Fuel cell stack

Abstract

A fuel cell stack (100; 200; 300; 400; 500; 600; 700), comprising: a cell laminate (110) formed by stacking a plurality of unit cells (112) in a predetermined stacking direction, and an area pressure setting unit (120; 220; 320; 420; 520; 620; 720) stacked on an area of ​​the cell laminate (110) and configured to set an area pressure applied to the unit cells (112) in the stacking direction, wherein the area pressure setting unit (120; 220; 320; 420; 520; 620; 720) comprises: a first electromagnet (124; 222; 322; 422; 522; 622; 722), a second electromagnet (126; 223; 323; 423; 523; 623; 723), which is located between a first surface of the cell laminate (110) and the first electromagnet (124; 222; 322; 422; 522; 622;722) is installed to press the unit cells (112), and a control device (150) is configured to adjust a pressure force applied to the unit cells (112) by the second electromagnet (126; 223; 323; 423; 523; 623; 723) by selectively applying a current to the first and second electromagnets (124; 222; 322; 422; 522; 622; 722; 126; 223; 323; 423; 523; 623; 723) so that an attractive or repulsive force acts between the first and second electromagnets, wherein one of the first and second electromagnets (522, 523; 622, 623) has a guide groove (522a; 622a) has a recess formed in the stacking direction, and a guide projection (522b; 622b) of the first and second electromagnets (522, 523; 622, 623) has a guide projection (522b; 622b) formed to protrude in order to insert the guide projection into the guide groove in order to be displaceable in the stacking direction.;

Description

Cross-reference to related application

[0001] This application is based on and claims priority from Korean Patent Application No. 10-2017-0147540, filed on November 7, 2017. Technical field

[0002] The present disclosure relates to a fuel cell stack, and more particularly to a fuel cell stack in which a surface pressure applied to the unit cells is adjusted. background

[0003] A fuel cell, a main power source in a fuel cell system, is a device to which oxygen, corresponding to an oxidizer, and hydrogen, corresponding to a fuel, are supplied to generate electricity while producing water. In the fuel cell, high-purity hydrogen is supplied from a hydrogen storage tank to an anode of the fuel cell stack, and atmospheric air containing oxygen is directly supplied to a cathode of the fuel cell stack through an air supply device such as an air compressor. Hydrogen supplied to the anode is separated into a proton and an electron by a catalyst of the anode, and the proton is moved to the cathode through a polymer electrolyte membrane.Oxygen in the air, which is supplied to the cathode, combines with the electrons introduced into the cathode through an external wire to produce electrical energy while producing water.

[0004] Typically, the fuel cell stack includes a cell laminate formed by stacking at least several hundred unit cells, end plates arranged at both ends of the cell laminate, a fixing member that fixes the end plates to apply a predetermined surface pressure to the unit cells of the cell laminate, and the like. Specifically, the term "unit cell" refers to a unit body formed by stacking a polymer electrolyte membrane, an anode, a cathode, a separator, a gasket, and the like.

[0005] Meanwhile, the surface pressure applied to the unit cells may change due to numerous causes, such as deterioration of the fuel cell stack, shrinkage of the gasket due to a temperature decrease, and the like. A change in the surface pressure applied to the unit cells as described above is a major cause of deterioration in the performance of the fuel cell stack, such as gas leakage, a decrease in output, deterioration in durability, or the like. However, since a fuel cell stack according to the related art does not have a configuration for compensating for a change in the surface pressure applied to the unit cells, the performance of the fuel cell stack is deteriorated due to the change in the surface pressure applied to the unit cells. Explanation of the invention

[0006] The present disclosure provides a fuel cell stack, a structure of which is improved by adjusting a surface pressure applied to unit cells.

[0007] According to an exemplary embodiment of the present disclosure, a fuel cell stack may include, for example: a cell laminate formed by stacking a plurality of unit cells in a predetermined stacking direction, and a surface pressure adjusting unit stacked on a surface of the cell laminate and configured to adjust a surface pressure applied to the unit cells in the stacking direction.The surface pressure adjusting unit may include: a first electromagnet, a second electromagnet installed between a surface of the cell laminate and the first electromagnet to press the unit cells, and a control device configured to adjust a pressing force applied to the unit cells by the second electromagnet by selectively applying a current to the first and second electromagnets so that an attractive force or a repulsive force acts between the first and second electromagnets.

[0008] The surface pressure adjusting unit may, for example, further include a housing having a receiving space in which the first and second electromagnets may be accommodated. The second electromagnet may be installed to be slidably movable in the stacking direction, to be spaced apart from the first electromagnet, or to abut against the first electromagnet. The housing may further include an opening allowing the receiving space to be open toward a first surface of the cell laminate. An end portion of the cell laminate may be inserted into the receiving space through the opening. The second electromagnet may have a predetermined cross-sectional area to guide an end portion thereof to the outside of the receiving space through the opening.

[0009] For example, the housing may further include a fluid chamber disposed within the first electromagnet and on an inner side surface of the housing, and having an internal space filled with a fluid. The first electromagnet may include a communication port open to connect a gap between the first and second electromagnets to the internal space of the fluid chamber, and an opening / closing valve configured to open or close the communication port to adjust fluid flow through the communication port. The opening / closing valve may have an area larger than that of the communication port so as to cover the communication port, and may be shaped to be elastically deformable by fluid pressure.The opening / closing valve may be mounted to cover the communication hole on a surface of the first electromagnet facing a surface of the second electromagnet to be selectively supported by a surface of the second electromagnet when a separation distance between the first and second electromagnets is less than a predetermined reference distance.

[0010] For example, one of the first and second electromagnets may have a guide groove shaped to be recessed in the stacking direction, and the other of the first and second electromagnets may have a guide projection shaped to protrude to insert the guide projection into the guide groove so as to be slidably movable in the stacking direction. The guide projection may have an internal space filled with a fluid, a communication port connecting a space between the guide projection and the guide groove to an internal space, and an opening / closing valve configured to open or close the communication port to adjust flow of the fluid through the communication port.

[0011] For example, the communication opening may include first and second communication openings each shaped to communicate the intermediate space with the internal space, and the opening / closing valve may include a first opening / closing valve configured to open or close the first communication opening to allow fluid to flow from the internal space to the communication opening through the first communication opening, and a second opening / closing valve configured to open or close the second communication opening to allow fluid to flow from the internal space to the communication opening through the second communication opening.

[0012] For example, the first opening / closing valve may have an area larger than that of the first communication hole to cover the first communication hole, and may be shaped to be elastically deformable by a pressure of the fluid. The first opening / closing valve may be mounted to cover the first communication hole on an outer side surface of the guide projection facing an inner side surface of the guide groove to be supported by the inner side surface of the guide groove when a distance between the first and second electromagnets is less than a predetermined reference distance. The other of the first and second electromagnets may further include a pressing element configured to elastically pressurize the fluid filled in the gap.

[0013] The second opening / closing valve may include, for example, a cover plate having an area larger than that of the second communication hole to cover the second communication hole and installed in the interior space, and an elastic member configured to elastically urge the cover plate toward an inner side surface of the interior space to cause the cover plate to abut against the inner side surface of the interior space when the cover plate covers the second communication hole.

[0014] The fuel cell stack may further include, for example, an end plate stacked on a second surface of the cell laminate, and a fastening member that fastens the end plate and the surface pressure adjustment unit to each other. The fastening member may be a fastening band elastically deformable in the stacking direction. The surface pressure adjustment unit may include a wedge and an elastic member configured to elastically press the wedge to be inserted into a gap between the first and second electromagnets when the second electromagnet is spaced apart from the first electromagnet. The wedge may have a slope structure in which a thickness in the stacking direction thereof gradually decreases from the elastic member to the gap. Character list

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Fig. 1 is a detailed view of a fuel cell stack according to a first exemplary embodiment of the present disclosure. Fig. 2 is a perspective assembly view of the fuel cell stack shown in the Fig. 1, according to a first exemplary embodiment of the present disclosure. Fig. 3 is a cross-sectional view of the fuel cell stack along a line AA of the Fig. 2 according to a first exemplary embodiment of the present disclosure. Fig. 4 is an enlarged partial view of part I of the Fig. 3 according to a first exemplary embodiment of the present disclosure. Fig. 5 is a view showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in FIG. Fig. 4, according to a first exemplary embodiment of the present disclosure. Fig. 6 is a partial cross-sectional view of a fuel cell stack according to a second exemplary embodiment of the present disclosure. Fig. Fig. 7 is a view for explaining a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 6, according to a second exemplary embodiment of the present disclosure. Fig. 8 is a plan view of an opening / closing valve used in the Fig. 6, according to a second exemplary embodiment of the present disclosure. Fig. 9 is a conceptual view showing the principle of opening and closing of the opening / closing valve used in the Fig. 6, according to a second exemplary embodiment of the present disclosure. Fig. 10 is a partial cross-sectional view of a fuel cell stack according to a third exemplary embodiment of the present disclosure. Fig. 11 and Fig. 12 are views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 10, according to a third exemplary embodiment of the present disclosure. Fig. 13 is a partial cross-sectional view of a fuel cell stack according to a fourth exemplary embodiment of the present disclosure. Fig. 14 and Fig. 15 are views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 13, according to a fourth exemplary embodiment of the present disclosure. Fig. 16 and Fig. 17 are views showing a method of lowering the surface pressure of the unit cells using the surface pressure adjusting unit shown in FIG. Fig. 13, according to a fourth exemplary embodiment of the present disclosure. Fig. 18 is a partial cross-sectional view of a fuel cell stack according to a fifth exemplary embodiment of the present disclosure. Fig. 19 is an enlarged detail view of Part II of the Fig. 18 according to a fifth exemplary embodiment of the present disclosure. Fig. 20 and Fig. 22 are views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 19, according to a fifth exemplary embodiment of the present disclosure. Fig. 23 is a partial cross-sectional view of a fuel cell stack according to a sixth exemplary embodiment of the present disclosure. Fig. 24 is an enlarged partial view of part III of the Fig. 23 according to a sixth exemplary embodiment of the present disclosure. Fig. 25 and Fig. 27 are views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 24, according to a sixth exemplary embodiment of the present disclosure. Fig. 28 and Fig. 29 are views showing a method of lowering the surface pressure of the unit cells using the surface pressure adjusting unit shown in FIG. Fig. 24, according to a sixth exemplary embodiment of the present disclosure. Fig. 30 is a partial cross-sectional view of a fuel cell stack according to a seventh exemplary embodiment of the present disclosure. Fig. 31 is a conceptual view showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 30, according to a seventh exemplary embodiment of the present disclosure. Detailed description

[0016] It is to be understood that the term "vehicle" or "vehicle-..." or any other similar term used herein includes motor vehicles in general, such as passenger vehicles, including so-called sport utility vehicles (SUVs), buses, trucks, numerous commercial vehicles, and watercraft, including a variety of boats and ships, as well as aircraft and the like, and further includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels produced from resources other than petroleum). A so-called hybrid vehicle, as referred to herein, is a vehicle that has two or more power sources, e.g., vehicles that are powered by both gasoline and electricity.

