Abstract:
In an embodiment, a flow battery system with power producing components, having one or multiple stacks, pumps and related components wherein such components are mechanically mounted into, and fully supported by, a common backplane. Electrical and hydraulic interconnections are provided by the backplane and the backplane consists of one electromechanical assembly that will substantially reduce costs, and improve energy efficiency and serviceability. Multiple stacks and pumps may be interconnected in a single backplane in various serial and parallel configurations. In turn, multiple backplanes may be interconnected in various serial and parallel configurations, to build larger systems, depending on the application.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/909,425, filed on Nov. 27, 2013 and titled “Flow Battery Power Module Backplane”, the contents of which are incorporated by reference as though fully set forth herein. 
     
    
     BACKGROUND 
       [0002]    A flow battery system generally consists of a liquid electrolyte pumped through an array of one or more stacks that allow one to both charge the liquid with electrical energy and discharge electrical energy from the liquid. Each stack is comprised of an array of electrochemical cells. The liquid is commonly referred to as the energy component of the system. The part of the system incorporating the stacks, pumps and associated balance of system we refer to as the power component and alternatively the power module. 
         [0003]    There are two different electrolytes required for the operation of the flow battery stack. One is called the catholyte and the other is called the anolyte and they travel along separate fluid paths in the stack and are stored in their respective external tanks. Typical power modules contain any number of stacks that 1) are both electrically and hydraulically interconnected in various series and parallel configurations depending on the requirements of the energy storage system and multiple engineering considerations and 2) require a separate support structure for the stacks and pumps. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments described herein and, together with the description, explain these embodiments. The components of the drawings are not necessarily drawn to scale, the emphasis instead being placed upon illustrating principles of the present disclosure. In the drawings: 
           [0005]      FIG. 1  illustrates an example assembly that includes an array of stacks with associated catholyte and anolyte electrolyte pumps and a backplane; 
           [0006]      FIG. 2  illustrates an example interface that may be associated with a stack that may be included in the assembly; and 
           [0007]      FIG. 3  illustrates an example of how a stack may connect to the backplane. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    Typical problems that may exist with some flow battery systems include: 1) they may require a complex network of hand-assembled piping and wiring, combined with a mechanical support framework that is material and labor intensive, and therefore costly, to manufacture, 2) they may require more volumetric space per kilowatt-hour (kWh) of energy storage since all interconnections must allow the entry of human hands in and around the stack arrays for manufacturing and maintenance, and 3) replacement of a failed stack or pump is labor intensive, time consuming and can result in fluid loss or spillage. 
         [0009]    Embodiments of a new system integration approach for flow battery power modules is described. The approach includes, for example, a modular unitized flow battery stack design that allows, inter alia, individual stacks to be easily inserted into and removed from a backplane. The backplane provides, for example, integrated functions in one electromechanical assembly. 
         [0010]    The provided functions may include, for example, (1) mechanical support and retention for the stacks and pumps, (2) hydraulic interconnections for liquid catholyte and anolyte flowing through the stacks, in a variety of serial and parallel configurations, (3) electrical interconnections for the stacks, in a variety of serial and parallel configurations, (4) provisions for obviating shunt current losses that may occur between stacks and (5) integration of the above functions 1 through 4 based on a fast connect “plug-n-play” backplane. The entire assembly may be oriented either vertically or horizontally or any inclination between these two orientations. 
         [0011]    In an embodiment, an assembly includes a backplane and a stack. The backplane may provide an electrical connection and a hydraulic connection. The electrical connection and hydraulic connection is provided by the backplane to the stack. The stack has an interface that is operable to insert the stack into the backplane and remove the stack from the backplane. The interface includes an electrical connection that interconnects with the electrical connection of the backplane after the stack is inserted into the backplane, and a hydraulic connection that interconnects with the hydraulic connection of the backplane after the stack is inserted into the backplane. The assembly operates as a flow battery after the stack is inserted into the backplane. 
         [0012]    In an embodiment, the assembly includes a pump that provides circulation of electrolyte flow material utilized by the stack. The pump includes a motor portion that is detachable from the pump. The motor portion is insertable into and removable from the backplane. The pump includes an impeller portion that may be embedded into a hydraulic manifold contained in the backplane. The pump is a magnetic drive pump although other types of pumps (e.g., direct drive pumps) may be used. 
