Fuel cell stack with integrated heat exchanger

Abstract

A fuel cell stack integrated with a heat exchanger, wherein the heat exchanger is integrated at the end of the stack body to provide insulation to prevent temperature reduction at the end of the stack body's stack, and the heat exchanger has a fuel flow field, an oxidant flow field, and a stack heat exchange medium flow field, wherein the stack heat exchange medium flow field is between the adjacent fuel flow field and oxidant flow field, wherein the fuel and oxidant are allowed to directly enter the stack body after being heat exchanged with the stack heat exchange medium by flowing through the fuel flow field and oxidant flow field, respectively, to participate in electrochemical reactions, thereby eliminating the need for a fuel warming heater and oxidant cooling intercooler, which are separately configured in conventional fuel cell systems, and heat exchange is efficiently performed by utilizing the temperature difference between the fuel and oxidant themselves by arranging the fuel and oxidant on opposite sides of the stack heat exchange medium, thereby enhancing heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more particularly to a fuel cell stack in which a heat exchanger is integrated into the stack body. Background Technology

[0002] A fuel cell system supplies fuel and oxidant to opposite sides of the membrane electrode assembly (MEA) to generate electricity through an electrochemical reaction. A typical traditional fuel cell system uses hydrogen as fuel and oxygen from the air as the oxidant, such as... Figure 1 As shown, it generally includes a fuel cell stack, a hydrogen supply system, an air supply system, and a thermal management system. The hydrogen supply system includes hydrogen cylinders, a hydrogen heater, and a hydrogen circulation loop for reusing hydrogen recovered from the fuel cell stack. The air supply system includes an air filter, an air compressor, an intercooler, and a humidifier. The thermal management system includes a fluid pump for circulating the heat exchange medium and a temperature control module for regulating the temperature of the heat exchange medium, thereby performing thermal management of the fuel cell stack through the heat exchange medium.

[0003] In the air supply system, the temperature of the air rises after passing through the air compressor, even reaching over 150°C, which is higher than the suitable operating temperature of the fuel cell stack (especially the membrane electrode assembly). Air that is too hot is not suitable for direct delivery to the fuel cell stack, so it needs to be cooled by an intercooler. The hydrogen gas coming out of the hydrogen cylinder will have its temperature reduced after depressurization, falling below the ambient temperature. The low-temperature hydrogen gas is also not suitable for direct mixing with the high-temperature (above the ambient temperature) wet hydrogen gas that is being recycled. The condensate produced by direct mixing will cause anode flooding if it is introduced into the fuel cell stack. Therefore, it needs to be heated by a hydrogen heater.

[0004] Traditional fuel cell systems, such as Figure 1 As shown, the hydrogen heater and intercooler are connected in parallel in the fluid circulation loop of the fuel cell stack's thermal management system. The heat exchange medium circulating in the thermal management system heats the hydrogen and cools the air, respectively. Furthermore, the hydrogen heater and intercooler are manufactured by different suppliers, requiring them to be installed independently. In summary, traditional fuel cell systems require dedicated, independent hydrogen heaters for heating hydrogen and intercoolers for cooling air. This inevitably results in a large fuel cell system size and low integration, significantly impacting the technical challenges faced by fuel cell system integration and manufacturing companies in achieving the crucial parameter of volumetric power density.

[0005] Furthermore, the end sides of the stack (multiple stacked cells) of a fuel cell system tend to cool more rapidly in the stacking direction compared to the central side due to greater heat dissipation via end plates. This leads to poorer temperature uniformity among the individual cells and can even reduce the power generation stability of the stack. Therefore, traditional fuel cell systems require additional dummy cells formed by flow field plates at the end sides of the stack to provide insulation and prevent the temperature from dropping at the ends, thus protecting the stack from external temperature fluctuations. However, these dummy cells cannot generate electricity, increasing both the overall stack size and cost. Summary of the Invention

[0006] One advantage of this invention is that it provides a fuel cell stack with an integrated heat exchanger, which simultaneously heats the fuel and cools the oxidant through the integrated heat exchanger. This eliminates the need for separate heaters for heating the fuel and intercoolers for cooling the oxidant, as is the case in conventional fuel cell systems. This helps to reduce the volume of the fuel cell system and increase the volumetric power density of the fuel cell system.

[0007] Another advantage of the present invention is that it provides a fuel cell stack with an integrated heat exchanger, which integrates the heat exchanger into the stack body and, in the heat exchanger, arranges the fuel and oxidant on opposite sides of the stack heat exchange medium before the fuel enters the anode of the stack body (especially before it is mixed with the circulating fuel) and before the oxidant enters the cathode of the stack body, thereby effectively utilizing the temperature difference between the fuel and the oxidant for heat exchange, so that the oxidant, the stack heat exchange medium and the fuel form a gradient heat exchange, thereby enhancing the heat exchange efficiency.

[0008] Another advantage of the present invention is that it provides a fuel cell stack with an integrated heat exchanger, wherein the heat exchanger forms a multi-layer fluid flow field to alternately arrange the fuel flow field, the stack heat exchange medium flow field and the oxidant flow field, and the stack heat exchange medium is located in the intermediate flow field between the fuel and the oxidant, so that the stack heat exchange medium can simultaneously exchange heat with the fuel and the oxidant to raise the temperature of the fuel and lower the temperature of the oxidant, thereby allowing both the fuel and the oxidant to be adjusted to their respective suitable temperatures.

[0009] Another advantage of the present invention is that it provides a fuel cell stack with an integrated heat exchanger, wherein the heat exchanger includes a plurality of stacked heat exchange plates to form a fluid flow field between two adjacent heat exchange plates. The core concept of the heat exchanger is based on a flow field plate with a structural design similar to that of the electrode plates of a fuel cell stack. This makes it easier for companies and technicians in the field of fuel cells to design the heat exchanger's heat exchange plates based on their technical accumulation in electrode plate design.

[0010] Another advantage of the present invention is that it provides a fuel cell stack with an integrated heat exchanger, wherein the heat exchanger is integrated at the end of the stack body, and the fuel and oxidant enter the stack body from between the heat exchanger and the stack body to participate in the electrochemical reaction after entering the heat exchanger for heat exchange, thereby further increasing the integration of the fuel cell stack.

[0011] Another advantage of the present invention is that it provides a fuel cell stack with an integrated heat exchanger, wherein the heat exchanger is integrated at the end of the stack body to provide thermal insulation to prevent the end of the stack body from cooling down due to excessive heat dissipation, and to avoid it from being affected by the external temperature, so that the stack body no longer needs to be configured with dummy cells.

[0012] Another advantage of the present invention is that it provides a fuel cell stack with an integrated heat exchanger, wherein by integrating the heat exchanger into the stack body, the integration of the entire fuel cell system is improved, making the structure of the entire system more compact, further reducing the volume of the fuel cell system, and increasing the volumetric power density of the fuel cell system.

[0013] According to one aspect of the present invention, a fuel cell stack with an integrated heat exchanger is provided, comprising:

[0014] The fuel cell stack itself; and

[0015] A heat exchanger, wherein the heat exchanger is integrated at the end of the fuel cell stack body, wherein the heat exchanger has multiple heat exchange flow fields, the multiple heat exchange flow fields including a fuel flow field, an oxidant flow field and a fuel cell stack heat exchange medium flow field, wherein the fuel cell stack heat exchange medium flow field is between adjacent fuel flow fields and oxidant flow fields, the adjacent heat exchange flow field of each fuel flow field is the fuel cell stack heat exchange medium flow field, and the adjacent heat exchange flow field of each oxidant flow field is the fuel cell stack heat exchange medium flow field, wherein fuel and oxidant are allowed to enter the fuel cell stack body from between the fuel cell stack body and the heat exchanger to participate in electrochemical reactions after flowing through the fuel flow field and the oxidant flow field respectively to exchange heat with the fuel cell stack heat exchange medium.

