A PEM electrolyzer

Abstract

The present invention proposes a PEM electrolyzer, comprising an upper end plate, a lower end plate and an electrolysis assembly located between the upper end plate and the lower end plate. The electrolysis assembly comprises a plurality of electrolysis spaces and an intermediate waterway plate located between adjacent electrolysis spaces. A first water outlet groove is provided on one side of the upper end plate, one end of the first water outlet groove penetrates the lower surface of the upper end plate, and the other end is connected to the first water outlet pipe; a first water inlet groove is provided on one side of the lower end plate, one end of the first water inlet groove penetrates the upper surface of the lower end plate, and the other end is connected to the first water inlet pipe. A second water outlet groove is provided on one side of the intermediate waterway plate, one end of the second water outlet groove penetrates the lower surface of the intermediate waterway plate, and the other end is connected to the second water outlet pipe; a second water inlet groove is provided on the other side of the intermediate waterway plate, one end of the second water inlet groove penetrates the upper surface of the intermediate waterway plate, and the other end is connected to the second water inlet pipe, so that water enters the electrolysis space from the bottom and discharges water from the top, effectively reducing the requirements of the electrolyzer for water inlet pressure.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic hydrogen production, and in particular to an industrial PEM electrolyzer. Background Art

[0002] As a clean energy source, hydrogen energy has great development prospects. Proton exchange membrane water electrolysis to produce hydrogen has the advantages of zero carbon emissions, fast reaction, high current density, small size, and strong adaptability to variable loads. It can be matched with photovoltaic and wind energy to realize the integration of wind and solar hydrogen storage, and has broad development prospects. The electrolyzer is a key equipment for proton exchange membrane water electrolysis to produce hydrogen. China Invention Patent Application Publication No. 115652327A discloses a PEM industrial electrolyzer, which provides a pure water channel with water inlet and outlet at the upper end. However, when this top-in and top-out structure is applied to electrolyzers with greater height, it requires a higher water inlet pressure to achieve, and there is still room for improvement. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention proposes a new industrial PEM electrolyzer, which can reduce the requirements of the electrolyzer on the water inlet pressure, effectively avoid the occurrence of uneven heat dissipation, and further improve the efficiency of the electrolyzer.

[0004] The technical solution of the present invention is achieved in this way:

[0005] A PEM electrolyzer comprises an upper end plate, a lower end plate and an electrolysis assembly, wherein the electrolysis assembly is arranged between the upper end plate and the lower end plate. The electrolysis assembly comprises a plurality of electrolysis spaces and an intermediate waterway plate located between adjacent electrolysis spaces. A plurality of first water outlet grooves are provided on one side of the upper end plate, one end of the first water outlet grooves penetrates the lower surface of the upper end plate, and the other end is connected to a first water outlet pipe. A plurality of first water inlet grooves are provided on one side of the lower end plate, one end of the first water inlet grooves penetrates the upper surface of the lower end plate, and the other end is connected to a first water inlet pipe. A plurality of second water outlet grooves are provided on one side of the intermediate waterway plate, one end of which penetrates the lower surface of the intermediate waterway plate to communicate with the electrolysis space below the intermediate waterway plate, and the other end is connected to the second water outlet pipe; a plurality of second water inlet grooves are provided on the other side of the intermediate waterway plate, one end of which penetrates the upper surface of the intermediate waterway plate to communicate with the electrolysis space above the intermediate waterway plate, and the other end is connected to the second water inlet pipe, so that each electrolysis space can be filled with water from the bottom and discharged from the top. At least one side of the intermediate waterway plate is provided with a plurality of hydrogen outlets that penetrate the thickness direction thereof, so that the hydrogen generated in the electrolysis space below the intermediate waterway plate can be collected to the electrolysis space above the intermediate waterway plate through the hydrogen outlets. A plurality of hydrogen external interfaces are provided on the other opposite side of the upper end plate, one end of which penetrates the lower surface of the upper end plate to communicate with the electrolysis space below the upper end plate, and is used to flow the collected hydrogen out of the electrolysis cell.

[0006] Preferably, a plurality of stacked electrolysis chambers are arranged in each electrolysis space, and each electrolysis chamber comprises a stacked anode plate, an anode assembly, a cathode assembly, a cathode plate, an electrode frame, a proton exchange membrane and a sealing gasket.

[0007] Preferably, the upper surface of the intermediate waterway plate serves as an anode plate of an adjacent electrolysis chamber above the intermediate waterway plate, and the lower surface of the intermediate waterway plate serves as a cathode plate of an adjacent electrolysis chamber below the intermediate waterway plate.

[0008] Preferably, a water inlet passage, a drainage passage and a hydrogen collecting channel are formed in each electrolysis space, the water inlet passage is connected to the first water inlet groove or the second water inlet groove, the drainage passage is connected to the first water outlet groove or the second water outlet groove, and the hydrogen collecting channel is connected to the hydrogen through hole.

[0009] Preferably, the pole frame is formed as a hollow structure, and a water inlet through hole, a water outlet through hole and a hydrogen through hole are provided on the periphery of the pole frame. The water outlet through hole is formed as a part of the drainage passage, the water inlet through hole is formed as a part of the water inlet passage, and the hydrogen through hole is formed as a part of the hydrogen collecting channel.

[0010] Preferably, guide grooves are respectively provided at the inner edge of the surface of the pole frame away from the proton exchange membrane corresponding to the water inlet through hole and the water outlet through hole, and the water inlet through hole and the water outlet through hole are respectively connected to the water inlet through groove or the water outlet through groove.

[0011] Preferably, the intermediate waterway plate is a split structure, including an upper flat plate and a lower flat plate, the lower surface of the upper flat plate is in contact with the upper surface of the lower flat plate, the thickness of the lower flat plate is greater than the thickness of the upper flat plate, the upper flat plate is a titanium plate with a corrosion-resistant coating on the surface, and the lower flat plate is a stainless steel plate.

[0012] Optionally, the intermediate waterway plate is an integral structure, made of a titanium plate with a corrosion-resistant coating on the surface, or made of a stainless steel plate with a corrosion-resistant coating on the surface.

