Abstract:
A device for suppressing fires generated by lithium-ion batteries exhibiting thermal runaway. The device can include a thermally insulating enclosure for housing one or more battery cells. A fluid delivery system having a heat/temperature sensitive tube passes through each enclosure and contains an agent capable of extinguishing fires. When the cell or battery starts to undergo thermal runaway, the increase in temperature or the eruption of open flame causes the fluid delivery system to rupture inside the enclosure. The agent leaks out of the rupture and is transported into the enclosure and onto the malfunctioning cell or battery. Any fire is suppressed and the cell or battery is cooled down by the agent.

Description:
FIELD OF THE INVENTION 
     The invention relates to a fire extinguishing system with a method to prevent or extinguish fires, and more particularly, a fire suppression system having frangible extinguishant holders and automatic receptacles. 
     BACKGROUND 
     Several systems have attempted to deal with the issue of electrical fires and lithium-ion battery fires in particular. U.S. Pub. Appl. No. 2009/0014188 describes a device for containing ignited electrical equipment. The device includes a main body having an opening and volume sufficient to contain the electrical device and a flap to cover the opening to the main body when the electrical device is contained within the main body. By covering the opening with the flap, the lithium ion battery fire is contained within the device and not allowed to spread. However such a system does not deal with a thermal runaway reaction or a resulting fire, the system merely isolates these dangerous conditions from other cells in the battery. 
     U.S. Pat. No. 8,273,474 is a battery thermal management system where electrochemical cell battery systems and associated methods of operation are provided based on the incorporation of a thermal management matrix including a supply of phase change material disposed at least in part to a heat conductive lattice member to effectively dissipate heat produced or generated by or in the battery system. However such a system is only meant to cool a battery cell and if fire still occurs there is no method to suppress it. 
     U.S. Pub. Appl. No. 2010/0078182 is a device for generating and storing electrical or mechanical energy, and method for fire avoidance where an encapsulation in which at least one element of the device serving to generate or store electrical or mechanical energy is positioned, and having a container for flame-retardant substance. The substance store in the container releases a flame-retardant component if need be. However this system does not isolate each cell from another to prevent damage to other cells. Furthermore, this system has no method for activating in the presence of open flame. 
     SUMMARY 
     A fire suppression system furnishes a device to suppress fires generated by lithium-ion batteries. The device can include one or more battery cells, where each cell can be encased in a protective enclosure. Each enclosure can have an opening on one end. The enclosures define an empty volume or free space after a cell is inserted. A fluid delivery system can carry a fire-retarding or heat-dissipating fluid agent for delivery of the agent to the empty volume or free space of any given enclosure. 
     The device can include one or more battery cells, where each battery cell can be encased in a protective enclosure. Each enclosure can have an opening on one end, and the opening can be fitted with a cap to close the enclosure. Each cap can be disengaged from the opening of the enclosure. Each cap can include a pressure relief system in order to decrease pressure inside the corresponding enclosure. One or more temperature and flame sensitive tubes carrying a fire-retarding or heat-dissipating fluid agent can pass through each enclosure. When the temperature increases or a fire starts inside a given enclosure, the part of the tube inside the enclosure ruptures and the fluid agent can be delivered to the empty volume or free space of the given enclosure. 
     The device can include multiple battery cells, where each cell can be encased in a separate independent protective enclosure. Each enclosure can have an opening at one end with a cap fitted to engage and to sealingly close the enclosure. Each cap can be disengaged from a corresponding enclosure for battery cell maintenance. One or more temperature sensitive tubes carrying a fire-retarding or heat-dissipating fluid agent can pass through each enclosure in a serpentine or straight line fashion. When the temperature increases inside one or more enclosures due to an enclosed battery cell exhibiting a thermal runaway, a portion of the tube inside the affected enclosure can rupture and the fluid agent can be delivered to the empty volume or free space defined between the battery cell and a wall of the corresponding enclosure. 
     Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
         FIG. 1  is a cross-sectional view of one enclosure; 
         FIG. 2  is a top view of one enclosure; 
         FIG. 3  is a bottom view of one enclosure; 
         FIG. 4  is a simplified isometric view of a plurality of enclosures mounted vertically; and 
         FIG. 5  is a simplified isometric view of a plurality of enclosures mounted horizontally. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 , a cross-sectional view shows an elongate enclosure  10 . The elongate enclosure  10  can have an opening  12  at one end defining an interior volume  14 . The elongate enclosure  10  can house a cell  28  of a lithium-ion battery. The elongate enclosure  10  can leave the positive and negative terminals  42  of the cell  28  exposed. The exposed positive and negative terminals  42  can be connected to a battery grid board  40  with one or more connectors  44 . The positive and negative terminals  42  can plug into the corresponding connectors  44  as the battery cell slides within the corresponding elongate enclosure  10  into place. A container  36  can enclose a supply of a fluid agent  18 . The container  36  can be in fluidic contact with the interior volume  14  of the elongate enclosure  10  via a fluid delivery system  16 . 
     The elongate enclosure  10  can be constructed in such a way so as to be airtight. In the event of a cell fire, the elongate enclosure  10  can prevent the entry of oxygen from the air and can prevent the fire and elevated temperatures from spreading. Each cell  28  can be housed separately in one elongate enclosure  10  or housed together. The elongate enclosure  10  can be made out of any thermally insulating material, by way of example and not limitation, such as ground glass, graphite or ceramic. The material chosen depends on the environment in which the invention is being used. For instance, in applications where cost is a consideration, but the weight and total volume occupied by the invention are not, ground glass can be used. If lower weight, lower total volume occupied and ability to withstand increased temperatures are desired, then ceramic or graphite can be used. However, since the elongate enclosure  10  serves to thermally insulate the cell  28 , any thermally insulating material can be used to fabricate the elongate enclosure  10 . 
     The fluid delivery system  16  can be fastened to the container  36  and can run through the interior volume  14  of the elongate enclosure  10 . Static or dynamic pressure can be used to move the fluid agent  18  from the container  36  into the fluid delivery system  16 . The fluid delivery system  16  can allow the delivery of the fluid agent  18  from the container  36  to the interior volume  14  of the elongate enclosure  10  in the event of a thermal runaway or cell fire. The fluid delivery system  16  can incorporate a temperature and/or flame sensitive tube  38 . In the event of a thermal runaway or cell fire, the elevated temperatures or open flame can cause the temperature and/or flame sensitive tube  38  to rupture, releasing the fluid agent  18  into the interior volume  14  of the elongate enclosure  10 . The release of the fluid agent  18  allows the fluid agent  18  to come into thermal contact with the cell  28  resulting in cooling of the cell  28  and retarding of any fires existing in the elongate enclosure  10 . This operation results in a passive system that does not require user intervention. However, it should be recognized by those skilled in the art that various levels of user intervention can be implemented, if so desired. The temperature and/or flame sensitive tube  38  can be made out of any material meant to rupture in response to exposure to a certain temperature and/or after exposure to open flame. A suitable material for the temperature and/or flame sensitive tube  38  should be resistant to rupture during the normal operating temperature of the cell  28 . The material can also be chosen so the fluid agent  18  resists chemical reaction with the temperature and/or flame sensitive tube  38  to cause a premature rupture. 
     The fluid agent  18  can be any agent meant to suppress, retard or prevent fires, or any agent meant to absorb or dissipate heat. By way of example and not limitation, the agent can be a foam or an aqueous based solution. The aqueous based solution can be water plus the inclusion of a water soluble additive meant to increase fire retarding effectiveness or decrease the volume of water needed to effectively fire retard such as FEM-12SC, FireBane 1170, or Cold Fire 302. The agent sold under the commercial name FEM-12SC is manufactured by TLI Group Ltd. located in Carver, Mass. The agent sold under the commercial name FireBane 1170 is manufactured by GSL, Inc. located in Tulsa, Okla. The agent sold under the commercial name Cold Fire 302 is manufactured by Firefreeze Worldwide, Inc. located in Rockaway, N.J. 
     The elongate enclosure  10  can incorporate a cap  20  on the opening  12  end. The cap  20  can serve to close the opening  12 . The cap  20  can be released from the elongate enclosure  10  for battery cell maintenance. In the event of a malfunctioning cell, by way of example and not limitation, exhibiting thermal runaway, the cap  20  can be disengaged from the elongate enclosure  10  in order to remove and properly handle the malfunctioning cell. 
