Fuel cell having heating unit therefor

A fuel cell includes a cell stack including a plurality of stacked unit cells and a heating unit configured to apply heat to the cell stack. The heating unit includes a heat-generating part and a heat-generating-part support part disposed on an end side of the cell stack. The heat-generating-part support part allows the heat-generating part to be fitted thereinto or to be drawn out therefrom.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefit of priority to Korean Patent Application No. 10-2018-0156606, filed on Dec. 7, 2018 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a fuel cell having a heating unit therefor.

BACKGROUND

In general, a fuel cell includes a polymer electrolyte membrane, and generates electricity using air supplied to one surface of the membrane and hydrogen supplied to the opposite surface of the membrane. This fuel cell serves to supply electricity to a vehicle. Studies on a heater for heating a cell stack of a fuel cell, in which a plurality of unit cells is stacked, have been conducted.

SUMMARY

Accordingly, embodiments are directed to a fuel cell that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of embodiments is to provide a fuel cell enabling replacement of a heating unit with less cost and time.

In one exemplary embodiment of the present disclosure, a fuel cell may include a cell stack including a plurality of stacked unit cells, and a heating unit configured to apply heat to the cell stack. The heating unit may include a heat-generating part and a heat-generating-part support part disposed on an end side of the cell stack. The heat-generating-part support part may allow the heat-generating part to be fitted thereinto or to be drawn out therefrom, and the heat-generating part fitted into the heat-generating-part support part may be mounted in the heat-generating-part support part so as to face the end side of the cell stack.

For example, the fuel cell may further include an end plate disposed on the end side of the cell stack, and a current collector arranged between the end of the cell stack and the end plate.

For example, the heat-generating-part support part may be arranged between the end of the cell stack and the end plate.

For example, the heat-generating-part support part may be arranged between the end of the cell stack and the current collector.

For example, the heat-generating-part support part may be arranged between the end plate and the current collector.

For example, the heat-generating-part support part may be integrally formed with the end plate.

For example, the heat-generating-part support part may be integrally formed with the current collector.

For example, the heating unit may further include a power connection part connected to a driving power source, and a cover part on which the power connection part is disposed. The heat-generating part may include a planar heating element, connected to the power connection part, which generates heat in response to the driving power source. The planar heating element is disposed on the end side of the cell stack.

For example, the fuel cell may further include an enclosure surrounding at least a portion of lateral sides of the cell stack.

For example, the heating unit may further include a fixing part configured to detachably secure the cover part to at least one of the end plate, the current collector, or the enclosure. The cover part, the planar heating element, and the power connection part may be integrally movable.

For example, the enclosure may include a receiving recess formed in a periphery of the heat-generating part. The fixing part and the power connection part may extend from the cover part, and may be received in the receiving recess.

For example, the fuel cell may further include a plurality of clamping members to clamp the unit cells together with the end plate.

For example, the heating unit may further include a fixing part configured to detachably secure the cover part to the heat-generating-part support part. The cover part, the planar heating element, and the power connection part may be integrally movable.

For example, the cover part may include a through-hole extending therein, and the fixing part may include a fixing screw that is fastened to the heat-generating-part support part through the through-hole in the cover part.

For example, the cover part may include a first surface, to which the planar heating element is connected, and a second surface, which is opposite the first surface. The power connection part may be disposed on the second surface.

For example, the heating unit may further include a heat conduction part configured to conduct heat from the heat-generating part to a periphery of the heat-generating part.

For example, the heat-generating-part support part may include a first region in which the heat-generating part is mounted, the first region being disposed on the end side of the cell stack, second regions in which manifolds are disposed, the second regions being opposite each other, with the first region interposed therebetween, and third regions in which the heat conduction part is disposed, each of the third regions being disposed between the first region and a respective one of the plurality of second regions.

For example, the heat conduction part may be arranged between the planar heating element and the end of the cell stack.

For example, the planar heating element may include a heater, and a heater support part surrounding at least a portion of the heater.

For example, the heater may have a film shape or a plate shape.

For example, the heater support part may include at least one of metal, ceramic, or an insulating material.

For example, the heat-generating-part support part may include a first side, on which some of the clamping bars are arranged, and a second side opposite to the first side, on which the remaining ones of the clamping bars are arranged. At least one of the first side or the second side may include at least one opening extending therein to allow the heat-generating part to be fitted thereinto or to be drawn out therefrom.

For example, the heat-generating-part support part may include a first region, in which the heat-generating part is disposed, a second region, which is disposed near the first region and in which manifolds are disposed, and a fourth region, which is interposed between the first region and the second region and in which clamping members are disposed so as to be opposite to each other.

For example, a plurality of first regions may be provided.

DETAILED DESCRIPTION

The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. The examples, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will more fully convey the scope of the disclosure to those skilled in the art.

It will be understood that when an element is referred to as being “on” or “under” another element, it may be directly on/under the element, or one or more intervening elements may also be present.

When an element is referred to as being “on” or “under”, “under the element” as well as “on the element” may be included based on the element.