[0013] Preferably, when the intermediate water channel plate is a split structure, a sealing groove is provided on the upper surface of the lower flat plate corresponding to the water outlet groove and the hydrogen passage hole, and a sealing ring is provided in the sealing groove.

[0014] Preferably, when the intermediate waterway plate is a split structure, the second water outlet groove and the second water inlet groove are respectively arranged on both sides of the lower flat plate, and a plurality of water inlet holes are provided on one side of the upper flat plate, and the positions of the plurality of water inlet holes correspond one-to-one to the positions of the plurality of second water inlet grooves.

[0015] Preferably, the second water outlet groove is L-shaped, the horizontal section of the second water outlet groove passes through the side wall of the middle waterway plate and is connected to the second water outlet pipe, and the vertical section of the second water outlet groove passes through the lower surface of the middle waterway plate.

[0016] Preferably, the second water inlet groove is L-shaped, the horizontal section of the second water inlet groove passes through the side wall of the middle waterway plate and is connected to the second water inlet pipe, and the vertical section of the second water inlet groove passes through the upper surface of the middle waterway plate.

[0017] Preferably, the middle waterway plate further comprises a plurality of water inlet branches, the water inlet branches are L-shaped elbows, and a second water inlet slot is connected to the second water inlet pipe through an inlet branch; the middle waterway plate further comprises a plurality of water outlet branches, the water outlet branches are straight pipes, and a second water outlet slot is connected to the second water outlet pipe through an outlet branch. By providing the water inlet branches of L-shaped elbows, a buffer is formed to reduce the turbulence of the water inlet; the water outlet branches are straight pipes, which can reduce the water outlet resistance.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] Since a plurality of first water inlet slots are provided on one side of the lower end plate for conveying water to the electrolysis space above it, a plurality of second water inlet slots and a plurality of second water outlet slots are provided on both sides of the middle waterway plate, respectively, the second water inlet slots convey water to the electrolysis space above it, and the second water outlet slots output the water in the electrolysis space below the middle waterway plate, and a plurality of first water outlet slots are provided on one side of the upper end plate for outputting the electrolyzed water in the electrolysis space below, that is, pure water flows upward from the water inlet slots of the lower end plate or the middle waterway plate The water after electrolysis enters the water outlet groove of the middle waterway plate or the upper end plate from the top of the electrolysis space and is output. In each electrolysis space, water enters from the bottom and exits from the top. This method of entering from the bottom and exiting from the top and in layers does not require a higher water inlet pressure, which can reduce the requirements of the electrolytic cell for the water inlet pressure. At the same time, the water flow field is more uniform, which can effectively avoid the occurrence of uneven heat dissipation, and can make the performance of the electrolytic cell more stable, further improve the electrolysis efficiency and further reduce the electrolysis energy consumption. It is suitable for electrolytic cells with higher power.

[0020] Furthermore, by optimizing the water inlet pipeline, the consistency of water inlet pressure is ensured, turbulence is reduced, and the uniformity of heat dissipation is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The three-dimensional structure schematic diagram of a PEM industrial electrolyzer according to an embodiment of the present invention is omitted in the figure;

[0022] Figure 2 for Figure 1 A schematic diagram of the exploded structure of a PEM industrial electrolyzer, in which the components and fixings of the individual electrolytic chambers are omitted;

[0023] Figure 3 for Figure 1 A longitudinal cross-sectional schematic diagram of an upper end plate of a PEM industrial electrolyzer;

[0024] Figure 4A for Figure 1 A top view of the lower end plate of a PEM industrial electrolyzer;

[0025] Figure 4B For along Figure 4A Sectional view along line AA;

[0026] Figure 5 It is a schematic diagram of the exploded structure of the middle waterway plate of the PEM industrial electrolyzer of the present invention;

[0027] Figure 6 A top view of the lower plate of the intermediate waterway plate of the PEM industrial electrolyzer of the present invention;

[0028] Figure 7 For along Figure 6 Sectional view along the midline BB;

[0029] Figure 8 A bottom view of the lower plate of the intermediate waterway plate of the PEM industrial electrolyzer of the present invention;

[0030] Fig. 9 For along Figure 8 Sectional view of the mid-CC line;

[0031] Fig.10 A schematic diagram of water flow in an electrolysis space of a PEM industrial electrolyzer according to an embodiment of the present invention;

[0032] Fig.11 A schematic diagram of hydrogen flow in an electrolysis space of a PEM industrial electrolyzer according to an embodiment of the present invention;

[0033] Fig.12 A schematic plan view of an electrolysis space formed by two adjacent intermediate waterway plates in a PEM industrial electrolyzer according to an embodiment of the present invention;

[0034] Fig.13 For along Fig.12 Sectional view along the mid-DD line;

[0035] Fig.14 for Fig.13 The enlarged schematic diagram of point E in the middle;

[0036] Fig.15 for Fig.13 The enlarged schematic diagram of F in the middle;

[0037] Fig.16 This is a schematic diagram of the exploded structure of an electrolysis unit in a PEM industrial electrolysis cell according to an embodiment of the present invention;

[0038] Fig.17 It is a schematic diagram of the exploded structure of the middle waterway plate and the adjacent electrolysis chambers on the upper and lower sides according to one embodiment of the present invention;

[0039] Fig.18 A top view of a pole frame in a PEM industrial electrolyzer according to an embodiment of the present invention;

[0040] Fig.19 for Fig.18 The enlarged schematic diagram of G in the middle;

[0041] Fig. 20 for Fig.18 Enlarged schematic diagram of point H in the middle. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 and Figure 2 A PEM electrolyzer comprises an upper end plate 2, a lower end plate 5 and an electrolytic assembly 3 disposed between the upper end plate 2 and the lower end plate 5. The upper end plate 2, the electrolytic assembly 3 and the lower end plate 5 can be fixed by a plurality of fixing members 8 such as screws.