     The cap  20  can incorporate a pressure relief system  22 . In the event of a cell fire, a gas will build up inside the elongate enclosure  10  causing an increase in pressure. As pressure inside the elongate enclosure  10  rises, the risk of explosion increases. The pressure relief system  22  can enable release of pressure from the interior volume  14  of the elongate enclosure  10  to a volume outside of the elongate enclosure  10 . The pressure for opening up the contact between the interior volume  14  of the elongate enclosure  10  to a volume outside the elongate enclosure  10  can be selected so the pressure can be relieved before becoming sufficiently high to cause an explosion. 
     A second seal member  32  can extend between the cap  20  and the wall of the elongate enclosure  10 . The second seal member  32  can be made out of any material which allows the second seal member to form an airtight seal between the cap  20  and the wall of the elongate enclosure  10 . 
     Referring now to  FIG. 2 , a top view illustrates the cap  20  can incorporate a fluid release system  34 . In the event of a cell fire, the fluid delivery system  16  delivers fluid agent to the interior volume  14  of the elongate enclosure  10 . The fluid release system  34  can enable a controlled rate of leakage from the interior volume  14  of the elongate enclosure  10  to the volume outside of the elongate enclosure after the interior volume  14  has been filled with liquid. The controlled rate of leakage can assist in temperature and/or heat dissipation as well as pressure relief. It should be recognized that the controlled rate of leakage determines a time period of delivery of the fluid agent  18  to any battery cell  28  within an elongate enclosure  10  experiencing an abnormal thermal event, and that the time period can be affected by the volume of agent storage, the controlled rate of leakage, and the number of battery cells experiencing abnormal thermal events simultaneously or consecutively. 
     Referring now to  FIG. 3 , a bottom view shows that a first seal member  30  can extend between the cell  28  and the wall of the elongate enclosure  10  adjacent an end opposite from the cap  20 . The first seal member  30  can be made out of any material which allows the first seal member  30  to form an airtight seal between the cell  28  and the wall of the elongate enclosure  10 . 
     Referring now to  FIG. 4 , a simplified isometric view shows a plurality of elongate enclosures  10  mounted with corresponding axes extending vertically and parallel to one another  24 . The fluid delivery system  16  can be fastened to the container  36  and can contain the fluid agent. The fluid agent can run through each of the elongate enclosures  10  in a serpentine and/or straight line fashion, terminating at the last elongate enclosure. The container  36  can provide fluid communication with one or more interior volumes of the elongate enclosures in response to the rupture of the fluid delivery system  16  within one or more elongate enclosures. 
     Referring now to  FIG. 5 , a simplified isometric view shows a plurality of elongate enclosures  10  mounted with corresponding axes extending horizontally and parallel to one another  26 . The fluid delivery system  16  can be fastened to the container  36  and can contain the fluid agent. The fluid agent can run through each of the elongate enclosures  10  in a serpentine and/or straight line fashion, terminating at the last elongate enclosure. The container  36  can provide fluid communication with one or more interior volumes of the elongate enclosures in response to the rupture of the fluid delivery system  16 . 
     Referring now to  FIG. 1 , in operation the fire suppression system moves fire retarding or heat dissipating fluid agent  18  from the container  36  into the temperature and/or flame sensitive tube  38  by gravity or pressure generating equipment such as, by way of example and not limitation, pumps or pressurized gas, such as nitrogen. When a cell  28  undergoes thermal runaway, heat is generated and eventually fire will erupt. In response to either the temperature reaching a certain threshold or open flames reaching the temperature and/or flame sensitive tube  38 , the temperature and/or flame sensitive tube  38  will rupture, causing the release of the fire-retarding or heat-dissipating fluid agent  18  onto the cell  28 . The cell  28  and the fire-retarding or heat-dissipating fluid agent  18  can come into thermal contact resulting in cooling of the cell  28  and suppression of any fires existing in the elongate enclosure  10 . The cap  20  on the elongate enclosure  10  can then be removed in order to properly remove and dispose of the malfunctioning cell. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.