In addition, relational terms, such as “first”, “second”, “on/upper part/above” and “under/lower part/below”, are used only to distinguish between one subject or element and another subject or element, without necessarily requiring or involving any physical or logical relationship or sequence between the subjects or elements.

Hereinafter, a fuel cell100A to100I according to embodiments will be described with reference to the accompanying drawings. The fuel cell100A to100I will be described using the Cartesian coordinate system (x, y, z) for convenience of description. However, other different coordinate systems may be used. In the drawings, an x-axis, a y-axis, and a z-axis of the Cartesian coordinate system are perpendicular to each other. However, the embodiment is not limited thereto. That is, the x-axis, the y-axis, and the z-axis may intersect each other. In the following description, the x-axis direction may be referred to as a “first direction”, the y-axis direction may be referred to as a “second direction”, and the z-axis direction may be referred to as a “third direction”.

FIG. 1is a perspective view showing the external appearance of a fuel cell100A according to one exemplary embodiment, andFIG. 2is a perspective view showing the external appearance of a fuel cell100B according to another exemplary embodiment of the present disclosure.

Each of the fuel cells100A and100B shown inFIGS. 1 and 2may include a cell stack (not shown) and end plates (pressing plates or compression plates)110A and110B.

The fuel cell100A shown inFIG. 1may further include an enclosure300, and the fuel cell100B shown in FIG. may further include clamping members400instead of an enclosure.

The enclosure300shown inFIG. 1may be disposed so as to surround at least a portion of the lateral sides of the cell stack disposed between the end plates110A and110B. For example, the enclosure300may surround all of the lateral sides of the cell stack. Alternatively, the enclosure300may surround a portion of the lateral sides of the cell stack, and an additional member may surround the remaining portion of the lateral sides of the cell stack. The enclosure300may serve to clamp a plurality of unit cells together with the end plates110A and110B in the first direction. That is, the clamping pressure of the cell stack may be maintained by the end plates110A and110B and the enclosure300, which have rigid structures.

The clamping members400serve to clamp a plurality of unit cells together with the end plates110A and110B in the first direction. For example, as shown inFIG. 2, the clamping members400may be formed in a bar shape, but the embodiment is not limited thereto. According to another embodiment, the clamping members400may be formed in a long bolt shape, a belt shape, or a rigid rope shape to clamp the unit cells. Although it is illustrated inFIG. 2that four clamping members400are provided, the embodiment is not limited as to the specific number of clamping members400. That is, the number of clamping members400may be more or less than four. For example, as shown inFIGS. 8C, 8D and 10, the number of clamping members400may be six.

FIG. 3is a cross-sectional view of the end plates110A and110B and the cell stack122of each of the fuel cells100A and100B shown inFIGS. 1 and 2. For convenience of description, an illustration of the enclosure300shown inFIG. 1and the clamping members400shown inFIG. 2is omitted fromFIG. 3. The same components are denoted by the same reference numerals, and a duplicate explanation thereof is omitted.

Each of the fuel cells100A and100B may be, for example, a polymer electrolyte membrane fuel cell (or a proton exchange membrane fuel cell) (PEMFC), which has been studied most extensively as a power source for driving vehicles. However, the embodiment is not limited to any specific form of the fuel cells100A and100B.

Each of the fuel cells100A and100B may include end plates110A and110B, current collectors112A and112B, and a cell stack122.

The cell stack122may include a plurality of unit cells122-1to122-N, which are stacked in the first direction. Here, “N” is a positive integer of 1 or greater, and may range from several tens to several hundreds. “N” may range, for example, from 100 to 300, but the embodiment is not limited to any specific value of “N”.

Each unit cell122-n(where 1≤n≤N) may generate 0.6 volts to 1.0 volts of electricity, on average 0.7 volts of electricity. Thus, “N” may be determined in accordance with the intensity of the power to be supplied from the fuel cell100A or100B to a load. Here, “load” may refer to a part of a vehicle that requires power when the fuel cell100A or100B is used in a vehicle.

Each unit cell122-nmay include a membrane electrode assembly (MEA)210, gas diffusion layers (GDLs)222and224, gaskets232,234and236, and separators (or bipolar plates)242and244.

The membrane electrode assembly210has a structure in which catalyst electrode layers, in which an electrochemical reaction occurs, are attached to both sides of an electrolyte membrane through which hydrogen ions move. Specifically, the membrane electrode assembly210may include a polymer electrolyte membrane (or a proton exchange membrane)212, a fuel electrode (a hydrogen electrode or an anode)214, and an air electrode (an oxygen electrode or a cathode)216. In addition, the membrane electrode assembly210may further include a sub-gasket238.

The polymer electrolyte membrane212is disposed between the fuel electrode214and the air electrode216.

Hydrogen, which is the fuel in the fuel cell100A or100B, may be supplied to the fuel electrode214through the first separator242, and air containing oxygen as an oxidizer may be supplied to the air electrode216through the second separator244.

