阅读说明：本技术 一种板框式可叠加的水电解制氢pem电解装置 (Plate-frame type superposable water electrolysis hydrogen production PEM electrolysis device ) 是由 钟拥军 于 2021-07-26 设计创作，主要内容包括：本申请涉及一种板框式可叠加的水电解制氢PEM电解装置,其包括多个电解槽、设在相邻电解槽之间的双极板和固定装置；电解槽包括两个具有绝缘属性的板框和单个膜电极,板框紧密贴合在膜电极的两面；板框上开设有通槽,形成阳极室和阴极室,通槽内设有与膜电极和双极板电性连接的电极材料；多个电解槽和双极板交错排列,形成电解槽串；板框、双极板和膜电极上均开设有正相对的氧气孔、正相对的进水孔以及正相对的氢气孔,以在电解槽串中分别形成氧气通道、进水通道和氢气通道,氧气通道和进水通道均与阳极室连通；氢气通道与阴极室连通；固定装置用于抵紧并固定多个电解槽和双极板。本申请具有在增加少量体积的情况下极大提高制氢效率的效果。(The application relates to a plate-frame type superposable PEM (proton exchange membrane) electrolysis device for water electrolysis hydrogen production, which comprises a plurality of electrolysis baths, bipolar plates arranged between the adjacent electrolysis baths and a fixing device; the electrolytic cell comprises two plate frames with insulation property and a single membrane electrode, wherein the plate frames are tightly attached to two surfaces of the membrane electrode; a through groove is formed on the plate frame to form an anode chamber and a cathode chamber, and electrode materials electrically connected with the membrane electrode and the bipolar plate are arranged in the through groove; a plurality of electrolytic tanks and bipolar plates are arranged in a staggered manner to form an electrolytic tank string; the plate frame, the bipolar plate and the membrane electrode are all provided with a positive oxygen hole, a positive water inlet hole and a positive hydrogen hole which are opposite, so that an oxygen channel, a water inlet channel and a hydrogen channel are respectively formed in the electrolytic cell string, and the oxygen channel and the water inlet channel are communicated with the anode chamber; the hydrogen channel is communicated with the cathode chamber; the fixing device is used for abutting against and fixing the plurality of electrolytic cells and the bipolar plates. The present application has the effect of greatly increasing hydrogen production efficiency with a small increase in volume.)

1. A plate-frame type superposable PEM electrolysis device for hydrogen production by water electrolysis is characterized in that: comprises a plurality of groups of mutually independent electrolytic tanks (1), bipolar plates (2) arranged between adjacent electrolytic tanks (1) and a fixing device (3); a plurality of the electrolytic cells (1) and the bipolar plates (2) are arranged in a staggered manner to form an electrolytic cell string;

the electrolytic cell (1) comprises two plate frames (11) with insulation property and a single membrane electrode (12), wherein the plate frames (11) are parallel to the membrane electrode (12), and the plate frames (11) are tightly attached to two opposite surfaces of the membrane electrode (12); through grooves are formed in the plate frames (11) on the two sides of the membrane electrode (12), an anode chamber (13) and a cathode chamber (14) are formed by taking the membrane electrode (12) as a boundary, electrode materials (15) electrically connected with the membrane electrode (12) and the bipolar plate (2) are arranged in the through grooves, and the electrode materials (15) are used for conducting electricity and generating an electrolytic reaction;

the plate frame (11), the bipolar plate (2) and the membrane electrode (12) are correspondingly provided with an oxygen hole (41), a water inlet hole (43) and a hydrogen hole so as to respectively form an oxygen channel, a water inlet channel and a hydrogen channel in the electrolytic cell string, and the oxygen channel and the water inlet channel are communicated with the anode chamber (13); the hydrogen passage communicates with the cathode chamber (14);

the fixing device (3) is used for tightly abutting against and fixing the plurality of electrolytic tanks (1) and the bipolar plates (2) which are arranged in a staggered mode.

2. The plate and frame type superposable water electrolysis hydrogen production PEM electrolysis device according to claim 1, characterized in that: and a sealing element (52) in an annular structure is arranged on one side of the plate frame (11) facing the membrane electrode (12), and the area enclosed by the projection of the sealing element (52) on the plate frame (11) comprises the area where the through groove is located.