[0044] The shapes of the upper end plate 2 and the lower end plate 5 are not limited, for example, they can be set to a square or circular structure. The lower end plate 5 is provided with a water inlet channel for introducing pure water to be electrolyzed, and the upper end plate 2 is provided with a liquid / gas outlet channel for outputting the gas-liquid mixture after electrolysis and the hydrogen generated by electrolysis.

[0045] The electrolysis assembly 3 is used to electrolyze the pure water to be electrolyzed to produce hydrogen and oxygen. The electrolysis assembly 3 includes a plurality of intermediate waterway plates 4 and a plurality of electrolysis chambers 7 stacked between the lower end plate 5 and the intermediate waterway plates 4, between two adjacent intermediate waterway plates 4, and between the intermediate waterway plates 4 and the upper end plate 2. The intermediate waterway plates 4 divide the space defined between the upper end plate 2 and the lower end plate 5 into a plurality of electrolysis spaces 32. When one intermediate waterway plate 4 is provided, the intermediate waterway plate 4 divides the space defined between the upper end plate 2 and the lower end plate 5 into two electrolysis spaces 32. When multiple intermediate waterway plates 4 are provided between the upper end plate 2 and the lower end plate 5, the intermediate waterway plates 4 divide the space defined between the upper end plate 2 and the lower end plate 5 into three or more layers. In this embodiment, two intermediate waterway plates 4 are provided to divide the space defined between the upper end plate 2 and the lower end plate 5 into three electrolysis spaces 32 stacked in the vertical direction.

[0046] See also Figure 2 and Figure 3, a plurality of first water outlet grooves 21 are provided on one side of the upper end plate 2, one end of the first water outlet groove 21 passes through the lower surface of the upper end plate 2, and the other end is connected to the first water outlet pipe 22, and the electrolyzed water in the electrolysis space below it enters the first water outlet groove 21 from the lower surface of the upper end plate 2, and then is output to the outside of the electrolyzer from the first water outlet pipe 22. A plurality of hydrogen external interfaces 24 are provided on the other side of the upper end plate 2, and one end of each hydrogen external interface 24 passes through the lower surface of the upper end plate 2 and is connected to the uppermost electrolysis space 32. In this embodiment, the first water outlet groove 21 and the hydrogen external interface 24 are basically L-shaped, including a horizontal extension section and a vertical extension section, the vertical extension section passes through the lower surface of the upper end plate 2 and is connected to the uppermost electrolysis space 32, and the horizontal extension section passes through the side wall of the upper end plate 2, and the horizontal extension sections of the first water outlet groove 21 and the hydrogen external interface 24 respectively pass through the two opposite side walls of the upper end plate 2. A plurality of fixing holes 26 are provided near the periphery of the upper end plate 2 . The fixing holes 26 penetrate the upper end plate 2 in the thickness direction for fixing members such as screws 8 to pass through.

[0047] See also Figure 2 , Figure 4A and Figure 4B , a plurality of first water inlet slots 51 are provided on one side of the lower end plate 5, one end of the first water inlet slots 51 penetrates the upper surface of the lower end plate 5, and the other end is connected to the first water inlet pipe 52. After the pure water enters the first water inlet slot 51 of the lower end plate 5 from the first water inlet pipe 52, it flows out from the upper surface of the lower end plate 5 and enters the electrolysis space above it. In this embodiment, the first water inlet slot 51 is L-shaped, including a horizontal section and a vertical section. The horizontal section of the first water inlet slot 51 penetrates the side wall of the middle waterway plate 4 and is connected to the first water inlet pipe 52, and the vertical section penetrates the upper surface of the lower end plate 5 and is connected to the electrolysis space above it. Preferably, the height of the vertical section (the distance from the upper surface of the lower end plate 5 to the connection with the horizontal section) is approximately between 40% and 60% of the thickness of the lower end plate 5. A plurality of fixing holes 54 are provided on the periphery of the lower end plate 5, and the fixing holes 54 penetrate the lower end plate 5 in the thickness direction for the fixing member such as the screw 8 to be inserted.

[0048] See also Figures 5 to 9, a plurality of second water inlet grooves 422 are provided on one side (one side in the width direction) of the middle waterway plate 4, one end of the second water inlet groove 422 penetrates the upper surface of the middle waterway plate 4, and the other end is connected to the second water inlet pipe 44, and a plurality of second water outlet grooves 421 are provided on the other side of the middle waterway plate 4, one end of the second water outlet groove 421 penetrates the lower surface of the middle waterway plate 4, and the other end is connected to the second water outlet pipe 43. One end of the second water outlet groove 421 penetrates the lower surface of the middle waterway plate 4, and the water in the electrolysis space below the middle waterway plate 4 enters the second water outlet groove 421 from the lower surface of the middle waterway plate 4, and then is output to the outside of the electrolytic cell from the second water outlet pipe 43; pure water is introduced into the second water inlet groove 422 by means of the second water inlet pipe 44, and the pure water flows from the upper surface of the middle waterway plate 4 into the electrolysis space above the middle waterway plate 4. A plurality of hydrogen holes 424 are also provided on one side of the intermediate waterway plate 4. The hydrogen holes 424 penetrate the thickness direction of the intermediate waterway plate 4, so that the hydrogen generated by electrolysis in the electrolysis space 32 below the intermediate waterway plate 4 can pass through the hydrogen holes 424. In this embodiment, a hydrogen hole 424 is provided between two adjacent second water inlet grooves 422. In this embodiment, seven second water inlet grooves 422 and six hydrogen holes 424 are provided on one side of the intermediate waterway plate 4. In this embodiment, the intermediate waterway plate 4 is provided with hydrogen holes 424 only on one side, which can reduce the number of openings of the intermediate waterway plate 4 and reduce the sealing requirements and difficulty. Of course, the other side of the middle waterway plate 4 may also be provided with a hydrogen hole 424, that is, both sides of the middle waterway plate 4 are provided with a hydrogen hole 424, and the corresponding upper end plate 2 is also provided with a hydrogen external interface 24 on both sides, so that the hydrogen generated by the electrolysis space 32 below the middle waterway plate 4 can be simultaneously collected upward from both sides of the middle waterway plate 4 and output from the hydrogen external interfaces 24 on both sides of the upper end plate 2. In this embodiment, a plurality of fixing holes 426 are provided on the periphery of the middle waterway plate 4, and the fixing holes 426 penetrate the middle waterway plate 4 in the thickness direction for fixing members such as screws 8 to pass through.

