阅读说明：本技术 一种双极板、燃料电池单元、燃料电池及其制作方法 (Bipolar plate, fuel cell unit, fuel cell and manufacturing method thereof ) 是由 陈明 袁蕴超 沈润 王海峰 王利生 于 2020-05-18 设计创作，主要内容包括：本发明是关于一种双极板、燃料电池单元、燃料电池及其制作方法,涉及燃料电池技术领域。主要采用的技术方案为：一种双极板包括阳极板和阴极板；其中,阳极板的发电区域处的流道设置为交指型流道；阴极板的发电区域处的流道设置为并行流道。阳极板包括阳极板本体和燃料分配盖板、阴极板包括阴极板本体和氧化剂分配盖板。一种燃料电池单元包括膜电极及上述的双极板。一种燃料电池包括多个上述的燃料电池单元。本发明主要用于提高燃料电池中的燃料向催化层的扩散能力、并避免燃料电池的阴极出现水淹现象,在强化传质的同时实现冷却液侧、气侧流体的均匀流通。(The invention relates to a bipolar plate, a fuel cell unit, a fuel cell and a manufacturing method thereof, relating to the technical field of fuel cells. The main technical scheme adopted is as follows: a bipolar plate includes an anode plate and a cathode plate; the flow channel at the power generation area of the anode plate is an interdigital flow channel; the flow channels at the power generation area of the cathode plate are arranged as parallel flow channels. The anode plate comprises an anode plate body and a fuel distribution cover plate, and the cathode plate comprises a cathode plate body and an oxidant distribution cover plate. A fuel cell unit comprises a membrane electrode and the bipolar plate. A fuel cell comprises a plurality of the above fuel cell units. The invention is mainly used for improving the diffusion capacity of fuel in the fuel cell to the catalyst layer, avoiding the cathode of the fuel cell from flooding, and realizing the uniform circulation of fluid on the cooling liquid side and the gas side while strengthening mass transfer.)

1. A bipolar plate, comprising an anode plate and a cathode plate; wherein the content of the first and second substances,

the flow channel at the power generation area of the anode plate is an interdigital flow channel;

and the flow channels at the power generation area of the cathode plate are arranged into parallel flow channels.

2. The bipolar plate of claim 1, wherein the anode plate comprises:

the interdigitated flow channel is positioned on the anode plate body, and a fuel inlet and a fuel outlet are formed in the anode plate body;

a fuel distribution cover plate comprising a first fuel distribution cover plate, a second fuel distribution cover plate; the first fuel distribution cover plate is provided with a fuel inlet distribution area, and the fuel inlet distribution area is used for communicating the fuel inlet with an inlet of the interdigital flow channel; the second fuel distribution cover plate is provided with a fuel outlet distribution area, and the fuel outlet distribution area is used for communicating the fuel outlet with an outlet of the interdigital flow channel;

preferably, the fuel inlet distribution area and the fuel outlet distribution area are provided with structures capable of guiding and distributing fuel; further preferably, the structure for guiding and distributing the fuel comprises one or two of a salient point and a guiding channel;

preferably, the first fuel distribution cover plate is disposed at a location on the anode plate body between the fuel inlet and the inlet of the interdigitated flow channels;

preferably, the second fuel distribution cover plate is positioned on the anode plate body at a location between the fuel outlet and the outlet of the interdigitated flow channels.

3. The bipolar plate of claim 1, wherein the cathode plate comprises:

the parallel flow channel is positioned on the negative plate body, and an oxidant inlet and an oxidant outlet are formed in the negative plate body;

an oxidant dispensing cover plate comprising a first oxidant dispensing cover plate, a second oxidant dispensing cover plate; the first oxidant distribution cover plate is provided with an oxidant inlet distribution area, and the oxidant inlet distribution area is used for communicating the oxidant inlet with inlets of the parallel flow channels; an oxidant outlet distribution area is arranged on the second oxidant distribution cover plate and is used for communicating the oxidant outlet with outlets of the parallel flow channels;

preferably, the oxidant inlet distribution area and the oxidant outlet distribution area are provided with structures capable of guiding and distributing the oxidant; further preferably, the structure for guiding and distributing the oxidant comprises one or two of a convex point and a guide channel;

preferably, the first oxidant dispensing cover plate is positioned on the cathode plate body at a location between the oxidant inlet and the inlets of the parallel flow channels;

preferably, the second oxidant distribution cover plate is positioned on the cathode plate body at a location between the oxidant outlet and the outlet of the parallel flow channels.