3. The plate and frame type superposable water electrolysis hydrogen production PEM electrolysis device according to claim 1, characterized in that: at least two fixing holes are formed in the plate frame (11) and the bipolar plate (2); the fixing device (3) comprises an end plate (31) provided with at least two fixing holes, screws (32) penetrating through all the fixing holes and nuts (33) connected to the screws (32), the end plate (31) is abutted to the plate frame (11), and the fixing holes in the end plate (31) correspond to the fixing holes in the plate frame (11) and the bipolar plate (2).

4. The plate and frame type superposable water electrolysis hydrogen production PEM electrolysis device according to claim 3, characterized in that: and insulating paint is arranged on the outer surface of the screw rod (32) and the outer surface of the end plate (31).

5. A plate and frame type superposable water electrolysis hydrogen production PEM electrolysis device according to claim 1 or 2, characterized in that: a first flow passage (71) or a second flow passage (72) is formed in the plate frame (11), and the first flow passage (71) is used for communicating an oxygen passage and a water inlet passage with the anode chamber (13); the second flow channel (72) is used for communicating a hydrogen gas passage with the cathode chamber (14).

6. The plate and frame superposable water electrolysis hydrogen production PEM electrolysis device according to claim 5, characterized in that: and the first flow channel (71) and the second flow channel (72) are provided with pressure bearing plates (73), and part of the sealing element (52) is fixedly arranged on the pressure bearing plates (73).

7. The plate and frame superposable water electrolysis hydrogen production PEM electrolysis device according to claim 6, characterized in that: the plate frame (11) and the bearing plate (73) are provided with clamping grooves (51), and the sealing element (52) is clamped and fixed in the clamping grooves (51).

8. The plate and frame superposable water electrolysis hydrogen production PEM electrolysis device according to claim 6, characterized in that: at least one support column (74) is arranged in the first flow passage (71) and the second flow passage (72).

9. The plate and frame superposable water electrolysis hydrogen production PEM electrolysis device according to claim 6, characterized in that: the end plate (31) is provided with an oxygen hole (41) opposite to the oxygen channel, a hydrogen hole (42) opposite to the hydrogen channel and a water inlet hole (43) opposite to the water inlet channel; the oxygen hole (41), the hydrogen hole (42) and the water inlet hole (43) are connected in a sealing mode and detachably connected with a sealing plug (44).

10. The plate and frame superposable water electrolysis hydrogen production PEM electrolysis device according to claim 9, characterized in that: end plate (31) with still press from both sides between sheet frame (11) and be equipped with wiring board (62) and insulation board (61) of taking oxygen hole (41), hydrogen hole (42) and inlet opening (43), insulation board (61) towards end plate (31) one side and with end plate (31) butt, wiring board (62) towards sheet frame (11) one side and with sheet frame (11) butt.

Technical Field

The application relates to the technical field of water electrolysis, in particular to a plate-frame type stackable water electrolysis hydrogen production PEM electrolysis device.

Background

The electrolytic cell consists of a cell body, an anode and a cathode, and an anode chamber and a cathode chamber are mostly separated by a diaphragm. The electrolytic bath is divided into three types, namely an aqueous solution electrolytic bath, a molten salt electrolytic bath and a non-aqueous solution electrolytic bath according to the difference of the electrolyte. When direct current passes through the electrolytic cell, an oxidation reaction occurs at the interface of the anode and the solution, and a reduction reaction occurs at the interface of the cathode and the solution, so as to prepare the required product.

The electrolytic hydrogen production in the PEM electrolyzer is mainly realized through electrolytic reaction in an electrolytic cell, the current of an electrode of the electrolytic cell determines the amount of electrolytic hydrogen production, the current is equal to the product of the effective area of the electrode and the current density, the current density is related to the efficiency of the adopted membrane electrode, and new breakthrough is difficult to occur under the current technical condition. The current method for improving the hydrogen production power of the PEM electrolyzer only improves the effective area of the electrode, so that the volume is enlarged, but the stability and the safety of the electrolyzer can not be ensured. With the development of the hydrogen energy industry and the application of hydrogen in the aspect of medical care, the PEM electrolysis device is gradually widely applied to the aspects of energy storage, production, hydrogen medical care and the like, users have larger and larger requirements on the consumption of hydrogen, and an electrolysis bath with a small sectional area cannot meet the requirements at all; and the processing flatness of the electrolytic cell with a large sectional area is difficult to ensure consistency, so that the sealing is easy to be poor, leakage is caused, and the working efficiency is difficult to improve.