[0049] The middle waterway plate 4 is usually made of metal materials, such as titanium, stainless steel or stainless steel with titanium coating on the surface, and can be an integral structure or a split structure. When the middle waterway plate 4 is an integral structure, it can be a titanium plate with a corrosion-resistant coating such as platinum added to the surface, or a stainless steel plate with a corrosion-resistant coating such as platinum added to the surface.

[0050] See also Figure 5 and Figure 6In this embodiment, the intermediate waterway plate 4 adopts a split structure, including an upper plate 41 and a lower plate 42 assembled together, and the lower surface of the upper plate 41 is arranged in contact with the upper surface of the lower plate 42. In some embodiments, the upper plate 41 mainly plays a role in preventing corrosion, and it is necessary to plate an anti-corrosion layer on the surface of the upper plate 41, such as platinum coating. The upper plate 41 can be made of metal plates such as titanium plates and stainless steel plates, and the lower plate 42 plays a supporting role. In order to save costs, a stainless steel plate can be used. The thickness of the lower plate is greater than that of the upper plate. In this way, the intermediate waterway plate 4 has sufficient rigidity, strength and corrosion resistance; and the bipolar intermediate waterway plate 4 formed by the combination of titanium plates and stainless steel plates can be set so that multiple bipolar intermediate waterway plates 4 are all arranged with the upper plate 41 facing upward, so that multiple electrolysis spaces can work in series. In addition, in order to ensure that the upper plate 41 and the lower plate 42 are in close contact and have low impedance, preferably, the upper plate 41 and the lower plate 42 can be bonded by coating a conductive layer.

[0051] The hydrogen permeation hole 424 and the fixing hole 426 penetrate the upper plate 41 and the lower plate 42 respectively (i.e., the through hole of the upper plate 41 corresponds to the through hole of the lower plate 42 and is interconnected). The second water inlet groove 422 and the second water outlet groove 421 are respectively arranged on both sides of the lower plate 42, such as both sides in the width direction. One side of the upper plate 41 is provided with a plurality of second water inlet holes 411, and the positions of the plurality of second water inlet holes 411 and the plurality of second water inlet grooves 422 correspond one to one. The inlet water passes through the second water inlet groove 422 of the lower plate 42 and the second water inlet hole 411 of the upper plate 41 in sequence from the second water inlet pipe 44 to enter the electrolysis space 32 above the middle waterway plate 4. A vent hole 414 is arranged corresponding to the hydrogen permeation hole 424.

[0052] In this embodiment, the lower plate 42 is made of SUS316L and is used to arrange the water inlet / outlet pipes and the airway. The upper plate 41 is made of a thin titanium plate and is plated with a platinum layer as an anode plate. In order to ensure that the lower plate 42 and the upper plate 41 as a whole can simultaneously play the role of electrode conduction and water / airway sealing, the upper plate 42 is provided with a water inlet through hole 411 / air vent 414, and an annular sealing groove 4221 and 4241 are respectively provided on the upper surface of the lower plate 42 corresponding to the water inlet groove 422 and the hydrogen permeation hole 424. The sealing grooves 4221 and 4241 surround the ends of the water inlet groove 422 and the hydrogen permeation hole 424 respectively and are spaced a certain distance from them in the radial direction (that is, the sealing grooves 4221 / 4241 are not connected to the water inlet groove 422 / hydrogen permeation hole 424), and an annular O-ring 427 is provided in the sealing grooves 4221 and 4241 ( Figure 7 and Fig.14 ), the sealing ring 427 is an elastic body, which is elastically clamped between the upper plate 41 and the lower plate 42, thereby playing the role of sealing the waterway or the airway.

[0053] like Figure 6 and Figure 7 As shown, the second water inlet groove 422 is L-shaped, and the horizontal section of the second water inlet groove 422 passes through the side wall of the intermediate waterway plate 4 (i.e., the wall connecting the upper surface and the lower surface of the intermediate waterway plate 4) and is connected to the second water inlet pipe 44, and the vertical section of the second water inlet groove 422 passes through the upper surface of the intermediate waterway plate 4, that is, the second water inlet pipe 44 is connected to one side of the intermediate waterway plate 4, which saves more space, especially the dimension in the height direction.

[0054] like Figure 8 and Fig. 9 As shown, the second water outlet groove 421 is L-shaped, the horizontal section of the second water outlet groove 421 passes through the other side wall of the intermediate waterway plate 4 and is connected to the second water outlet pipe 43, and the vertical section of the second water outlet groove 421 passes through the lower surface of the intermediate waterway plate 4, that is, the second water outlet pipe 43 is connected to the other side of the intermediate waterway plate 4, which saves more space.

[0055] Preferably, the intermediate waterway plate 4 also includes a plurality of water inlet branches 46, which are L-shaped elbows, and a second water inlet slot 422 is connected to the second water inlet pipe 44 through a water inlet branch 46; the intermediate waterway plate 4 also includes a plurality of water outlet branches 45, which are straight pipes, and a second water outlet slot 421 is connected to the second water outlet pipe 43 through a water outlet branch 45. By setting the water inlet branch 46 of the L-shaped elbow, a buffer is formed to reduce the turbulence of the water inlet; the water outlet branch 45 is a straight pipe, which can reduce the water outlet resistance. Similarly, the first water inlet slot 51 can also be connected to the first water inlet pipe 52 by setting a corresponding water inlet branch, and the first water outlet slot 21 can also be connected to the first water outlet pipe 22 by setting a corresponding water outlet branch.