The hydrogen supplied to the fuel electrode214is decomposed into hydrogen ions (protons) (H+) and electrons (e−) by the catalyst. Only the hydrogen ions may be selectively transferred to the air electrode216through the polymer electrolyte membrane212, and at the same time, the electrons may be transferred to the air electrode216through the separators242and244, which are conductors. In order to realize the above operation, a catalyst layer may be applied to each of the fuel electrode214and the air electrode216. The movement of the electrons described above causes the electrons to flow through an external wire, thus generating current. That is, the fuel cell100A or100B may generate power due to the electrochemical reaction between hydrogen, which is fuel, and oxygen contained in the air.

In the air electrode216, the hydrogen ions supplied through the polymer electrolyte membrane212and the electrons transferred through the separators242and244meet oxygen in the air supplied to the air electrode216, thus causing a reaction that generates water (“condensate water” or “product water”).

In some cases, the fuel electrode214may be referred to as an anode, and the air electrode216may be referred to as a cathode. Alternatively, the fuel electrode214may be referred to as a cathode, and the air electrode216may be referred to as an anode.

The gas diffusion layers222and224serve to uniformly distribute hydrogen and oxygen, which are reaction gases, and to transfer the generated electrical energy. To this end, the gas diffusion layers222and224may be disposed on respective sides of the membrane electrode assembly210. That is, the first gas diffusion layer222may be disposed on the left side of the fuel electrode214, and the second gas diffusion layer224may be disposed on the right side of the air electrode216.

The first gas diffusion layer222may serve to diffuse and uniformly distribute hydrogen supplied as a reactant gas through the first separator242, and may be electrically conductive. The second gas diffusion layer224may serve to diffuse and uniformly distribute air supplied as a reactant gas through the second separator244, and may be electrically conductive.

Each of the first and second gas diffusion layers222and224may be a microporous layer in which fine carbon fibers are combined. However, the embodiment is not limited to any specific configuration of the first and second gas diffusion layers222and224.

The gaskets232,234and236may serve to maintain the airtightness and clamping pressure of the cell stack at an appropriate level with respect to the reactant gases and the coolant, to disperse the stress when the separators242and244are stacked, and to independently seal the flow paths. As such, since airtightness and water tightness are maintained by the gaskets232,234and236, the flatness of the surfaces that are adjacent to the cell stack122, which generates power, may be managed, and thus surface pressure may be distributed uniformly over the reaction surface of the cell stack122.

The separators242and244may serve to move the reactant gases and the cooling medium and to separate each of the unit cells from the other unit cells. In addition, the separators242and244may serve to structurally support the membrane electrode assembly210and the gas diffusion layers222and224and to collect the generated current and transfer the collected current to the current collectors112A and112B.

The separators242and244may be disposed outside the gas diffusion layers222and224, respectively. That is, the first separator242may be disposed on the left side of the first gas diffusion layer222, and the second separator244may be disposed on the right side of the second gas diffusion layer224.

The first separator242serves to supply hydrogen as a reactant gas to the fuel electrode214through the first gas diffusion layer222. The second separator244serves to supply air as a reactant gas to the air electrode216through the second gas diffusion layer224. In addition, each of the first and second separators242and244may form a channel through which a cooling medium (e.g. coolant) may flow. Further, the separators242and244may be formed of a graphite-based material, a composite graphite-based material, or a metal-based material. However, the embodiment is not limited to any specific material of the separators242and244.

The end plates110A and110B shown inFIGS. 1 and 2may be respectively disposed on the two ends122E1and122E2of the cell stack122, and may support and fix the unit cells122-1to122-N. That is, the first end plate110A may be disposed on one end122E1of the two ends122E1and122E2of the cell stack122, and the second end plate110B may be disposed on an opposite end122E2of the two ends122E1and122E2of the cell stack122.

Each of the end plates110A and110B may be configured such that a metal insert is surrounded by a plastic injection-molded product. The metal insert of each of the end plates110A and110B may have high rigidity to withstand internal surface pressure, and may be formed by machining a metal material. For example, each of the end plates110A and110B may be formed by combining a plurality of plates. However, the embodiment is not limited to any specific configuration of the end plates110A and110B.

The current collectors112A and112B may be disposed between the two ends122E1and122E2of the cell stack122and the inner surfaces110AI and110BI of the end plates110A and110B that are arranged on opposite sides of the cell stack122, respectively. The current collectors112A and112B serve to collect the electrical energy generated by the flow of electrons in the cell stack122and to supply the electrical energy to a load that uses the fuel cell100A or100B.

Further, the first end plate110A may include a plurality of manifolds (or communicating portions) M. Each of the first and second separators242and244shown in FIG.3may include manifolds that are formed in the same shape at the same positions as the manifolds M of the first end plate110A shown inFIGS. 1 and 2. Here, the manifolds M may include an inlet manifold and an outlet manifold. Hydrogen and oxygen, which are reactant gases necessary in the membrane electrode assembly210, may be introduced from the outside into the cell stack122through the inlet manifold M. Gas or liquid, in which the reactant gases humidified and supplied to the cell and the condensate water generated in the cell are combined, may be discharged to the outside of the fuel cell100A or100B through the outlet manifold M. The cooling medium may flow from the outside into the cell stack122through the inlet manifold M and may flow from the cell stack122to the outside through the outlet manifold M. As described above, the manifolds M allow the fluid to flow into and out of the membrane electrode assembly210.