[0017] Although example embodiments are described using a plurality of units to perform the example operations, it is understood that the example operations may also be performed by one or a plurality of modules. Furthermore, it is understood that the term "controller / controller unit" refers to a hardware device comprising a memory and a processor. The memory is configured to store the modules, and the processor is specifically configured to execute said modules to perform one or more operations described further below.

[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms "a," "an," and "the," "which," as used herein, are intended to include the plural forms, unless the context clearly indicates otherwise. Further, it is to be understood that the terms "comprising" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, acts, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, acts, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the relatedly enumerated items.

[0019] Unless otherwise stated or otherwise clear from the context, the term "approximately" as used herein should be understood as "within the range of usual tolerances for this technique," for example, within two standard deviations of the mean. "Approximately" can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from the context, all numerical values ​​provided herein are modified by the term "approximately."

[0020] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that when assigning reference numerals to components of the accompanying drawings, the same components are denoted by the same reference numerals even though they are illustrated in different drawings. Furthermore, in describing exemplary embodiments of the present disclosure, well-known structures or functions will not be described in detail in the event that it is determined that they might unnecessarily obscure the understanding of the exemplary embodiments of the present disclosure.

[0021] Terms such as "first...", "second...", A, B, (a), (b), and the like are used to describe the components of exemplary embodiments of the present disclosure. The terms used are only to distinguish any components from other components, features, sequences, or the like of corresponding components and are not limited by these terms. Furthermore, unless defined to the contrary, all terms used in this specification, including technical and scientific terms, have the same meanings as those commonly understood by one of ordinary skill in the art to which the present disclosure pertains.It should be understood that terms defined in a commonly used dictionary are identical to the meanings within the context of the related technology, and they should not be interpreted in an ideal or excessively formal manner unless the context clearly indicates the contrary.

[0022] The Fig. 1 is a detailed view of a fuel cell stack according to a first exemplary embodiment of the present disclosure, Fig. 2 is a perspective assembly view of the fuel cell stack shown in the Fig. 1 is shown, and the Fig. 3 is a cross-sectional view of the fuel cell stack along a line AA of the Fig. 2 and the Fig. 4 is an enlarged detail view of part I of the Fig. 3.

[0023] With reference to the Fig. 1 and Fig. 2 a fuel cell stack 100according to the first exemplary embodiment of the present disclosure, a cell laminate 110 , which is formed by stacking a plurality of unit cells 112 in a predetermined stacking direction, a surface pressure adjustment unit 120 which is applied to a first surface of the cell laminate 110 stacked and is designed to set a surface pressure which acts on the unit cells 112 is applied, an end plate 130 which is applied to a second surface of the cell laminate 110 is stacked, a fastening element 140 , which is designed to support the end plate 130 and the surface pressure adjustment unit 120 to each other, and a control device 150 which is configured to control the surface pressure setting unit 120 to operate, etc.

[0024] First, as it is in the Fig. 1, the cell laminate 110 be formed by stacking the majority of unit cells 112 in the predetermined stacking direction. Since the unit cells 112 and the cell laminate 110 as described above have the same structure as the unit cells 112 a cell laminate of a conventional fuel cell stack 100 , a detailed description of it is omitted. As it is in the Fig. 2, the surface pressure adjustment unit 120 in the stacking direction onto the first surface of the cell laminate 110 be stacked. The surface pressure adjustment unit 120 can have the same cross-sectional area as that of the first surface of the cell laminate 110 have, but is not limited to, the surface pressure adjustment unit as described above 120 can reduce the surface pressure acting on the unit cells in the stacking direction 112is applied by pressing a surface of the cell laminate 110 in the stacking direction. The surface pressure adjustment unit 120 is described in detail below.

[0025] As it is in the Fig. 1 and Fig. 2, the end plate 130 on the second surface of the cell laminate 110 opposite to the first surface of the cell laminate 110 be stacked in the stacking direction. A material of the end plate as described above 130 is not particularly limited. For example, the end plate 130 be made of a material such as an aluminum alloy, a stainless material, a glass fiber reinforced plastic or the like. As stated in the Fig. 2, the fastening element 140 be set up to support the end plate 130 and the surface pressure adjustment unit 120to each other in order to exert a predetermined surface pressure on the unit cells in the stacking direction 112 A structure of the fastener 140 is not particularly limited. For example, the fastener 140 a fastening band which is elastically deformable in the stacking direction. A material of the fastening element 140 is not particularly limited. For example, the fastener 140 be made of a material such as glass fiber reinforced plastic, stainless steel or the like.

[0026] A method of attaching the end plate 130 and the surface pressure adjustment unit 120 using the fastener as described above 140 , is not particularly limited. For example, as it is described in the Fig. 2, the fastening element 140 with each of the end plates130 and the surface pressure adjustment unit 120 be screwed together by screws B, whereby the end plate 130 and the surface pressure adjustment unit 120 Accordingly, the fastening element 140 curved parts 142 and 144 which are curved at both ends to the end plate 130 or the surface pressure adjustment unit 120 to be facing, and screw holes 146 and 148 which are open to be screw coupled with a screw part S of the screw B. If the end plate 130 and the surface pressure adjustment unit 120 through the fastening element 140 as described above, the predetermined surface pressure on the unit cells 112 which is located between the end plate 130 and the surface pressure adjustment unit 120arranged in the stacking direction. To facilitate the explanation, the surface pressure acting on the unit cells 112 applied in the stacking direction, as a “surface pressure of the unit cells 112 " designated.

[0027] Meanwhile, as it is in the Fig. 4, a surface pressure measuring sensor 160 , which is designed to determine the surface pressure of the unit cells 112 to measure on the fastening element 140 The surface pressure measurement sensor 160 can be a strain gauge sensor, which is used to move the fastening element 140 in the stacking direction. The surface pressure of the unit cells 112 , which is measured by the surface pressure sensor 160 as described above, a control device 150 which is described below.

[0028] Although the case is described in which the surface pressure measurement sensor 160 the strain gauge sensor, which is attached to the fastening element 140 is attached, the surface pressure measurement sensor 160 not limited to this. In other words, the surface pressure measurement sensor 160 at least one sensor which is configured to measure the surface pressure of the unit cells 112 to measure, such as a load cell, which is able to measure a load acting on the unit cells 112 is applied, and the like. The control device 150 may be configured to perform overall operation of a fuel cell system comprising the fuel cell stack 100 The control device as described above 150 can be further configured to control the surface pressure adjustment unit 120based on the surface pressure of the unit cells 112 which is controlled by the surface pressure measuring sensor 160 is entered. A method of controlling the surface pressure setting unit 120 is described in detail below.

[0029] The Fig. 5 is a view showing a method of increasing the surface pressure of the unit cells using the surface pressure adjusting unit shown in FIG. Fig. 4. The surface pressure adjustment unit 120 can be set up to unit cells 112 using electromagnets 124 and 126 in the stacking direction in order to reduce the surface pressure of the unit cells 112 As is the case, for example, in the Fig. 4, the surface pressure adjustment unit 120 a fixing plate 122 which is permanently installed to be used from one surface of the cell laminate110 to be at a distance, a first electromagnet 124 , which is located between the fixing plate 122 and a first surface of the cell laminate 110 is permanently installed, a second electromagnet 126 , which is located between the first electromagnet 124 and a first surface of the cell laminate 110 installed to be movable in the stacking direction, a printing plate 128 which is located between the second electromagnet 126 and the first surface of the cell laminate 110 installed to be movable in the stacking direction, and the like.

[0030] As it is in the Fig. 4, the fixing plate 122 a screw hole 122a which has an inner peripheral surface on which a screw thread is formed, which is capable of being screw-coupled with the screw part S of the screw B. The fixing plate as described above122 can be screwed together by screw coupling the screw part S of the screw B and the screw hole 122a the fixing plate 122 be firmly installed together in order to be able to use the first surface of the cell laminate 110 to keep your distance. As it is in the Fig. 4, the first electromagnet 124 a screw hole 124a which has an inner peripheral surface on which a screw thread is formed, which is capable of being screw-coupled with the screw part S of the screw B. The first electromagnet as described above 124 can be screwed together by screw coupling the screw part S of the screw B and the screw hole 124a the first electromagnet 124 be firmly installed together in order to be able to connect the fixing plate 122 and the first surface of the cell laminate 110 to be positioned.

[0031] As it is in the Fig. 4, the second electromagnet 126 a guide opening 126s in which the screw part S of the screw B can be inserted. The guide opening 126a has a diameter which is larger than that of the screw part S of the screw B, in order to allow the screw part S of the screw B to slide along the guide hole 126a to be displaceable in the stacking direction. The second electromagnet as described above 126 can be installed to be arranged in the stacking direction between the first electromagnet 124 and the first surface of the cell laminate 110 to be movable by inserting the screw part S of the screw B into the guide hole 126a of the second electromagnet 126 .

[0032] As it is in the Fig. 4, the printing plate 128 a guide opening 128ainto which the screw part S of the screw B can be inserted. The guide opening 128a has a diameter which is larger than that of the screw part S of the screw B, in order to allow the screw part S of the screw B to slide along the guide hole 128a to be movable in the stacking direction. The printing plate as described above 128 can be installed to be arranged in the stacking direction between the second electromagnet 126 and the first surface of the cell laminate 110 to be movable by inserting the screw part S of the screw B into the guide hole 128a the printing plate 128 .