         [0013]    In an embodiment, a flow battery system includes, for example, a backplane, a plurality of stacks, and a plurality of pumps. The stacks and pumps are mechanically mounted into the backplane. The backplane provides electrical and hydraulic interconnections to the stacks and pumps. 
         [0014]      FIG. 1  illustrates an assembly  100  that includes stacks  160 , with associated catholyte and anolyte electrolyte pumps  170 , mounted on, and plugged into a backplane  110 . The assembly  100  may be included in a flow battery system. The assembly  100  may be either horizontal or vertical in orientation. 
         [0015]    Referring to  FIG. 1 , assembly  100  may include various components such as, for example, stacks  160 , pumps  170 , a backplane  110 , a positive electrical busbar connector  120 , a negative busbar connector  140 , catholyte hydraulic connectors  130 , and anolyte hydraulic connectors  150 . 
         [0016]    As illustrated in  FIG. 1 , assembly  100  includes three stacks  160  and two pumps  170  for backplane  110 . It should be noted, however, for any one backplane  110 , there can be any number of stacks  160  and pumps  170 . These stacks  160  and pumps  170  may also be arrayed in multiple rows on a backplane  110 . 
         [0017]    Single and multiple backplanes  110  may be connected directly to catholyte and anolyte tanks, and to power conversion equipment. Multiple backplanes  110  may be interconnected both electrically and hydraulically, in various serial and parallel configurations to meet the overall requirements of the flow battery system. 
         [0018]    Within any one backplane  110 , stacks  160  and electrolyte pumps  170  may be interconnected both electrically and hydraulically in various parallel and/or serial array configurations. Hydraulic flow paths and electrical conduction paths may be embedded and supported within the backplane  110  and mechanically protected by its structure. This mechanical protection will provide additional safety for service personnel. Stacks  160  and pumps  170  are typically fully supported by the backplane  110  and may require no other support mechanical structure. 
         [0019]    Within any one backplane  110 , there may be provided specially configured hydraulic paths, the purpose of which may be to obviate shunt current losses that may occur between the stacks  160  in the backplane  110 , thereby increasing, for example, a net energy efficiency of the flow battery system. 
         [0020]    Provisions to add and replace stacks  160 , pumps  170 , and/or other components may necessitate that any one backplane  110  be removed from the overall system operation, isolated both electrically and hydraulically, thereby facilitating fast and safe servicing by trained personnel. 
         [0021]    A stack  160  may include an interface that may interface the stack  160  with the backplane  110 . The interface may be “keyed” to allow the stack  160  to be inserted into the backplane  110  in only one way. The interface may contain a set of connectors that allow easy “plug-n-play” operation, so that the stack  160  can be easily inserted into and removed from the backplane  110 . Individual connectors in the stack  160  may be designed to mate with corresponding connectors in the backplane  110 . 
         [0022]      FIG. 2  illustrates an example interface  200  that may be used with a stack  160 . The interface  200  may interface the stack  160  with the backplane  110 . The interface  200  may be located on a back side of the stack  160 . The interface  200  may be operable to insert the stack  160  into the backplane  110  and remove the stack from the backplane  110 . Assembly  100  may operate as a flow battery after the stack  160  is inserted into the backplane  110  via the interface  200 . 
         [0023]    Referring to  FIG. 2 , the interface  200  may include, for example, four types of connectors. These connectors may include, for example, (1) a pair of anolyte hydraulic connectors  220 , (2) a pair of catholyte hydraulic connectors  230 , (3) a pair of electrical connectors  240 , and (4) four alignment/fastener connectors  210 . Stacks  160  may typically have male type connectors and the backplane  110  will typically have female type connectors. The connectors may be reversed or intermixed as required. 
         [0024]    The connectors may provide mechanical alignment when inserting the stack  160  into the backplane  110 . Here, for example, a user inserting the stack may not be able to see the connectors but alignment may be assured by a design of the connector. This type of connector may be referred to as a blind-mating connector. 
         [0025]    Hydraulic connectors  220 ,  230  may be, for example, blind-mating, self-aligning, low insertion force, self-sealing connectors. Hydraulic connectors  220 ,  230  may, for example, employ multiple sets of seals per connector for reliability and leak-proof operation. 
