Bipolar plate for producing hydrogen by electrolyzing water and electrolytic bath

Abstract

The utility model discloses a bipolar plate for producing hydrogen by electrolyzing water and an electrolytic bath. The bipolar plate comprises a plate body, a jet flow micro-channel network is arranged on the anode side surface of the plate body and comprises a plurality of groups of jet flow micro-channel units which are arranged at intervals in the width direction of the plate body; the jet flow micro-channel unit comprises a main flow channel, a plurality of first-stage branch flow channels and a plurality of last-stage branch flow channels which are arranged in the length direction of the plate body, the main flow channel is a through hole of which the two ends are communicated with the water inlet area and the water outlet area respectively, and the first-stage branch flow channels and the last-stage branch flow channels are blind holes of which one ends are communicated with the main flow channel and the first-stage branch flow channels and the other ends are closed; a plurality of jet flow holes are formed in the top of the last-stage branch flow channel at intervals in the length direction of the last-stage branch flow channel. The jet flow micro-channel network adopts a vein bionic structure layout, so that the water-membrane contact efficiency is improved, the problems that a water / oxygen mass transfer boundary layer is thick, laminar flow is formed in a channel and the contact with the surface of a proton exchange membrane is insufficient and the like can be well solved, and the hydrogen production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to hydrogen production equipment technical field, concretely relates to a kind of water electrolysis hydrogen production bipolar plate and electrolytic cell. BACKGROUND

[0002] PEM (Proton exchange membrane, proton exchange membrane) water electrolysis hydrogen production technology is to use polymer electrolyte membrane to decompose water into hydrogen and oxygen, with the advantages of high efficiency, compact design and fast response. PEM water electrolysis hydrogen production bipolar plate is an important component of proton exchange membrane electrolytic cell, used to support current transmission and water electrolysis reaction. They are usually made of titanium alloy or other corrosion-resistant metal materials, with good electrical conductivity and mechanical strength.

[0003] Currently, flow field design in PEM hydrogen production technology directly affects hydrogen production efficiency, and existing PEM hydrogen production flow field bipolar plate mainly adopts parallel flow channel, serpentine flow channel and other structures. These flow field structures have the following problems: thick water / oxygen mass transfer boundary layer on the anode side flow field, local overheating, serious bubble retention; electrolytic water is prone to form laminar flow when flowing in flow channel, resulting in insufficient contact with the surface of proton exchange membrane, reducing reaction efficiency; in traditional flow field structure, the contact area of electrolytic water with reaction surface is limited, and the residence time of electrolytic water with reaction surface is short, which is not conducive to improving hydrogen production efficiency. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of water electrolysis hydrogen production double board and electrolytic cell to solve the above-mentioned technical problems existing in the anode side flow channel design in existing bipolar plate.

[0005] The utility model realizes by the following technical scheme:

[0006] Water electrolysis hydrogen production bipolar plate, including plate body;

[0007] Along plate body length direction, water inlet area and water outlet area are respectively arranged at both ends of plate body, along plate body width direction, hydrogen outlet area is respectively arranged at both sides of plate body;

[0008] The anode side surface of the plate body is provided with jet micro-channel network, and the jet micro-channel network includes multiple groups of jet micro-channel units arranged at intervals along the width direction of the plate body.

[0009] The jet micro-channel unit comprises a main flow channel arranged along the length direction of the plate body, a plurality of first branch flow channels arranged at intervals along the length direction of the main flow channel, and a plurality of final branch flow channels arranged at intervals along the length direction of the first branch flow channel, the main flow channel is a through hole with the water inlet area and the water outlet area communicated at two ends respectively, the first branch flow channel and the final branch flow channel are blind holes with one end communicated with the main flow channel and the first branch flow channel and the other end closed, a plurality of jet holes are arranged at intervals along the length direction of the final branch flow channel at the top of the final branch flow channel, the jet hole is communicated with the final branch flow channel, and the flow area of the main flow channel, the first branch flow channel and the final branch flow channel gradually decreases.

[0010] In some embodiments, the main flow channel comprises an inlet section, a gradual change section and an outlet section connected in sequence;

[0011] The inlet section is communicated with the water inlet area at one end and connected with the gradual change section at the other end, and the flow channel width of the inlet section gradually decreases from the water inlet area to the gradual change section;

[0012] The outlet section is connected with the gradual change section at one end and communicated with the water outlet area at the other end;

[0013] The gradual change section gradually increases the flow area of the flow channel from the inlet section to the outlet section.