[0016] According to some embodiments, the plurality of heat exchange flow fields include a plurality of flow field units, the adjacent flow field of each flow field unit is the fuel stack heat exchange medium flow field, and each flow field unit includes three heat exchange flow fields arranged sequentially adjacent to each other, namely the fuel flow field, the fuel stack heat exchange medium flow field and the oxidant flow field, so that a temperature gradient of sequentially decreasing temperature is formed in each flow field unit of the oxidant flow field, the fuel stack heat exchange medium flow field and the fuel flow field, so as to facilitate sufficient heat exchange along the same heat transfer direction.

[0017] According to some embodiments, when the odd-numbered heat exchange flow field of the heat exchanger is the heat exchange medium flow field of the fuel cell stack, the even-numbered heat exchange flow field of the heat exchanger is alternately configured as the fuel flow field and the oxidant flow field.

[0018] According to some embodiments, when the even-numbered heat exchange flow fields of the heat exchanger are the heat exchange medium flow fields of the fuel cell stack, the odd-numbered heat exchange flow fields of the heat exchanger are alternately configured as the fuel flow field and the oxidant flow field.

[0019] According to some embodiments, the fuel cell stack of the integrated heat exchanger further includes a partition, which is positioned between the heat exchanger and the stack body, wherein fuel and oxidant are allowed to pass through the partition into the stack body to participate in electrochemical reactions after flowing through the fuel flow field and the oxidant flow field, respectively, to exchange heat with the stack heat exchange medium.

[0020] According to some embodiments, the heat exchanger includes multiple heat exchange plates, the fuel cell stack body includes multiple single cells, and the fuel cell stack also includes two current collectors, wherein the single cells and the heat exchange plates are located between the two current collectors.

[0021] According to some embodiments, the fuel cell stack body includes a plurality of single cells, and the fuel cell stack also includes perforated end plates and encapsulated end plates located on opposite sides of the plurality of single cells, wherein the heat exchanger is stacked on the perforated end plates to integrate the heat exchanger into the fuel cell stack body, and the perforated end plates serve as a partition between the heat exchanger and the fuel cell stack body.

[0022] According to some embodiments, the heat exchanger includes an open end plate having a fuel inlet, an oxidant inlet, a fuel cell stack heat exchange medium inlet, and a fuel cell stack heat exchange medium outlet. The open end plate also has a fuel cell stack inlet, a fuel cell stack outlet, and an oxidant cell stack outlet, wherein the fuel cell stack heat exchange medium inlet and the fuel cell stack heat exchange medium outlet simultaneously serve as the fuel cell stack heat exchange medium inlet and outlet of the heat exchanger and the fuel cell stack body.

[0023] According to some embodiments, the fuel cell stack of the integrated heat exchanger further includes a partition, and the partition is located between the heat exchanger and the stack body, wherein the fuel cell stack forms a fuel inlet channel, an oxidant fluid channel, a stack heat exchange medium inlet channel, a fuel outlet channel, an oxidant outlet channel and a stack heat exchange medium outlet channel that simultaneously penetrate the heat exchanger, the stack body and the partition.

[0024] According to some embodiments, fuel enters the heat exchanger through the fuel inlet of the open end plate, undergoes heat exchange, and then flows into the fuel inlet channel. It then enters the fuel stack body from the partition fuel inlet of the partition to participate in the electrochemical reaction. Fuel that leaves the fuel stack body and is recovered also enters the fuel stack body through the fuel inlet channel.

[0025] According to some embodiments, the fuel cell stack forms a fuel inlet channel, an oxidant fluid channel, a stack heat exchange medium inlet channel, a fuel outlet channel, an oxidant outlet channel, and a stack heat exchange medium outlet channel that simultaneously penetrate the heat exchanger, the stack body, and the partition.

[0026] The heat exchanger includes a plurality of heat exchange plates to form a plurality of heat exchange flow fields, wherein each heat exchange plate has a heat exchange plate fuel inlet, a heat exchange plate oxidant inlet, a heat exchange plate stack heat exchange medium inlet, a heat exchange plate fuel outlet, a heat exchange plate oxidant outlet, a heat exchange plate stack heat exchange medium outlet, a heat exchange plate stack fuel outlet, and a heat exchange plate stack oxidant outlet.

[0027] The baffle has a baffle fuel inlet, a baffle oxidant inlet, a baffle electric stack heat exchange medium inlet, a baffle fuel outlet, a baffle oxidant outlet, and a baffle electric stack heat exchange medium outlet;

[0028] The battery body includes multiple single cells, and each electrode of each single cell has an electrode fuel inlet, an electrode oxidant inlet, an electrode stack heat exchange medium inlet, an electrode fuel outlet, an electrode oxidant outlet, and an electrode stack heat exchange medium outlet.

[0029] The fuel inlet channel includes the heat exchange plate fuel outlet of the heat exchange plate, the separator fuel inlet of the separator, and the electrode fuel inlet of the single cell's electrode plate, which are located and connected to each other.

[0030] The oxidant fluid channel includes the heat exchange plate oxidant outlet of the heat exchange plate, the separator oxidant inlet of the separator, and the electrode oxidant inlet of the electrode plate of the single cell, which are located and connected to each other.

[0031] The heat exchange medium inlet channel of the fuel cell includes the heat exchange plate fuel cell heat exchange medium inlet of the heat exchange plate, the partition fuel cell heat exchange medium inlet of the partition plate, and the electrode plate fuel cell heat exchange medium inlet of the single cell, which are located and connected to each other.

[0032] The fuel outlet channels include the fuel outlet of the heat exchange plate stack, the fuel outlet of the separator, and the fuel outlet of the electrode plate of the single cell, which are located and connected to each other.

[0033] The oxidant outlet channel includes the heat exchange plate stack oxidant outlet of the heat exchange plate, the separator oxidant outlet of the separator, and the electrode plate oxidant outlet of the single cell, which are located and connected to each other.

[0034] The heat exchange medium outlet channel of the fuel cell includes the heat exchange plate fuel cell outlet of the heat exchange plate, the heat exchange medium outlet of the partition plate, and the heat exchange medium outlet of the electrode plate of the single cell, which are located and connected to each other.

[0035] According to some embodiments, the heat exchanger and the partition are configured such that the fuel cell stack heat exchange medium is simultaneously delivered into the heat exchanger and the fuel cell stack body, or the fuel cell stack heat exchange medium enters the fuel cell stack body after flowing through the fuel cell stack heat exchange medium flow field of the heat exchanger.

[0036] According to some embodiments, the heat exchanger includes a plurality of heat exchange plates to form a plurality of said fuel flow fields, a plurality of said oxidant flow fields, and a plurality of said fuel stack heat exchange medium flow fields, wherein one of fuel, oxidant, and fuel stack heat exchange medium is allowed to flow between two adjacent heat exchange plates, thereby correspondingly forming the fuel flow field, the oxidant flow field, or the fuel stack heat exchange medium flow field between the two adjacent heat exchange plates.