In addition, the fuel cell100A or100B according to an exemplary embodiment of the present disclosure may further include a heating unit500A or500B.

FIGS. 4A to 4Care perspective views of an example of the heating unit500A included in the fuel cell100A shown inFIG. 1.

FIG. 5is a perspective view showing a part of the external appearance of a fuel cell100C according to still another exemplary embodiment of the present disclosure. The fuel cell100C shown inFIG. 5is the same as the fuel cell100B shown inFIG. 2, except that a heat-generating-part support part520C is disposed at a position different from the position at which the heat-generating-part support part520B shown inFIG. 2is disposed. Thus, inFIG. 5, the same components as those shown inFIG. 2are denoted by the same reference numerals.

The heating units500A,500B, and500C may serve to heat the cell stack122, and may be respectively disposed at the two end sides of the cell stack122. The heating units500A,500B, and500C may include heat-generating parts510A,510B, and510C and heat-generating-part support parts520A,520B, and520C.

The heat-generating-part support parts520A,520B, and520C may be respectively disposed at the two ends122E1and122E2of the cell stack122. The heat-generating-part support parts520A,520B, and520C may have a structure that allows the heat-generating parts510A,510B, and510C to be fitted thereinto or to be drawn out therefrom. Here, the heat-generating parts510A,510B, and510C fitted into the heat-generating-part support parts520A,520B, and520C may be mounted in the heat-generating-part support parts520A,520B, and520C so as to be on opposite ends122E1and122E2of the cell stack122. According to an exemplary embodiment of the present disclosure, the heat-generating parts510A,510B, and510C may be freely fitted into and drawn out of the heat-generating-part support parts520A,520B, and520C, whereas the heat-generating-part support parts520A,520B, and520C are disposed at fixed positions.

The heat-generating-part support parts520A and520B may be respectively disposed in the space between one end122E1of the two ends122E1and122E2of the cell stack122and the first end plate110A and the space between the opposite end122E2of the two ends122E1and122E2of the cell stack122and the second end plate110B. For example, as shown inFIG. 2, the heat-generating-part support part520B may be disposed in the space between one of the two ends of the cell stack122and the second end plate110B.

A more detailed description will be made below with reference toFIG. 3.

According to one exemplary embodiment of the present disclosure, the heat-generating-part support parts520A and520B may be respectively disposed in the space {circle around (1)} between the first end plate110A and the first current collector112A and the space {circle around (2)} between the second end plate110B and the second current collector112B.

According to another exemplary embodiment of the present disclosure, the heat-generating-part support parts520A and520B may be respectively disposed in the space {circle around (3)} between one end122E1of the two ends122E1and122E2of the cell stack122and the first current collector112A and the space {circle around (4)} between the opposite end122E2of the two ends122E1and122E2of the cell stack122and the second current collector112B.

According to still another exemplary embodiment of the present disclosure, the heat-generating-part support parts may be integrally formed with the end plates110A and110B. That is, the heating units may serve as the end plates110A and110B and may also serve to heat the cell stack122. For example, as shown inFIG. 5, the heat-generating-part support part520C may serve as the second end plate110B and may also serve to heat the cell stack122. The heat-generating-part support part520C shown inFIG. 5may be disposed at the position of the second end plate110B shown inFIG. 2.

According to still another exemplary embodiment of the present disclosure, although not shown in the drawings, the heat-generating-part support parts may be integrally formed with the current collectors112A and112B. That is, the heat-generating-part support parts may serve as the current collectors112A and112B and may also serve to heat the cell stack122.

In addition, the heating units500A,500B, and500C may further include power connection parts530A and530B and cover parts540A and540B.

The power connection parts530A and530B are connected to a driving power source, and serve to supply driving power to the heat-generating parts510A,510B, and510C. That is, the heat-generating parts510A,510B, and510C may generate heat in response to the driving power.

The heat-generating parts510A,510B, and510C may include planar heating elements, which are disposed on the opposite ends122E1and122E2of the cell stack122and which are connected to the power connection parts530A and530B to generate heat in response to the driving power.

FIGS. 6A, 6B, and 6Care cross-sectional views showing various examples of the planar heating element according to exemplary embodiments of the present disclosure.

The planar heating element according to an exemplary embodiment of the present disclosure may include a heater512A (512B or512C) and a heater support part514A (514B or514C) disposed so as to surround at least a portion of the heater512A (512B or512C).

As shown inFIG. 6B, the heater512B may be implemented as a plate-shaped heating element. As shown inFIG. 6C, the heater512C may be formed in a film shape.

The heater support part514A (514B or514C) may include at least one of metal, ceramic, or an insulating material. For example, the heater support part514A shown inFIG. 6Amay be formed of ceramic, the heater support part514B shown inFIG. 6Bmay be coated with an insulating material, and the heater support part514C shown inFIG. 6Cmay be formed of a metal material.