[0014] In some embodiments, the gradual change section gradually increases the width of the flow channel and gradually decreases the depth of the flow channel from the inlet section to the outlet section.

[0015] In some embodiments, the first branch flow channels are all located on the same side of the main flow channel, and the first branch flow channels are all arranged obliquely between the main flow channel and the water flow direction.

[0016] In some embodiments, the included angle between the first branch flow channel and the main flow channel is 30°-45°.

[0017] In some embodiments, the included angle between the first branch flow channel and the main flow channel gradually decreases along the water flow direction.

[0018] In some embodiments, the flow area at each position in the first branch flow channel is the same.

[0019] In some embodiments, the final branch flow channels are all located on the side of the first branch flow channel towards the outlet area, and the final branch flow channels are arranged obliquely between the first branch flow channel.

[0020] In some embodiments, the width of the final branch flow channel gradually increases along the water flow direction, and the depth of the flow channel of the final branch flow channel is smaller than the depth of the first branch flow channel.

[0021] In another aspect, the utility model also provides a kind of electrolytic cell, including the electrolytic water hydrogen production bipolar plate of the described;

[0022] The plurality of water electrolysis hydrogen production bipolar plates are sequentially stacked, and first carbon paper, a proton exchange membrane and second carbon paper are sequentially arranged between adjacent water electrolysis hydrogen production bipolar plates.

[0023] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0024] The utility model discloses anode side surface arrangement jet micro - flow path network, jet micro - flow path network adopts leaf vein bionic structure layout, main stream channel, first branch flow channel and last branch flow channel all adopt relatively closed hole structure, only set up jet orifice on last branch flow channel, through the design of jet orifice, water flow can be shot to proton exchange membrane, has improved water - film contact efficiency, can very good solution water / oxygen mass transfer boundary layer thick, form laminar flow in flow channel and not sufficient with proton exchange membrane surface contact etc.

[0025] Through the layout design of main stream channel, first branch flow channel and last branch flow channel, can very solve the problem of the shortage of water flow in the hole flow channel structure, further improve the utilization efficiency of bipolar plate, improve the hydrogen production efficiency of electrolytic tank. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be briefly introduced to the drawing in the embodiment, it should be understood that the following drawings only show some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0027] Figure 1 It is anode side structure schematic diagram of the water electrolysis hydrogen production bipolar plate of the embodiment of the utility model.

[0028] Figure 2 It is anode side jet micro - flow path unit local structure schematic diagram of the embodiment of the utility model.

[0029] Figure 3 It is last branch flow channel longitudinal section schematic diagram of the jet micro - flow path unit of the embodiment of the utility model.

[0030] Figure 4 It is cathode side structure schematic diagram of the bipolar plate of the embodiment of the utility model.

[0031] Figure 5 It is cathode side three-dimensional fishbone-micro rib structure local schematic diagram of the bipolar plate of the embodiment of the utility model.

[0032] Among them:

[0033] 11, plate body, 12, water inlet, 13, water outlet, 14, hydrogen outlet;

[0034] 110. Jet microchannel unit; 111. Main channel; 111a. Inlet section; 111b. Gradient section; 111c. Outlet section; 112. First-stage branch channel; 113. Final-stage branch channel; 114. Jet orifice; 115. Rib.

[0035] 121. Flow guide channel; 122. Straight channel; 123. Rib; 124. Blind hole matrix; 125. Combination channel; 126. Air inlet; 127. Multi-hole outlet. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0037] In some embodiments of this utility model, reference is made to... Figure 1 , Figure 2 The bipolar plate for hydrogen production via water electrolysis includes a plate body 11. Along the length of the plate body, a water inlet area is provided at one end of the plate body, and a water outlet area is provided at the other end of the plate body. One or more water inlets 12 are arranged side by side in the water inlet area, and one or more water outlets 13 are arranged side by side in the water outlet area. The water inlet area and the water outlet area are diagonally arranged on the plate body. Along the width of the plate body, hydrogen outlet areas are provided on both sides of the plate body 11, and one or more hydrogen outlets 14 are provided in each hydrogen outlet area. The two hydrogen outlet areas are diagonally arranged on the plate body.

[0038] A jet microchannel network is provided on the anode side surface of the plate. The jet microchannel network includes multiple sets of jet microchannel units 110 arranged at intervals along the width direction of the plate.