[0037] According to some embodiments, the heat exchanger includes a plurality of heat exchange plates to form a plurality of fuel flow fields, a plurality of oxidant flow fields, and a plurality of fuel cell stack heat exchange medium flow fields. Each heat exchange plate of the heat exchanger has a heat exchange plate fuel inlet, a heat exchange plate oxidant inlet, a heat exchange plate fuel cell stack heat exchange medium inlet, a heat exchange plate fuel outlet, a heat exchange plate oxidant outlet, a heat exchange plate fuel cell stack heat exchange medium outlet, a heat exchange plate fuel outlet, and a heat exchange plate fuel cell stack oxidant outlet. A seal is provided between two adjacent heat exchange plates, the seal connecting the fuel flow fields to the heat exchange plate fuel inlet and the heat exchange plate fuel outlet, and to the heat exchange plate oxidant inlet, the heat exchange plate oxidant outlet, the heat exchange plate fuel cell stack heat exchange medium inlet, and the heat exchange plate fuel cell stack heat exchange medium outlet. The fuel outlet of the heat exchange plate stack and the oxidant outlet of the heat exchange plate stack are not connected; the seal connects the oxidant flow field to the oxidant inlet and the oxidant outlet of the heat exchange plate stack, but not to the fuel inlet, fuel outlet, heat exchange medium inlet, heat exchange medium outlet, fuel outlet, and oxidant outlet of the heat exchange plate stack. The seal connects the heat exchange medium flow field to the heat exchange medium inlet and the heat exchange medium outlet of the heat exchange plate stack, but not to the fuel inlet, fuel outlet, oxidant inlet, oxidant outlet, fuel outlet, and oxidant outlet of the heat exchange plate stack. Attached Figure Description

[0038] Figure 1 This is a block diagram of a fuel cell system based on existing technology.

[0039] Figure 2 This is a block diagram of a specific example of a fuel cell system according to a preferred embodiment of the present invention.

[0040] Figure 3 This is a cross-sectional schematic diagram of a fuel cell stack according to the above-described preferred embodiment of the present invention.

[0041] Figure 4 This is an exploded view of the fuel cell stack according to the above-described preferred embodiment of the present invention.

[0042] Figure 5 This is a schematic diagram of the structure of the open end plate of the heat exchanger of the fuel cell stack according to the above preferred embodiment of the present invention.

[0043] Figure 6 This is a schematic diagram of the structure of the heat exchange plate of the heat exchanger of the fuel cell stack according to the above preferred embodiment of the present invention.

[0044] Figure 7 This is a schematic diagram of the structure of the separator of the fuel cell stack according to the above preferred embodiment of the present invention.

[0045] Figure 8 This is a schematic cross-sectional view illustrating the flow of oxidant in the heat exchanger and the stack body of a fuel cell stack according to the above-described preferred embodiment of the present invention.

[0046] Figure 9 This is a schematic cross-sectional view illustrating the flow of fuel in the heat exchanger and the stack body of a fuel cell stack according to the above-described preferred embodiment of the present invention.

[0047] Figure 10 This is a schematic cross-sectional view illustrating the flow of the heat exchange medium of the fuel cell stack in the heat exchanger and the stack body according to the above-described preferred embodiment of the present invention.

[0048] Figure 11 This is a schematic diagram illustrating the distribution of the oxidant flow field in the heat exchanger of a fuel cell stack according to the above-described preferred embodiment of the present invention.

[0049] Figure 12 This is a schematic diagram illustrating the distribution of the fuel flow field in the heat exchanger of a fuel cell stack according to the above-described preferred embodiment of the present invention.

[0050] Figure 13 This is a schematic diagram illustrating the distribution of the heat exchange medium flow field in the heat exchanger of the fuel cell stack according to the above-described preferred embodiment of the present invention.

[0051] Figure 14 This is a schematic diagram illustrating an example of a heat exchange flow field formed between heat exchange plates in the heat exchanger of a fuel cell stack according to the above-described preferred embodiment of the present invention.

[0052] Figure 15 This is a cross-sectional schematic diagram of a fuel cell stack according to the first modified embodiment of the preferred embodiment described above according to the present invention.

[0053] Figure 16 This is an exploded schematic diagram of a fuel cell stack according to the first modified embodiment of the preferred embodiment described above according to the present invention.

[0054] Figure 17 This is a cross-sectional schematic diagram of a fuel cell stack according to a second modified embodiment of the preferred embodiment described above according to the present invention.

[0055] Figure 18 This is a three-dimensional schematic diagram of a fuel cell stack according to a second modified embodiment of the preferred embodiment described above according to the present invention.

[0056] Figure 19 This is a schematic diagram illustrating the structure of the heat exchange plate of the heat exchanger of a fuel cell stack according to a third modified embodiment of the preferred embodiment described above.

[0057] Figure 20 This is a schematic diagram illustrating the fluid flow of the heat exchange medium in a fuel cell stack according to a third modified embodiment of the preferred embodiment described above. Detailed Implementation

[0058] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0059] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0060] like Figures 2 to 14 The diagram illustrates a fuel cell system 1000 and a fuel cell stack 100 according to a preferred embodiment of the present invention. The fuel cell system 1000 includes the fuel cell stack 100, a fuel supply system 200, an oxidant supply system 300, and a thermal management system 400. The fuel cell stack 100 includes a stack body 10 and a heat exchanger 20, wherein the heat exchanger 20 is integrated into the end of the stack body 10 as shown below. Figure 3 and Figure 4 The top end is shown in the diagram, so the fuel cell system 1000 does not require additional configuration of separate fuel heaters (such as hydrogen heaters) and oxidant cooling devices (such as intercoolers).

[0061] The fuel cell stack 10 includes a plurality of stacked individual cells 11. The fuel cell stack 100 also includes endplate assemblies 12 and separator assemblies 13 located on opposite sides of the plurality of stacked individual cells 11. The endplate assembly 12 includes a current collector 121 and an encapsulation endplate 123. The current collector 121 is located on the side adjacent to the individual cell 11 for collecting current. The encapsulation endplate 123 may include an insulating plate, on which the current collector 121 is disposed; or the encapsulation endplate 123 includes an insulating plate and a metal endplate, wherein the insulating plate is located between the metal endplate and the current collector 121. The separator assembly 13 includes a current collector 131 and a separator 132. The current collector 131 is located on the side adjacent to the individual cell 11 for collecting current, and the separator 132 is disposed between the individual cell 11 and the heat exchanger 20.

[0062] The heat exchanger 20 includes a plurality of stacked heat exchange plates 21 to form a plurality of heat exchange flow fields 22, each heat exchange flow field 22 being formed between two adjacent heat exchange plates 21. The plurality of heat exchange flow fields 22 includes one or more fuel flow fields 221, one or more oxidant flow fields 222, and one or more fuel cell stack heat exchange medium flow fields 223, wherein the fuel cell stack heat exchange medium flow field 223 is located between adjacent fuel flow fields 221 and oxidant flow fields 222, the adjacent heat exchange flow field 22 of each fuel flow field 221 is the fuel cell stack heat exchange medium flow field 223, and the adjacent heat exchange flow field 22 of each oxidant flow field 222 is the fuel cell stack heat exchange medium flow field 223. Without considering the two outermost heat exchange flow fields 22, each... Each of the fuel cell stack heat exchange medium flow fields 223 is located between a fuel flow field 221 and an oxidant flow field 222. The two adjacent flow fields of each fuel flow field 221 are the fuel cell stack heat exchange medium flow fields 223, and the two adjacent flow fields of each oxidant flow field 222 are also the fuel cell stack heat exchange medium flow fields 223. In this way, the fuel and oxidant are arranged on opposite sides of the fuel cell stack heat exchange medium to effectively utilize the temperature difference between the fuel and oxidant for heat exchange, so that the oxidant, fuel cell stack heat exchange medium and fuel form a gradient heat exchange, thereby enhancing the heat exchange efficiency.