[0033] The printing plate as described above 128 may be configured to cover an area of ​​the cell laminate 110 to press in order to reduce the surface pressure of the unit cells 112 Especially when a current is applied to the electromagnets 124 and126 is applied so that the electromagnets 124 and 126 have the same polarity, a repulsive force acts between the electromagnets 124 and 126 However, as described above, the first electromagnet 124 be permanently installed and the second electromagnet can 126 be installed to be movable in the stacking direction. Therefore, as stated in the Fig. 5, the second electromagnet 126 in the direction of the cell laminate 110 be shifted and moved by the repulsive force and the printing plate can 128 by the second electromagnet 126 be pressed in the direction of the cell laminate 110 to be shifted and moved to form the first surface of the cell laminate 110 Therefore, the pressure plate 128 the surface pressure of the unit cells 112increase by pressing the first surface of the cell laminate 110 by the pressure force exerted by the second electromagnet 126 is upset.

[0034] The control device 150 can be set up to control the surface pressure setting unit as described above 110 to operate in order to reduce the surface pressure of the unit cells 112 to be a predetermined surface reference pressure. For example, the control device 150 be set up to supply the current to the electromagnets 124 and 126 to apply it to the printing plate 128 to allow the compressive force on the first surface of the cell laminate 110 to be applied when the surface pressure of the unit cells 112 which is measured by the surface pressure sensor 160 measured to be less than the predetermined surface reference pressure. A compressive force acting on the cell laminate110 through the printing plate 128 is proportional to the repulsive force acting between the electromagnets 124 and 126 Therefore, the control device 150 be set up to determine the surface pressure of the unit cells 112 to adjust to the surface reference pressure by applying the current to the electromagnets 124 and 126 , so that between the electromagnets a repulsive force proportional to a difference between the surface pressure of the unit cells 112 , which is measured by the surface pressure sensor 160 is measured and the surface reference pressure.

[0035] As described above, the fuel cell stack 100 the surface pressure adjustment unit 120 which is designed to reduce the surface pressure of the unit cells 112 by pressing the cell laminate 110using the magnetic force acting between the electromagnets 124 and a 126 Therefore, the fuel cell stack can 100 prevent the performance of the fuel cell stack 100 by a decrease in the surface pressure of the unit cells 112 is deteriorated.

[0036] The Fig. 6 is a partial cross-sectional view of a fuel cell stack according to a second exemplary embodiment of the present disclosure, and the Fig. Fig. 7 is a view showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in Fig. 6. With reference to the Fig. 6 is a fuel cell stack 200 according to the second exemplary embodiment of the present disclosure of the above-mentioned fuel cell stack 100different in that a structure of a surface pressure adjustment unit 220 is modified to achieve a surface pressure of unit cells 112 using a pressure of a fluid F, even when a current is applied to the electromagnets 222 and 223 is not used and therefore the electromagnets 222 and 223 can be stopped. The fuel cell stack is shown below 200 based on the surface pressure adjustment unit 220 described.

[0037] The surface pressure adjustment unit 220 can a housing 221 , which has a recording room 221a formed therein and which is firmly attached to the first surface of a cell laminate 110 is installed, a first electromagnet 222 , which is fixed in the recording room 221a of the housing 221 is installed, a second electromagnet 223which is installed to be stacked in a stacking direction in the receiving space 221a of the housing 221 to be displaceable in order to move between the first electromagnet 222 and the first surface of the cell laminate 110 to be positioned, a fluid chamber 224 which is located between the first electromagnet 222 and an inner surface of the housing 221 and which has an interior 224a which is filled with the fluid F, a pressure plate 225 which is installed to move in the stacking direction in the receiving space 221a of the housing 221 to be displaceable in order to move between the second electromagnet 223 and the first surface of the cell laminate 110 to be positioned, and the like.

[0038] As it is in the Fig. 6, the housing 221 the recording room 221a have formed in it, an opening can221b which allows the recording room 221a allowed in the direction of the first surface of the cell laminate 110 to be open, a screw hole 221c for screw coupling of a fastening element 140 and the housing 221 with each other, and the like. The recording room 221a may have a predetermined volume in which components of the surface pressure adjustment unit 220 , such as the first electromagnet 222 , the second electromagnet 223 , the fluid chamber 224 , the printing plate 225 and the like may be installed.

[0039] The opening 221b may have a predetermined cross-sectional area to allow it to be connected to a first end portion of the cell laminate 110 , which is the first surface of the cell laminate 110 to allow entry into the recording room 221a through the opening 221bto be inserted so as to be displaceably movable in the stacking direction. A screw thread capable of being screw-coupled with a screw part S of a screw B is formed on an inner peripheral surface of the screw hole 221c The screw hole as described above 221c is screw-coupled with the screw part S of the screw B to secure the housing 221 in a state in which the first end portion (e.g., one end portion) of the cell laminate 110 into the opening 221b is used.

[0040] As it is in the Fig. 6, the first electromagnet 222 in the recording room 221a be permanently installed to switch between the fluid chamber 224 and the first surface of the cell laminate 110 For example, the first electromagnet 222 in a fixing frame 223ainserted and coupled to it, which in the recording room 221a is permanently installed to switch between the fluid chamber 224 and the first surface of the cell laminate 110 The first electromagnet, as described above, 222 can be a connection opening 222b which is open in the stacking direction to create a space 226 between the electromagnets 222 and 223 with an interior 224a the fluid chamber 224 to connect, which is described below.

[0041] As it is in the Fig. 7, the space 226 between the electromagnets 222 and 223 a space which is between the electromagnets 222 and 223 is formed when the second electromagnet 223 from the first electromagnet 222 by the repulsive force that exists between the electromagnets 222 and223 The fluid F, which enters the interior 224a the fluid chamber 224 filled, can be placed in the space 226 between the electromagnets 222 and 223 through the connection opening 222b A movement of the fluid F through the connection opening as described above 222b is described in detail below.

[0042] As it is in the Fig. 6, the second electromagnet 223 be installed in the stacking direction in the receiving space 221a to be displaceable in order to move between the first electromagnet 222 and the first surface of the cell laminate 110 For example, the second electromagnet 223 in a fixing frame 223a inserted and coupled, which is installed to be in the stacking direction between the first electromagnet 222and the first surface of the cell laminate 110 to be movable. As it is in the Fig. 6 and Fig. 7, the second electromagnet as described above 223 be shifted and moved in the stacking direction in order to move in the direction of the cell laminate 110 or in the direction towards the opposite side of the cell laminate 110 to be guided by an attractive force and a repulsive force which exists between the electromagnets 222 and 223 works.

[0043] As it is in the Fig. 6, the fluid chamber 224 the interior 224a , which is filled with the fluid F, and a pressure element 224b which is designed to elastically press the fluid F, which enters the interior 224a is filled. The interior 224a can be switched between the first electromagnet 222 and the inside surface of the housing221 shaped. A subdivision plate 224e a printing element 224b , which is described below, can protect the interior 224 into a first interior 224c , which is connected to the connection opening 222b the first electromagnet 222 communicates, and into a second inner electrode 224d which is divided by the subdivision plate 224e is prevented from connecting to the connection opening 222b the first electromagnet 222 to be connected.

[0044] In addition, in the first interior 224c a section of the first interior 224c with the connection opening to 222b the first electromagnet 222 communicates and a remaining section of it can be closed. The fluid F can enter the first interior 224cas described above. The type of fluid F is not particularly limited. For example, fluid F may be a mineral oil-based working fluid, a synthetic oil-based working fluid, a flame-retardant working fluid, or the like. The mineral oil-based working fluid is prepared by adding a corrosion inhibitor, an anti-wear agent, and the like to pure lubricating oil, but is not limited thereto. The flame-retardant working fluid may be an ester-phosphate, a polyol ester, or the like.

[0045] The pressure element 224b the subdivision plate can 224e which is installed to be stacked in the interior 224a to be movable in order to 224a into the first and second interior 224c and 224d to divide, an elastic element 224f , which is set up to divide the subdivision plate 224eelastically support, and the like. The partition plate 224e may be provided to prevent the fluid F entering the first interior 224c is filled, to the second interior 224d through a gap between the subdivision plate 224e and the inside surface of the housing 221 Accordingly, an O-ring (not shown) may be attached to a periphery of the partition plate 224e be installed.

[0046] The elastic element 224f can be set up to form the subdivision plate as described above 224 elastically. As for example in the Fig. 6, the elastic element 224f a compression coil spring which is located between the partition plate 224e and the inside surface of the housing 221 is arranged to form the subdivision plate 224eelastically. The number of installed elastic elements 224f is not particularly limited, and at least one elastic element 224f may vary depending on environmental conditions, such as the area of ​​the subdivision plate 224e , a load on the fluid F and the like. The elastic element as described above 224f The fluid F, which enters the first interior 224c is filled, by interposing the subdivision plate 224e Therefore, a predetermined pressure can be exerted on the fluid F, which enters the first space 224c is filled, depending on the elastic force applied by the elastic element 224f is upset.

[0047] The Fig. 8 is a plan view of an opening / closing valve used in the Fig. 6 is shown, the Fig. 9 is a conceptual view showing the principle of opening and closing of the opening / closing valve used in the Fig. 6. As shown in the Fig. 6, the printing plate 225 be installed in the stacking direction in the receiving space 221a to be displaceable in order to move between the second electromagnet 223 and the first surface of the cell laminate 110 to be positioned. As it is in the Fig. 7 is shown when the second electromagnet 223 in the direction of the cell laminate 110 by the repulsive force that exists between the electromagnets 222 and 223 acts, is moved, the pressure plate can 225 by the second electromagnet 223 be pressed in the direction of the cell laminate 110 to be shifted and moved. Therefore, the printing plate 225 the surface pressure of the unit cells 112by pressing the first surface of the cell laminate 110 by the pressure force which is exerted by the second electromagnet 223 is upset.

[0048] Meanwhile, as described above, the fluid F, which enters the first interior 224a is filled, through the pressure element 224b under pressure. Therefore, when the second electromagnet 223 is shifted and moved to be moved by the first electromagnet 222 to be at a distance, the fluid F can enter the space 226 between the electromagnets 222 and 223 through the connection opening 222b the first electromagnet 222 by applying pressure to it. The surface pressure adjustment unit 220 can also be an opening / closing valve 227 which is arranged to form the connection opening 222bto open or close to prevent the fluid F from flowing through the connection opening as described above 222b to set.