[0039] The jet microchannel unit 110 includes a main channel 111 arranged along the length of the plate, a plurality of primary branch channels 112 arranged at intervals along the length of the main channel, and a plurality of final branch channels 113 arranged at intervals along the length of the primary branch channels. The main channel 111 is a through hole with both ends connected to the inlet area and the outlet area, respectively. The primary branch channels 112 and the final branch channels 113 are blind holes with one end connected to the main channel and the primary branch channels 112 and the other end closed. A plurality of jet holes 114 are arranged at intervals along the length of the top of the final branch channels 113. The jet holes 114 are connected to the final branch channels. The flow area of ​​the main channel 111, the primary branch channels 112, and the final branch channels 113 decreases step by step.

[0040] The main flow channel, the first branch flow channel and the second branch flow channel in the jet micro-flow channel unit form a vein biomimetic structure. Water flows from the water inlet into the main flow channel through hole, and then flows into each first branch flow channel and the last branch flow channel through the main flow channel in turn, and is ejected from the jet orifice at the top of the last branch flow channel to the proton exchange membrane, so as to realize sufficient contact between water and membrane and effectively improve the hydrogen production efficiency.

[0041] In some embodiments, the main flow channel 111 comprises an inlet section 111a, a gradual change section 111b and an outlet section 111c connected in sequence.

[0042] The inlet section 111a is in communication with the water inlet area at one end and connected with the gradual change section 111b at the other end. The flow channel width of the inlet section gradually decreases from the water inlet area to the gradual change section. The outlet section 111c is connected with the gradual change section 111b at one end and in communication with the water outlet area at the other end. The flow channel of the gradual change section gradually increases in flow area from the inlet section to the outlet section.

[0043] The inlet section of the main flow channel adopts a necked structure, and the flow area gradually decreases from the inlet to the outlet. A local high pressure is formed at the outlet of the inlet section to ensure the inlet static pressure of each first branch flow channel. The gradual change section of the main flow channel adopts a wedge-shaped gradual change structure, so that the flow area of the flow channel gradually increases, the flow velocity reduction is controllable, and a certain static pressure can be maintained at the outlet of the gradual change section, thereby avoiding the problem of insufficient water flow at the outlet end of the main flow channel.

[0044] In some embodiments, the width of the flow channel of the gradual change section 111b gradually increases from the inlet section to the outlet section, and the depth of the flow channel gradually decreases. For example, the width of the flow channel of the gradual change section gradually increases from 1.2 mm to 2.0 mm, and the depth of the flow channel gradually decreases from 0.3 mm to 0.2 mm, so that the increase of the flow area is less than 50%, so as to control the flow velocity reduction.

[0045] In some embodiments, the first branch flow channels 112 are all located on the same side of the main flow channel, and each first branch flow channel is inclined to the main flow channel in the water flow direction. The included angle between the first branch flow channel 112 and the main flow channel 111 is 30°-45°.

[0046] In the water flow direction, the included angle between the first branch flow channel 112 and the main flow channel 111 gradually decreases.

[0047] The first branch flow channel forms the vein skeleton of the jet micro-flow channel unit and is distributed on the same side of the main flow channel, so as to optimize the layout of the jet micro-flow channel network on the anode side. The first branch flow channel is arranged to be inclined at an angle of 30°-45°, so as to reduce the water flow pressure and water flow velocity loss of the main flow channel flowing into the first branch flow channel.

[0048] The inclination angle of the primary branch flow channel is gradually reduced to compensate for the pressure loss and flow velocity loss of the water flow in the main flow channel from the inlet to the outlet, to ensure the water pressure and flow velocity in the final branch flow channel at the outlet end of the main flow channel, to ensure the water flow jetting effect on the entire area of the jet micro-flow channel network, and to reduce the inclination angle of the final branch flow channel at the outlet end of the main flow channel to effectively reduce the water flow fractal resistance, ensure the water pressure, and avoid the problem of water flow drying out at the outlet end.

[0049] In some embodiments, the flow area at each position in the primary branch flow channel 112 is the same. The flow channel width of the primary branch flow channel is 0.5 mm, and the flow channel depth can be 0.2 mm. The primary branch flow channels are arranged equidistantly on the main flow channel.

[0050] In some embodiments, the final branch flow channel 113 is located on one side of the primary branch flow channel towards the outlet area, and the final branch flow channel is inclined to the primary branch flow channel.

[0051] In the direction of the water flow, the width of the final branch flow channel gradually increases, and the depth of the flow channel is smaller than that of the primary branch flow channel.

[0052] The final branch flow channel is arranged at an angle towards the direction of the main flow channel, for example, it is arranged inwardly at an angle of 15°, and its end extends to the direction of the next primary branch flow channel, to optimize the arrangement of the final branch flow channel on the anode side, so that the jet flow hole can effectively cover the active area on the anode side, and the hydrogen production efficiency is improved.