[0063] In other words, the flow fields 221, 223, and 222 of fuel, fuel stack heat exchange medium, and oxidant are alternately arranged in the heat exchanger 20, and the fuel stack heat exchange medium flow field 223 is located in the intermediate flow field between the fuel flow field 221 and the oxidant flow field 222. Thus, the fuel stack heat exchange medium can simultaneously exchange heat with the fuel and oxidant to raise the fuel temperature and lower the oxidant temperature, thereby allowing both the fuel and oxidant to be adjusted to their respective suitable temperatures.

[0064] It is understood that the oxidant, located at a high temperature in the oxidant flow field 222, transfers heat through the heat exchange plate 21 between the oxidant flow field 222 and the stack heat exchange medium flow field 223 to the stack heat exchange medium in the stack heat exchange medium flow field 223, thereby cooling the oxidant. Simultaneously, heat is transferred from the stack heat exchange medium in the stack heat exchange medium flow field 223 to the fuel in the fuel flow field 221 through the heat exchange plate 21 between the fuel flow field 221 and the stack heat exchange medium flow field 223, thereby heating the fuel. This allows both the high-temperature oxidant and the low-temperature fuel to exchange heat with the stack heat exchange medium. The three media enter the corresponding heat exchange flow fields 22 in descending order of temperature; that is, before heat exchange, the oxidant has the highest temperature. The fuel has the lowest temperature, while the heat exchange medium of the fuel stack has a temperature between that of the oxidant and the fuel. The three media form a temperature gradient that increases or decreases sequentially in the heat exchange flow field 22 of the heat exchanger 20. That is, the arrangement of these three different media adjacent to each other ensures that the direction of heat transfer is the same and does not cause heat transfer disturbance. This allows the three media to fully exchange heat, so that the oxidant can be adjusted to its appropriate temperature before entering the fuel stack body 10, and the fuel can be adjusted to its appropriate temperature before entering the anode of the fuel stack body 10 (especially before mixing with the circulating fuel). This prevents the generation of condensate due to the mixing of low-temperature fuel with high-temperature and humid circulating fuel, and prevents the high-temperature oxidant from damaging the membrane electrode assembly (especially the proton exchange membrane of the membrane electrode assembly) of the single cell 11.

[0065] like Figures 11 to 13As shown in the diagram, the heat exchanger 20 in this embodiment is schematically configured to have seventeen heat exchange flow fields 22, numbered sequentially from the first to the seventeenth. The second, sixth, tenth, and fourteenth heat exchange flow fields 22 are configured as the oxidant flow field 222, the fourth, eighth, twelfth, and sixteenth heat exchange flow fields 22 are configured as the fuel flow field 221, and the first, third, fifth, seventh, ninth, eleventh, thirteenth, fifteenth, and seventeenth heat exchange flow fields 22 are configured as... The heat exchanger 20 forms four fuel flow fields 221, four oxidant flow fields 222, and nine heat exchange medium flow fields 223 through the stacked heat exchange plates 21. This allows the fuel and oxidant to be diverted to multiple fuel flow fields 221 and multiple oxidant flow fields 222 respectively, thereby increasing the heat exchange area between the fuel and oxidant and the heat exchange medium of the fuel stack, thus efficiently heating the fuel and cooling the oxidant to improve heat exchange efficiency. It is understood that, in other embodiments, the outermost heat exchange flow fields 22 may not be the stack heat exchange medium flow fields 223, but may be the fuel flow field 221 and / or the oxidant flow field 222. For example, in an embodiment with seven heat exchange flow fields 22, the first and fifth heat exchange flow fields 22 are the fuel flow fields 221, the third and seventh heat exchange flow fields 22 are the oxidant flow fields 222, and the second, fourth, and sixth heat exchange flow fields 22 are the stack heat exchange medium flow fields 223.

[0066] In the embodiment having seventeen heat exchange flow fields 22, according to Figures 11 to 13 As shown in the diagram, the heat exchange flow field 22 comprises multiple flow field units. Each flow field unit is adjacent to the fuel cell heat exchange medium flow field 223. Each flow field unit includes three sequentially adjacent heat exchange flow fields 22: the fuel flow field 221, the fuel cell heat exchange medium flow field 223, and the oxidant flow field 222. In each flow field unit, the direction of heat transfer is along the oxidant flow field 222 towards the fuel flow field 221. This creates a temperature gradient where the oxidant flow field 222, the fuel cell heat exchange medium flow field 223, and the fuel flow field 221 successively decrease in temperature, facilitating gradient heat exchange. In other words, in each flow field unit, the fuel cell heat exchange medium at an intermediate temperature is placed in the intermediate flow field, rather than the oxidant at a high temperature or the fuel at a low temperature. This is more conducive to forming a heat gradient and heat transfer along a fixed direction, thereby enhancing heat exchange efficiency and preventing turbulence in heat exchange.

[0067] Accordingly, according to the flow field arrangement in this embodiment, without considering the two outermost heat exchange flow fields 22, each fuel flow field 221 is flanked by the stack heat exchange medium flow fields 223, so that each fuel flow field 221 is heated by the stack heat exchange medium in the two adjacent stack heat exchange medium flow fields 223, thereby achieving rapid temperature rise. Similarly, each oxidant flow field 222 is flanked by the stack heat exchange medium flow fields 223, so that each oxidant flow field 222 is cooled by the stack heat exchange medium in the two adjacent stack heat exchange medium flow fields 223, thereby achieving rapid temperature drop.

[0068] It is worth mentioning that when the odd-numbered heat exchange flow fields 22 of the heat exchanger 20 are the heat exchange medium flow fields 223 of the fuel cell stack, that is, when the (2n+1)th heat exchange flow field 22 is the heat exchange medium flow field 223 of the fuel cell stack, the even-numbered heat exchange flow fields 22 of the heat exchanger 20 are alternately constructed as the fuel flow field 221 and the oxidant flow field 222. That is, if the (4n+2)th heat exchange flow field 22 is the fuel flow field 221, then the (4n+4)th heat exchange flow field 22 is the oxidant flow field 222; if the (4n+2)th heat exchange flow field 22 is the oxidant flow field 222, then the (4n+4)th heat exchange flow field 22 is the fuel flow field 221, where n≥0, and n The value is an integer. When the even-numbered heat exchange flow field 22 of the heat exchanger 20 is the heat exchange medium flow field 223 of the fuel cell stack, that is, when the (2n+2)th heat exchange flow field 22 is the heat exchange medium flow field 223 of the fuel cell stack, the odd-numbered heat exchange flow fields 22 of the heat exchanger 20 are alternately constructed as the fuel flow field 221 and the oxidant flow field 222. That is, if the (4n+1)th heat exchange flow field 22 is the fuel flow field 221, then the (4n+3)th heat exchange flow field 22 is the oxidant flow field 222; if the (4n+1)th heat exchange flow field 22 is the oxidant flow field 222, then the (4n+3)th heat exchange flow field 22 is the fuel flow field 221, where n≥0 and n is an integer.