The power connection parts530A and530B may be disposed on the cover parts540A and540B. For example, referring toFIG. 2, the cover part540B may include a first surface542and a second surface544. The first surface542may correspond to the surface to which the heat-generating part510B is connected, and the second surface544may be the surface that is opposite the first surface542. As shown inFIGS. 2 and 5, the power connection part530B may be disposed on the second surface544of the cover part540B, but the embodiment is not limited thereto.

The heating units500A,500B, and500C according to exemplary embodiments of the present disclosure may further include fixing parts550A and550B.

FIG. 7is an enlarged perspective view of portion ‘A’ shown inFIG. 1.FIG. 7shows a configuration in which the heating unit500A is interposed between the first end plate110A and the cell stack122.

According to one exemplary embodiment of the present disclosure, the fixing part550A of the heating unit500A shown inFIGS. 4A to 4Cmay detachably secure the cover part540A to at least one of the end plates110A and110B, the current collectors112A and112B, or the enclosure300. To this end, the fixing part550A may include a fixing plate550A1and a first fixing screw550A2.

The fixing plate550A1may include at least one through-hole H1and H2extending therein, and may have a shape that protrudes from the cover part540A. The first fixing screw550A2may be fastened through the through-hole H1and H2in order to secure the fixing plate550A1to at least one of the end plates110A and110B, the current collectors112A and112B, or the enclosure300.

According to an exemplary embodiment of the present disclosure, the cover part540A, the planar heating element510A, and the power connection part530A may be integrally movable. Therefore, when the cover part540A is secured by the fixing part550A, the planar heating element510A and the power connection part530A may also be secured therewith. When the cover part540A is not secured by the fixing part550A, the planar heating element510A and the power connection part530A may be drawn out of the heat-generating-part support part520A.

For example, referring toFIG. 7, the fixing plate550A1may extend so as to protrude from the cover part540A in the first direction, and the first fixing screw550A2is fastened to the current collector112A through the through-hole H1and H2shown inFIG. 4B, whereby the cover part540A connected to the fixing plate550A1may be, for example, secured to the current collector112A. Thereafter, when the first fixing screw550A2is released from the current collector112A, the cover part540A may also be, for example, released from the current collector112A.

As illustrated inFIG. 7, the enclosure300may include a receiving recess AH formed in the periphery of the heat-generating part510A. The fixing part550A and the power connection part530A may extend from the cover part540A and may be received in the receiving recess AH in the enclosure300.

According to another exemplary embodiment of the present disclosure, the fixing parts of the heating units500B and500C shown inFIGS. 2 and 5may detachably secure the cover part540B to the heat-generating-part support parts520B and520C. To this end, the fixing part may include a second fixing screw550B2.

The cover part540B may include at least one through-hole H3and H4, and the heat-generating-part support parts520B and520C may include at least one blind hole H5and H6. In this case, the second fixing screw550B may be fastened to the heat-generating-part support parts520B and520C through the through-holes H3to H6to secure the cover part540B to the heat-generating-part support parts520B and520C.

According to an exemplary embodiment of the present disclosure, the cover part540B, the planar heating elements510B and510C, and the power connection part530B may be integrally movable. Therefore, when the cover part540B is secured to the heat-generating-part support parts520B and520C using the second fixing screw550B, the planar heating elements510B and510C and the power connection part530B may also be secured therewith. When the cover part540B is released from the heat-generating-part support parts520B and520C using the second fixing screw550B, the planar heating elements510B and510C and the power connection part530B may be drawn out of the heat-generating-part support parts520B and520C.

As described above, the planar heating elements510A,510B, and510C may be received in the heat-generating-part support parts520A,520B, and520C and may be secured thereto using the fixing parts550A and550B, or may be drawn out of the heat-generating-part support parts520A,520B, and520C using the fixing parts550A and550B.

Therefore, when it is desired to replace the heat-generating parts510A,510B, and510C, it is not necessary to remove the enclosure300or to disassemble the clamping members400. That is, the fixed state of the cover parts540A and540B owing to the fixing parts550A and550B may be released, and subsequently the heat-generating parts510A,510B, and510C may be drawn out of the heat-generating-part support parts520A,520B, and520C.

The heating units500A,500B, and500C may further include heat conduction parts560A and560B. Although an illustration of the heat conduction part560B is omitted from the heating unit500C shown inFIG. 5, the heat conduction part560B may be disposed at the heat-generating part510C, as shown inFIG. 2.

Referring toFIGS. 2 and 4B, the heat conduction parts560A1,560A2, and560B serve to conduct the heat from the heat-generating parts510A and510B to the periphery of the heat-generating parts510A and510B. Since heat transfer from the heat-generating parts510A and510B to the periphery thereof is promoted due to the heat conduction parts560A1,560A2, and560B, the heating efficiency of the heating units500A and500B may be improved.

