阅读说明：本技术 一种包括波浪能发电部及燃料电池发电部的组合发电装置 (Combined power generation device comprising wave power generation part and fuel cell power generation part ) 是由 韩冰峰 程敏 刘振 窦永香 于 2020-12-31 设计创作，主要内容包括：本发明提供一种包括波浪能发电部及燃料电池发电部的组合发电装置,包括介电弹性体波浪能发电部、海水电解部、燃料电池发电部和阻尼板；所述介电弹性体波浪能发电部包括浮漂体、上发电单元、下发电单元和移动轴；所述上发电单元和所述下发电单元均由锥形介电弹性体和扇形电极组成；所述燃料电池发电部包括封装结构、盲端集流板、若干单电池、气口端集流板以及盲端端板和气口端板；所述移动轴下端部、所述海水电解部、所述封装结构和所述阻尼板依次刚性连接；所述海水电解部用于利用所述上发电单元和所述下发电单元产生的电能电解海水为所述燃料电池发电部提供氢气和氧气。本发明的技术方案能够将海洋波浪能转换为电能,具有很高的稳定性。(The invention provides a combined power generation device comprising a wave energy power generation part and a fuel cell power generation part, which comprises a dielectric elastomer wave energy power generation part, a seawater electrolysis part, a fuel cell power generation part and a damping plate, wherein the dielectric elastomer wave energy power generation part is connected with the seawater electrolysis part; the dielectric elastomer wave energy power generation part comprises a float body, an upper power generation unit, a lower power generation unit and a moving shaft; the upper power generation unit and the lower power generation unit are both composed of a conical dielectric elastomer and a sector electrode; the fuel cell power generation part comprises a packaging structure, a blind end current collecting plate, a plurality of monocells, a gas port end current collecting plate, a blind end plate and a gas port end plate; the lower end part of the moving shaft, the seawater electrolysis part, the packaging structure and the damping plate are sequentially and rigidly connected; the seawater electrolysis part is used for electrolyzing seawater by using the electric energy generated by the upper power generation unit and the lower power generation unit to provide hydrogen and oxygen for the fuel cell power generation part. The technical scheme of the invention can convert ocean wave energy into electric energy and has high stability.)

1. A combined power generation device comprising a wave energy power generation part and a fuel cell power generation part is characterized by comprising a dielectric elastomer wave energy power generation part, a seawater electrolysis part, a fuel cell power generation part and a damping plate;

the dielectric elastomer wave energy power generation part comprises a float body, an upper power generation unit, a lower power generation unit and a moving shaft; the upper power generation unit and the lower power generation unit are both composed of a conical dielectric elastomer and a sector electrode bonded on the dielectric elastomer; the bottom surface of the dielectric elastomer is fixed on the upper side and the lower side of the floating body; the moving shaft penetrates through the dielectric elastomer and the floating body, is fixed with the top of the dielectric elastomer and is connected with the floating body in a sliding mode;

the fuel cell power generation part comprises a packaging structure, a blind end current collecting plate, a plurality of monocells, a gas port current collecting plate, a blind end plate and a gas port end plate, wherein the blind end current collecting plate, the monocells, the gas port current collecting plate and the blind end plate and the gas port end plate are sequentially packaged in the packaging structure, the blind end plate is fixed to one side of the blind end current collecting plate in a pressing mode through pretightening force, and the gas port end plate is located to one side of the; the single cells comprise bipolar plates and MEA, and a plurality of single cells are connected in series in sequence;

the lower end part of the moving shaft, the seawater electrolysis part, the packaging structure and the damping plate are sequentially and rigidly connected;

the upper power generation unit and the lower power generation unit are respectively electrically connected with the seawater electrolysis part, and the seawater electrolysis part is used for electrolyzing seawater by using electric energy generated by the upper power generation unit and the lower power generation unit to provide hydrogen and oxygen for the fuel cell power generation part.

2. The combined power plant comprising a wave energy power generation section and a fuel cell power generation section according to claim 1, wherein the blind end plate and the gas port end plate are bolted to both sides of the enclosure.

3. The combined power plant comprising a wave energy power plant and a fuel cell power plant of claim 1, wherein the packaging structure is a cylindrical packaging structure, and the blind end collector plate, the bipolar plate, the MEA, the gas port collector plate, the blind end plate, and the gas port plate are all circular.