4. A bipolar plate as in any one of claims 1 to 3,

the anode plate is provided with a cooling liquid inlet and a first cooling liquid distribution area; wherein the first coolant distribution region is located at a position between the coolant inlet and the interdigitated flow channels for distributing coolant flowing from the coolant inlet into the coolant flow field; preferably, when the anode plate comprises an anode plate body and a fuel distribution cover plate, the cooling liquid inlet and the first cooling liquid distribution area are both arranged on the anode plate body; and/or

The anode plate is provided with a cooling liquid outlet and a second cooling liquid distribution area; wherein the second coolant distribution region is located at a position between a coolant outlet and the interdigitated flow channels for directing coolant of the coolant flow field to the coolant outlet; preferably, when the anode plate comprises an anode plate body and a fuel distribution cover plate, the coolant outlet and the second coolant distribution region are both arranged on the anode plate body.

5. A bipolar plate as in any one of claims 1 to 3,

the interdigitated flow channels on the anode plate comprise a plurality of first single flow channels and the parallel flow channels on the cathode plate comprise a plurality of second single flow channels; wherein the first single channel and the second single channel have the same shape; and/or

The edge position of the anode plate is provided with a channel for installing a first sealing gasket so as to realize the sealing connection of the anode plate in one fuel cell unit and the cathode plate in the other fuel cell unit; and/or

The cathode plate is provided with a first side and a second side which are oppositely arranged; wherein the parallel flow channels form a plurality of protrusions at an edge of the cathode plate opposite the first side of the cathode plate and a plurality of recesses at an edge of the cathode plate opposite the second side of the cathode plate; wherein the first side of the cathode plate is an oxidant flow field side and the second side of the cathode plate is a coolant flow field side.

6. The bipolar plate of any one of claims 1 to 3 wherein the interdigitated flow channels of the anode plate include a flow channel inlet portion, a primary flow channel, and a flow channel outlet portion; wherein the content of the first and second substances,

the height of the flow channel inlet part and the flow channel outlet part is lower than that of the main flow channel;

preferably, the height of the channel inlet portion and the height of the channel outlet portion are 0.3 to 0.7, preferably 0.5, of the height of the main channel.

7. A fuel cell unit, characterized by comprising: a membrane electrode and the bipolar plate of any one of claims 1 to 6; wherein the anode plate of the bipolar plate is positioned at one side of the membrane electrode, and the cathode plate of the bipolar plate is positioned at the other side of the membrane electrode;

preferably, the grooves of the interdigitated flow channels on the anode plate are arranged opposite to the parallel flow channel grooves on the cathode plate, and the ridges of the interdigitated flow channels on the anode plate are arranged opposite to the ridges of the parallel flow channels on the cathode plate;

preferably, the anode plate, the membrane electrode and the cathode plate are hermetically connected through a second sealing gasket; further preferably, the cathode plate is hermetically connected with the proton exchange membrane of the membrane electrode through a first part of a second sealing gasket, and the anode plate is hermetically connected with the cathode plate through a second part of the second sealing gasket;

further preferably, the membrane electrode comprises a first gas diffusion layer, a second gas diffusion layer, and a proton exchange membrane with a catalyst layer between the first gas diffusion layer and the second gas diffusion layer; wherein a first gas diffusion layer is in contact with the cathode plate and a second gas diffusion layer is in contact with the anode plate; wherein, the length and the width of the first gas diffusion layer are both smaller than those of the second gas diffusion layer.

8. A method of making a fuel cell unit as claimed in claim 7, comprising the steps of:

performing the rubber compound to obtain a preformed second sealing gasket;

and sequentially stacking the anode plate, the membrane electrode, the preformed second sealing gasket and the cathode plate in a preformed mold, and vulcanizing in a hot press to obtain the fuel cell unit.

9. A fuel cell, characterized in that the fuel cell is composed of a plurality of fuel cell units according to claim 7; one fuel cell unit of any two adjacent fuel cell units is a first fuel cell unit, and the other fuel cell unit is a second fuel cell unit; a cooling liquid flow field is formed between the anode plate in the first fuel cell unit and the cathode plate of the second fuel cell unit;

preferably, the anode plate in the first fuel cell unit and the cathode plate of the second fuel cell unit are hermetically connected through a first sealing gasket.