For example, referring toFIG. 4B, since heat transfer from the heat-generating part510A in the directions indicated by the arrows AR1and AR2is promoted, it is possible to supply heat to an area otherwise characterized by poor heat transfer. Referring toFIG. 4C, the direction in which heat is conducted by the heat conduction part560A1is indicated by the arrow AR3.

The heat-generating-part support part520A of the fuel cell100A according to one exemplary embodiment of the present disclosure, as shown inFIG. 4B, may include a first region A1, second regions A21and A22, and third regions A31and A32.

Hereinafter, the first region A1may be defined as a region that faces the end122E1or122E2of the cell stack122and a region in which the heat-generating part (e.g.510A) is mounted. The plurality of second regions A21and A22may be defined as regions in which the manifolds M are formed and regions that are opposite each other, with the first region A1interposed therebetween. Each of the plurality of third regions A31and A32may be defined as a region that is interposed between the first region A1and a corresponding one of the plurality of second regions A21and A22. According to one exemplary embodiment of the present disclosure, the heat conduction parts560A1and560A2may be disposed in the third regions A31and A32.

According to another exemplary embodiment of the present disclosure, the heat conduction part560B, as shown inFIG. 2, may be disposed between the heat-generating part510B, which is a planar heating element, and the ends122E1and122E2of the cell stack122.

Hereinafter, various exemplary embodiments100D to100G of the fuel cell100B, which includes the clamping members400instead of the enclosure300, as shown inFIGS. 2and5, will be described with reference to the accompanying drawings.

FIGS. 8A to 8Dare plan views of the fuel cells100D to100G according to still other exemplary embodiments of the present disclosure.

The heat-generating-part support part520B shown inFIGS. 8A to 8Dmay perform the same function as the heat-generating-part support part520B shown inFIG. 2, and may include a first side520S1and a second side520S2opposite to the first side520S1. Some of the clamping bars410to460may be disposed on the first side520S1. The remaining ones of the clamping bars410to460may be disposed on an opposite side to the first side520S1, i.e., the second side520S2. Each of the configurations shown inFIGS. 8A and 8B, as shown inFIGS. 2 and 5, includes four clamping bars400(410to440), whereas each of the configurations shown inFIGS. 8C and 8Dincludes six clamping bars400(410to460).

For example, as shown inFIGS. 8A and 8B, the heat-generating-part support part520B may include a first side520S1, on which some clamping bars410and420of the clamping bars410to440are arranged, and a second side520S2, on which the remaining ones430and440of the clamping bars410to440are arranged. Alternatively, as shown inFIGS. 8C and 8D, the heat-generating-part support part520B may include a first side520S1, on which some clamping bars410,420and450of the clamping bars410to460are arranged, and a second side520S2, on which the remaining ones430,440and460of the clamping bars410to460are arranged.

At least one of the first side520S1or the second side520S2of the heat-generating-part support part520B may include at least one opening (or slit) extending therein to allow the heat-generating part to be fitted thereinto or to be drawn out therefrom.

As shown inFIG. 8A, the first side520S1of the heat-generating-part support part520B may include an opening OP2extending therein to allow the heat-generating part510B2to be fitted thereinto or to be drawn out therefrom, and the second side520S2of the heat-generating-part support part520B may include an opening OP1extending therein to allow the heat-generating part510B1to be fitted thereinto or to be drawn out therefrom.

As shown inFIG. 8B, the first side520S1of the heat-generating-part support part520B may include an opening OP3extending therein to allow the heat-generating part510B3to be fitted thereinto or to be drawn out therefrom, and the second side520S2of the heat-generating-part support part520B may include an opening OP4extending therein to allow the heat-generating part510B4to be fitted thereinto or to be drawn out therefrom.

As shown inFIG. 8C, the first side520S1of the heat-generating-part support part520B may include an opening OP5extending therein to allow the heat-generating part510B2to be fitted thereinto or to be drawn out therefrom, and the second side520S2of the heat-generating-part support part520B may include an opening OP6extending therein to allow the heat-generating part510B1to be fitted thereinto or to be drawn out therefrom.

As shown inFIG. 8D, the first side520S1of the heat-generating-part support part520B may include openings OP7and OP8extending therein to allow the heat-generating parts510B5and510B6to be fitted thereinto or to be drawn out therefrom, and the second side520S2of the heat-generating-part support part520B may include openings OP9and OP10extending therein to allow the heat-generating parts510B7and510B8to be fitted thereinto or to be drawn out therefrom.

The heat-generating-part support part520B may include a first region, a second region, and a fourth region. The above-described definition of the first and second regions may be applied to the fuel cells100D to100G shown inFIGS. 8A to 8D. The fourth region may be defined as a region that is interposed between the first region and the second region and a region in which the clamping members are disposed so as to be opposite to each other.

The heat-generating-part support part520B shown inFIGS. 8A and 8Bmay include one first region A1, two second regions A21and A22, and two fourth regions A41and A42.

The heat-generating-part support part520B shown inFIGS. 8C and 8Dmay include two first regions A11and A12, two second regions A21and A22, and three fourth regions A41, A42and A43.