[0056] The water inlet branch 46 and the water inlet pipe 44 together form a water inlet pipe assembly, and the water outlet branch 45 and the water outlet pipe 43 together form a water outlet pipe assembly. The water inlet pipe assembly and the water outlet pipe assembly can be respectively installed to the two opposite side walls of the lower flat plate 42 through the mounting plate 47. The mounting plate 47 can be fixed to the side wall of the lower flat plate 42 by screws and other fixing parts. The water outlet branch 45 / water inlet branch 46 is fixed relative to the mounting plate 47, and the mounting plate 47 is provided with a through hole corresponding to the water outlet branch 45 / water inlet branch 46 to connect the water outlet branch 45 / water inlet branch 46 with the water outlet groove 421 / water inlet groove 422.

[0057] If the thickness of the upper plate 41 is too thin, it may bend during the coating process, thereby affecting the coating effect. If the thickness of the upper plate 41 is too thick, the resistance is too large and the cost is high. Preferably, the thickness of the upper plate 41 is between 0.5mm-1.0mm, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm; the thickness of the lower plate 42 is slightly larger than the height of the mounting plate 47 (i.e., the dimension parallel to the thickness direction of the lower plate 42) and the diameter of the outlet branch 45 / inlet branch 46. Preferably, the thickness of the lower plate 42 is between 40mm-50mm.

[0058] See also Figures 3 to 10 , since a plurality of first water inlet grooves 51 for conveying water to the electrolysis space 32 above the lower end plate 5 are provided on one side thereof, the first water inlet grooves 51 are connected to the first water inlet pipe 52, a plurality of second water outlet grooves 421 and a plurality of second water inlet grooves 422 are respectively provided on both sides of the intermediate waterway plate 4, the second water outlet grooves 421 are connected to the second water outlet pipe 43, and are used to convey water in the electrolysis space 32 below the intermediate waterway plate 4, and the second water inlet grooves 422 are connected to the second water inlet pipe 44, and are used to convey water to the electrolysis space 32 above the upper end plate 2; a plurality of first water outlet grooves 21 are provided on one side of the upper end plate 2, one end of the first water outlet grooves 21 is connected to the first water outlet pipe 22, and the other end is connected to the electrolysis space 32 below it (that is, the uppermost electrolysis space 32), and are used to convey the electrolyzed water in the uppermost electrolysis space 32. In this way, pure water is transported upward from the bottom of the corresponding electrolysis space 32 through the water inlet grooves 51 / 422 of the lower end plate 5 and the middle waterway plate 4 respectively. The electrolyzed water is gathered and enters the water outlet grooves of the middle waterway plate 4 or the upper end plate 2 from the top of the corresponding electrolysis space 32 and is output. The water inlet grooves 51 / 422 of the lower end plate 5 and the middle waterway plate are on the same side, and the water outlet grooves 421 / 21 of the middle waterway plate 4 or the upper end plate 2 are on the other same side. In each electrolysis space, water enters from the bottom and exits from the top. This bottom-in and top-out method does not require a higher water inlet pressure, can reduce the requirements for the water inlet pressure of the electrolytic cell, and is suitable for electrolytic cells with a larger height. Moreover, the multi-layer electrolysis space adopts a multi-layer waterway design (each electrolysis space adopts a separate / independent waterway), and the water flow field is more uniform, which can effectively improve the hydrogen production efficiency of each electrolysis chamber in the electrolysis space.

[0059] Usually, the water inlet mode can be selected from the form of single-side water inlet or double-side water inlet of the water inlet pipe. In this embodiment, the first water inlet pipe 52 of the lower end plate 5 and the second water inlet pipe 44 of the middle waterway plate 4 both adopt double-side water inlet. When the single-side water inlet mode is adopted, one end of the first water inlet pipe 52 / the second water inlet pipe 44 is a closed structure, and the other end is provided with a water inlet.

[0060] See also Fig.11In this embodiment, a hydrogen hole 424 is provided on one side of the intermediate waterway plate 4, and a hydrogen collecting channel 79 is formed on one side of the electrolysis space 32 corresponding to the hydrogen hole 424. The hydrogen collecting channel 79 is aligned with and connected to the hydrogen hole 424. The hydrogen generated in each layer of the electrolysis space 32 passes through the hydrogen collecting channel 79 in the electrolysis space 32 and the hydrogen hole 424 of the intermediate waterway plate 4 above the electrolysis space 32 to enter the hydrogen collecting channel 79 in another upper electrolysis space 32, and so on. Finally, the hydrogen is collected on the lower surface of the upper end plate 2 and output through the hydrogen external interface 24.

[0061] Preferably, the hydrogen external port 24 is located on the same side as the water inlet groove 422 and on the side opposite to the water outlet groove 421 .

[0062] It can be understood that in other embodiments, hydrogen external interfaces 24 are respectively provided on both sides of the upper end plate 2, and hydrogen holes 424 are provided on both sides of the middle water channel plate 4, which are respectively aligned and connected with the hydrogen collecting channels 79 on both sides of the electrolysis space 32 below it. In this way, the hydrogen generated in the electrolysis space 32 below the middle water channel plate 4 can be respectively collected from the hydrogen collecting channels 79 on both sides of the electrolysis space 32 through the hydrogen holes 424 on both sides of the middle water channel plate 4 to the upper electrolysis space 32, and finally collected to the bottom of the upper end plate 2, and flow out through the hydrogen external interface 24.

[0063] Figures 12 to 16 The detailed structure of the electrolysis space 32 formed by two adjacent middle water channel plates 4 is shown.

[0064] See also Figures 12 to 16 , a plurality of electrolysis units also called electrolysis chambers 7 are arranged in each layer of electrolysis space 32, and each electrolysis unit 7 includes a pair of pole plates 71, an anode layer assembly 72, a pair of pole frames 73, a cathode layer assembly 74, a proton exchange membrane 75 and a plurality of sealing gaskets 76. The two sides of the proton exchange membrane 75 are pole frames 73, anode layer assembly 72 / cathode layer assembly 74, and pole plates 71. The anode layer assembly 72 is arranged between the pole frame 73 and the pole plate 71 on the anode side, and the cathode layer assembly 74 is arranged between the pole frame 73 and the pole plate 71 on the cathode side. A sealing gasket 76 is arranged between the proton exchange membrane 75 and the pole frame 73, a sealing gasket 76 is arranged between the pole frame 73 and the anode layer assembly 72 / cathode layer assembly 74, and a sealing gasket 76 is arranged between the pole plate 71 and the anode layer assembly 72 / cathode layer assembly 74.