Disclosure of Invention

In order to improve the hydrogen production efficiency of the electrolytic cell, the application provides a plate-frame type superposable water electrolysis hydrogen production PEM electrolytic device.

The name provided by the application adopts the following technical scheme:

a plate-frame type superposable PEM electrolysis device for hydrogen production by water electrolysis is characterized in that: the electrolytic cell comprises a plurality of groups of mutually independent electrolytic cells, bipolar plates arranged between adjacent electrolytic cells and a fixing device, wherein the plurality of electrolytic cells and the bipolar plates are staggered to form an electrolytic cell string;

the electrolytic cell comprises two plate frames with insulation property and a single membrane electrode, wherein the plate frames are parallel to the membrane electrode, and the plate frames are tightly attached to two opposite surfaces of the membrane electrode; through grooves are formed in the plate frames on the two sides of the membrane electrode, an anode chamber and a cathode chamber are formed by the membrane electrode in a boundary mode, electrode materials electrically connected with the membrane electrode and the bipolar plate are arranged in the through grooves, and the electrode materials are used for conducting electricity and generating an electrolytic reaction;

the plate frame, the bipolar plate and the membrane electrode are correspondingly provided with an oxygen hole, a water inlet hole and a hydrogen hole so as to respectively form an oxygen channel, a water inlet channel and a hydrogen channel in the electrolytic cell string, and the oxygen channel and the water inlet channel are communicated with the anode chamber; the hydrogen passage is communicated with the cathode chamber;

the fixing device is used for abutting against and fixing the plurality of the electrolytic tanks and the bipolar plates which are arranged in a staggered mode.

Optionally, a sealing element in an annular structure is arranged on one side of the plate frame facing the membrane electrode, and an area defined by a projection of the sealing element on the plate frame includes an area where the through groove is located.

Optionally, the plate frame and the bipolar plate are both provided with at least two fixing holes; the fixing device comprises an end plate provided with at least two fixing holes, screws penetrating through all the fixing holes and nuts in threaded connection with the screws, the end plate is abutted to the plate frame, and the fixing holes in the end plate correspond to the fixing holes in the plate frame and the bipolar plate.

Optionally, the outer surface of the screw and the outer surface of the end plate are both provided with insulating paint.

Optionally, the plate frame is provided with a first flow channel or a second flow channel, and the first flow channel is used for communicating the oxygen channel and the water inlet channel with the anode chamber; the second flow passage is used to communicate a hydrogen gas passage with the cathode chamber.

Optionally, a pressure-bearing plate is arranged on the first flow passage and the second flow passage, and part of the sealing element is fixedly arranged on the pressure-bearing plate.

Optionally, the plate frame and the bearing plate are provided with clamping grooves, and the sealing element is clamped and fixed in the clamping grooves.

Optionally, at least one supporting column is arranged in the first flow passage and the second flow passage.

Optionally, the end plate is provided with an oxygen hole right opposite to the oxygen channel, a hydrogen hole right opposite to the hydrogen channel, and a water inlet hole right opposite to the water inlet channel; the oxygen hole, the hydrogen hole and the water inlet hole are connected in a sealing mode and detachably connected with sealing plugs.

Optionally, the end plate with still press from both sides between the sheet frame and be equipped with wiring board and the insulation board of taking oxygen hole, hydrogen hole and inlet opening, the insulation board towards end plate one side and with the end plate butt, the wiring board towards sheet frame one side and with the sheet frame butt.

In summary, the present application includes at least one of the following beneficial technical effects:

the electrolytic tank adopts an ultrathin plate frame structure, the volume of the electrolytic tank can be greatly reduced, the thickness of the electrolytic tank is thinned, and a plurality of electrolytic tanks can be superposed and connected in series through the connection effect of the bipolar plates; the oxygen holes, the hydrogen holes and the water inlet holes which are arranged on the plate frame and the bipolar plate can form a public channel by connecting the electrolytic cells in parallel, so that the uniform injection of water flow can be realized, the hydrogen is discharged from the hydrogen channel in a centralized way, namely, after the electrolytic cells can be stacked in batches, the efficiency and the hydrogen production quantity of hydrogen production can be multiplied under the condition of increasing the volume of the electrolytic cell string by a small amount, and the electrolytic hydrogen production effect with small volume and high power is realized.

