir  102  allows there to be a single interface  210  for the two sensors  208   a - b , thus simplifying the architecture. Thus, each chamber  206   a - b  is fitted with a sensor  208   a - b  suitable for monitoring the pressure of the extinguishing fluid in the chamber  206   a - b , and the two sensors  208   a - b  are connected to the same interface  210  which can then simply be connected to the control unit. 
     While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.