As shown inFIGS. 8A and 8B, a plurality of heat-generating parts510B1and510B2or a plurality of heat-generating parts510B3and510B4may be disposed in one first region A1so as to be spaced apart from each other. Alternatively, as shown inFIG. 8C, the heat-generating part510B1may be disposed in one A11of the two first regions A11and A12, and the heat-generating part510B2may be disposed in the other one A12of the two first regions A11and A12. Alternatively, as shown inFIG. 8D, the heat-generating parts510B5and510B7may be disposed in one A11of the two first regions A11and A12, and the heat-generating parts510B6and510B8may be disposed in the other one A12of the two first regions A11and A12.

As shown inFIGS. 8A, 8B, 8C and 8D, it is possible to efficiently heat the cell stack122by variously setting the positions and the sizes of the heat-generating parts510B1to510B8.

The heat-generating parts510A and510C may be disposed in the heat-generating-part support parts520A and520C in the same manner as shown inFIGS. 8A to 8D.

FIGS. 9A and 9Bare perspective views of a fuel cell100H according to still another exemplary embodiment of the present disclosure.

FIG. 9Ashows the state in which the heat-generating parts510B9and510B10are fitted into the heat-generating-part support part520B, andFIG. 9Bshows the state in which the heat-generating parts510B9and510B10are drawn out of the heat-generating-part support part520B or the state before the heat-generating parts510B9and510B10are fitted into the heat-generating-part support part520B. InFIGS. 9A and 9B, the same components as those of the fuel cell100B shown inFIG. 2are denoted by the same reference numerals, and a duplicate explanation thereof is omitted. When the heat-generating-part support part520B shown inFIGS. 9A and 9Bis replaced with the heat-generating-part support part520C shown inFIG. 5, the following description may also be applied thereto.

According to one exemplary embodiment of the present disclosure, as shown inFIG. 2, one cover part540B may be connected to one heat-generating part510B, and only one heat-generating part510B may be fitted into or drawn out of the heat-generating-part support part520B. As shown inFIGS. 8A to 8C, since one cover part540B1to540B4is connected to one heat-generating part510B1to510B4, only one heat-generating part510B1to510B4may be fitted into or drawn out of the heat-generating-part support part520B.

According to another exemplary embodiment of the present disclosure, as shown inFIGS. 8D, 9A, and 9B, one cover part540B may be connected to a plurality of heat-generating parts. That is, as shown inFIG. 8D, one cover part540B5may be connected to the plurality of heat-generating parts510B5and510B6, and one cover part540B6may be connected to the plurality of heat-generating parts510B7and510B8. As shown inFIGS. 9A and 9B, one cover part540B may be connected to the plurality of heat-generating parts510B9and510B10.

FIG. 10is a perspective view of a fuel cell100I according to still another exemplary embodiment of the present disclosure.

In the fuel cells100B to100H shown inFIGS. 2, 5, 8A to 8D, 9A, and 9B, the openings (e.g. OP1to OP10shown inFIGS. 8A to 8D), through which the heat-generating parts510B (510B1to510B10) and510C of the heating units500B,500C and500I are fitted into or drawn out of the heat-generating-part support parts520B and520C, do not overlap the clamping members400. That is, it is not necessary to remove the clamping members400(410to460) in order to fit or draw the heat-generating parts510B (510B1to510B10) and510C into or out of the heat-generating-part support parts520B and520C.

According to another exemplary embodiment of the present disclosure, in the fuel cell100I shown inFIG. 10, the opening OP11, through which the heat-generating part510I of the heating unit500I is fitted into or drawn out of the heat-generating-part support part520B, may overlap some (e.g., a clamping member470) of the clamping members400. In this case, it is required to remove the clamping member470, which overlaps the opening OP11, in order to fit or draw the heat-generating part510I into or out of the heat-generating-part support part520B. Except for this configuration, the fuel cell100I shown inFIG. 10is the same as the fuel cell100B shown inFIG. 2. Thus, the same components are denoted by the same reference numerals, and a duplicate explanation thereof is omitted.

Hereinafter, a fuel cell according to a comparative example and the fuel cell according to an exemplary embodiment of the present disclosure will be described with reference to the accompanying drawings.

FIG. 11is a perspective view of a fuel cell according to a comparative example.

The fuel cell shown inFIG. 11includes an end plate10, a cell stack22, clamping bars40, and a heater50. The end plate10, the cell stack22, the clamping bars40, and the heater50perform the same function as the end plate110B, the cell stack122, the clamping members400, and the heating unit500A to500C and500I, respectively.

In the fuel cell according to the comparative example, the heater50is inserted between the end plate10and the cell stack22.