10. The method of manufacturing a fuel cell according to claim 9, comprising the steps of:

manufacturing a fuel cell unit;

assembling a plurality of fuel cell units into a fuel cell;

preferably, a fuel cell is produced by the method for producing a fuel cell according to claim 8;

preferably, in the step of assembling the plurality of fuel cell units into the fuel cell, the method includes: and placing a first sealing gasket on the channel of the anode plate of the first fuel battery unit, and then enabling the anode plate of the first fuel battery unit and the cathode plate of the second fuel battery unit to be sealed in a fitting mode through the first sealing gasket, so that the assembly of two adjacent fuel battery units is realized.

Technical Field

The invention relates to the technical field of fuel cells, in particular to a bipolar plate, a fuel cell unit, a fuel cell and a manufacturing method thereof.

Background

The proton exchange membrane fuel cell is a new type of energy conversion device, which is used to convert the chemical energy in the fuel into electric energy for output. The proton exchange membrane fuel cell has the advantages of high energy conversion efficiency, no restriction of Carnot cycle, high operation reliability, low working temperature, quick start, simple structure, no noise and the like, and can be widely applied to the fields of traffic industry, movable facility power sources, distributed power generation and the like. The proton exchange membrane fuel cell unit consists of bipolar plate, membrane electrode, sealing part, etc. and several cell units may be assembled serially into electric pile structure.

The power generation performance and reliability of the fuel cell are greatly influenced by the uniformity of the cooling liquid side flow field and the gas side flow field. Specifically, if the gas side flow field is not uniform, local gas shortage of the flow field can be caused, concentration polarization is generated, the electricity generation performance of the fuel cell is further influenced, and the catalyst is degraded due to the reverse pole, so that the galvanic pile is damaged. If the coolant lateral flow field is uneven, the heat generated locally during the power generation of the battery can not be taken away in time, so that the local overtemperature field of a monocell is generated, the dehydration of the proton exchange membrane is caused, the conductivity is reduced, and even the proton exchange membrane is perforated, so that the performance and the safety of the battery are influenced. Therefore, when the bipolar plate is designed, the reaction gas can uniformly reach each flow path of the reaction area as much as possible, so that the current density is uniformly distributed, the operation reliability and uniformity of the battery are improved, and the performance of the battery is improved; meanwhile, the side flow field of the cooling liquid is designed uniformly, so that redundant heat can be timely taken away from the battery by the cooling liquid, the uniformity of the temperature distribution of the battery is ensured, and the uniformity of the electricity generation performance of the battery is further ensured. However, due to the limitations of the size and design of the bipolar plate, the accuracy of the mold, the sealing process, etc., the uniformity of the gas side and the cooling liquid side cannot be adjusted simultaneously, or additional manufacturing processes, materials and equipment are required, which increases the manufacturing difficulty and cost.

The power generation performance of the fuel cell in a high-current working interval is mainly influenced by concentration polarization, and the fuel concentration in the catalyst layer is a main factor for limiting the performance of the cell. However, the current anode bipolar plate mainly adopts a parallel flow channel or a parallel serpentine flow channel design, and the flow structure of the design causes that the transmission mode is mainly convection, the diffusion transmission capability of fuel to the catalyst layer is weak, and the fuel concentration in the catalyst layer is low. The interdigital flow channel has better diffusion transmission capability compared with a parallel and serpentine flow channel due to the characteristic of discontinuous flow channel; however, the same flow channel design of the cathode plate and the anode plate in the prior art is not beneficial to discharge of water generated by the cathode, so that cathode flooding is easily caused, gas transmission of the cathode is influenced, and further the electricity generation performance of the battery is influenced; moreover, the existing interdigital bipolar plate has single design and neglects the effect of the distribution area on the uniformity of the flow field; in addition, the traditional interdigitated bipolar plate cooling liquid side mostly adopts a welding and sealing process, so that the development of the integration of the fuel cell unit is limited.