[0049] As it is in the Fig. 6 and Fig. 8, the opening / closing valve 227 have a cross-sectional area which is larger than that of the connecting opening 222b , and can be attached to a first surface of the first electromagnet 222 which is directed towards the first surface of the second electromagnet 223 points to the connection opening 222b to open and close. In particular, a first end portion of the opening / closing valve 227 on the first surface of the first electromagnet 222 be fixed and a second section of the opening / closing valve 227 except for the end section. The opening / closing valve 227may be shaped to be elastically deformed by a pressure applied by the fluid F. For example, as shown in the Fig. 9, the opening / closing valve 227 in a direction opposite to a direction in which the pressure is applied when the pressure applied by the fluid F is equal to or greater than a predetermined reference pressure. A predetermined reference pressure is not particularly limited. For example, the predetermined reference pressure for an opening / closing valve 227 to open 2 mm, be approximately 6.3 MPa if the opening / closing valve 227 has a shape of a disc with 20 mm diameter and 2 mm thickness, is made of a SUS316L material and is installed to be pressed by the fluid F which is in the first interior space 224a as an area of ​​a circle which has a diameter of 10 mm.

[0050] Further, as in the Fig. 6, the opening / closing valve 227 selectively by the first surface of the second electromagnet 223 be supported if a distance between the electromagnets 222 and 223 is less than a predetermined reference distance. Accordingly, the second electromagnet 223 a support groove 223b which has a shape that corresponds to the opening / closing valve 227 corresponds to the opening / closing valve 227 therein, and which is arranged to exert a pressure on a surface of the opening / closing valve 227 to apply the opening / closing valve 227 to support when the electromagnets 222 and 223 are arranged close to each other (e.g. when the electromagnets are adjacent to each other).

[0051] When the electromagnets 222 and 223are adjacent to each other, the opening / closing valve 227 towards the cell laminate 110 by a fluid pressure of the fluid F, which flows into the connection opening 222b However, as stated in the Fig. 6, since the upper surface of the opening / closing valve 227 through the support groove 223b supported, a state can be maintained in which the connection opening 222b is closed. However, if the second electromagnet 223 from the first electromagnet 222 is spaced to support the opening / closing valve 227 through the support groove 223b to release, as required in the Fig. 7, the opening / closing valve 227 towards the cell laminate 110 by the fluid pressure of the fluid F, which flows into the connection opening 222bis initiated based on a first end portion thereof which is attached to a first surface of the first electromagnet 222 is fixed, can be elastically deformed.

[0052] In particular, the connection opening 222b be opened and the fluid F, which enters the first interior 224c is filled into the space 226 between the electromagnets 222 and 223 through the connection opening 222b Then the subdivision plate can 224e towards the cell laminate 110 by the elastic element 224f be shifted and moved with a distance corresponding to a quantity of fluid F that is moved from the first interior 224c As stated in the Fig. 7, when the introduction of the fluid F into the space 226 between the electromagnets 222 and 223is finished, the opening / closing valve can 227 elastically return to an initial state to open the connection 222b to close again. Especially since the opening / closing valve 227 has a cross-sectional area which is larger than that of the connecting opening 222b , even though the opening / closing valve 227 under pressure or to the opposite side of the cell laminate 110 is pressed by the fluid F, which is in the space 226 between the electromagnets 222 and 223 is initiated, the opening / closing valve can be opened / closed by the first surface of the first electromagnet 222 be supported to ensure the closed state of the connection opening 222b to remain closed.

[0053] A control device 150 can be set up to control the surface pressure setting unit as described above 220to operate the surface pressure of the unit cells 112 to become a predetermined surface reference pressure. For example, the control device 150 be set up to determine the surface pressure of the unit cells 112 to the surface reference pressure by applying a current to the electromagnets 222 and 223 to apply the second electromagnet 223 and the printing plate 225 towards the cell laminate 110 to shift and move, and to exert a compressive force on the first surface of the cell laminate 110 to be applied if a surface pressure of the unit cells 112 , which is measured by a surface pressure measuring sensor, is reduced to be lower than the predetermined surface reference pressure. In particular, after the opening / closing valve 227 is opened by the pressure of the fluid F flowing into the first inner space 224chas been elastically deformed to form the connection opening 222b to open when the introduction of the fluid F into the space 226 between the electromagnets 222 and 223 is finished, the opening / closing valve 227 elastically return to an initial state in order to thus open the connection 222b to close again.

[0054] However, even though the current applied to the electromagnets 222 and 223 is applied, is blocked and the electromagnets 222 and 223 stopped, the fluid F, which enters the space 226 between the electromagnets 222 and 223 is initiated, in the space 226 between the electromagnets 222 and 223 remain, and thus the surface pressure of the unit cells 112be maintained to be the surface reference pressure. Therefore, the fuel cell stack 200 the surface pressure of the unit cells 112 as the surface reference pressure using the pressure of the fluid F, even when the electromagnets 222 and 223 be operated for a predetermined period and the operation of the electromagnets 222 and 223 is stopped instead of a continuous operation 222 and 223 if there is no need to adjust the surface pressure of the unit cells 112 Therefore, the fuel cell stack 200 reduce the amount of power required to reduce the surface pressure of the unit cells 112 which makes it possible to improve the fuel efficiency of a fuel cell system.

[0055] The Fig. 10 is a partial cross-sectional view of a fuel cell stack according to a third exemplary embodiment of the present disclosure, and Fig. 11 and Fig. 12 are views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 10. A fuel cell stack 300 According to the third exemplary embodiment of the present disclosure, from the above-mentioned fuel cell stack 200 in the modified design of the surface pressure adjustment unit 320 different. The fuel cell stack will follow 300 based on the surface pressure adjustment unit 320 described.

[0056] With reference to the Fig. 10 the fuel cell stack 300 an end plate 370 which are applied to the first surface of a cell laminate 110is stacked. The surface pressure adjustment unit 320 can be fixed with a fastening element 140 be coupled to apply a compressive force to the end plate as described above 370 in the stacking direction. Accordingly, the surface pressure adjustment unit 320 have a screw shape which is connected to the fastening element 140 For example, the surface pressure adjustment unit 320 a housing 321 which fits into a screw hole 146 of the fastener 140 inserted and fixed, a first electromagnet 322 , which is attached to a recording room 321c of the housing 321 is permanently installed, a second electromagnet 323 which is installed to move in the stacking direction in the receiving space 321c of the housing 321 to be displaceably movable, and the like.

[0057] As it is in the Fig. 10, the housing 321 a body 321a , which is connected to the screw hole 146 of the fastener 140 coupled, and a flange 321b which is connected to a first side of the body 321a is coupled. The body 321a may have a screw thread (not shown) formed on an outer peripheral surface thereof to engage with the screw hole 146 of the fastener 140 to be screw-coupled, the receiving space formed therein 321c , a first opening 321d which is located at the first end section of the housing 321 shaped to accommodate the recording space 321c towards the cell laminate 110 to open, and a second opening 321e which are arranged at a second end portion of the housing 321 shaped to accommodate the recording space 321c towards the opposite side of the cell laminate 110to open up. The body 321a can have a cylindrical shape, but the shape of the body 321 not limited to this.

[0058] As it is in the Fig. 10, the body as described above 321a with the screw hole 146 of the fastener 140 be screw-coupled to connect to the fastening element 140 to be coupled so that the first end section thereof is connected to the end plate 370 comes into contact. The flange 321b may have a diameter larger than that of the screw hole 146 of the fastener 140 . The flange 321b may have an insert part which is shaped to fit into the receiving space 321c through the second opening 321e to be inserted into it. The insert part may have a screw thread formed on an outer periphery thereof, and the receiving space 321cmay have a screw thread formed on an inner periphery thereof to be screw-coupled with the screw thread of the insert part. Therefore, the flange 321b with the first side of the body 321a be coupled to compare with the fastener 140 outside the fuel cell stack 300 to be positioned by screw coupling the screw thread of the insert part and the screw thread of the receiving space 321c each other.

[0059] The first electromagnet 322 can be in the recording room 321c be permanently installed to ensure that between the insert part of the flange 321b and the end plate 370 to be positioned. The first electromagnet 322 can create an interior 323a , which is filled with a fluid F, a connecting opening 322b which allows the interior 322a allowed towards the cell laminate 110to be open, and a pressure element 323c which is designed to elastically control the fluid F which is introduced into the interior 322a filled with water. The interior 322a can be converted into a first interior 322d , which is connected to the connection opening 322b communicates, and into a second interior 222e which is divided by a subdivision plate described below 322f is prevented from connecting to the connection opening 322b The fluid F can be connected to the first interior 322d The pressure element 322c can be an elastic element 322g , which allows the subdivision plate 322e allowed to be elastically pre-tensioned to protect the interior 323a into the first and second interior 322d and 322e to divide, and the like.

[0060] The second electromagnet 323can be installed to stack in the receiving space 321c to be displaceable in order to move between the first electromagnet 322 and the end plate 370 to be positioned. As it is in the Fig. 10, the second electromagnet 323 have a predetermined cross-sectional area which is separated from the receiving space 321c through the first opening 321d Furthermore, the second electromagnet can 323 have a predetermined length. In particular, if a first surface of the second electromagnet 323 on the first surface of the first electromagnet 323 the second surface of the second electromagnet can 323 on the same line as the first opening 321d of the body 321a be positioned. As it is in the Fig. 11 and Fig. 12, the second electromagnet 323be shifted and moved in the stacking direction in order to move in the direction of the cell laminate 110 or in the direction towards an opposite side of the cell laminate 110 to be oriented by an attractive force and a repulsive force which exists between the electromagnets 322 and 323 works.

[0061] If the second electromagnet as described above 323 in the direction of the cell laminate 110 is shifted and moved by the repulsive force that exists between the electromagnets 322 and 323 acts, the fluid F, which enters the first interior 323 de is filled into a space 324 between the electromagnets 322 and 323 through the connection opening 322b The surface pressure adjustment unit 320 can also be an opening / closing valve 325which is arranged to form the connection opening 322b to open or close to prevent the fluid F from flowing through the connection opening as described above 322b to set.

[0062] The opening / closing valve 325 is provided to be elastically deformed by a pressure of the fluid F and has a larger area than that of the connecting hole 322b to open the connection opening 322b A first end section of the opening / closing valve as described above 325 can be applied to the first surface of the electromagnet 322 be attached to the opening / closing valve 325 and the connecting opening 322b to close. The second electromagnet 323 can be a support groove 323a which has a shape that corresponds to the opening / closing valve 325 corresponds to the opening / closing valve 325therein, and may be configured to form an upper surface of the opening / closing valve 325 to press the opening / closing valve 325 to support when the electromagnets 322 and 323 are arranged so that the first surface of the first electromagnet 322 and the first surface of the second electromagnet 323 lie against each other.