4. A combined power plant comprising a wave energy power generation section and a fuel cell power generation section according to claim 1, characterized in that the seawater electrolysis section comprises an electrolyzer, a hydrogen collector and an oxygen collector; the upper power generation unit and the lower power generation unit provide direct current for the electrolytic bath through a bridge rectifier circuit to electrolyze seawater to generate hydrogen and oxygen; the hydrogen collector and the oxygen collector are respectively used for storing the hydrogen and the oxygen generated by the electrolytic cell and providing the hydrogen and the oxygen for the fuel cell power generation part.

5. A combined power plant including a wave energy power generation section and a fuel cell power generation section according to claim 1, characterized in that the sector electrode includes an upper electrode and a lower electrode; the lower electrode and the upper electrode are respectively adhered to the inner side and the outer side of the dielectric elastomer through conductive adhesives.

Technical Field

The invention relates to the field of fuel cell and wave energy power generation, in particular to a combined power generation device comprising a wave energy power generation part and a fuel cell power generation part.

Background

With the development of society, energy crisis and environmental problems become more serious day by day, and ocean energy reserves are huge, and the ocean energy is a clean pollution-free renewable energy. Scientists in various countries are studying and utilizing various combination technologies to extract ocean energy and provide stable energy for ocean wireless network sensors or small-sized electronic devices. For example, wind power and wave power generators which are formed by collecting ocean wave energy and offshore wind energy are large in size and easy to damage. For example, a small generator formed by combining an electromagnetic linear technology and wave energy is low in electromagnetic power generation efficiency.

The dielectric elastomer has the advantages of excellent electromechanical conversion characteristics, high energy density, easy forming, difficult fatigue damage and the like, and the method for collecting ocean wave energy by using the dielectric elastomer is more and more concerned by people, and the dielectric elastomer can also be used for manufacturing a soft, light and handy power generation device with high energy conversion efficiency.

A fuel cell is a device capable of converting chemical energy of fuel into electric energy, has a high energy density, and is rapidly developed in the field of oceans, and the limitation of the application of the fuel cell in oceans is the supply of hydrogen fuel.

Disclosure of Invention

The invention provides a combined power generation device comprising a wave energy power generation part and a fuel cell power generation part, and aims to solve the problem that the combined power generation of a dielectric elastomer wave energy device and a fuel cell is needed to supply power for a marine wireless sensor network node or a small electronic sensor. The invention mainly utilizes the wave energy power generation part of the dielectric elastomer to collect wave energy, then utilizes the wave energy to electrolyze seawater to produce hydrogen, and further supplies a hydrogen source to the power generation part of the fuel cell to generate power.

The technical means adopted by the invention are as follows:

a combined power generation device comprising a wave energy power generation part and a fuel cell power generation part comprises a dielectric elastomer wave energy power generation part, a seawater electrolysis part, a fuel cell power generation part and a damping plate;

the dielectric elastomer wave energy power generation part comprises a float body, an upper power generation unit, a lower power generation unit and a moving shaft; the upper power generation unit and the lower power generation unit are both composed of a conical dielectric elastomer and a sector electrode bonded on the dielectric elastomer; the bottom surface of the dielectric elastomer is fixed on the upper side and the lower side of the floating body; the moving shaft penetrates through the dielectric elastomer and the floating body, is fixed with the top of the dielectric elastomer and is connected with the floating body in a sliding mode;

the fuel cell power generation part comprises a packaging structure, a blind end current collecting plate, a plurality of monocells, a gas port current collecting plate, a blind end plate and a gas port end plate, wherein the blind end current collecting plate, the monocells, the gas port current collecting plate and the blind end plate and the gas port end plate are sequentially packaged in the packaging structure, the blind end plate is fixed to one side of the blind end current collecting plate in a pressing mode through pretightening force, and the gas port end plate is located to one side of the; the single cells comprise bipolar plates and MEA, and a plurality of single cells are connected in series in sequence;

the lower end part of the moving shaft, the seawater electrolysis part, the packaging structure and the damping plate are sequentially and rigidly connected;

the upper power generation unit and the lower power generation unit are respectively electrically connected with the seawater electrolysis part, and the seawater electrolysis part is used for electrolyzing seawater by using electric energy generated by the upper power generation unit and the lower power generation unit to provide hydrogen and oxygen for the fuel cell power generation part.

Furthermore, the blind end plate and the gas port end plate are fixed on two sides of the packaging structure through bolts.