[0065] Furthermore, the cathode layer assembly 74 includes a cathode stainless steel mesh 741 and a cathode stainless steel felt 742; the cathode stainless steel mesh 741 is installed on a side of the cathode stainless steel felt 742 away from the proton exchange membrane 75, and the cathode stainless steel mesh 741 can be a stamped stainless steel mesh. The cathode stainless steel felt 742 is used to replace the traditional cathode carbon felt. For the design of a large-sized electrolysis chamber, the problem of affecting the electrolysis stability due to the poor stability of the large-sized cathode carbon felt can be avoided, and the stability and reliability of the electrolysis chamber can be ensured; at the same time, the cathode stainless steel mesh 741 of the stamped stainless steel mesh is used to replace the traditional woven mesh, and the support is tighter, which can reduce the contact resistance, reduce the voltage, ensure the stability of the electrolysis performance, and improve the overall service life. In addition, the design of the cathode stainless steel felt 742 and the cathode stainless steel mesh 741 is also conducive to assembly, improves assembly production efficiency, and reduces costs.

[0066] As for the anode layer assembly 72 , reference may be made to existing structural designs, for example, including an anode titanium mesh 721 and an anode titanium felt 722 , wherein the anode titanium mesh 721 is disposed on a side of the anode titanium felt 722 away from the proton exchange membrane 75 , and the anode titanium mesh 721 may be a stamped titanium mesh.

[0067] A plurality of coaxial through holes are arranged around the electrode plate 71, the electrode frame 73, the proton exchange membrane 75 and the plurality of sealing gaskets 76, and some of the coaxial through holes are connected to the water inlet groove 51 or the water inlet groove 422 to form a water inlet passage 77 (see Fig.10 and Fig.14 ), so that the pure water entering from the water inlet groove 51 or the water inlet groove 422 can flow upward through the water inlet passage 77 (see Fig.10 The water entering the anode side of each electrolysis unit / electrolysis chamber 7 flows from the water inlet side of the anode side to the water outlet side (see arrow in the vertical direction of the water inlet side of the anode side). Fig.10 Some of the coaxial through holes are connected to the water outlet groove 51 or the water outlet groove 421 to form a drainage passage 78 (see Fig.10 and Fig.15 ), so that the electrolyzed water and oxygen mixture can flow upward from the drainage passage 78 and enter the water outlet groove 51 or the water outlet groove 421; some coaxial through holes form a hydrogen collection channel 79 (see Fig.11), connected with the hydrogen gas hole 424, so that the hydrogen generated by electrolysis can be collected upward through the hydrogen gas collection channel 79, collected to the lower surface of the upper end plate 2 through the hydrogen gas hole 424, and finally output from the hydrogen gas external interface 24 of the upper end plate 2. When the hydrogen gas hole 424 is provided on one side of the width direction of the intermediate waterway plate 4, the hydrogen generated by each electrolysis chamber 7 in each layer of the electrolysis space 32 flows out from the cathode side of the chamber (that is, horizontally collected to the side where the hydrogen gas collection channel 79 is provided), passes through the hydrogen gas collection channel 79 on one side of the electrolysis space 32 and the hydrogen gas hole 424 of the intermediate waterway plate 4 above the electrolysis space 32, and enters the hydrogen gas collection channel 79 in the other upper electrolysis space 32, and so on. Finally, the hydrogen is collected to the lower surface of the upper end plate 2 and output through the hydrogen gas external interface 24. When hydrogen holes 424 are provided on both sides of the width direction of the middle water channel plate 4, the hydrogen generated in the electrolysis space 32 can be collected upward through the hydrogen collecting channels 79 on both sides and the hydrogen holes 424 on both sides of the middle water channel plate 4 until it is collected on the lower surface of the upper end plate 2, and finally output through the hydrogen external interface 24.

[0068] See also Fig.17 The upper surface of the middle waterway plate 4 can be used as the anode plate 71 of the adjacent electrolytic chamber 7 above it, i.e., the anode plate. The upper surface of the middle waterway plate 4 is in a strongly acidic and corrosive environment. The upper surface of the middle waterway plate 4 is plated with a corrosion-resistant coating, such as a platinum coating, which can effectively improve the corrosion resistance of the middle waterway plate 4; the lower surface of the middle waterway plate 4 can be used as the cathode plate 71 of the adjacent electrolytic chamber 7 below it, i.e., the cathode plate. When the middle waterway plate 4 adopts a split structure, the upper plate 41 can be used as the anode plate of the adjacent electrolytic chamber 7 above it, and the lower plate 42 can be used as the cathode plate of the adjacent electrolytic chamber 7 below it.

[0069] See also Fig.18The pole frame 73 is formed into a hollow structure. In this embodiment, the pole frame 73 is square, and four frames are arranged around the hollow part. When the pole frame 73 is used as an anode frame, the two side frames of the pole frame 73 corresponding to the water inlet groove 422 / 51 and the water outlet groove 421 / 21 are respectively provided with a plurality of through holes. The through hole 732 (also called water inlet through hole 732) corresponding to the water inlet groove 422 or 51 is formed as a part of the water inlet passage 77 (that is, the water inlet passage 77 passes through the water inlet through hole 732), aligned with and connected to the vertical section of the water inlet groove 422 or 51; the through hole 734 (also called water outlet through hole 734) corresponding to the water outlet groove 421 or 21 is formed as a part of the water outlet passage 78 (that is, the water outlet passage 78 passes through the water outlet through hole 734), aligned with and connected to the vertical section of the water outlet groove 421 or 21, so that the electrolyzed water and oxygen mixture can pass through; the through hole 733 (also called hydrogen through hole 733) corresponding to the hydrogen collecting channel 79 is formed as a part of the hydrogen collecting channel 79 (that is, the hydrogen collecting channel 79 passes through the hydrogen through hole 733); some of the through holes form fixing holes 735 for fasteners such as screws 8 to pass through.