[0069] The heat exchanger 20 includes an open end plate 23 having a fuel inlet 231, an oxidant inlet 232, a fuel cell heat exchange medium inlet 233, and a fuel cell heat exchange medium outlet 236. In this illustrated embodiment, the fuel inlet 231, the oxidant inlet 232, and the fuel cell heat exchange medium inlet 233 may be located at the same end or different ends of the open end plate 23. The fuel cell heat exchange medium inlet 233 and the fuel cell heat exchange medium outlet 236 are located at opposite ends of the open end plate 23. It is understood that in this embodiment, the fuel inlet 231 and the oxidant inlet 232 are located at opposite ends of the open end plate 23, meaning that both fuel and oxidant enter the heat exchanger 20 from opposite ends of the open end plate 23 and then exchange heat with the fuel cell heat exchange medium, so that the low-temperature fuel and the high-temperature oxidant are each adjusted to the desired temperature when they reach the other end of the heat exchanger 20. In another embodiment, the fuel inlet 231 and the oxidant inlet 232 may be located at the same end of the open end plate 23, so that the fuel and oxidant enter the heat exchanger 20 from the same end of the open end plate 23, exchange heat with the fuel cell stack heat exchange medium, and are adjusted to the desired temperature when they reach the same other end of the heat exchanger 20. The fuel cell stack heat exchange medium inlet 233 may be located at the same end of the open end plate 23 as the fuel inlet 231 and the oxidant inlet 232, or it may be located at the same end of the open end plate 23 as one inlet and at opposite ends of the open end plate 23 as the other inlet.

[0070] In this embodiment, the open end plate 23 also serves as an inlet / outlet end plate for guiding fuel and oxidant into and out of the fuel cell stack body 10. That is, in this embodiment, fuel, oxidant, and the fuel cell stack heat exchange medium enter the heat exchanger 20 and the fuel cell stack body 100 from the same side, such as the top side. Accordingly, the open end plate 23 also has a fuel inlet 237, a fuel outlet 239, and an oxidant outlet 230.

[0071] Each heat exchange plate 21 of the heat exchanger 20 has a heat exchange plate fuel inlet 211, a heat exchange plate oxidant inlet 212, a heat exchange plate electric stack heat exchange medium inlet 213, a heat exchange plate fuel outlet 214, a heat exchange plate oxidant outlet 215, and a heat exchange plate electric stack heat exchange medium outlet 216, and also has a heat exchange plate electric stack fuel outlet 219 and a heat exchange plate electric stack oxidant outlet 210.

[0072] The fuel inlet 211 and fuel outlet 214 of the heat exchange plate are located at opposite ends of the heat exchange plate 21, as are the oxidant inlet 212 and oxidant outlet 215. The fuel cell stack heat exchange medium inlet 213 and outlet 216 of the heat exchange plate are also located at opposite ends of the heat exchange plate 21. In other words, when fuel enters a corresponding fuel flow field 221 from a fuel inlet 211, it fills the entire fuel flow field 221 and flows out from the fuel outlet 214 at the opposite end. This ensures that the fuel in the entire fuel flow field 221 exchanges heat with the adjacent fuel cell stack heat exchange medium through the heat exchange plate 21 while flowing, thus allowing the fuel in each fuel flow field 221 to be heated as uniformly as possible. Similarly, when the oxidant enters the corresponding oxidant flow field 222 from the oxidant inlet 212 of a heat exchange plate, it fills the entire oxidant flow field 222 and flows out from the oxidant outlet 215 of the heat exchange plate located at the opposite end. This allows the oxidant in the entire oxidant flow field 222 to exchange heat with the heat exchange medium of the adjacent two sides of the fuel cell stack through the heat exchange plate 21 while flowing, so that the oxidant in each oxidant flow field 222 can be cooled down as uniformly as possible.

[0073] The partition 132 of the partition assembly 13 also has a partition fuel inlet 1321, a partition oxidant inlet 1322, a partition stack heat exchange medium inlet 1323, a partition fuel outlet 1324, a partition oxidant outlet 1325, and a partition stack heat exchange medium outlet 1326.

[0074] like Figures 8 to 10 As shown, in this embodiment, the fuel cell stack 100 forms a series of fluid channels 25 passing through the heat exchanger 20 and the stack body 10, including a fuel inlet channel 251, an oxidant fluid channel 252, a stack heat exchange medium inlet channel 253, a fuel outlet channel 254, an oxidant outlet channel 255, and a stack heat exchange medium outlet channel 256.

[0075] Each electrode of the single cell 11 has an electrode fuel inlet 111, an electrode oxidant inlet 112, an electrode stack heat exchange medium inlet 113, an electrode fuel outlet 114, an electrode oxidant outlet 115, and an electrode stack heat exchange medium outlet 116.

[0076] The fuel inlet 237 of the open end plate 23, the fuel outlet 214 of the heat exchange plate 21, the fuel inlet 1321 of the partition plate 132, and the fuel inlet 111 of the electrode plate of the single cell 11 are located in corresponding positions and connected to form the fuel inlet channel 251.

[0077] The heat exchange plate oxidant outlet 215 of the heat exchange plate 21, the separator oxidant inlet 1322 of the separator 132, and the electrode oxidant inlet 112 of the electrode of the single cell 11 are located in corresponding positions and connected to form the oxidant fluid channel 252.

[0078] The heat exchange medium inlet 233 of the open end plate 23, the heat exchange plate heat exchange medium inlet 213 of the heat exchange plate 21, the heat exchange medium inlet 1323 of the partition plate 13, and the heat exchange medium inlet 113 of the electrode plate of the single cell 11 are positioned correspondingly and connected to form the heat exchange medium inlet channel 253 of the fuel cell.

[0079] The fuel outlet 239 of the open end plate 23, the fuel outlet 219 of the heat exchange plate, the fuel outlet 1324 of the partition plate 132, and the fuel outlet 114 of the electrode plate of the single cell 11 are positioned correspondingly and connected to form the fuel outlet channel 254.

[0080] The positions of the oxidant outlet 230 of the open end plate 23, the oxidant outlet 210 of the heat exchange plate 21, the oxidant outlet 1325 of the separator 132, and the oxidant outlet 115 of the electrode plate of the single cell 11 are corresponding and connected to form the oxidant outlet channel 255.

[0081] The heat exchange medium outlet 236 of the open end plate 23, the heat exchange plate heat exchange medium outlet 216 of the heat exchange plate 21, the heat exchange medium outlet 1326 of the partition plate 132, and the heat exchange medium outlet 116 of the electrode plate of the single cell 11 are positioned correspondingly and connected to form the heat exchange medium outlet channel 256 of the fuel cell 11.

[0082] like Figure 9As shown, fuel such as hydrogen enters the heat exchanger 20 from the hydrogen source through the fuel inlet 231 of the open end plate 23. After heat exchange, it flows into the fuel inlet channel 251 on the other side and passes through the partition fuel inlet 1321 of the partition 132 into the fuel stack body 10 to participate in the electrochemical reaction. Then it flows through the fuel outlet channel 254 and passes through the partition 132 and the open end plate 23. After passing through a gas-liquid separator 240 and a fuel circulation device such as a hydrogen circulation device 230, it forms recovered hydrogen. The recovered hydrogen then enters the heat exchanger 20 from the fuel inlet 237 of the open end plate 23, mixes with the heat-exchanged hydrogen, and flows back into the fuel stack body 10 through the fuel inlet channel 251.