Drawings

Fig. 1 is an exploded structural view provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of an anode side plate frame provided in an embodiment of the present application;

FIG. 3 is a drawing showing opposite sides of a bezel in a single electrolytic cell according to an embodiment of the present application;

FIG. 4 is an enlarged schematic view of portion A of FIG. 3;

FIG. 5 is a schematic view of an end of an electrolyzer provided in an embodiment of the present application.

Reference numerals: 1. an electrolytic cell; 11. a plate frame; 12. a membrane electrode; 13. anode chamber, 14, cathode chamber; 15. an electrode material; 2. a bipolar plate; 3. a fixing device; 31. an end plate; 32. a screw; 33. a nut; 41. an oxygen hole; 42. a hydrogen hole; 43. a water inlet hole; 44. a sealing plug; 51. a card slot; 52. a seal member; 61. an insulating plate; 62. a wiring board; 71. a first flow passage; 72. a second flow passage; 73. a pressure bearing plate; 74. and (4) a support column.

Detailed Description

The technical solutions in the present application will be described in further detail below with reference to the accompanying drawings.

The embodiment of the application discloses a plate-frame type superposable water electrolysis hydrogen production PEM electrolysis device. Referring to fig. 1, the electrolytic apparatus includes a plurality of independent electrolytic cells 1, bipolar plates 2 interposed between the electrolytic cells 1, and a fixing device 3 for fixing the electrolytic cells 1 and the bipolar plates 2.

The electrolytic cell 1 comprises at least two plate frames 11 with insulation property and a membrane electrode 12 parallel to the plate frames 11, two plate frames 11 in one electrolytic cell 1 can be arranged, or a plurality of small plate frames 11 can be spliced to form two plate frames 11 with larger areas, the two plate frames 11 are mutually in an axisymmetric structure, and the membrane electrode 12 is clamped between the two plate frames 11. The panel frame 11 may be made of plastic material, for example: polyphenylene Sulfone (PPSU) material, Polyethylene (PE) material, etc., in some small-sized electrolyzers, the thickness of the plate frame 11 is between 2 to 5mm, which has good insulation, light weight, high structural strength and high plasticity.

Referring to fig. 2 and 3, a through groove is formed in the middle of the plate frame 11, that is, the through groove penetrates through two side surfaces of the plate frame 11, the two plate frames 11 are respectively attached to two side surfaces of the membrane electrode 12, so that an independent electrolytic cell 1 can be formed, the through grooves of the plate frames 11 located on two sides of the same membrane electrode 12 respectively form an anode chamber 13 and a cathode chamber 14, electrode materials 15 are filled in the anode chamber 13 and the cathode chamber 14, and the electrode materials 15 are electrically contacted with the membrane electrode 12 and used for electrifying and generating an electrolytic reaction after water injection. The bipolar plate 2 is clamped between two adjacent electrolytic tanks 1, namely a plurality of electrolytic tanks 1 and the bipolar plate 2 are alternately overlapped to form an electrolytic tank string.

Referring to fig. 2 to 4, the plate frame 11, the bipolar plate 2 and the membrane electrode 12 are all provided with water inlet holes 43, oxygen holes 41 and hydrogen holes 42, the water inlet holes 43 are located below, and the oxygen holes 41 and the hydrogen holes 42 are located on two sides of the above. When the plate frame 11, the bipolar plate 2, and the membrane electrode 12 are stacked together, the oxygen holes 41 are opposed and form oxygen channels, the water inlet holes 43 are opposed and form water inlet channels, and the hydrogen holes 42 are opposed and form hydrogen channels. A first flow channel 71 is further formed in one of the plate frames 11 of the electrolytic cell 1, and is used for communicating the oxygen channel and the water inlet channel with the through grooves in the plate frame 11, namely the oxygen channel and the water inlet channel are both communicated with the anode chamber 13; the other plate frame 11 is provided with a second flow channel 72 for communicating the hydrogen channel with the through groove of the plate frame 11, that is, the hydrogen channel is communicated with the cathode chamber 14.