         [0026]    Removing stack  160  from backplane  110  may cause connectors  220 ,  230  to become disengaged. After being disengaged, connectors  220 ,  230  may automatically close. Moreover, after connectors  220 ,  230  are disengaged, corresponding connectors on the backplane  110  may automatically close. Automatic closing of connectors  220 ,  230  and the corresponding connectors on the backplane  110  may prevent fluid leakage and provide no-drip operation. An example of a connector that may be used to implement connectors  220 ,  230  is the commercially available Koolance® Quick Connect Series hydraulic connector, available from Koolance Incorporated, Auburn, Wash. 
         [0027]    The electrical connectors  240  may typically be blind-mating, self-aligning, low insertion force, multi-contact connectors. An example of a connector that may be used to implement connectors  240  is the commercially available TE Elcon Drawer Series electrical connector, available from TE Connectivity Ltd., Rheinstrasse 20 Ch-8200 Schaffhausen, Switzerland. 
         [0028]      FIG. 3  illustrates an example of how a stack  160  may connect to the backplane  110 . Referring now to  FIGS. 2 and 3 , in an embodiment, alignment/fastener connectors  210  may contact the backplane  110  first, thereby facilitating the alignment process. This may allow the stack  160  to be well aligned to the backplane  110  before other connectors, such as, for example, connectors  220 ,  230 , and/or  240  physically touch corresponding connections on backplane  110 . 
         [0029]    The alignment/fastener connectors  210  may be self-centering (such as, for example, cone shaped rods) in order to guide the connections on the backplane  110  and stack  160  into proper position. This may reduce mechanical stress on connectors  320 ,  330  contained on the backplane  110  and/or connectors  210 ,  220 ,  230 ,  240  contained on the stack  160  during insertion of the stack  160  into the backplane  110  and/or removal of the stack  160  from the backplane  110 . The alignment/fastener connectors  210  may mate (interconnect) with corresponding connectors  320  that may be contained on backplane  110 . 
         [0030]    The alignment/fastener connectors  210  may have a fastening mechanism that may be engaged to mechanically lock the stack  160  into the backplane  110  after the stack  160  is fully inserted into the backplane  110 . The fastening mechanism may be as simple as a through-bolt or a more complex locking cam mechanism. The fastening mechanism may also be external to the stack  160  using, for example, mating clamps that may grasp an outer shell of the stack  160  and mechanically secure it to the backplane  110 . 
         [0031]    The backplane  110  may include one or more connections that may interconnect with, for example, one or more hydraulic connections and/or the one or more electrical connections contained on the stacks  160  and/or pumps  170  ( FIG. 1 ). For example, backplane  110  may contain hydraulic connections that may interconnect with connections  220  and/or  230  after stack  160  is inserted into backplane  110 . Moreover, backplane  110  may contain one or more electrical connectors  330  that may interconnect with connectors  240  after stack  160  is inserted into backplane  110 . 
         [0032]    Referring back to  FIG. 1 , pumps  170  may also mate to the backplane  110  in a keyed fashion. Moreover, pumps  170  may be fastened to the backplane  110  and/or mechanically supported by the backplane  110 . In an embodiment, pumps  170  are connected to backplane  110  using a number of machine bolts. 
         [0033]    A pump  170  may be, for example, a magnetic drive pump although other types of pumps may be used. The pump may include a motor portion and/or a fluid impeller portion. The fluid impeller portion of the pump  170  may be embedded into and/or be an integral part of a hydraulic manifold that may be contained in the backplane  110 . This may allow a fluid path to remain completely sealed to the environment, which may be a major advantage if motor portion of the pump  170  needs to be replaced in the field. This replacement may be performed, for example, in order to either provide a more powerful pump  170  in order to increase the flow rate and/or pressure beyond the capacity of the existing pump  170 , or to replace a failed pump  170 . 
         [0034]    Provisions may also be made in the backplane  110 , for example, for multiple pumps  170  for each electrolyte side separately, i.e. the catholyte and anolyte. Here, for example, the backplane  110  may have multiple embedded impellers with mating surfaces for multiple pump  170  but only have some pumps  170  installed depending on the needs of the energy storage application. 
         [0035]    It should be noted that backplane  110  may support a full integration of other components. For example, backplane  110  may support a full integration of a number of sensors, valves, auxiliary wiring and plumbing, and other necessary flow battery system components. 
         [0036]    The foregoing description of embodiments is intended to provide illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. 
         [0037]    No element, act, or instruction used herein should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. 
         [0038]    It is intended that the invention not be limited to the particular embodiments disclosed above, but that the invention will include any and all particular embodiments and equivalents falling within the scope of the following appended claims.