[0083] like Figure 8 As shown, an oxidant, such as air, enters the heat exchanger 20 from the oxidant inlet 232 of the open end plate 23. After heat exchange, it flows from the oxidant outlet 215 of the heat exchange plate 21 into the oxidant fluid channel 252, and then enters the fuel cell stack 10 through the oxidant inlet 1322 of the partition 132 to participate in the electrochemical reaction. It then flows through the oxidant outlet channel 255 and is discharged from the fuel cell stack 100 after passing through the partition 132 and the open end plate 23. Figure 10 As shown, the fuel cell heat exchange medium flows into the fuel cell heat exchange medium inlet channel 253 through the fuel cell heat exchange medium inlet 233 of the open end plate 23. Part of the fuel cell heat exchange medium flows into the fuel cell heat exchange medium flow field 223 of the heat exchanger 20 for heat exchange with the low-temperature fuel and high-temperature oxidant. The other fuel cell heat exchange medium passes through the partition fuel cell heat exchange medium inlet 1323 of the partition 132 and enters the fuel cell body 10 for thermal management (temperature control) of the fuel cell body 10. Then, the fuel cell heat exchange medium that enters the heat exchanger 20 and the fuel cell body 10 flows out of the heat exchanger 20 through the fuel cell heat exchange medium outlet channel 256.

[0084] The heat exchange medium of the electric stack is in the process of transferring heat from... Figure 10As illustrated, the fuel cell stack 100, after entering the heat exchanger 20 from its top side, is guided into multiple spaced-apart heat exchange medium flow fields 223 to heat the fuel and cool the oxidant. It then exits the heat exchanger 20 and flows back into the loop of the thermal management system 400. The heat exchange medium, after flowing through the heat exchanger 20, flows into the stack body 10 to exchange heat with it, and after exiting the stack body 10, flows back through the heat exchanger 20 and into the loop of the thermal management system 400. It is understood that the thermal management system 400 is used to circulate the heat exchange medium through the corresponding flow fields within the stack body 10 and the heat exchange medium flow fields 223 of the heat exchanger 20, thereby managing the temperature of the stack body 10 and regulating the temperature of the fuel and oxidant flowing through the heat exchanger 20. The heat exchange medium of the fuel cell stack can be deionized water, ethylene glycol solution, or other types of fuel cell coolant. It is used to cool the fuel cell stack when the fuel cell is working. However, during the cold start process of some fuel cells, the heat exchange medium can also be used to heat the fuel cell stack to achieve cold start. The term "fuel cell coolant" is only a term in the art and does not mean that the heat exchange medium can only be used to cool the fuel cell stack.

[0085] Furthermore, taking three adjacent heat exchange flow fields 22 as an example, they respectively form the fuel flow field 221, the fuel cell stack heat exchange medium flow field 223, and the oxidant flow field 222. To ensure that the three adjacent heat exchange flow fields 22 form three different flow fields, the corresponding flow field can be connected to the inlet and outlet of the corresponding fluid, but not connected to the inlet and outlet of other fluids. For example, the fuel flow field 221 is connected to the fuel inlet 211 and fuel outlet 214 of the heat exchange plate, but not to the oxidant inlet 212, oxidant outlet 215, fuel cell stack heat exchange medium inlet 213, fuel cell stack heat exchange medium outlet 216, fuel cell stack fuel outlet 219, and oxidant outlet 210 of the heat exchange plate, thus forming a fuel flow field 221 between two adjacent heat exchange plates 11 that only allows fuel to flow. The oxidant flow field 222 is connected to the oxidant inlet 212 and the oxidant outlet 215 of the heat exchange plate, but not to the fuel inlet 211, the fuel outlet 214, the heat exchange medium inlet 213, the heat exchange medium outlet 216, the fuel outlet 219, and the oxidant outlet 210 of the heat exchange plate, thereby forming an oxidant flow field 222 between two adjacent heat exchange plates 11 that is only for oxidant to flow through. The heat exchange medium flow field 223 of the electric stack is connected to the heat exchange medium inlet 213 and the heat exchange medium outlet 216 of the heat exchange plate, but is not connected to the fuel inlet 211, the fuel outlet 214, the oxidant inlet 212, the oxidant outlet 215, the fuel outlet 219, and the oxidant outlet 210 of the heat exchange plate, thereby forming a heat exchange medium flow field 223 between two adjacent heat exchange plates 11 that only supplies the heat exchange medium of the electric stack.

[0086] like Figure 14 As shown, adjacent heat exchange plates 21 are sealed to their respective flow fields and inlets / outlets via seals 24. The specific shape and construction of the seals 24 are matched to the specific structural design of the heat exchange plates 21 to ensure that only the correct fluid can flow into the flow field from its inlet and out its outlet, while guaranteeing an external seal for the flow field and all inlets / outlets. For example, in one embodiment, the seals 24 can be implemented as an adhesive layer or a welded layer. Figure 14In the diagram, the seal 24 is schematically shown to surround the corresponding flow field and inlet / outlet, visually demonstrating the communication between the flow field and the corresponding inlet / outlet, the isolation from other inlets / outlets, and the seal relative to the external environment. Since the fluid guiding method of the heat exchange plate 21 is essentially the same as that of the fuel cell electrode plates, the specific structural design of the heat exchange plate 21 and the seal 24 can refer to the design of the fuel cell electrode plates and their sealing structures. Figure 14 The connection structure between the flow field and the corresponding inlet and outlet (the connecting channel is formed on the same side of the flow field) shown is only one optional fluid guiding method in the electrode design of fuel cells. For example, the connection between the flow field and the inlet and outlet can be achieved through a connecting channel formed on the back side of the flow field and a turning hole penetrating into the flow field, or other methods known in the fuel cell field. These can also be implemented in the heat exchange plate 21 and the seal 24 of this invention. Their specific structures are well known to those skilled in the art and will not be further described or illustrated here. In other words, the specific flow guiding structure of the heat exchange plate 21 and the specific shape and structure of the seal 24 are not considered as limitations on the scope of protection of this invention.

[0087] In this embodiment, such as Figure 2 As shown, hydrogen is used as the fuel and air containing oxygen is used as the oxidant. The fuel supply system 200 accordingly includes a hydrogen source 210, a valve 220, a hydrogen circulation device 230, and a gas-water separator 240. The hydrogen source 210 can be a hydrogen cylinder. The hydrogen from the hydrogen source 210 enters the heat exchanger 20 after passing through the valve 220 and is heated. After being heated, the hydrogen flows out of the heat exchanger 20 and is mixed with the recycled hydrogen before being introduced into the fuel cell stack 10 to participate in the electrochemical reaction. The hydrogen circulation device 230 is used to recover unreacted hydrogen from the fuel cell stack 10 for recycling, and the gas-water separator 240 is used to remove liquid water carried by the recycled hydrogen.

[0088] The oxidant supply system 300 correspondingly includes an air filter 310 and an air compressor 320. Air is filtered by the air filter 310 and compressed by the air compressor 320 before entering the heat exchanger 20 for cooling. Then, it enters the fuel cell stack body 10 directly without being humidified by a humidifier to participate in the electrochemical reaction. The thermal management system 400 includes a fuel cell stack heat exchange circulation pipeline for supplying the fuel cell stack heat exchange medium to the heat exchanger 20 and the fuel cell stack body 10, and includes a temperature regulation module 420 and a pump 430.