Further, the packaging structure is a cylindrical packaging structure, and the blind end current collecting plate, the bipolar plate, the MEA, the gas port current collecting plate, the blind end plate and the gas port end plate are all circular.

Further, the seawater electrolysis part comprises an electrolysis bath, a hydrogen collector and an oxygen collector; the upper power generation unit and the lower power generation unit provide direct current for the electrolytic bath through a bridge rectifier circuit to electrolyze seawater to generate hydrogen and oxygen; the hydrogen collector and the oxygen collector are respectively used for storing the hydrogen and the oxygen generated by the electrolytic cell and providing the hydrogen and the oxygen for the fuel cell power generation part.

Further, the sector electrode comprises an upper electrode and a lower electrode; the lower electrode and the upper electrode are respectively adhered to the inner side and the outer side of the dielectric elastomer through conductive adhesives.

Compared with the prior art, the invention has the following advantages:

the combined power generation device comprising the wave energy power generation part and the fuel cell power generation part can convert ocean wave energy into electric energy, has high stability, and can provide sufficient energy for ocean wireless sensor network nodes and small-sized electronic equipment.

Based on the reason, the invention can be widely popularized in the field of wave energy power generation.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a power generation device combined by a wave energy device and a fuel cell, wherein the wave energy device comprises a dielectric elastomer.

Fig. 2 is a schematic structural diagram of the power generation unit according to the present invention.

Fig. 3 is a schematic structural view of a power generation part of a fuel cell according to the present invention.

FIG. 4 is a schematic view of the working principle of the seawater electrolysis part according to the present invention.

Fig. 5 is a schematic diagram of a bipolar plate structure according to embodiment 2 of the present invention.

In the figure: 1. a movable shaft; 2. an upper power generation unit; 3. a float body; 4. a lower power generation unit; 5. a fuel cell power generation section; 6. a damping plate; 7. a blind end plate; 8. a blind end collector plate; 9. an MEA; 10. a bipolar plate; 11. a gas port end collector plate; 12. a gas port end plate; 13. a packaging structure; 14. a seawater electrolysis unit; 15. a direct current power supply; 16. an electrolytic cell; 17. a cathode; 18. an anode; 19. an oxygen collector; 20. a hydrogen gas collector; 21. an upper electrode; 22. a lower electrode; 23. a dielectric elastomer; 101. a cooling chamber inlet; 102. an oxygen cavity outlet I; 103. a hydrogen chamber inlet; 104. an oxygen chamber outlet II; 105. a cooling chamber outlet; 106. an oxygen chamber inlet II; 107. a hydrogen chamber outlet; 108. oxygen chamber entry I.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. Any specific values in all examples shown and discussed herein are to be construed as exemplary only and not as limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the absence of any contrary indication, these directional terms are not intended to indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be considered as limiting the scope of the present invention: the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

Example 1

As shown in fig. 1 to 3, the present invention provides a combined power generation apparatus including a wave energy power generation section and a fuel cell power generation section, including a dielectric elastomer wave energy power generation section, a seawater electrolysis section 14, a fuel cell power generation section 5, and a damping plate 6;

the dielectric elastomer wave energy power generation part comprises a floating body 3, an upper power generation unit 2, a lower power generation unit 4 and a moving shaft 1; the upper power generation unit 2 and the lower power generation unit 4 are both composed of a conical dielectric elastomer 23 and a sector electrode adhered to the dielectric elastomer 23; the bottom surface of the dielectric elastomer 23 is fixed on the upper side and the lower side of the floating body 3; the moving shaft 1 penetrates through the dielectric elastomer 23 and the floating body 3, is fixed with the top of the dielectric elastomer 23, and is connected with the floating body 3 in a sliding manner;

the fuel cell power generation part 5 comprises a packaging structure 13, a blind end current collecting plate 8, a plurality of single cells, a gas port current collecting plate 11, a blind end plate 7 and a gas port end plate 12, wherein the blind end current collecting plate 8, the single cells, the gas port current collecting plate 11 and the blind end plate 7 and the gas port end plate 12 are sequentially packaged in the packaging structure, the blind end current collecting plate 7 is positioned on one side of the blind end current collecting plate 8, and the gas port end plate 12 is positioned on one side of the gas port current; the single cell comprises a bipolar plate 10 and an MEA9, and a plurality of single cells are connected in series in sequence;

the lower end part of the moving shaft 1, the seawater electrolysis part 14, the packaging structure 13 and the damping plate 6 are rigidly connected in sequence;

the upper power generation unit 2 and the lower power generation unit 4 are electrically connected to the seawater electrolysis unit 14, respectively, and the seawater electrolysis unit 14 is configured to electrolyze seawater by using electric energy generated by the upper power generation unit 2 and the lower power generation unit 4 to provide hydrogen and oxygen for the fuel cell power generation unit 5.