[0063] A control device 150 can be set up to control the surface pressure setting unit as described above 320 to operate the surface pressure of the unit cells 112 to become a predetermined surface reference pressure. For example, as shown in the Fig. 11 and Fig. 12, the control device 150 be set up to determine the surface pressure of the unit cells 112 to the reference surface pressure by applying a current to the electromagnets 322 and323 to adjust the second electromagnet 323 towards the cell laminate 110 to shift and move, and to exert a compressive force on the cell laminate 110 through the end plate 370 to be applied if a surface pressure of the unit cells 112 , which is controlled by a surface pressure measuring sensor 160 measured is reduced to be less than the predetermined surface reference pressure.

[0064] In particular, as it is in the Fig. 11 and Fig. 12, the fluid F, which enters the first interior space 323d is filled, partially into the space 324 between the electromagnets 322 and 323 be initiated while the opening / closing valve 325 is elastically deformed to close the connection opening 322b to open, and, if the introduction of the fluid F into the space 324 between the electromagnets322 and 323 is finished, the opening / closing valve 325 elastically return to an initial state in order to thus open the connection 322b Therefore, even though the current flowing to the electromagnets 322 and 323 is applied, is blocked and therefore the electromagnets 222 and 323 stopped, the fluid F, which enters the space 324 between the electromagnets 322 and 323 is initiated, in the space 324 between the electromagnets 322 and 223 remain, and thus the surface pressure of the unit cells 112 than the surface reference pressure.

[0065] The Fig. 13 is a partial sectional view of a fuel cell stack according to a fourth exemplary embodiment of the present disclosure, Fig. 14 and Fig. 15 are views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 13 is shown, and the Fig. 16 and Fig. 17 are views showing a method of lowering the surface pressure of the unit cells using the surface pressure adjusting unit shown in FIG. Fig. 13 is shown.

[0066] A fuel cell stack 400 According to the fourth exemplary embodiment of the present disclosure, from the above-mentioned fuel cell stack 300 in a modified structure of a surface pressure adjustment unit 420 different to achieve a surface pressure of the unit cells 112 The fuel cell stack is shown below 400 based on the surface pressure adjustment unit 420 described. The first electromagnet 423 can be in a recording room 421ca housing 421 be permanently installed. The first electromagnet as described above 422 can create an interior 422a which is filled with a fluid F, first and second connecting openings 422b and 422c to the interior 422a towards the cell laminate 110 to open, and a pressure element 422d which is designed to transfer the fluid F which is introduced into the interior 422a is filled, to put under elastic pressure.

[0067] The interior 422a can be converted into a first interior 422e , which is used to communicate with the first and second connection opening 422b and 422c furnished, and into a second interior 422f which is divided by a subdivision plate described below 422g is prevented from connecting to the connection opening 422b and 422cThe fluid F can be connected to the first interior 422e Each of the first and second connecting holes 422b and 422c can be shaped to form the first interior 422e towards the cell laminate 110 to open. The pressure element 422d the subdivision plate can 422g which is installed to be stacked in a direction inside 422a to be movable in order to adapt the interior 442a into the first and second interior 422e and 422f to divide, and an elastic element 422h which is arranged to form the subdivision plate 422g to prestress elastically.

[0068] The second electromagnet 423 can be installed to stack in the receiving space 421c of the housing 421 to be displaceable in order to move between the first electromagnet 422and an end plate 470 The second electromagnet as described here 423 can be shifted and moved in the stacking direction to the cell laminate 110 or in the direction towards an opposite side of the cell laminate 110 to be guided by an attractive force and a repulsive force which exists between the electromagnets 422 and 423 However, a gap 424 between the electromagnets 422 and 423 with the first interior 422e through the connecting openings 422b and 422c be connected.

[0069] Therefore, while the second electromagnet 423 in the stacking direction and moved in the direction of the cell laminate 110 or in the direction towards an opposite side of the cell laminate 110facing, the fluid F can flow through the connecting openings 422b and 422c from the first interior 422e to the space 424 between the electromagnets 422 and 423 flow or can be from the space 424 between the electromagnets 422 and 423 to the first interior 422e Therefore, the surface pressure adjustment unit 420 further an opening / closing valve 425 which is arranged to selectively open each of the connecting openings 422b and 422c to open or close to prevent the fluid F from flowing through the connecting openings 422b and 422c to set.

[0070] The opening / closing valve 425 a first opening / closing valve 425a , which is set up to form the first connection opening 422bto open or close to allow the fluid F to flow from the first interior 422e to the space 424 between the electromagnets 422 and 423 through the first connection opening 422b to flow, and a second opening / closing valve 425b which is arranged to form the second connection opening 422c to open or close to allow the fluid F to flow from the space 424 between the electromagnets 422 and 423 to the first interior 422e through the second connection opening 422c to flow.

[0071] The first opening / closing valve 425a can be elastically deformed by a pressure of the fluid F and can have an area which is larger than that of the first connection opening 422b to the first connection opening 422b The opening / closing valve as described above 425can be applied to the first surface of the first electromagnet 422 be fixed, which of the first surface of the second electromagnet 423 facing to the first connection opening 422b In response, the second electromagnet can 423 a support groove 423a which has a shape that corresponds to the first opening / closing valve 425a corresponds to the first opening / closing valve 425a therein, and which is arranged to form an upper surface of the first opening / closing valve 425a to press the first opening / closing valve 425a to support when the electromagnets 422 and 423 with the first surface of the first electromagnet 422 and the first surface of the second electromagnet 423 are arranged adjacent to one another.

[0072] The second opening / closing valve 425b can be a cover plate 425c, which has a larger area than that of the second connection opening 422c to open the second connection opening 422c to cover, and which in the first interior 422e is installed, and an elastic element 425d which is elastically arranged to support the cover plate 425c towards an inner surface of the first interior space 422e to press to release the cover plate 425c to condition, on the inner surface of the first interior 422e to be applied when the cover plate 425c the second connection opening 422c In particular, the elastic element 425d be shaped to cover the plate 425c towards the opposite side (e.g. second side) of the cell laminate 110 by a pressure of the fluid F, which is in the space 424 between the electromagnets 422 and 423is initiated when the pressure of the fluid F, which enters the space 424 between the electromagnets 422 and 423 is introduced, with a predetermined pressure greater than a pressure of the fluid F, which is introduced into the first interior 425e The elastic element 425d can be a compression coil spring, but the elastic element 425d is not limited to this.

[0073] The following describes the procedure for increasing the surface pressure of the unit cells 112 using the surface pressure adjustment unit 420 with reference to the Fig. 14 and Fig. 15. As described in the Fig. 14 and Fig. 15, the control device 150 be set up to determine the surface pressure of the unit cells 112 to the surface reference pressure by applying a current to the electromagnets 422 and 423to adjust the second electromagnet 423 in the direction of the cell laminate 110 to shift and move, and to exert a compressive force on the cell laminate 110 through the end plate 470 to be applied if a surface pressure of the unit cells 112 , which is controlled by a surface pressure measuring sensor 160 measured, is reduced to be less than the predetermined surface reference pressure. In particular, the fluid F which enters the first interior space 422e is filled, partially into the space between the electromagnets 422 and 423 be initiated while the first opening / closing valve 425a is elastically deformed to form the first connection opening 422b to open.

[0074] Further, if the introduction of the fluid F into the space 424 between the first and second electromagnet 422 and 423is finished and the pressure of the fluid F, which enters the space 424 between the electromagnets 422 and 423 is introduced, and the pressure of the fluid F, which enters the first interior 422e filled, are balanced with each other, the opening / closing valve 425a elastically return to an initial state, and therefore the first connection opening 422b In addition, since the cover plate 425c of the second opening / closing valve 425b is in a state in which the cover plate 425c by the elastic element 422h is elastically compressed to form the inner surface of the first interior 422e To support the closed state of the second connection opening 422c Therefore, even though the current applied to the electromagnets 422 and 423is blocked and therefore the electromagnets 422 and 423 stopped, the fluid F, which enters the space 424 between electromagnets 422 and 423 is initiated, in the space 424 between the electromagnets 422 and 423 remain, and therefore the surface pressure of the unit cells 112 be maintained on the area reference pressure.

[0075] The following describes the procedure for reducing the surface pressure of the unit cells 112 using the surface pressure adjustment unit 420 with reference to the Fig. 16 and Fig. 17. As described above, after the surface pressure of the unit cells 112 to the surface reference pressure by shifting and moving the second electromagnet 423 in the direction of the cell laminate 110has been increased, the surface pressure of the unit cells 112 additionally by thermal expansion of the fuel cell stack 400 be increased in order to reduce the surface pressure of the unit cells 112 above the reference pressure. However, if the surface pressure of the unit cells 112 is increased to exceed the reference pressure, a polymer electrolyte membrane, a gas diffusion layer and the like may be excessively pressed, and therefore the mechanical durability of the fuel cell stack 400 deteriorated, or diffusion of gas and release of concentrated water may be prevented.

[0076] Accordingly, the control device 150 be set up to determine the surface pressure of the unit cells 112 to the surface reference pressure by applying the current to the electromagnets 422 and 423to the second electromagnet 423 in the direction towards the opposite side (e.g. the second side) of the cell laminate 110 to shift and move when the surface pressure of the unit cells 112 , which is measured by the surface pressure sensor 160 measured exceeds the surface reference pressure. As stated in the Fig. 16, when the second electromagnet 423 towards the opposite side of the cell laminate 110 is shifted and moved to the first electromagnet 422 The fluid F, which is in the space between 424 between the electromagnets 422 and 423 is introduced, by the second electromagnet 423 be put under pressure.

[0077] Therefore, the fluid F, which enters the space 424 between the electromagnets 422 and 423 is introduced, the cover plate425c towards the opposite side of the cell laminate 110 press to create an elastic element 425d of the second opening / closing valve 425c to press to release the cover plate 425c to be determined from the inside surface of the first interior 422e Then the second connection opening 422c be opened to allow the fluid F to flow from the space 424 between the electromagnets 422 and 423 to the first interior 422e through the second connection opening 422c to flow. As it is in the Fig. 17, when the displacement movement of the second electromagnet 423 is stopped, the pressure of the fluid F, which enters the space 424 between electromagnets 422 and 423 is introduced, and the pressure of the fluid F, which enters the first interior 422efilled, balanced with each other and can cover the plate 425c on the inside surface of the first interior 422e by the elastic element 422h which has elastically returned to an initial state, whereby the second connection opening 492c is closed again. As described above, when the second electromagnet 423 in the direction towards the opposite side of the cell laminate 110 is shifted and moved and the fluid F, which is in the space 424 between the electromagnets 422 and 423 is introduced, to the first interior 422e can flow, a compressive force acting on the cell laminate 110 by the second electromagnet 423 or the fluid F is applied, in order to reduce the surface pressure of the unit cells 112 to the surface reference pressure.