[0070] Preferably, the pole frame 73 is rectangular. When used as an anode frame, a plurality of water inlet through holes 732 and a plurality of water outlet through holes 734 are respectively located on both sides of the width direction of the pole frame 73. Along the length direction of the pole frame 73, a plurality of water inlet through holes 732 and a plurality of water outlet through holes 734 are staggered. Correspondingly, the hydrogen through holes 733 on both sides of the pole frame 73 are also staggered along the length direction of the pole frame 73. Under this design, the flow field distribution of the electrolysis chamber can be made smoother and more uniform, and mixed flow is not easy to occur, and the water pressure loss is smaller, which is conducive to the smooth discharge of gas and liquid, reduces the pressure drop, and is conducive to improving the electrolysis efficiency.

[0071] Please also read Fig.19 and Fig. 20 Preferably, a plurality of guide grooves 736 are provided on one surface of the anode frame 73 corresponding to the water inlet through hole 1 732, and a guide groove 738 is provided corresponding to the water outlet through hole 734. The guide grooves 736 and 738 can be formed by at least two convex strips arranged at intervals, or by a plurality of grooves. The provision of the guide grooves 736 and 738 facilitates the water flow in and out of the electrolysis chamber to flow in and out more evenly. The pole frame 73 can also be used as a cathode frame. When used as a cathode frame, the through holes 732 and 734 are used as hydrogen outlet through holes and as a part of the hydrogen collecting channel 79 (that is, the hydrogen collecting channel 79 passes through the hydrogen outlet through holes). When stacked, the anode frame and the cathode frame are respectively provided with a first conduction groove 736 and a second conduction groove 738 on one side facing away from each other, and then the cathode frame is rotated 180 degrees and cooperates with each other so that the hydrogen outlet through hole on the cathode frame corresponds to the hydrogen through hole 733 on the anode frame; the proton exchange membrane 750 is arranged between the two pole frames 73.

[0072] Preferably, a sealing structure is provided on the surface of the pole frame 73 away from the proton exchange membrane 75, specifically including an inner ring sealing pattern 81 arranged in the circumferential direction of the pole frame 73, an outer ring sealing pattern 82 arranged in the circumferential direction of the pole frame 73, and a sealing ring 83 arranged outside each through hole 743 and each fixing hole 735. The inner ring sealing pattern 81 is designed to pass around the outside of each water inlet through hole 732 and the outside of each water outlet through hole 734, avoiding the first conduction groove 736 and the second conduction groove 738, and can seal both sides of the first conduction groove 736 and the second conduction groove 738.

[0073] The proton exchange membrane 750 is disposed between the two pole frames 73. During electrolysis, pure water undergoes electrolysis reaction at the anode side to form oxygen, electrons and hydrogen ions (protons). The protons migrate through the proton exchange membrane 750 to the cathode side, where the hydrogen ions form hydrogen. Fig.10 The water flow path shown is finally output from the first water outlet pipe 22 or the second water outlet pipe 43 , and the hydrogen generated in each electrolysis space is collected to the upper end plate 2 through the hydrogen collecting channels 79 connected in series, and flows out from the hydrogen external interface 24 of the upper end plate 2 .

[0074] The uppermost plate 71 in the uppermost electrolysis space 32 (i.e., the plate close to the upper end plate 2) is also used to connect to an external power source, so it can also be called a current collecting plate, a conductive plate, etc. The lowermost plate 71 in the lowermost electrolysis space 32 (i.e., the plate 71 close to the lower end plate 5) is also used to connect to an external power source, so it can also be called a current collecting plate, a conductive plate, etc. The plate 71 in other electrolysis units can be a bipolar plate, that is, one side of the plate is used as an anode and the other side is used as a cathode.

[0075] For further information, see Figure 1 , an upper pressure plate 1 is provided at the upper end of the upper end plate 2, and a lower pressure plate 6 is provided at the lower end of the electrolytic assembly 3. The upper pressure plate 1 and the lower pressure plate 6 limit the electrolytic assembly 3 through fixing parts such as screws 9, thereby improving the reliability of the installation of the electrolytic assembly 3. An intermediate buffer plate 102 can also be provided between the upper pressure plate 1 and the lower pressure plate 6 to ensure that the intermediate diffusion layer is evenly pressurized, while ensuring that the intermediate diffusion layer is stably and tightly fitted, thereby ensuring the stability of the layer voltage and the hydrogen production efficiency of the electrolyzer. At least one buffer plate 102 is provided between the upper end plate 2 and the upper pressure plate 1 or between the lower end plate 5 and the lower pressure plate 6. In this embodiment, buffer plates 102 are provided between the upper end plate 2 and the upper pressure plate 1 and between the lower end plate 5 and the lower pressure plate 6, respectively.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A PEM electrolyzer, comprising an upper end plate (2), a lower end plate (5) and an electrolysis assembly (3), wherein the electrolysis assembly (3) is arranged between the upper end plate (2) and the lower end plate (5), characterized in that: The electrolysis assembly (3) comprises a plurality of electrolysis spaces (32) and an intermediate waterway plate (4) located between adjacent electrolysis spaces (32); A plurality of first water outlet grooves (21) are provided on one side of the upper end plate (2), one end of the first water outlet groove (21) passes through the lower surface of the upper end plate (2), and the other end is connected to the first water outlet pipe (22); A plurality of first water inlet grooves (51) are provided on one side of the lower end plate (5), one end of the first water inlet groove (51) passes through the upper surface of the lower end plate (5), and the other end is connected to the first water inlet pipe (52); A plurality of second water outlet grooves (421) are provided on one side of the intermediate waterway plate (4), one end of the second water outlet groove (421) passes through the lower surface of the intermediate waterway plate (4) so ​​as to communicate with the electrolysis space below the intermediate waterway plate (4), and the other end is connected to the second water outlet pipe (43); a plurality of second water inlet grooves (422) are provided on the other side of the intermediate waterway plate (4), one end of the second water inlet groove (422) passes through the upper surface of the intermediate waterway plate (4) so ​​as to communicate with the electrolysis space above the intermediate waterway plate (4), and the other end is connected to the second water inlet pipe (44), so that each electrolysis space can have water inlet from the bottom and outlet from the top; At least one side of the intermediate waterway plate (4) is provided with a plurality of hydrogen gas holes (424) penetrating the thickness direction thereof, so that hydrogen generated in the electrolysis space (32) below the intermediate waterway plate (4) can be collected upward through the hydrogen gas holes (424); A plurality of hydrogen external interfaces (24) are provided on the other opposite side of the upper end plate (2), one end of each hydrogen external interface (24) passes through the lower surface of the upper end plate (2) and is connected to the electrolysis space (32) adjacent to the lower surface of the upper end plate (2), so as to output the collected hydrogen to the electrolytic cell.