Further, the blind end plate 7 and the gas port end plate 12 are fixed on both sides of the packaging structure 13 through bolts.

Further, the seawater electrolytic part 14 includes an electrolytic bath 16, a hydrogen collector 20 and an oxygen collector 19; the upper power generation unit 2 and the lower power generation unit 4 provide direct current for the electrolytic bath 16 through a bridge rectifier circuit to electrolyze seawater to generate hydrogen and oxygen; the hydrogen collector 20 and the oxygen collector 19 are used to store the hydrogen and oxygen generated by the electrolyzer 16 and to provide the hydrogen and oxygen to the fuel cell power generation section 5, respectively.

Further, the sector electrodes are flexible electrodes and comprise an upper electrode 21 and a lower electrode 22; the lower electrode 22 and the upper electrode 21 are respectively adhered to the inner side and the outer side of the dielectric elastomer 23 through conductive adhesives.

Further, the outer surfaces of the upper power generation unit 2 and the lower power generation unit 4 are sealed by covering a layer of insulating film or a layer of flexible insulating material, so that electric leakage is prevented.

Under the action of the seawater damping force, the dielectric elastomer 23 is slightly deformed under the action of the force, so that the moving shaft 1 is slightly deformed relative to the floating body 3 and can move up and down in the floating body 3, and the moving shaft 1, the seawater electrolysis part 14, the packaging structure 13 and the damping plate 6 are rigidly connected together, so that the damping plate 6 and the floating body 3 generate relative displacement. The conical dielectric elastomers 23 of the upper and lower power generating units are equivalent to two springs, play a role of a balancing device, maintain the relative balance of the damping plate 5 and the floating body 3, meanwhile, the conical dielectric elastomers 23 are continuously stretched and compressed, the flexible electrodes continuously generate current, and the dielectric elastomers 23 continuously convert ocean kinetic energy into electric energy under the action of external voltage; the dielectric elastomer wave energy power generation part utilizes wave acting force to directly act on the conical dielectric elastomer 23, and compared with the scheme that wave acting force is utilized in the prior art, the wave acting force is firstly converted into compressed internal energy of gas, and then the gas is utilized to push the dielectric generator unit, the direct conversion efficiency is superior to the indirect conversion efficiency in terms of energy conversion efficiency, and the power generation unit not only serves as an energy generation module, but also serves as an elastic unit in terms of the structure of the power generation unit, so that the wave energy device can be coordinated to reciprocate at a balance position;

alternating current generated by the upper power generation unit 2 and the lower power generation unit 4 is converted into direct current through a bridge rectifier circuit to be used as a direct current power supply 15 for electrolyzing water by the seawater electrolysis part 14, a cathode 17 and an anode 18 in the electrolysis bath 16 filled with seawater are connected with the direct current power supply 15 through leads, after the water is electrolyzed, the anode 18 generates hydrogen, the cathode 17 generates oxygen, and the hydrogen and the oxygen generated by electrolyzing the water are respectively stored by the hydrogen collector 20 and the oxygen collector 19 to provide reaction gas for the fuel cell power generation part 5;

the fuel cell power generation section 5 can convert chemical energy of hydrogen and oxygen into electric energy, and by controlling the hydrogen collector 20 and the oxygen collector 19 to maintain stable supply of hydrogen and oxygen, the fuel cell power generation section 5 can stably output electric energy.

The combined power generation device comprising the wave energy power generation part and the fuel cell power generation part can convert ocean wave energy into electric energy, has high stability, and can provide sufficient energy for ocean wireless sensor network nodes and small-sized electronic equipment.

Example 2

Based on example 1, in this example, the package structure 13 is a cylindrical package structure, and the blind end collector 8, the bipolar plate 10, the MEA9, the gas port collector 11, the blind end plate 7, and the gas port plate 12 are all circular.