[0078] The Fig. 18 is a partial cross-sectional view of a fuel cell stack according to a fifth embodiment of the present disclosure. Referring to Fig. 18 is a fuel cell stack 500 according to the fifth exemplary embodiment of the present disclosure of the above-mentioned fuel cell stack 200 different in that an installation structure of the surface pressure adjustment unit 520 The fuel cell stack is shown below 500 based on the surface pressure adjustment unit 520 described.

[0079] The surface pressure adjustment unit 520 can a housing 521 , which the recording room 521a formed in it and which is attached to a surface of the cell laminate 110 is permanently installed, a first electromagnet 522 , which in the recording room 521a of the housing 521is permanently installed, and a second electromagnet 523 which is installed to be stacked in the receiving space 521a of the housing 521 to be displaceable in order to move between the first electromagnet 522 and the first surface of the cell laminate 110 to be positioned.

[0080] As it is in the Fig. 18, the housing 521 the recording room 521a have formed in it, an opening can 521b which allows the recording room 521a allowed in the direction of the first surface of the cell laminate 110 to be open, and the like. The recording room 521a may have a predetermined volume to accommodate components of the surface pressure adjustment unit 520 The opening 521b may have a predetermined cross-sectional area to define a first end portion of the cell laminate 110, which is the first surface of the cell laminate 110 into the recording room 521a through the opening 521b to be used in order to be movable in the stacking direction.

[0081] As it is in the Fig. 18, the first electromagnet 522 a guide groove 522a which is shaped to be recessed in the stacking direction and a guide projection 522b which is shaped to protrude in the stacking direction. The guide groove 522a may be shaped to face towards the opposite side of the cell laminate 110 to be left out, and the lead 522b may be shaped to be in the direction of the cell laminate 110 The number of guide grooves 522a and the leadership advantage 522b is not particularly limited, and at least one guide groove 522a and at least a lead 522bcan be formed alternately with a predetermined distance.

[0082] As it is in the Fig. 18, the second electromagnet 523 a guide groove 523a which is shaped to be recessed in the stacking direction and a guide projection 523b which is shaped to protrude in the stacking direction. The guide groove 523a may be shaped to be in the direction of the cell laminate 110 to be left out in order to maintain the lead 522b the first electromagnet 522 to be inserted therein in order to be movable in the stacking direction, and the guide projection 523b may be shaped to face towards the opposite side of the cell laminate 110 to lead in order to maintain the leadership 523b into the guide groove 522a the first electromagnet 522to be movable in the stacking direction. The number of guide grooves 523a and the leadership advantage 523b can be the same as the number of guide grooves 522a and the leadership advantage 522b the first electromagnet 522 .

[0083] The second electromagnet as described above 523 can be caused by an attractive force or a repulsive force that exists between the electromagnets 522 and 523 acts, can be shifted and moved in the stacking direction in order to move in the direction of the cell laminate 110 or to the opposite side of the cell laminate 110 The second electromagnet, as described above, 523 can be directed towards the cell laminate 110 be shifted and moved to form the first surface of the cell laminate 110 to press, whereby the surface pressure of the unit cells 112 is increased.

[0084] The Fig. 19 is a partial enlarged view of part II of the Fig. 18, and the Fig. 20 to Fig. 22 are views showing a method of increasing the surface pressure of unit cells using the surface pressure adjusting unit shown in the Fig. 19. The guide grooves 522a and 523a , and the leadership advantages 522b and 523b the above-mentioned electromagnets 522 and 523 can provide a structure for maintaining the surface pressure of the unit cells 112 using a pressure of a fluid F, even if the electromagnets 522 and 523 To facilitate the explanation, the lead is shown below 522b the first electromagnet 522 and the guide groove 523a of the second electromagnet 523 described in which the leadership advantage 522bthe first electromagnet 522 can be used as described above. A description of the guide projection 522b the first electromagnet 522 and the guide groove 523a of the second electromagnet 523 can be placed on the guide groove 522a the first electromagnet 522 and the lead 523b of the second electromagnet 523 be used as they are.

[0085] The leadership advantage 522b can create an interior 522c , which is filled with the fluid F, a connecting opening 522d which allows the interior 522c allowed in the direction of the cell laminate 110 to be open, and a pressure element 522e which is designed to transfer the fluid F which is introduced into the interior 522c is filled, elastically pressurized. The interior 522ccan be divided into a subdivision plate as described below 522h into a first interior 522f , which is connected to the connection opening 522d communicates, and into a second interior 522g which is prevented from communicating with the connecting opening 522d The fluid F can be connected to the first interior 522f be filled.

[0086] The pressure element 522e the subdivision plate can 522h to stack in the interior 522c to be movable in order to adapt the interior 522c into the first and second interior 522f and 522g to share, an elastic element 224i which allows the subdivision plate 522h allowed to be elastically pre-tensioned, and the like. If the guide projection as described above 522b is provided when the second electromagnet 523in the direction of the cell laminate 110 by the repulsive force that exists between the electromagnets 522 and 523 acts, is displaced and moved, the fluid F, which enters the first interior 522f is filled into a space 525 between the lead 522b and the guide groove 523a through the connection opening 522d The surface pressure adjustment unit 520 can also be an opening / closing valve 526 to the connection opening 522d to open or close to prevent the fluid F from flowing through the connection opening 522d to set.

[0087] The opening / closing valve 526 can be elastically deformed by a pressure of the fluid F and can have an area which is larger than that of the connection opening 522d to open the connection opening 522dA first end section of the opening / closing valve as described above 526 can be attached to an outer surface of the guide projection 522b be fixed, which is an inner surface of the guide groove 523a facing the opening / closing valve 526 to condition the connection opening 522d In response, the guide groove can 523a a support groove 523c which has a shape that corresponds to the opening / closing valve 526 corresponds to the opening / closing valve 526 to be accommodated therein, and can form an upper surface of the opening / closing valve 526 Press to open / close the valve 526 to support when the electromagnets 522 and 523 are arranged to cover the outer surface of the guide projection 522b and the inner surface of the guide groove 523a to cause them to lie against each other.

[0088] The following describes the procedure for increasing the surface pressure of the unit cells 112 using the surface pressure adjustment unit 520 with reference to the Fig. 20 to Fig. 22. A control device 150 can be set up to control the surface pressure setting unit as described above 520 to operate the surface pressure of the unit cells 112 to become a predetermined surface reference pressure. For example, as shown in the Fig. 20 to Fig. 22, the control device 150 be set up to determine the surface pressure of the unit cells 112 to adjust to the surface reference pressure by applying a current to the electromagnets 522 and 523 to the second electromagnet 523 in the direction of the cell laminate 110 to shift and move, and can exert a compressive force on the cell laminate110 apply when the surface pressure of the unit cells 112 , which is controlled by a surface pressure measuring sensor 160 measured is reduced to be less than the predetermined surface reference pressure.

[0089] In particular, the fluid F, which enters the first interior 522f is filled into the space 525 between the lead 522b and the guide groove 523a be initiated while the opening / closing valve 526 is elastically deformed to close the connection opening 522d to open, and, if the introduction of the fluid F into the space 525 between the lead 522b and the guide groove 523a is finished, the opening / closing valve can 526 elastically return to an initial state to open the connection 522d Therefore, even if the current applied to the electromagnets 522and 523 is blocked and therefore the electromagnets 522 and 523 stopped, the fluid F, which enters the space 525 between the lead 522b and the guide groove 523a has been initiated, in the space between 525 between the lead 522b and the guide groove 523a remain in order to reduce the surface pressure of the unit cells 112 to maintain the surface reference pressure.

[0090] The Fig. 23 is a partial sectional view of a fuel cell stack according to a sixth exemplary embodiment of the present disclosure, and Fig. 24 is an enlarged partial view of part III of the Fig. 23. Furthermore, the Fig. 25 to Fig. 27 views showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 24 is shown, and are the Fig. 28 and Fig. 29 views showing a method of lowering the surface pressure of the unit cells using the surface pressure adjusting unit shown in the Fig. 24 is shown.

[0091] With reference to the Fig. 23 is a fuel cell stack 600 according to the sixth exemplary embodiment of the present disclosure of the above-mentioned fuel cell stack 500 different in that a structure of a surface pressure adjustment unit 620 is modified to achieve a surface pressure of unit cells 112 The fuel cell stack is shown below 600 based on the surface pressure adjustment unit 620In addition, to simplify the description, a guide projection 622b a first electromagnet 622 and a guide groove 623a a second electromagnet 623 described in which the leadership advantage 622b the first electromagnet 622 A description of the leadership advantage 622b the first electromagnet 622 and the guide groove 623a of the second electromagnet 623 can be placed on a guide groove 622a the first electromagnet 622 and a lead 623b of the second electromagnet 623 be used as they are.

[0092] As it is in the Fig. 24, the lead can be 622b an interior 622c , which is filled with a fluid F, a first and a second connecting hole 622d and622e which allows the interior 622c allow in the direction of the cell laminate 110 to be open, and a pressure element 622f which can be configured to control the fluid F which is introduced into the interior 622c is filled, elastically pressurized. The interior 622c can be divided by a subdivision plate 622i , which is described below, into a first interior 622g , which is connected to the connecting holes 622d and 622e communicates, and into a second interior 622h which is prevented from communicating with the connecting opening 622d and 622e The fluid F can be connected to the first interior 622g be filled.

[0093] Each of the first and second connection openings 622d and 622e can be shaped to form the first interior 622g in the direction of the cell laminate110 to open. The pressure element 622f the subdivision plate can 622i to stack in the interior 622c to be movable in order to adapt the interior 622c into the first and second interior 622g and 622h to divide, an elastic element 622j , which allows the subdivision plate 622i allowed to be elastically prestressed, and the like installed.

