Methods and systems for assembling electrolyzer stacks

Abstract

The present techniques provide systems and methods for assembling electrolyzers from parts which have internal structures that form fluid flow channels when placed adjacent to one another. In a contemplated embodiment, the assembly technique may use alignment bars, inserted through openings in the individual parts to hold the parts in alignment, while other structures apply pressure to hold the structure together. In another contemplated embodiment, the parts may be aligned by having ridges, or other protrusions, formed on the parts that mate with openings on adjacent parts. The applied pressure seals fluid flow channels formed in the electrolyzer and extending through the joined parts. The use of pressure to hold the structure together allows for the servicing and replacement of individual parts.

1 . An electrolyzer, comprising:
 a plurality of electrolyzer cells placed adjacent to one another to form a stack, wherein each electrolyzer cell comprises an electrode assembly and a diaphragm assembly, and wherein the diaphragm assembly of each electrolyzer cell is placed adjacent to an electrode assembly of another electrolyzer cell;   an internal fluid channel through the stack formed by an internal structure of each of the electrolyzer cells;   a mounting configured to maintain a compressive force on the stack sufficient to seal the internal fluid channel.   
   
   
       2 . The electrolyzer of  claim 1 , wherein the compressive force creates a pressure between cells of between about 3 bar and a pressure less than the maximum allowable compressive load of the cell material. 
   
   
       3 . The electrolyzer of  claim 1 , wherein the mounting is configured to be opened to permit access to any one of the plurality of electrolyzer cells. 
   
   
       4 . The electrolyzer of  claim 1 , wherein either the electrode assembly, the diaphragm assembly, or both, comprises a plastic material that is chemically resistant to an oxidative environment, a reducing environment, an acidic environment, a basic environment, or any combination thereof. 
   
   
       5 . The electrolyzer of  claim 1 , wherein either the electrode assembly, the diaphragm assembly, or both, comprises polyimides, polyamides, polyether ether ketones, polyethylenes, fluorinated polymers, polypropylenes, polysulfones, polyphenylene oxides, polyphenylene sulfides, polyphenylene ethers, polystyrenes, polyether imides, epoxies, polycarbonates, impact-modified polyethylene, impact-modified fluorinated polymers, impact-modified polypropylenes, impact-modified polysulfones, impact-modified polyphenylene oxides, impact-modified polyphenylene sulfides, impact-modified polystyrene, impact-modified polyetherimide, impact-modified epoxies, impact-modified polycarbonates, or any combination thereof. 
   
   
       6 . The electrolyzer of  claim 1 , wherein the mounting comprises a body around the stack, an end cap comprising a manifold configured to be in fluid contact with the internal fluid channel, and a base plate, wherein the end cap and the base plate are configured to maintain the compressive force. 
   
   
       7 . The electrolyzer of  claim 6 , wherein the end cap comprises a lip configured to extend into the body and maintain the compressive force. 
   
   
       8 . The electrolyzer of  claim 6 , comprising a spacer between the stack and the end cap, wherein the spacer plate maintains the compressive force. 
   
   
       9 . The electrolyzer of  claim 1 , wherein the electrode assembly and the diaphragm assembly of each electrolyzer cell form a single unit. 
   
   
       10 . The electrolyzer of  claim 1 , wherein the electrode assembly and the diaphragm assembly of each electrolyzer cell are held together by the compressive force. 
   
   
       11 . The electrolyzer of  claim 1 , comprising an inlet channel for introducing an electrolyte solution into the electrolyzer, a hydrogen outlet channel, an oxygen outlet channel, or any combination thereof. 
   
   
       12 . A method of assembling an electrolyzer, comprising:
 assembling a plurality of cells in an aligned stack, each cell comprising a metal plate and a diaphragm, and each cell having aligned apertures forming a fluid channel when aligned with an adjacent cell; and   maintaining a compressive force on the stack to seal the fluid channel.   
   
   
       13 . The method of  claim 12 , comprising placing an alignment bar through the cells to align the plurality of cells. 
   
   
       14 . The method of  claim 12 , comprising mating a protrusion on each cells with a depression on each adjacent cell to align the plurality of cells. 
   
   
       15 . The method of  claim 12 , wherein the compressive force creates a pressure between cells of between about 3 bar and about 9 bar. 
   
   
       16 . The method of  claim 12 , wherein the compressive force is maintained by a spacer. 
   
   
       17 . The method of  claim 12 , wherein the compressive force is maintained on the device by a lip on an end cap disposed adjacent to the stack. 
   
   
       18 . The method of  claim 12 , comprising releasing the pressure to access one of the plurality of cells. 
   
   
       19 . A method of assembling an electrolyzer, comprising:
 assembling a plurality of electrolyzer cells, wherein each electrolyzer cell comprises a metal plate and a diaphragm, and wherein each electrolyzer cell has a structure configured to form a fluid channel when aligned with other electrolyzer cells;   aligning the plurality of electrolyzer cells to form an electrolyzer stack having a first end, a second end, and an internal fluid channel;   placing a body around the electrolyzer stack;   placing an end cap over an end of the body, the end cap having an aperture aligned with the channel in the electrolyzer stack;   placing a base plate over another end of the body to create a compressive force to seal the internal channel in the electrolyzer stack securing the end cap and the base plate to the body.   
   
   
       20 . The method of  claim 19 , comprising disposing at least one spacing element in contact with the electrolyzer stack to create the compressive force.