The area of the membrane electrode 12 is larger than the area of the through groove on the plate frame 11, and is used for isolating the anode chamber 13 from the cathode chamber 14, and simultaneously is used for contacting the electrode material 15 to pass current, the membrane electrode 12 can be one of an ion exchange membrane, an asbestos diaphragm or a metal diaphragm, and the membrane electrode 12 has a certain porosity for passing ions and has the function of isolating water molecules.

The electrode material 15 in the anode chamber 13 may be a combination of one or more of platinum, iridium, ruthenium, or other alloys containing one or more of the foregoing elements, and may have high activity for oxygen evolution reactions; the electrode material 15 in the cathode chamber 14 may be one of platinum, palladium or activated carbon containing an alloy of one or more of the foregoing elements; the bipolar plate 2 is made of titanium or titanium alloy material, has good structural strength and corrosion resistance, has good electrical conductivity and is easy to manufacture.

In the working process, one end of the anode of the electrolytic cell string is connected with the anode of the direct current power supply, and the other end is connected with the cathode of the direct current power supply, as shown in fig. 1, the current sequentially passes through the electrode material 15 in the anode chamber 13, the electrode material 15 in the cathode chamber 14 of the membrane electrode 12 and the bipolar plate 2, and passes through the electrode material 15 in the anode chamber 13 of the adjacent electrolytic cell 1 again, and finally reaches the cathode of the direct current power supply; water enters the water inlet pipeline through the water inlet holes 43 and enters the anode chambers 13 of the electrolytic cells 1 through the first flow channels 71 on the plate frames 11, the water flow contacts the anode plates to generate an electrolytic reaction and separate out oxygen, hydrogen ions and electrons, and the oxygen and redundant water flow enters the oxygen channel through the first flow channels 71 and is discharged to the electrolytic cell string; the electrons are transferred to the cathode through the peripheral circuit, the hydrogen ions pass through the membrane electrode 12 in hydrated form to the electrode material 15 in the cathode chamber 14, the hydrogen ions and electrons recombine to form hydrogen gas, which enters the hydrogen gas channel through a second flow channel 72 in communication with the cathode chamber 14 until it exits the cell string.

Referring to fig. 2 and 3, in order to improve the sealing performance of the anode chamber 13 and the cathode chamber 14 and reduce leakage of produced gas and water flow, an annular clamping groove 51 is formed in one side surface of the plate frame 11 facing the membrane electrode 12, a sealing member 52 which is also annular is clamped in the clamping groove 51, the sealing member 52 may be made of rubber or fluororubber, and a projection of an area defined by clamping of the sealing member 52 in the clamping groove 51 on the plate frame 11 covers an area where the through groove is located.

Referring to fig. 4, step grooves are formed in the first flow channel 71 and the second flow channel 72, a pressure-bearing plate 73 is erected and fixed on the step grooves, the material of the pressure-bearing plate 73 is the same as that of the plate frame 11, and the pressure-bearing plate 73 is flush with the outer surface of the plate frame 11 when being fixedly arranged or erected on the step grooves, a clamping groove 51 is formed in the outer surface of the pressure-bearing plate 73 and is connected with the clamping groove 51 on the plate frame 11 end to end, so that the sealing element 52 is clamped in the clamping groove 51, the positions of the sealing element 52 can be uniformly loaded, and the poor sealing performance caused by insufficient pressure-bearing of the sealing element 52 at the positions of the first flow channel 71 and the second flow channel 72 is reduced.

In order to enable the bearing plate 73 to bear a large extrusion force between the plate frame 11 and the membrane electrode 12, at least one supporting column 74 arranged at equal intervals is fixedly arranged in the first flow channel 71 and the second flow channel 72, and the supporting columns 74 are perpendicular to the bearing plate. The supporting column 74 may be a rectangular columnar structure, in which case the long side of the supporting column 74 is parallel to the axial direction of the first flow channel 71 or the second flow channel 72; the support posts 74 can also be cylindrical structures, and the axis of the support posts 74 is opposite to the back of the position of the slot 51 of the bearing plate. The arrangement of the supporting columns 74 does not affect the passage of water or gas through the gaps between the supporting columns 74 while improving the structural strength of the pressure bearing plate 73.