Further, the outer edge portion of the bipolar plate 10 has a set of hydrogen chamber inlet 103 and hydrogen chamber outlet 107, at least one set of oxygen chamber inlet and oxygen chamber outlet, and a set of cooling chamber inlet 101 and cooling chamber outlet 105 axially penetrating the bipolar plate 10, and the inlet and outlet of each set are symmetrically arranged around the axial center of the bipolar plate 10; the bipolar plate 10 comprises an oxygen unipolar plate and a hydrogen unipolar plate which are attached and fixed together;

a hydrogen flow field arranged in the middle of the hydrogen unipolar plate is arranged on one side of the hydrogen unipolar plate, which is far away from the oxygen unipolar plate, and the hydrogen flow field is respectively communicated with the hydrogen cavity inlet 103 and the hydrogen cavity outlet 107;

an oxygen flow field arranged in the middle of the oxygen unipolar plate is arranged on one side of the oxygen unipolar plate, which is far away from the hydrogen unipolar plate, and the oxygen flow field is respectively communicated with the oxygen cavity inlet and the oxygen cavity outlet;

one side of the oxygen unipolar plate, which is close to the hydrogen unipolar plate, is provided with a coolant flow field arranged in the middle of the oxygen unipolar plate, and the coolant flow field is respectively communicated with the cooling cavity inlet 101 and the cooling cavity outlet 105;

the gas port end plate 12 and the MEA9 are each provided with openings corresponding to the hydrogen chamber inlet 103, the hydrogen chamber outlet 107, the oxygen chamber inlet, the oxygen chamber outlet, the cooling chamber inlet 101, and the cooling chamber outlet 105, respectively, for enabling supply and output of hydrogen, oxygen, and coolant.

Further, the oxygen cavity comprises two groups of oxygen cavity inlets and two groups of oxygen cavity outlets, namely an oxygen cavity inlet I108, an oxygen cavity outlet I102, an oxygen cavity inlet II 106 and an oxygen cavity outlet II 104, wherein the oxygen cavity inlets are communicated through an external pipeline, and the oxygen cavity outlets are communicated through an external pipeline.

Further, the hydrogen unipolar plate and the oxygen unipolar plate are bonded and fixed through glue.

Further, the blind end plate 7 and the packaging structure 13 are made of insulating materials.

Further, the blind end collector plate 8 and the gas port end collector plate 11 are both made of pure copper materials.

Further, the bipolar plate 10, the MEA9, the gas port collector plate 11, and the gas port end plate 12 are provided with positioning holes, and are axially positioned by circular shafts inserted into the positioning holes.

Further, one of the oxygen chamber outlets is disposed between the cooling chamber inlet and the hydrogen chamber inlet, and the other of the oxygen chamber outlets is disposed between the hydrogen chamber inlet and the cooling chamber outlet.

Further, the hydrogen flow field, the oxygen flow field, and the coolant flow field are all direct flow fields.

Furthermore, the hydrogen flow field, the oxygen flow field and the coolant flow field all comprise circular grooves and a plurality of rib plates which are fixed in the circular grooves and arranged in parallel, and straight flow channels are formed between two adjacent rib plates.

Further, the hydrogen unipolar plate and the oxygen unipolar plate are manufactured by machining or molding a graphite plate.

Further, the medium flowing in the hydrogen flow field is hydrogen, the medium flowing in the oxygen flow field is air or oxygen, and the medium flowing in the coolant flow field is deionized water.

The length of the fuel cell power generation part 5 of the present embodiment can be set by changing the number of the single cell segments and the length of the circular packaging structure as required; assuming that the length of 2 fuel cell rods is a, the thickness of the bipolar plate 10 in a single fuel cell rod is b, and the thickness of the MEA4 is c, the length of n fuel cells is a + (b + c) (n-2), and the length dimension of the circular packaging structure is increased correspondingly.

Furthermore, the blind end plate 7 may be connected to the package structure 13 by bolts, the number of the connecting bolts may be 4 or 8, and the connecting form is not limited to bolt connection, and rigid connection between the two may also be achieved by welding.

Further, the sizes and shapes of the openings of the gas-port current collecting plate 11 and the MEA9 correspond to and completely coincide with those of the openings of the bipolar plate 10.

Further, the openings on the bipolar plate 10 may change the positions or the number of the gas inlet/outlet channels according to the flow field condition, and is not limited to the layout mode of setting the oxygen chamber flow field of the bipolar plate 10 to 2 inlets and 2 outlets in this embodiment.

The fuel cell power generation part provided by the embodiment has a compact overall structure, and the space utilization rate of the device is improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.