Disclosure of Invention

In view of the above, the present invention provides a bipolar plate, a fuel cell unit, a fuel cell and a method for manufacturing the same, which mainly aims to improve the diffusion capability of fuel to a catalyst layer and avoid the cathode of the fuel cell from flooding.

In order to achieve the purpose, the invention mainly provides the following technical scheme:

in one aspect, embodiments of the present invention provide a bipolar plate, wherein the bipolar plate includes an anode plate and a cathode plate; wherein the content of the first and second substances,

the flow channel at the power generation area of the anode plate is an interdigital flow channel;

and the flow channels at the power generation area of the cathode plate are arranged into parallel flow channels.

Preferably, the anode plate includes:

the interdigitated flow channel is positioned on the anode plate body, and a fuel inlet and a fuel outlet are formed in the anode plate body;

a fuel distribution cover plate comprising a first fuel distribution cover plate, a second fuel distribution cover plate; the first fuel distribution cover plate is provided with a fuel inlet distribution area, and the fuel inlet distribution area is used for communicating the fuel inlet with an inlet of the interdigital flow channel; and a fuel outlet distribution area is arranged on the second fuel distribution cover plate and is used for communicating the fuel outlet with an outlet of the interdigital flow channel.

Preferably, the fuel inlet distribution area and the fuel outlet distribution area are provided with structures capable of guiding and distributing fuel; further preferably, the structure for guiding and distributing the fuel comprises one or both of a salient point and a guiding channel.

Preferably, the first fuel distribution cover plate is disposed at a location on the anode plate body between the fuel inlet and the inlet of the interdigitated flow channels.

Preferably, the second fuel distribution cover plate is positioned on the anode plate body at a location between the fuel outlet and the outlet of the interdigitated flow channels.

Preferably, the cathode plate includes:

the parallel flow channel is positioned on the negative plate body, and an oxidant inlet and an oxidant outlet are formed in the negative plate body;

an oxidant dispensing cover plate comprising a first oxidant dispensing cover plate, a second oxidant dispensing cover plate; the first oxidant distribution cover plate is provided with an oxidant inlet distribution area, and the oxidant inlet distribution area is used for communicating the oxidant inlet with inlets of the parallel flow channels; and an oxidant gas outlet distribution area is arranged on the second oxidant distribution cover plate and is used for communicating the oxidant outlet with the outlets of the parallel flow channels.

Preferably, the oxidant inlet distribution area and the oxidant outlet distribution area are provided with structures capable of guiding and distributing the oxidant; further preferably, the structure for guiding and distributing the oxidant comprises one or both of a convex point and a guide channel.

Preferably, the first oxidant dispensing cover plate is positioned on the cathode plate body at a location between the oxidant inlet and the inlets of the parallel flow channels.

Preferably, the second oxidant distribution cover plate is positioned on the cathode plate body at a location between the oxidant outlet and the outlet of the parallel flow channels.

Preferably, the anode plate is provided with a cooling liquid inlet and a first cooling liquid distribution area; wherein the first coolant distribution region is located at a position between the coolant inlet and the interdigitated flow channels for distributing coolant flowing from the coolant inlet into the coolant flow field; preferably, when the anode plate comprises an anode plate body and a fuel distribution cover plate, the coolant inlet and the first coolant distribution region are both arranged on the anode plate body.

Preferably, the anode plate is provided with a cooling liquid outlet and a second cooling liquid distribution area; the second cooling liquid distribution area is positioned between the cooling liquid outlet and the interdigital flow channel and is used for guiding the cooling liquid of the cooling liquid flow field to the cooling liquid outlet; preferably, when the anode plate comprises an anode plate body and a fuel distribution cover plate, the coolant outlet and the second coolant distribution region are both arranged on the anode plate body.

Preferably, the interdigitated flow channels on the anode plate comprise a plurality of first single flow channels, and the parallel flow channels on the cathode plate comprise a plurality of second single flow channels; wherein the first single channel and the second single channel have the same shape; and/or a channel for installing a first sealing gasket is arranged at the edge position of the anode plate so as to realize the sealing connection of the anode plate in one fuel cell unit and the cathode plate in the other fuel cell unit; and/or the cathode plate has a first side and a second side arranged oppositely; wherein the parallel flow channels form a plurality of protrusions at an edge of the cathode plate opposite the first side of the cathode plate and a plurality of recesses at an edge of the cathode plate opposite the second side of the cathode plate; wherein the first side of the cathode plate is an oxidant flow field side and the second side of the cathode plate is a coolant flow field side.