Referring to fig. 1 and 5, the fixing device 3 includes a plurality of screws 32, nuts 33 in the same number as the screws 32, and two end plates 31. The plate frame 11, the bipolar plate 2 and the membrane electrode 12 are all provided with a plurality of fixing holes (not shown in the figure), and are arranged on the screw rods 32 through the fixing holes. The two end plates 31 are respectively abutted against both ends of the electrolytic cell string, the screw 32 penetrates the end plates 31 and the electrolytic cell string, and the end plates are screwed to the screw 32 through the nuts 33 and abutted against the outer side surface of the end plates 31, so that the plurality of independent electrolytic cells 1 and the bipolar plates 2 alternately interposed between the electrolytic cells 1 can be fixed.

The end plate 31 may be any plate material with good structural strength, such as a wood plate, a plastic plate, a metal plate, and the like, preferably, the end plate 31 is a metal plate, such as carbon steel, iron, aluminum, or a metal alloy, and the outer surfaces of the end plate 31 and the screw 32 are both sprayed with an insulating varnish for isolating the current on the electrode material 15 and the bipolar plate 2 in the electrolytic cell 1; nut 33 may be a conventional hex nut or a wing nut to facilitate the use of tools by a worker or the tightening of nut 33 by hand. Further, an insulating plate 61 and a wiring board 62 are interposed between the end plate 31 and the adjacent plate frame 11, wherein the insulating plate 61 faces the shim plate and abuts against the end plate 31, and the wiring board 62 faces the plate frame 11 and abuts against the plate frame 11 and the electrode material 15 in the plate frame 11, so as to further prevent the occurrence of a current leakage phenomenon through the end plate 31.

The insulating plate 61, the wiring board 62 and the end plate 31 are provided with an oxygen hole 41 opposite to the oxygen channel, a hydrogen hole 42 opposite to the hydrogen channel, a water inlet hole 43 communicated with the water inlet channel and a fixing hole for penetrating the screw rod 32.

Referring to fig. 5, the oxygen hole 41, the hydrogen hole 42, and the water inlet 43 of the end plate 31 are detachably connected with sealing plugs 44, and in one of the realizable manners, the sealing plugs 44 are made of rubber, and are in interference fit with the oxygen hole 41, the hydrogen hole 42, and the water inlet 43, so as to seal the oxygen hole 41, the hydrogen hole 42, and the water inlet 43; in another realizable mode, the sealing plug 44 is made of one of rubber, plastic and metal materials, and the sealing plug 44 is in threaded connection with the oxygen hole 41, the hydrogen hole 42 and the water inlet hole 43, so as to realize the sealing of the oxygen hole 41, the hydrogen hole 42 and the water inlet hole 43, be used for water flow injection and gas collection at one end of the device, and simultaneously reduce the phenomenon that impurities enter each channel to cause blockage in the non-working state.

The implementation principle of the embodiment of the application is as follows: the positive electrode and the negative electrode of the direct current power supply are respectively connected to the wiring boards 62 close to the two end parts of the electrolytic bath 1, the wiring boards 62 are abutted against the adjacent plate frame 11 and the electrode material 15 in the plate frame 11, and the current sequentially passes through the electrode material 15 in the anode chamber 13, the membrane electrode 12, the electrode material 15 in the cathode chamber 14, the bipolar plate 2, the electrode material 15 in the anode chamber 13 in the adjacent electrolytic bath 1 from the wiring boards 62 to the negative electrode of the direct current power supply. Water flow is injected from the water inlet channel and enters the anode chamber 13, the water flow spreads to the upper part in the anode chamber 13 at a gap between the electrode material 15 and the plate frame 11, at the moment, the water flow is in contact with the electrode material 15 in the anode chamber 13 to separate out hydrogen, hydrogen ions and electrons, the electrons move to the cathodes of the electrolytic cells 1 through a peripheral circuit, the hydrogen ions are in contact with the electrode material 15 in the cathode chamber 14 through the membrane electrode 12 in a hydrated form, due to the effect of the membrane electrode 12 in separating the anode chamber 13 from the cathode chamber 14, the hydrogen ions and free electrons can be combined to form hydrogen to be discharged from the hydrogen channel, and part of the water flow and oxygen enter the oxygen channel from the anode chamber 13 and are discharged from the oxygen channel.

The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.