[0053] The flow channel width of the final branch flow channel gradually increases from the inlet end to the end, for example, from 0.5 mm to 0.9 mm, and the flow channel depth of the final branch flow channel is smaller than that of the primary branch flow channel, so that a stepped ladder structure with gradually decreasing flow channel depth can be formed between the main flow channel, the primary branch flow channel, and the final branch flow channel.

[0054] Referring to Figure 3 A convex rib 115 inclined to the reverse water flow direction can be arranged equidistantly at the bottom of the final branch flow channel. The water flow in the final branch flow channel collides with the convex rib structure and turns upward, forming a transverse vortex, which destroys the boundary layer of the water flow, prevents the jet flow hole from being blocked by bubbles, and promotes rapid oxygen stripping.

[0055] In some embodiments, referring to Figure 4 and Figure 5 The cathode side of the plate body 11 includes a gas inlet section, a gas transmission section, and a gas outlet section, which are arranged in sequence from one hydrogen outlet area to another hydrogen outlet area.

[0056] The gas inlet section is provided with a plurality of flow guide grooves 121 arranged side by side, the flow guide grooves 121 are gradually reduced in width along the flow direction, and the flow guide grooves as a whole have a trumpet structure, which is an open groove structure arranged on the cathode side of the plate body.

[0057] The flow guide grooves 121 also have a gradually changing structure in the depth direction, for example, the groove depth at the inlet of the flow guide groove is 0.3mm, and the groove depth at the outlet is 0.1mm.

[0058] The gradually changing structure design of the gas inlet section flow guide groove can rectify and accelerate the hydrogen-rich fluid flowing from the anode side, avoid hydrogen stagnation at the inlet end, and quickly remove gas bubbles by accelerating hydrogen, thereby avoiding gas flow blockage at the gas inlet section.

[0059] The gas transmission section adopts a parallel straight groove array structure of three-dimensional fishbone-micro-rib structure, including a plurality of straight grooves 122 arranged side by side, the inlet of the straight groove 122 is connected with the outlet end of the flow guide groove 121.

[0060] Fishbone-shaped ribs 123 are arranged on the two side walls of the straight groove 122 at equal intervals, the ribs 123 are arranged obliquely along the gas flow direction, the oblique angle is 20°-30°, and the interval between adjacent ribs is 1mm.

[0061] The straight groove width is 0.5-0.6mm, the groove depth is 0.1mm, and the ridge width of the ridge formed between adjacent straight grooves is 0.3-0.4mm, so as to reduce the contact resistance.

[0062] The straight groove length covers 70% of the active area on the cathode side, and the parallel straight groove array structure of three-dimensional fishbone-micro-rib structure in the gas transmission section can form secondary transverse vortex flow during gas transmission, ensuring that hydrogen and carbon paper surface fully interact without water accumulation.

[0063] The gas outlet section is provided with a gradient porous suction disc convergence area, a honeycomb-shaped blind hole matrix is arranged on the other end of the plate body opposite to the gas inlet section; the blind hole matrix 124 has a gradient gradually changing structure in the flow direction, the hole diameter is 0.8mm-1.2mm, the porosity of the gas outlet section area is 55%-70%. The through hole has a chamfer at a certain angle, such as 30°, which forms a low-pressure suction effect, uniformly processes the uneven transverse flow at the end of the straight groove, and reduces the unevenness of the overall pressure drop and flow.

[0064] A collecting groove 125 is arranged between the honeycomb blind hole matrix and the second hydrogen outlet area, the collecting groove 125 is arranged in a relative vertical manner with the parallel straight groove, the outlet end of the parallel straight groove respectively flows into the collecting groove through the gas inlet 126 arranged on the collecting groove, and the hydrogen gas flowing out of the straight groove is collected and rectified, and the transverse velocity difference is reduced.

[0065] The collecting groove 125 is a semi-open shallow groove structure, the width is 2-3mm, the groove bottom of the collecting groove 125 is arranged to be 0.05mm lower than the straight groove, water-hydrogen gravity separation is formed in the collecting groove, and the separated liquid water is discharged along the collecting groove.

[0066] Since the cathode side mainly plays a role of guiding the flow of hydrogen, the open straight groove can meet the needs of low-pressure hydrogen discharge, and the three-dimensional fishbone-micro-rib structure can be directly laser ablated and formed in the straight groove.