Preferably, the interdigitated flow channel of the anode plate includes a flow channel inlet portion, a main flow channel and a flow channel outlet portion; wherein the content of the first and second substances,

the height of the flow channel inlet part and the flow channel outlet part is lower than that of the main flow channel.

Preferably, the height of the channel inlet portion and the height of the channel outlet portion are 0.3 to 0.7, preferably 0.5, of the height of the main channel.

In another aspect, an embodiment of the present invention further provides a fuel cell unit, where the fuel cell unit includes: a membrane electrode and a bipolar plate according to any one of the above; wherein the anode plate of the bipolar plate is positioned at one side of the membrane electrode, and the cathode plate of the bipolar plate is positioned at the other side of the membrane electrode;

preferably, the grooves of the interdigitated flow channels on the anode plate are arranged opposite to the parallel flow channel grooves on the cathode plate, and the ridges of the interdigitated flow channels on the anode plate are arranged opposite to the ridges of the parallel flow channels on the cathode plate;

preferably, the anode plate, the membrane electrode and the cathode plate are hermetically connected through a second sealing gasket; further preferably, the cathode plate and the membrane electrode are hermetically connected through a first part of a second sealing gasket, and the anode plate and the cathode plate are hermetically connected through a second part of a second sealing gasket;

further preferably, the membrane electrode comprises a first gas diffusion layer, a second gas diffusion layer, and a proton exchange membrane with a catalyst layer between the first gas diffusion layer and the second gas diffusion layer; wherein a first gas diffusion layer is in contact with the cathode plate and a second gas diffusion layer is in contact with the anode plate; wherein, the length and the width of the first gas diffusion layer are both smaller than those of the second gas diffusion layer.

On the other hand, the method for manufacturing the fuel cell unit includes the steps of:

performing the rubber compound to obtain a preformed second sealing gasket;

and sequentially stacking the anode plate, the membrane electrode, the preformed second sealing gasket and the cathode plate in a preformed mold, and vulcanizing in a hot press to obtain the fuel cell unit.

In yet another aspect, embodiments of the present invention provide a fuel cell, wherein the fuel cell is composed of a plurality of fuel cell units; one fuel cell unit of any two adjacent fuel cell units is a first fuel cell unit, and the other fuel cell unit is a second fuel cell unit; a cooling liquid flow field is formed between the anode plate in the first fuel cell unit and the cathode plate of the second fuel cell unit;

preferably, the anode plate in the first fuel cell unit and the cathode plate of the second fuel cell unit are hermetically connected through a first sealing gasket.

In another aspect, a method of making a fuel cell, comprising the steps of:

manufacturing a fuel cell unit;

assembling a plurality of fuel cell units into a fuel cell;

preferably, the fuel cell is manufactured by the method for manufacturing the fuel cell;

preferably, in the step of assembling the plurality of fuel cell units into the fuel cell, the method includes: and placing a first sealing gasket on the channel of the anode plate of the first fuel battery unit, and then enabling the anode plate of the first fuel battery unit and the cathode plate of the second fuel battery unit to be sealed in a fitting mode through the first sealing gasket, so that the assembly of two adjacent fuel battery units is realized.

Compared with the prior art, the bipolar plate, the fuel cell unit, the fuel cell and the manufacturing method thereof have the following beneficial effects:

the bipolar plate provided by the embodiment of the invention can strengthen the fuel diffusion capability of the anode gas side of the fuel cell and increase the fuel concentration in the catalyst layer in the membrane electrode by setting the flow channel at the power generation area of the anode plate as the interdigitated flow channel, thereby improving the power generation performance of the fuel cell; meanwhile, the flow channel at the power generation area of the cathode plate is set to be the parallel flow channel, so that water generated by the cathode reaction of the fuel cell flows along the parallel flow channel along with cathode gas and is discharged out of the fuel cell, the cathode of the fuel cell is prevented from being flooded, and the gas transmission of the cathode of the fuel cell is facilitated.