[0094] However, a gap 625 between the lead 622b and the guide groove 623a with the first interior 622g through the connecting openings 622d and 622e Therefore, while the second electromagnet 623 in the stacking direction and moved in the direction of the cell laminate 110 or in the direction towards an opposite side of the cell laminate 110The fluid F can be guided from the first interior 622g to the space 625 between the lead 622b and the guide groove 623a flow or can be from the space 625 between the lead 622b and the guide groove 623a to the first interior 622g through the connecting openings 622d and 622e Therefore, the surface pressure adjustment unit 620 further an opening / closing valve 626 which is arranged to selectively open each of the connecting openings 622d and 622b to open or close to prevent the fluid F from flowing through the connecting openings 622d and 622e to set.

[0095] The opening / closing valve 626 a first opening / closing valve 626a , which is set up to form the first connection opening 622dto open or close to allow the fluid F to flow from the first interior 622g to the space 625 between the lead 622b and the guide groove 623a through the first connection opening 622d to flow, and a second opening / closing valve 626b which is arranged to form the second connection opening 622e to open or close to allow the fluid F to flow from the space 625 between the lead 622b and the guide groove 623a to the first interior 622g through the second connection opening 622e to flow.

[0096] The first opening / closing valve 626a can be elastically deformed by a pressure of the fluid F and can have an area which is larger than that of the first connection opening 622d to the first connection opening 622dThe opening / closing valve as described above 626 can be attached to an outside of the guide projection 622b which is an inner surface of the guide groove 623a facing, to fix the opening / closing valve 626 to condition the first connection opening 622d to open / close. In response, the guide groove 623a a support groove 623c which has a shape that corresponds to the first opening / closing valve 626a corresponds to the first opening / closing valve 626a therein, and which forms an upper surface of the first opening / closing valve 626a presses to open / close the first valve 626a to support when the electromagnets 622 and 623 are arranged to cover the outer surface of the guide projection 622b and the inner surface of the guide groove 623a to cause them to lie against each other.

[0097] The second opening / closing valve 626b can be a cover plate 626c , which has a larger area than that of the second connection opening 622e to open the second connection opening 622e to cover, and which in the first interior 622g is installed, and an elastic element 626d which the cover plate 626c elastic in the direction towards an inner surface of the first interior space 622g presses to release the cover plate 626c to condition, on the inner surface of the first interior 622g to be applied when the cover plate 626c the second connection opening 622e covers. The elastic element 626d can be shaped to cover plate 626c in the direction towards the opposite side of the cell laminate 110 by a pressure of the fluid F, which is in the space 625 between the lead622b and the guide groove 623a is initiated when the pressure of the fluid F, which enters the space 625 between the lead 622b and the guide groove 623a is introduced, with a predetermined pressure is greater than a pressure of the fluid F, which is introduced into the first interior 622g The elastic element as described above 626d can be a compression coil spring, but the elastic element 626d is not limited to this.

[0098] The following describes the procedure for increasing the surface pressure of the unit cells 112 using surface pressure adjustment unit 620 with reference to the Fig. 25 to Fig. 27. As described in the Fig. 25 to Fig. 27, the control device 150 be set up to determine the surface pressure of the unit cells 112to the surface reference pressure by applying a current to the electromagnets 622 and 623 to adjust the second electromagnet 623 in the direction of the cell laminate 110 to shift and move, and to exert a compressive force on the cell laminate 110 to be applied if a surface pressure of the unit cells 112 , which is controlled by a surface pressure measuring sensor 160 is lowered to be lower than the predetermined surface reference pressure. In particular, the fluid F which enters the first interior space 622g is filled, partially into the space 625 between the lead 622b and the guide groove 623a initiated, while the first opening / closing valve 626a is elastically deformed to form the first connection opening 622d to open.

[0099] Further, if the introduction of the fluid F into the space 625between the lead 622b and the guide groove 623a is finished and the pressure of the fluid F, which enters the space 625 between the lead 622b and the guide groove 623a is introduced, and the pressure of the fluid F, which enters the first interior 622g filled, are balanced with each other, the first opening / closing valve 626a elastically return to an initial state to open the first connection 622d to close. In addition, since the cover plate 626c of the second opening / closing valve 626b is in a state in which the cover plate 626c by the elastic element 626d is pressed to pass through the inner surface of the first interior 626g supported, the state in which the second connection opening 622eclosed. Therefore, even if the current applied to the electromagnets 622 and 623 is blocked and therefore the electromagnets 622 and 623 stopped, the fluid F, which enters the space 625 between the lead 622b and the guide groove 623a is initiated, in the space 625 between the lead 622b and the guide groove 623a remain as it is, which makes it possible to reduce the surface pressure of the unit cells 112 than maintaining the surface reference pressure.

[0100] The following describes the procedure for reducing the surface pressure of the unit cells 112 using the surface pressure adjustment unit 620 with reference to the Fig. 28 and Fig. 29. As described above, the surface pressure of the unit cells 112increased to a surface reference pressure by shifting and moving the second electromagnet 623 in the direction of the cell laminate 110 , where the surface pressure of the unit cells 112 additionally by other causes of thermal expansion of the fuel cell stack 600 can be increased so that the surface pressure of the unit cells 112 can be increased to exceed the reference pressure.

[0101] Accordingly, the control device 150 be set up to determine the surface pressure of the unit cells 112 to the surface reference pressure by applying the current to the electromagnets 622 and 623 to the second electromagnet 623 in the direction towards the opposite side of the cell laminate 110 to shift and move when the surface pressure of the unit cells 112, which is measured by the surface pressure sensor 160 measured exceeds the surface reference pressure. As stated in the Fig. 28 is shown when the second electromagnet 623 in the direction towards the opposite side of the cell laminate 110 is shifted and moved to the first electromagnet 622 The fluid F, which is in the space between 625 between the lead 622b and the guide groove 623a is initiated, the second electromagnet 623 press.

[0102] Therefore, the fluid F, which enters the space 625 between the lead 622b and the guide groove 623 a is introduced, the cover plate 626c in the direction towards the opposite side of the cell laminate 110 press to release the elastic element 626d of the second opening / closing valve 626bto press to release the cover plate 626c to be determined from the inside surface of the first interior 622g Then the second connection opening 622e be open to condition the fluid F, from the space 625 between the lead 622b and the guide groove 623a to the first interior 622g through the second connection opening 622e to flow. As it is in the Fig. 29, when the displacement movement of the second electromagnet 623 can be stopped, the pressure of the fluid F, which enters the space 625 between the lead 622b and the guide groove 623a is introduced, and the pressure of the fluid F, which enters the first interior 622g filled, be balanced with each other, and the cover plate can 626c on the inside surface of the first interior 626gby the elastic element 626d which has elastically returned to an initial state, whereby the second connection opening 622e is closed again.

[0103] As described above, when the second electromagnet 623 in the direction towards the opposite side of the cell laminate 110 is shifted and moved, and when the fluid F, which enters the space 625 between the lead 622b and the guide groove 623a is introduced, to the first interior 622g can flow, a compressive force acting on the cell laminate 110 by the second electromagnet 623 or the fluid F acts, in order to reduce the surface pressure of the unit cells 112 to the surface reference pressure.

[0104] The Fig. 30 is a partial cross-sectional view of a fuel cell stack according to a seventh exemplary embodiment of the present disclosure, and the Fig. 31 is a conceptual view showing a method of increasing a surface pressure of unit cells using a surface pressure adjusting unit shown in the Fig. 30. With reference to the Fig. 30 is a fuel cell stack 700 according to the seventh exemplary embodiment of the present disclosure of the above-mentioned fuel cell stack 200 different in that a structure of the surface pressure adjustment unit 720 The fuel cell stack is shown below 700 based on the surface pressure adjustment unit 720 described.

[0105] The surface pressure adjustment unit 720 can a housing 721 , which has a recording room 721aformed therein and attached to a first surface of the cell laminate 110 is permanently installed, a first electromagnet 722 , which in the recording room 721a of the housing 721 is permanently installed, a second electromagnet 723 which is installed to be stacked in a stacking direction in the receiving space 721a of the housing 721 to be displaceable in order to move between the first electromagnet 722 and the first surface of the cell laminate 110 to be positioned, a wedge 724 which is shaped to fit into a space 726 between the electromagnets 722 and 723 to be used, and an elastic element 725 which is designed to hold the wedge 724 elastically to press the wedge 724 to cause the space between the electromagnets 722 and 723to occur when the second electromagnet 723 from the first electromagnet 722 is at a distance.

[0106] The recording room 721a may be shaped to have a predetermined volume to accommodate components of the surface pressure adjustment unit 720 to include it. An opening 721b may have a predetermined cross-sectional area to form the first end portion of the cell laminate 110 , which is the first surface of the cell laminate 110 in the recording room 721a through the opening 721b to be movable in the stacking direction. The first electromagnet 722 can be placed at a predetermined position in the recording room 721a be permanently installed, and the second electromagnet 723 can be installed to stack in the receiving space 721a to be displaceable in order to move between the first electromagnet 722and the first surface of the cell laminate 110 to be movable.

[0107] As it is in the Fig. 30, the wedge 724 be installed, a first end portion of which is fixed by the elastic element 725 is elastically supported and a second end portion thereof is formed by a side surface of the second electromagnet 723 is supported. The wedge 724 can be in a horizontal direction of the second electromagnet 723 be installed, but the wedge 724 is not limited to this. The wedge 724 may have a slope structure in which a thickness thereof in the stacking direction from the elastic element 725 in the direction of the second electromagnet 723 gradually decreases. The number of wedges installed 724 is not particularly limited, but at least a wedge 724 can be installed. The elastic element 725can be set up to wedge 724 in the direction of the side surface of the second electromagnet 723 elastically. The type of elastic element 725 is not particularly limited. For example, the elastic element 725 be a disc spring.

[0108] The following describes the procedure for increasing the surface pressure of unit cells 112 using the surface pressure adjustment unit 720 with reference to the Fig. 31. A control device 150 can be set up to control the surface pressure setting unit as described above 720 to operate the surface pressure of the unit cells 112 to a predetermined surface reference pressure. For example, as described in the Fig. 31, the control device 150 be set up to determine the surface pressure of the unit cells 112to adjust to the surface reference pressure by applying a current to the electromagnets 722 and 723 to the second electromagnet 723 in the direction of the cell laminate 110 to shift and move and to exert a compressive force on the cell laminate 110 to be applied if a surface pressure of the unit cells 112 , which is controlled by a surface pressure measuring sensor 160 measured is reduced to be less than the predetermined surface reference pressure.