[0067] On the other hand, the utility model also provides a kind of electrolytic cell, including electrolytic water hydrogen production bipolar plate;

[0068] A plurality of electrolytic water hydrogen production bipolar plates are sequentially stacked, wherein adjacent electrolytic water hydrogen production bipolar plates are arranged at a deflection of 180°, and the water inlet area of one electrolytic water hydrogen production bipolar plate is arranged opposite to the water outlet area of another electrolytic water hydrogen production bipolar plate;First carbon paper, proton exchange membrane and second carbon paper are sequentially arranged between adjacent electrolytic water hydrogen production bipolar plates.

[0069] In the description of the utility model, it should be explained that the adopted terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the utility model product is used, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation of the utility model.

[0070] In addition, the terms "horizontal", "vertical" and the like in the description of the utility model do not mean that the components must be absolutely horizontal or suspended, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0071] In the description of the utility model, still need to explain, unless another explicit provision and limitation, if appear term " set ", " install ", " link ", " connect " should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can be indirectly connected through the intermediate medium, can be two elements inside the communication.

[0072] The above is only the preferred embodiment of the utility model, and does not limit the utility model in any form, and any simple modification, equivalent change of the above embodiment according to the technical essence of the utility model falls within the protection scope of the utility model.

Claims

1. Bipolar plate for the production of hydrogen by electrolysis of water, characterized in that, The plate body comprises: An inlet water area and an outlet water area are arranged at both ends of the plate body along the length direction of the plate body, and a hydrogen outlet area is arranged at both sides of the plate body along the width direction of the plate body; A jet micro-channel network is arranged on the anode side surface of the plate body, and the jet micro-channel network comprises a plurality of groups of jet micro-channel units arranged at intervals along the width direction of the plate body; The jet micro-channel unit comprises a main flow channel arranged along the length direction of the plate body, a plurality of first branch flow channels arranged at intervals along the length direction of the main flow channel, and a plurality of final branch flow channels arranged at intervals along the length direction of the first branch flow channel, the main flow channel is a through hole with two ends communicating with the inlet water area and the outlet water area, the first branch flow channel and the final branch flow channel are blind holes with one end communicating with the main flow channel and the first branch flow channel and the other end being closed, a plurality of jet holes are arranged at intervals along the length direction of the final branch flow channel at the top of the final branch flow channel and face the direction perpendicular to the anode side surface, the jet hole communicates with the final branch flow channel, and the flow area of the main flow channel, the first branch flow channel and the final branch flow channel gradually decreases.

2. The hydrogen generation bipolar plate for water electrolysis according to claim 1, characterized in that, The main flow channel comprises an inlet section, a gradual change section and an outlet section connected in sequence; The inlet section communicates with the inlet water area at one end and is connected with the gradual change section at the other end, and the flow channel width of the inlet section gradually decreases from the inlet water area to the gradual change section; The outlet section is connected with the gradual change section at one end and communicates with the outlet water area at the other end; The flow area of the flow channel of the gradual change section gradually increases from the inlet section to the outlet section.

3. The hydrogen generation bipolar plate for water electrolysis according to claim 2, characterized in that, The width of the flow channel of the gradual change section gradually increases and the depth of the flow channel gradually decreases from the inlet section to the outlet section.

4. The hydrogen generation by electrolysis of water bipolar plate according to any one of claims 1 or 2 or 3, characterized in that, The first branch flow channel is located on the same side of the main flow channel, and the first branch flow channel is inclined to the main flow channel in the water flow direction.

5. The hydrogen generation bipolar plate for water electrolysis according to claim 4, characterized in that, The included angle between the first branch flow channel and the main flow channel is 30°-45°.

6. The hydrogen generation bipolar plate for water electrolysis according to claim 5, wherein The included angle between the first branch flow channel and the main flow channel gradually decreases in the water flow direction.

7. The hydrogen generation bipolar plate of claim 4, wherein The flow area at each position in the first branch flow channel is the same.

8. The hydrogen generation bipolar plate of claim 4, wherein The final branch flow channel is located on the side of the first branch flow channel facing the outlet area, and the final branch flow channel is inclined to the first branch flow channel.

9. The hydrogen generation by electrolysis of water bipolar plate according to claim 8, characterized in that, The width of the final branch flow channel gradually increases in the water flow direction, and the depth of the flow channel is smaller than that of the first branch flow channel.

10. An electrolytic cell characterized by The electrolytic water hydrogen production bipolar plate comprises: A plurality of electrolytic water hydrogen production bipolar plates are arranged in sequence, and a first carbon paper, a proton exchange membrane and a second carbon paper are arranged between adjacent electrolytic water hydrogen production bipolar plates in sequence.

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