Furthermore, the bipolar plate provided by the embodiment of the invention has the advantages that the fuel distribution cover plate is designed to serve as an intermediate structure for connecting the fuel inlet/outlet and the anode plate power generation area flow channel, the oxidant distribution cover plate is designed to serve as an intermediate structure for connecting the oxidant inlet/outlet and the cathode plate power generation area flow channel, on one hand, the fuel cell air inlet distribution is more uniform through the flow guide and distribution structures on the fuel distribution cover plate and the oxidant cover plate, and the flow guide angle and form can be analyzed and optimized through numerical simulation, so that the optimal result is obtained, and the adjustable space is larger; on the other hand, the design of the fuel distribution cover plate and the oxidant cover plate can prevent the sealing glue from blocking the channel when the fuel cell unit and the fuel cell are assembled by adopting the density glue.

Furthermore, in the bipolar plate provided by the embodiment of the invention, the first cooling liquid distribution area is arranged at the position between the cooling liquid inlet of the anode plate and the interdigitated flow channels, and the second cooling liquid distribution area is arranged at the position between the cooling liquid outlet of the anode plate and the interdigitated flow channels, so that the cooling liquid is guided and distributed, the cooling liquid can be uniformly distributed in the flow channels, and a certain supporting effect can be provided for the bipolar plate when the stack is assembled.

Further, the interdigitated flow channels on the anode plate provided by the embodiment of the present invention include a plurality of first single flow channels, and the parallel flow channels on the cathode plate include a plurality of second single flow channels. The first single channel and the second single channel are in the same shape, and the two channels are regularly distributed, so that the structure of the cooling liquid channel formed between the two channels is regular and uniform, a uniform cooling liquid flow field can be obtained, and the service life and the stability of the battery are improved.

Furthermore, the interdigitated flow channel of the anode plate provided by the embodiment of the present invention includes a flow channel inlet portion, a main flow channel and a flow channel outlet portion; wherein, the height of the runner inlet part and the runner outlet part is lower than that of the main runner. Preferably, the height of the channel inlet part and the height of the channel outlet part are 0.3-0.7, preferably 0.5 of the height of the main channel; this arrangement makes it possible to connect the coolant-side flow channels, so that the coolant-side region is kept in flow communication.

Further, the fuel cell unit, the fuel cell and the manufacturing method provided by the embodiment of the invention include the bipolar plate, so that the fuel cell unit, the fuel cell and the manufacturing method provided by the embodiment of the invention have the beneficial effects described in any one of the above. On the basis, the cooling liquid side between the adjacent fuel cell units is mainly extruded and sealed by adopting a silica gel sealing gasket, the gas side is vulcanized, bonded and sealed after the bipolar plate, the membrane electrode, the cover plate and the like are sequentially assembled by utilizing the preformed rubber gasket to form the integrated fuel cell unit, and the integrated fuel cell unit has higher sealing reliability compared with the traditional cooling liquid side welding sealing connection and gas side extrusion sealing modes.

In summary, compared with the prior art, the bipolar plate, the fuel cell unit, the fuel cell and the manufacturing method thereof provided by the embodiment of the invention have the advantages of high mass transfer efficiency, low cost, good flow uniformity, large design and adjustment space, high reliability, simple manufacturing process and the like, can adopt a single-sheet pre-formed rubber pad bonding process, are firmer in compression sealing and improved in reliability, do not need additional materials, processes and equipment such as an injection molding machine and the like, and save the cost. And fluid distribution areas are arranged on the gas side and the cooling liquid side, so that the whole flow uniformity is good and the distribution is easy to adjust.

The foregoing is a summary of the present invention, and in order to provide a clear understanding of the technical means of the present invention and to be implemented in accordance with the present specification, the following is a preferred embodiment of the present invention and is described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of an anode plate body according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a cathode plate body provided by an embodiment of the present invention;

FIG. 3 is a schematic structural view of a fuel distribution cover plate provided by an embodiment of the present invention;

FIG. 4 is a schematic structural view of an oxidant distribution cover plate according to an embodiment of the present invention;

FIG. 5 is a schematic view of the assembly of an anode plate body and a fuel distribution cover plate according to an embodiment of the present invention;

fig. 6 is a schematic structural view of the assembly of a cathode plate body and an oxidant distribution cover plate according to an embodiment of the present invention;

fig. 7 is an assembly schematic view of a fuel cell unit provided by an embodiment of the present invention.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined object, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.