In this case, if the heater50breaks down, the clamping bars50need to be completely removed from the fuel cell in order to disassemble the cell stack22, and the cell stack22needs to be reassembled after the broken heater50is replaced, which leads to inconvenience in use and maintenance thereof. Further, in the case of the comparative example, in which the heater50is inserted between the end plate10and the cell stack22, even if the heater50does not break down, the clamping force of the cell stack22may be lowered due to the degradation of the material of the heater50, thus requiring unscheduled replacement of the heater50. Furthermore, when all of the clamping members are removed in order to replace the heater50, the performance of the fuel cell may be changed, and thus various aspects of the performance of the fuel cell, such as airtightness and output performance, need to be rechecked. To this end, expensive performance evaluation equipment such as electronic load equipment may be required, the performance test time may increase due to the process of injecting and discharging coolant, and labor costs required for testing may increase.

On the other hand, in the case of the fuel cell100A to100H according to an exemplary embodiment of the present disclosure, when it is desired to replace the heat-generating part510A,510B (510B1to510B10) and510C of the heating unit500A to500C, only the heat-generating part510A,510B (510B1to510B10) and510C is drawn out of the fixed heat-generating-part support part520A,520B and520C and is replaced with a new one, and the new heat-generating part is fitted into the heat-generating-part support part520A,520B and520C. Thus, it is not necessary to remove the enclosure300or the clamping members400in order to replace the heat-generating part. Alternatively, in the case of the fuel cell100I according to an exemplary embodiment of the present disclosure, when it is desired to replace the heat-generating part510I of the heating unit500I, only some (e.g.470) of the clamping members400are removed instead of removing all of the clamping members400, only the heat-generating part510I is drawn out of the heat-generating-part support part520B and is replaced with a new one, the new heat-generating part is fitted into the heat-generating-part support part520B, and only the removed clamping member470is mounted again. Thus, it is not necessary to check many inspection points, such as airtightness and output performance, unlike the comparative example. As a result, in the case of the fuel cell according to an exemplary embodiment of the present disclosure, it is possible to accomplish the replacement of the heat-generating part510A,510B (510B1to510B10) and510C without checking the output performance, thereby reducing investment costs and the time and labor required for maintenance.

That is, as described above, according to an exemplary embodiment of the present disclosure, it is possible to reduce the time, cost and labor required for the replacement of the heat-generating part510A,510B (510B1to510B10),510C and510I compared to the comparative example. Even if the airtightness performance is inspected after disassembling the cell stack22and replacing the heater50, the airtightness performance may be deteriorated. However, according to the fuel cell of the embodiment, since the cell stack122is not disassembled, it is possible to fundamentally prevent the above problem.

When a vehicle equipped with a fuel cell in which a plurality of unit cells122-1to122-N is stacked is started at a low temperature (e.g. below zero), the temperature of the fuel cell needs to rise to a temperature suitable for the driving of the vehicle. In this case, the time required for the temperature of the plurality of unit cells122-1to122-N to rise depends on the positions of the cells. In particular, since the cells122-1and122-N positioned at the two ends of the cell stack122dissipate a large amount of heat outside, the rate of temperature increase thereof is low, which may increase the total time required to start the vehicle.

Therefore, in the case of the fuel cell100A to100I according to an exemplary embodiment of the present disclosure, the heating units500A,500B and500C are disposed on the two ends of the fuel cell, thereby shortening the time required to start a vehicle equipped with the fuel cell and preventing heat loss.

In the case in which the heating units500A,500B and500C are disposed outside the clamping device (e.g. the enclosure300or the clamping member400), the heat conducted to the cells inevitably passes through the clamping device. Thus, the capacity of the heating units may need to be increased in order to compensate for undesirable heat loss.

However, in the case of the fuel cell100A to100I according to an exemplary embodiment of the present disclosure, since the heating units500A,500B and500C are disposed close to the cells (e.g. in contact with the cells) inside the clamping device, the rate of temperature increase of the fuel cell may increase, and the capacity of the heating units500A,500B and500C may be reduced.

As is apparent from the above description, according to a fuel cell of the embodiment, when it is desired to replace a heat-generating part of a heating unit, only the heat-generating part is drawn out of a fixed heat-generating-part support part and is replaced with a new one, and the new heat-generating part is fitted into the heat-generating-part support part. Thus, it is not necessary to remove an enclosure or clamping members in order to replace the heat-generating part. Alternatively, only some of the clamping members are removed. As a result, it is possible to greatly reduce the time, expense, and labor required to replace the heat-generating part. Further, through the application of a heat conduction part, it is possible to improve the heating efficiency of the heating unit, to increase the rate of temperature increase, to reduce the capacity of the heating unit, to shorten the time required to start up a vehicle equipped with a fuel cell, and to prevent heat loss.

The above-described various embodiments may be combined with each other without departing from the object of the present disclosure unless being contrary to each other. In addition, for any element, which is not described in detail, of any of the various embodiments, refer to the description of the element having the same reference numeral of another embodiment.

While the present disclosure has been particularly shown and described with reference to exemplary embodiments thereof, these embodiments are only proposed for illustrative purposes and do not restrict the present disclosure, and it will be apparent to those skilled in the art that various changes in form and detail may be made without departing from the essential characteristics of the embodiments set forth herein. For example, respective configurations set forth in the embodiments may be modified and applied. Further, differences in such modifications and applications should be construed as falling within the scope of the present disclosure as defined by the appended claims.