Bipolar plate for an electrochemical reactor with a compact homogenization zone and a low pressure differential

1. A bipolar plate for an electrochemical reactor including first and second opposing outer conductive faces, comprising:

first flow channels formed on the first outer conductive face, extending in a same direction;

first injection orifices formed in the first outer conductive face;

a first homogenization zone formed on the first outer conductive face and including homogenization channels,

each of the homogenization channels sub-dividing into a plurality of branches,

each of the homogenization channels including a first section into which one of the first injection orifices discharges and a second section including the plurality of branches discharging into the first flow channels,

each of the homogenization channels in the first section connecting one of the first injection orifices to a corresponding plurality of the branches,

each of the plurality of branches connecting one of the flow channels to one of the homogenization channels in the first section, and

branches in the second section being at an angle of at least 20° relative to a direction of the first flow channels, the homogenization channels in the first section being at an angle of at least 20° relative to a direction of the branches in the second section and at least 40° relative to the direction of the first flow channels, and the homogenization channels in the first section bend away from the first flow channels in a first direction to form a first angle with respect to the first flow channels and the branches in the second section bend away from the first flow channels in the first direction to form a second angle with respect to the first flow channels smaller than the first angle.

2. The bipolar plate as claimed in claim 1 , wherein each branch of the plurality of branches of the second section discharges into the first flow channels.

3. The bipolar plate as claimed in claim 1 , wherein a cross section of each of the homogenization channels in the first section is identical to a cross section of each of the first flow channels.

4. The bipolar plate as claimed claim 1 , wherein a ratio between a cross section of the homogenization channels in the first section and a cross section of the branches of the second section is between 0.95 and 1.25 inclusive, and a cross section of each of the homogenization channels is identical in the first section and in each branch of the second section.

5. The bipolar plate as claimed in claim 1 , wherein each branch of the plurality of branches of the second section is in fluid communication with a corresponding single first flow channel.

6. The bipolar plate as claimed in claim 1 , further comprising cooling liquid flow channels disposed between the first and second opposing outer conductive faces.

7. The bipolar plate as claimed in claim 1 , wherein each of the homogenization channels is divided into the plurality of branches at a level of at least one junction therebetween, a homogenization channel among the homogenization channels being divided into at most three branches at the level of the at least one junction.

8. The bipolar plate as claimed in claim 7 , wherein each junction of the at least one junction is disposed in the homogenization channel at a distance from the first injection orifice among the first injection orifices between 0.3* Lch and 0.7* Lch inclusive, wherein Lch is a length of the homogenization channel in which said each junction is disposed.

9. The bipolar plate as claimed in claim 1 , through which a flow manifold passes, the first injection orifices establishing fluid communication between the flow manifold and the homogenization channels of the first homogenization zone.

10. The bipolar plate as claimed in claim 1 , further comprising first and second conductive sheets fastened together, the first outer conductive face being disposed on the first conductive sheet, the second outer conductive face being disposed on the second conductive sheet.

11. The bipolar plate as claimed in claim 1 , further comprising:

second flow channels formed on the second outer conductive face;

second injection orifices formed in the second outer conductive face, the first and second injection orifices being disposed on opposite sides of a plane perpendicular to the bipolar plate and including the same direction of the first flow channels; and

a second homogenization zone formed on the second outer conductive face, superposed on the first homogenization zone, and including additional homogenization channels connecting the second injection orifices to the second flow channels.

12. An electrochemical reactor, comprising:

two bipolar plates according to the bipolar plate claimed in claim 11 ; and

a membrane-electrodes assembly disposed between the two bipolar plates, the membrane-electrodes assembly including a proton exchange membrane, a first electrode disposed on a first face of the proton exchange membrane and covering the first flow channels of one bipolar plate of the two bipolar plates, a second electrode disposed on a second face of the proton exchange membrane and covering the second flow channels of the other bipolar plate of the two bipolar plates, the membrane-electrodes assembly having no electrodes in vertical alignment with respective homogenization zones of the two bipolar plates.

13. The bipolar plate as claimed in claim 1 , further comprising:

third injection orifices formed in the first outer conductive face; and

a third homogenization zone formed on the first outer conductive face, the first and third homogenization zones being disposed at opposite ends of the first flow channels, the third homogenization zone being symmetrical to the first homogenization zone with respect to an axis perpendicular to the bipolar plate.

14. The bipolar plate as claimed in claim 1 , further comprising:

third injection orifices formed in the first outer conductive face;

a third homogenization zone formed on the first outer conductive face, the third homogenization zone including homogenization channels each connecting a third injection orifice among the third injection orifices to a plurality of the first flow channels, said homogenization channels of the third homogenization zone; each being divided into a plurality of branches extending from the third injection orifice to one of the first flow channels; and

the first and third homogenization zones being disposed at opposite ends of the first flow channels, a homogenization channel among the homogenization channels after “homogenization channel” of the first homogenization zone and a homogenization channel among the homogenization channels after “homogenization channel” of the third homogenization zone being in fluid communication with a same first flow channel of the plurality of first flow channels and being disposed on opposite sides of a plane perpendicular to the bipolar plate and extending in the direction of the same first flow channel of the plurality of first flow channels.

15. The bipolar plate as claimed in claim 14 , wherein the homogenization channels of the third homogenization zone each include a first section with which one of the third injection orifices is in fluid communication, and a second section including a plurality of branches in fluid communication with the first flow channels, branches in the second section being at an angle of at least 20° relative to the direction of the first flow channels, and homogenization channels in the first section being at an angle of at least 20° to the direction of the branches in the second section and at least 40° relative to the direction of the first flow channels.

16. The bipolar plate as claimed in claim 1 , wherein an angle between the homogenization channels in the first section and the branches in the second section is less than an angle between the branches in the second section and the first flow channels.