[0089] Additionally, the heat exchanger 20 is integrated on the end side of the fuel cell stack body 10, such as... Figure 3The top side of the stack body 10, as shown in the diagram, provides thermal insulation to prevent the temperature of the ends of the stack body 10 (multiple stacked single cells 11) from dropping, thus avoiding the influence of external temperature on the fuel cell stack 100, so that the stack body 10 no longer needs to be configured with dummy cells.

[0090] like Figures 15 to 16 The image shows a fuel cell stack 100 according to a first modified embodiment of the preferred embodiment described above, comprising a stack body 10 and a heat exchanger 20, wherein the heat exchanger 20 is integrated into the stack body 10. In this embodiment, the heat exchanger 20 is integrated into the end of the stack body 10 as shown in the image. Figure 15 The top side end is shown in the diagram.

[0091] Similarly, the fuel cell stack body 10 includes a plurality of stacked individual cells 11, and the fuel cell stack 100 further includes an endplate assembly 12 located on one side of the plurality of stacked individual cells 11. The endplate assembly 12 includes a current collector 121 and an encapsulated endplate 123, wherein the current collector 121 is located on the side adjacent to the individual cell 11 for collecting current, and the encapsulated endplate 123 may include an insulating plate, on which the current collector 121 is disposed; or the encapsulated endplate 123 includes an insulating plate and a metal endplate, wherein the insulating plate is located between the metal endplate and the current collector 121. On the other side of the individual cell 11 is the heat exchanger 20, which includes an open endplate 23 and the heat exchange plate 21, wherein the current collector 131 is disposed inside the open endplate 23. In other words, in this embodiment, the heat exchange plate 21 of the heat exchanger 20 and the single cell 11 of the fuel cell stack body 10 can be disposed between the current collector 121 and the current collector 131. It is understood that the single cell 11 is connected to the current collector 131 located inside the open end plate 23 of the heat exchanger 20 via the conductive heat exchange plate 21 of the heat exchanger 20. Thus, the heat exchange plate 21 of the heat exchanger 20 and the single cell 11 can be located between the two current collectors 121 and 131.

[0092] like Figures 17 to 18 The image shows a second modified embodiment of a fuel cell stack 100 according to the preferred embodiment described above. The fuel cell stack 100 includes a stack body 10 and a heat exchanger 20. In this embodiment, the fuel cell stack 100 does not require modification of the original stack body 10 structure; instead, the heat exchanger 20 can be directly integrated onto an existing stack body 10, such as by integrating the heat exchanger 20 as a stacked structure at the end of the stack body 10. Figure 17 The top end, as shown in the diagram, is where the heat exchanger 20 is stacked on an open end plate 122 of the fuel cell stack body 10. The open end plate 122 has the fluid inlet and outlet configuration of the aforementioned partition 132, allowing the heat exchanger 20 to be integrated into the top side of the fuel cell stack body 10, thus facilitating the assembly of the fuel cell stack 100. In the preferred embodiment described above, when assembling the fuel cell stack 100, the partition assembly 13 and the heat exchange plate 21 can be added between the two end plates of the stack body 10, namely the open end plate 122 and the aforementioned encapsulated end plate 123, thereby integrating the heat exchanger 20 into the stack body 10. In other words, the open end plate 122 and the encapsulated end plate 123 are used as the two end plates of the fuel cell stack 100 for assembly, facilitating the assembly of the stack body 10 and the heat exchanger 20. The open end plate 122 forms the open end plate 23 of the heat exchanger 20.

[0093] It is understood that in the above embodiments, the manifolds 121 and 131 are not used to form fluid inlets or outlets, thereby preventing fluid from contacting the manifolds 121 and 131 and causing corrosion and damage to the manifolds 121 and 131.

[0094] like Figures 19 to 20 The image shows a third modified embodiment of the fuel cell stack 100 according to the above-described preferred embodiment of the present invention. More specifically, in this embodiment, the heat exchange plate 21 of the heat exchanger 20 correspondingly has a heat exchange plate stack heat exchange medium inlet 213 and [1] a first heat exchange plate stack heat exchange medium outlet 216a and [2] a second heat exchange plate stack heat exchange medium outlet 216b located at opposite ends of the heat exchange plate 21. The stack heat exchange medium enters the corresponding stack heat exchange medium flow field 223 from the heat exchange plate stack heat exchange medium inlet 213 for heat exchange with the fuel and oxidant in the adjacent flow field, and flows out from the first heat exchange plate stack heat exchange medium outlet 216a at the opposite end and further flows back into the stack body 10 for thermal management of the stack body 10. After flowing through the stack body 10, the fuel cell stack 100 flows out from the second heat exchange plate stack heat exchange medium outlet 216b of each of the heat exchange plates 21 of the heat exchanger 20.

[0095] In other words, in this embodiment, the aforementioned heat exchange medium inlet channel 253 passing through the open end plate 23 and heat exchange plate 21 of the heat exchanger 20 and the fuel cell stack body 10 is not formed. The fuel cell heat exchange medium does not directly enter the fuel cell stack body 10 through the heat exchange medium inlet channel 253 as in the above embodiment. Instead, it flows through the heat exchange medium flow field 223 before entering the fuel cell stack body 10. The fuel cell heat exchange medium entering the heat exchanger 20 does not directly exit the fuel cell stack 100 from the heat exchanger 20 after flowing through the heat exchange medium flow field 223. Instead, it flows through the fuel cell stack body 10 and then through the heat exchanger 20 before exiting the fuel cell stack 100.

[0096] It should be noted that in the apparatus and method of this application, the components or steps in different embodiments can be disassembled and / or recombined without departing from the principle of the present invention. These disassemblies and / or recombinations should be considered as included within the inventive concept of this application.

[0097] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A fuel cell stack with an integrated heat exchanger, characterized in that, include: The stack body; A heat exchanger, wherein the heat exchanger is integrated at the end of the fuel cell stack body, wherein the heat exchanger has multiple heat exchange flow fields, the multiple heat exchange flow fields including a fuel flow field, an oxidant flow field, and a fuel cell stack heat exchange medium flow field, wherein the fuel cell stack heat exchange medium flow field is located between adjacent fuel flow fields and oxidant flow fields, the adjacent heat exchange flow field of each fuel flow field is the fuel cell stack heat exchange medium flow field, and the adjacent heat exchange flow field of each oxidant flow field is the fuel cell stack heat exchange medium flow field, wherein fuel and oxidant are allowed to exchange heat with the fuel cell stack heat exchange medium after flowing through the fuel flow field and the oxidant flow field respectively. The fuel enters the fuel cell from between the fuel cell stack body and the heat exchanger to participate in the electrochemical reaction. The plurality of heat exchange flow fields include a plurality of flow field units. The adjacent flow field of each flow field unit is the fuel cell heat exchange medium flow field. Each flow field unit includes three heat exchange flow fields arranged sequentially adjacent to each other: the fuel flow field, the fuel cell heat exchange medium flow field, and the oxidant flow field. This creates a temperature gradient in each flow field unit where the oxidant flow field, the fuel cell heat exchange medium flow field, and the fuel flow field are successively cooled, facilitating sufficient heat exchange along the same heat transfer direction. A partition is provided, and the partition is positioned between the heat exchanger and the stack body, wherein fuel and oxidant, after flowing through the fuel flow field and the oxidant flow field respectively to exchange heat with the stack heat exchange medium, are allowed to pass through the partition into the stack body to participate in electrochemical reactions.