[0109] In particular, if the second electromagnet 723 can be moved and moved, a state can be released in which the wedge 724 by the second electromagnet 723 Therefore, the elastic element 725 expand and the wedge can 724 into the space 726 between the electromagnets 722 and 723by the elastic element as described above 725 to thereby act between the electromagnets 722 and 723 to be arranged. The wedge 724 , which is located between the electromagnets described above 722 and 723 supports the first electromagnet 722 to the second electromagnet 723 from moving in the direction of the first electromagnet 722 to be shifted and moved when the current applied to the electromagnets 722 and 723 is applied, is blocked and the electromagnets 722 and 723 are stopped. Therefore, the fuel cell stack 700 the surface pressure of the unit cells 112 on the surface reference pressure using the wedge 724 maintained, even when the electromagnets 722 and 723be operated for a predetermined period of time and then the operation of the electromagnets 722 and 723 is terminated, instead of continuously operating the electromagnets 722 and 723 , if there is no need to increase the surface pressure of the unit cells 112 to set.

[0110] The following describes the procedure for reducing the surface pressure of the unit cells 112 using the surface pressure adjustment unit 720 with reference to the Fig. 30. As described above, the surface pressure of the unit cells 112 up to a reference pressure by shifting and moving the second electromagnet 723 in the direction of the cell laminate 110 increased, whereby the surface pressure of the unit cells 112 additionally by other causes of thermal expansion of the fuel cell stack 700can be increased to reduce the surface pressure of the unit cells 112 to increase to exceed the reference pressure.

[0111] Accordingly, the control device 150 be set up to determine the surface pressure of the unit cells 112 to the surface reference pressure by applying the current to the electromagnets 723 and 722 to the second electromagnet 723 in the direction towards the opposite side of the cell laminate 110 to shift and move when the surface pressure of the unit cells 112 , which is measured by the surface pressure sensor 160 measured exceeds the surface reference pressure. As described above, the wedge 724 have a slope structure in which a thickness thereof starting from the elastic element 725 in the direction of the side surface of the second electromagnet 723gradually decreases. Therefore, as stated in the Fig. 30 is shown when an inclined surface 724a of the wedge 724 by the second electromagnet 723 , which in the direction to the opposite side of the cell laminate 110 is moved and moved, is pressed to a predetermined pressure, the wedge 724 be moved to get out of the space 726 between the electromagnets 722 and 723 to be released to pass through the side surface of the second electromagnet 723 to be supported, and then the elastic element 725 be pressed again.

[0112] As described above, according to the exemplary embodiment of the present disclosure, since the fuel cell stack can adjust the surface pressure of the unit cells by applying a pressing force to the unit cells using a magnetic force acting between electromagnets, it may be possible to prevent the performance of the fuel cell stack from being deteriorated due to a decrease or an increase in the surface pressure of the unit cells.

[0113] Although the present disclosure has been described herein with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but can be variously modified and altered by those skilled in the art to which the present invention pertains without departing from the scope of the present invention as claimed in the following claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 1020170147540

[0001]

Claims

[1] A fuel cell stack (100; 200; 300; 400; 500; 600; 700), comprising: a cell laminate (110) formed by stacking a plurality of unit cells (112) in a predetermined stacking direction, and a surface pressure adjusting unit (120; 220; 320; 420; 520; 620; 720) stacked on a surface of the cell laminate (110) and configured to adjust a surface pressure applied to the unit cells (112) in the stacking direction, wherein the surface pressure adjustment unit (120; 220; 320; 420; 520; 620; 720) comprises: a first electromagnet (124; 222; 322; 422; 522; 622; 722), a second electromagnet (126; 223; 323; 423; 523; 623; 723) installed between a first surface of the cell laminate (110) and the first electromagnet (124; 222; 322; 422; 522; 622; 722) to press the unit cells (112), and a control device (150) configured to adjust a compressive force applied to the unit cells (112) by the second electromagnet (126; 223; 323; 423; 523; 623; 723) by selectively applying a current to the first and second electromagnets (124; 222; 322; 422; 522; 622; 722; 126; 223; 323; 423; 523; 623; 723) so that an attractive force or a repulsive force acts between the first and second electromagnets. [2] The fuel cell stack (100; 200; 300; 400; 500; 600; 700) according to claim 1, wherein the surface pressure adjusting unit (120; 220; 320; 420; 520; 620; 720) further comprises a housing (221; 321; 421; 521; 721) having an accommodating space (221a; 321c; 421c; 521a, 721c) in which the first and second electromagnets (124; 222; 322; 422; 522; 622; 722, 126; 223; 323; 423; 523; 623; 723) are accommodated. [3] The fuel cell stack (100; 200; 300; 400; 500; 600; 700) according to claim 1 or 2, wherein the second electromagnet (126; 223; 323; 423; 523; 623; 723) is installed to be slidably movable in the stacking direction to be spaced from or abut against the first electromagnet (124; 222; 322; 422; 522; 622; 722). [4] The fuel cell stack (200; 300; 400; 500; 700) according to claim 2 or 3, wherein the casing (221; 321; 421; 521; 721) further comprises an opening (221b; 321d; 421d; 521b; 721b) allowing the accommodation space (221a; 321c; 421c; 521a, 721c) to be open toward a surface of the cell laminate (110). [5] The fuel cell stack (200; 300; 400; 500; 700) according to any one of claims 2 to 4, wherein a first end portion of the cell laminate (110) is inserted into the receiving space (221a; 321c; 421c; 521a, 721c) through the opening (221b; 321d; 421d; 521b; 721b). [6] The fuel cell stack (200; 300; 400; 500; 700) according to any one of claims 2 to 5, wherein the second electromagnet (223; 323; 423; 523; 723) has a predetermined cross-sectional area to guide a first end portion thereof to the outside of the accommodating space (221a; 321c; 421c; 521a, 721c) through the opening (221b; 321d; 421d; 521b; 721b). [7] The fuel cell stack (200) according to any one of claims 2 to 6, wherein the housing (221) further comprises: a fluid chamber (224) arranged in the first electromagnet (222) and an inner side surface of the housing (221) and having an internal space filled with a fluid (F), and the first electromagnet (222) has a communication hole (222b) open to connect a gap (226) between the first and second electromagnets (222, 223) to the internal space of the fluid chamber (224), and an opening / closing valve (227) configured to open or close the communication hole (222b) to adjust a flow of the fluid (F) through the communication hole (222b). [8] The fuel cell stack (200) according to claim 7, wherein the opening / closing valve (227) has an area larger than that of the communication hole (222b) to cover the communication hole and is shaped to be elastically deformed by a pressure of the fluid (F). [9] The fuel cell stack (200) according to claim 7 or 8, wherein the opening / closing valve (227) is arranged to cover the communication hole (222b) on a first surface of the first electromagnet (222) facing a first surface of the second electromagnet (223) to be selectively supported by the first surface of the second electromagnet (223) when a separation distance between the first and second electromagnets (222, 223) is less than a predetermined reference distance. [10] The fuel cell stack (500; 600) according to any one of claims 1 to 9, wherein one of the first and second electromagnets (522, 523; 622, 623) has a guide groove (522a; 622a) shaped to be recessed in the stacking direction, and one of the first and second electromagnets (522, 523; 622, 623) has a guide projection (522b; 622b) shaped to protrude for inserting the guide projection into the guide groove to be slidably movable in the stacking direction. [11] The fuel cell stack (500; 600) according to claim 10, wherein the guide projection (522b; 622b) has an inner space (522c; 622c) filled with a fluid (F), a communication opening (522d, 622d) connecting a space between the guide projection (522b; 622b) and the guide groove (522a; 62a) to the inner space (522c; 622c), and an opening / closing valve (526; 626) configured to open or close the communication opening to adjust a flow of the fluid (F) through the communication opening (522d, 622d). [12] The fuel cell stack (600) according to claim 11, wherein the communication hole has first and second communication holes (622d, 622e) which are respectively shaped to communicate the gap with the internal space (622c), and the opening / closing valve (626) comprises a first opening / closing valve (626a) which is configured to open or close the first communication hole (622d) to allow the fluid (F) to flow from the internal space (622c) through the first communication hole (622d) to the communication hole, and a second opening / closing valve (626b) which is configured to open or close the second communication hole (622e) to allow the fluid (F) to flow from the gap through the second communication hole (622e) to the internal space (622c). [13] The fuel cell stack (600) according to claim 12, wherein the first opening / closing valve (626a) has a larger area than that of the first communication hole (622d) to cover the first communication hole (622d) and is shaped to be elastically deformed by a pressure of the fluid (F). [14] The fuel cell stack (600) according to claim 12 or 13, wherein the first opening / closing valve (626a) is mounted to cover the first communication hole (622d) on an outer side surface of the guide projection facing an inner side surface of the guide groove to be supported by the inner side surface of the guide groove when a distance between the first and second electromagnets (622, 623) is less than a predetermined reference distance. [15] The fuel cell stack (500; 600) according to any one of claims 11 to 14, wherein one of the first and second electromagnets (522, 523; 622, 623) further comprises a pressing member (522e, 622f) configured to elastically pressurize the fluid (F) filled in the internal space (522c, 622c). [16] The fuel cell stack (600) according to any one of claims 12 to 15, wherein the second opening / closing valve comprises: a cover plate (626c) which has an area larger than that of the second connection opening (622e) to cover the second connection opening and which is installed in the interior space (622c), and an elastic member (626d) configured to elastically urge the cover plate (626d) toward an inner side surface of the interior space (622c) to cause the cover plate (626d) to abut against the inner side surface of the interior space (622c) when the cover plate (626d) covers the second communication opening (622e). [17] The fuel cell stack (100; 200; 300; 400; 500; 600; 700) according to any one of claims 1 to 16, further comprising: an end plate (130) stacked on a second surface of the cell laminate (110), and a fastening element (140) which is arranged to fasten the end plate (130) and the surface pressure adjustment unit (120; 220; 320; 420; 520; 620; 720) to each other. [18] The fuel cell stack (100; 200; 300; 400; 500; 600; 700) according to claim 17, wherein the fastening member (140) is a fastening band provided to be elastically deformable in the stacking direction. [19] The fuel cell stack (700) according to any one of claims 1 to 18, wherein the surface pressure adjusting unit (720) comprises: a wedge (724) and an elastic member (725) adapted to elastically urge the wedge (724) to be inserted into a gap (726) between the first and second electromagnets (722, 723) when the second electromagnet is spaced from the first electromagnet. [20] The fuel cell stack (700) according to claim 19, wherein the wedge (724) has a slope structure in which a thickness thereof gradually decreases in the stacking direction from the elastic member (725) to the gap (726).

Images