2. The PEM electrolyzer according to claim 1, characterized in that: A water inlet passage (77), a drainage passage (78) and a hydrogen collecting channel (79) are formed in each electrolysis space. The water inlet passage (77) is connected to the first water inlet groove (51) or the second water inlet groove (422), the drainage passage (78) is connected to the first water outlet groove (21) or the second water outlet groove (421), and the hydrogen collecting channel (79) is connected to the hydrogen through hole (424).

3. The PEM electrolyzer according to claim 2, characterized in that: Each electrolysis space comprises a plurality of stacked electrolysis chambers (7), each electrolysis chamber (7) comprising stacked electrode plates (71), an anode assembly (72), a cathode assembly (74), an electrode frame (73), a proton exchange membrane (75) and a sealing gasket (76); The upper surface of the intermediate waterway plate serves as the pole plate on the anode side of the adjacent electrolysis chamber above the intermediate waterway plate, and the lower surface of the intermediate waterway plate serves as the pole plate on the cathode side of the adjacent electrolysis chamber below the intermediate waterway plate.

4. The PEM electrolyzer according to claim 3, characterized in that: The pole frame (73) is formed into a hollow structure, and a water inlet through hole (732), a water outlet through hole (734) and a hydrogen through hole (733) are provided on the periphery of the pole frame (73), the water outlet through hole (734) forms a part of the drainage passage (78), the water inlet through hole (732) forms a part of the water inlet passage (77), and the hydrogen through hole (733) forms a part of the hydrogen collecting flow channel (79); Guide grooves (736, 738) are respectively provided at the inner edge of the surface of the pole frame (73) away from the proton exchange membrane (75) corresponding to the water inlet through hole 1 (732) and the water outlet through hole (734); the water inlet through hole 1 (732) and the water outlet through hole (734) are respectively connected to the water inlet through groove or the water outlet through groove via the guide grooves (736, 738).

5. The PEM electrolyzer according to claim 1, characterized in that: The intermediate waterway plate (4) is an integral structure, made of a titanium plate with a corrosion-resistant coating on the surface, or made of a stainless steel plate with a corrosion-resistant coating on the surface; or The intermediate waterway plate (4) is a split structure, comprising an upper plate (41) and a lower plate (42), the lower surface of the upper plate (41) being in contact with the upper surface of the lower plate (42), the thickness of the lower plate (42) being greater than the thickness of the upper plate (41), the upper plate (41) being a titanium plate with a corrosion-resistant coating on the surface, and the lower plate (42) being a stainless steel plate.

6. The PEM electrolyzer according to claim 5, characterized in that: When the intermediate water channel plate (4) is of a split structure, a sealing groove (4221, 4241) is provided on the upper surface of the lower flat plate (42) corresponding to the water inlet groove (422) and the hydrogen permeation hole (424), and a sealing ring (427) is provided in the sealing groove (4221, 4241). The sealing ring (427) is clamped between the upper flat plate (41) and the lower flat plate (42) and surrounds the water inlet groove (422) or the hydrogen permeation hole (424) to seal them.

7. The PEM electrolyzer according to claim 5, characterized in that: When the intermediate waterway plate (4) is a split structure, the second water outlet groove (421) and the second water inlet groove (422) are respectively arranged on both sides of the lower plate (42), and one side of the upper plate (41) is provided with a plurality of second water inlet holes (411), and the positions of the plurality of second water inlet holes (411) correspond one to one with the positions of the plurality of second water inlet grooves (422).

8. The PEM electrolyzer according to claim 1, characterized in that: The second water outlet groove (421) is L-shaped, the horizontal section of the second water outlet groove (421) passes through the side wall of the intermediate waterway plate (4) and is connected to the second water outlet pipe (43), and the vertical section of the second water outlet groove (421) passes through the lower surface of the intermediate waterway plate (4); or The second water inlet groove (422) is L-shaped, the horizontal section of the second water inlet groove (422) passes through the side wall of the intermediate waterway plate (4) and is connected to the second water inlet pipe (44), and the vertical section of the second water inlet groove (422) passes through the upper surface of the intermediate waterway plate (4).

9. The PEM electrolyzer according to claim 8, characterized in that: The intermediate water channel plate (4) further comprises a plurality of water inlet branches (46), wherein the water inlet branches (46) are L-shaped elbows, and one of the second water inlet grooves (422) is connected to the second water inlet pipe (44) through one of the water inlet branches (46); or The intermediate water channel plate (4) further comprises a plurality of water outlet branches (45), wherein the water outlet branches (45) are straight pipes, and one of the second water outlet grooves (421) is connected to the second water outlet pipe (43) via one of the water outlet branches (45).

10. The PEM electrolyzer according to any one of claims 1 to 9, characterized in that: An upper pressing plate (1) is provided at the upper end of the upper end plate (2), and a lower pressing plate (6) is provided at the lower end of the lower end plate (5), wherein the upper pressing plate (1) and the lower pressing plate (6) are used to limit the electrolytic assembly (3) via a screw rod (9); At least one buffer is arranged between the upper end plate (2) and the upper pressing plate (1) or between the lower end plate (5) and the lower pressing plate (6).

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