2. The fuel cell stack with the integrated heat exchanger according to claim 1, characterized in that, When the odd-numbered heat exchange flow field of the heat exchanger is the heat exchange medium flow field of the fuel cell stack, the even-numbered heat exchange flow field of the heat exchanger is alternately configured as the fuel flow field and the oxidant flow field.

3. The fuel cell stack with the integrated heat exchanger according to claim 1, characterized in that, When the even-numbered heat exchange flow field of the heat exchanger is the heat exchange medium flow field of the fuel cell stack, the odd-numbered heat exchange flow field of the heat exchanger is alternately configured as the fuel flow field and the oxidant flow field.

4. The fuel cell stack with the integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The heat exchanger includes multiple heat exchange plates, the fuel cell stack body includes multiple single cells, and the fuel cell stack also includes two current collectors, wherein the single cells and the heat exchange plates are located between the two current collectors.

5. The fuel cell stack with an integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The fuel cell stack body includes multiple single cells, and the fuel cell stack also includes perforated end plates and encapsulated end plates located on opposite sides of the multiple single cells, wherein the heat exchanger is stacked on the perforated end plates to integrate the heat exchanger into the fuel cell stack body, and the perforated end plates serve as partitions between the heat exchanger and the fuel cell stack body.

6. The fuel cell stack with the integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The heat exchanger includes an open end plate having a fuel inlet, an oxidant inlet, a fuel cell stack heat exchange medium inlet, and a fuel cell stack heat exchange medium outlet. The open end plate also has a fuel cell stack inlet, a fuel cell stack outlet, and an oxidant cell stack outlet. The fuel cell stack heat exchange medium inlet and the fuel cell stack heat exchange medium outlet serve as the inlet and outlet of the fuel cell stack heat exchange medium for both the heat exchanger and the fuel cell stack body.

7. The fuel cell stack with the integrated heat exchanger according to claim 6, characterized in that, It also includes a partition, and the partition is located between the heat exchanger and the stack body, wherein the fuel cell stack forms a fuel inlet channel, an oxidant fluid channel, a stack heat exchange medium inlet channel, a fuel outlet channel, an oxidant outlet channel and a stack heat exchange medium outlet channel that simultaneously penetrate the heat exchanger, the stack body and the partition.

8. The fuel cell stack with the integrated heat exchanger according to claim 7, characterized in that, Fuel enters the heat exchanger through the fuel inlet of the open end plate, undergoes heat exchange, and then flows into the fuel inlet channel. It then enters the fuel stack body through the partition fuel inlet of the partition to participate in the electrochemical reaction. Fuel that leaves the fuel stack body and is recovered also enters the fuel stack body through the fuel inlet channel.

9. The fuel cell stack with an integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The fuel cell stack forms a fuel inlet channel, an oxidant fluid channel, a stack heat exchange medium inlet channel, a fuel outlet channel, an oxidant outlet channel, and a stack heat exchange medium outlet channel that simultaneously penetrate the heat exchanger, the stack body, and the partition. The heat exchanger includes a plurality of heat exchange plates to form a plurality of heat exchange flow fields, wherein each heat exchange plate has a heat exchange plate fuel inlet, a heat exchange plate oxidant inlet, a heat exchange plate stack heat exchange medium inlet, a heat exchange plate fuel outlet, a heat exchange plate oxidant outlet, a heat exchange plate stack heat exchange medium outlet, a heat exchange plate stack fuel outlet, and a heat exchange plate stack oxidant outlet. The baffle has a baffle fuel inlet, a baffle oxidant inlet, a baffle electric stack heat exchange medium inlet, a baffle fuel outlet, a baffle oxidant outlet, and a baffle electric stack heat exchange medium outlet; The stack body includes multiple single cells, each of the single cells having a plate fuel inlet, a plate oxidant inlet, a plate stack heat exchange medium inlet, a plate fuel outlet, a plate oxidant outlet, and a plate stack heat exchange medium outlet. The fuel inlet channel includes the heat exchange plate fuel outlet of the heat exchange plate, the separator fuel inlet of the separator, and the electrode fuel inlet of the single cell's electrode plate, which are located and connected to each other. The oxidant fluid channel includes the heat exchange plate oxidant outlet of the heat exchange plate, the separator oxidant inlet of the separator, and the electrode oxidant inlet of the electrode plate of the single cell, which are located and connected to each other. The heat exchange medium inlet channel of the fuel cell includes the heat exchange plate fuel cell heat exchange medium inlet of the heat exchange plate, the partition fuel cell heat exchange medium inlet of the partition plate, and the electrode plate fuel cell heat exchange medium inlet of the single cell, which are located and connected to each other. The fuel outlet channels include the fuel outlet of the heat exchange plate stack, the fuel outlet of the separator, and the fuel outlet of the electrode plate of the single cell, which are located and connected to each other. The oxidant outlet channel includes the heat exchange plate stack oxidant outlet of the heat exchange plate, the separator oxidant outlet of the separator, and the electrode plate oxidant outlet of the single cell, which are located and connected to each other. The heat exchange medium outlet channel of the fuel cell includes the heat exchange plate fuel cell outlet of the heat exchange plate, the heat exchange medium outlet of the partition plate, and the heat exchange medium outlet of the electrode plate of the single cell, which are located and connected to each other.

10. The fuel cell stack with an integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The heat exchanger and the partition are configured such that the fuel cell heat exchange medium is simultaneously delivered into the heat exchanger and the fuel cell body, or the fuel cell heat exchange medium enters the fuel cell body after flowing through the fuel cell heat exchange medium flow field of the heat exchanger.

11. The fuel cell stack of the integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The heat exchanger includes multiple heat exchange plates to form multiple fuel flow fields, multiple oxidant flow fields, and multiple fuel cell stack heat exchange medium flow fields, wherein one of fuel, oxidant, and fuel cell stack heat exchange medium is allowed to flow between two adjacent heat exchange plates, thereby correspondingly forming the fuel flow field, the oxidant flow field, or the fuel cell stack heat exchange medium flow field between the two adjacent heat exchange plates.

12. The fuel cell stack with an integrated heat exchanger according to any one of claims 1 to 3, characterized in that, The heat exchanger includes multiple heat exchange plates to form multiple fuel flow fields, multiple oxidant flow fields, and multiple fuel cell stack heat exchange medium flow fields. Each heat exchange plate has a fuel inlet, an oxidant inlet, a fuel cell stack heat exchange medium inlet, a fuel outlet, an oxidant outlet, a fuel cell stack heat exchange medium outlet, a fuel outlet, and an oxidant outlet. A seal is provided between two adjacent heat exchange plates, connecting the fuel flow field to the fuel inlet and fuel outlet of the heat exchange plate, and to the oxidant inlet, oxidant outlet, fuel cell stack heat exchange medium inlet, and fuel cell stack heat exchange medium outlet. The fuel outlet and the oxidant outlet of the heat exchange plate stack are not connected; the seal connects the oxidant flow field to the oxidant inlet and the oxidant outlet of the heat exchange plate, but not to the fuel inlet, fuel outlet, heat exchange medium inlet, heat exchange medium outlet, fuel outlet, and oxidant outlet of the heat exchange plate stack. The seal connects the heat exchange medium flow field to the heat exchange medium inlet and the heat exchange medium outlet of the heat exchange plate stack, but not to the fuel inlet, fuel outlet, oxidant inlet, oxidant outlet, fuel outlet, and oxidant outlet of the heat exchange plate stack.

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