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 against temperature drop at the end of the stack body laminate, and the heat exchanger has alternating fuel flow field and stack heat exchange medium flow field, so that the fuel is heat exchanged with the stack heat exchange medium before entering the stack body to participate in electrochemical reaction, thus eliminating the need for a separate heater to heat up the fuel as in conventional fuel cell systems.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell technology, and in particular to a fuel cell stack integrating a heat exchanger in the stack body. BACKGROUND

[0002] A fuel cell system generates electric energy by supplying fuel and oxidant to both sides of a membrane electrode to cause electrochemical reactions. A conventional fuel cell system using hydrogen as fuel and air as oxidant, for example, generally includes a stack, a hydrogen supply system, an air supply system, and a thermal management system. The hydrogen supply system includes a hydrogen tank, a hydrogen heater, and a hydrogen circulation loop for recycling hydrogen recovered from the stack. The hydrogen coming out of the hydrogen tank is depressurized and thus has a low temperature. The low-temperature hydrogen is not suitable for mixing with high-temperature (higher than ambient temperature) humid hydrogen that is recycled. Direct mixing of the low-temperature hydrogen with the high-temperature humid hydrogen results in condensed water that, when introduced into the stack, causes flooding of the anode. Therefore, the hydrogen heater is needed to heat the hydrogen. Figure 1

[0003] In summary, the conventional fuel cell system needs to be equipped with a separate hydrogen heater for heating hydrogen, which inevitably leads to a large volume and low integration of the fuel cell system, and has a significant impact on the fuel cell system integration manufacturer's research and development of the volume power density, an important technical parameter of the fuel cell system.

[0004] In addition, the end portion of the stack body (a plurality of single cells stacked with each other) in the stacking direction of the fuel cell system is easily cooled down compared with the central portion of the stack body in the stacking direction because the end portion is cooled down to a greater extent by the end plate. This results in poor temperature consistency of each single cell of the stack body and even causes a decrease in power generation stability of the stack. Therefore, the end portion of the stack of the conventional fuel cell system needs to be equipped with an additional dummy cell formed by a flow field plate to prevent the temperature of the end portion of the stack body from decreasing by using the heat insulation effect of the dummy cell and to avoid the influence of the external air temperature on the stack. However, the dummy cell cannot be used for power generation, which not only increases the volume of the entire stack but also increases the cost of the stack. SUMMARY

[0005] One advantage of the present application is to provide a fuel cell stack integrating a heat exchanger, which integrates the heat exchanger in the stack body and uses the temperature difference between the stack heat exchange medium and the fuel to exchange heat before the fuel enters the anode of the stack body (especially before mixing with the recycled fuel), so as to heat the fuel and enhance the heat exchange efficiency, without the need for a separate heater for heating the fuel as in the conventional fuel cell system.

[0006] ​Another advantage of the present application is to provide a fuel cell stack with integrated heat exchanger, wherein the heat exchanger forms multiple fluid flow fields to arrange fuel flow field and stack heat exchange medium flow field alternately, so that fuel and stack heat exchange medium are fully heat exchanged to adjust the temperature of fuel to a proper temperature.

[0007] Another advantage of the present application is to provide a fuel cell stack with integrated heat exchanger, wherein the heat exchanger comprises multiple heat exchange plates stacked with each other to form fluid flow field between two adjacent heat exchange plates, and based on the core concept of using flow field plate similar to the polar plate of fuel cell stack in structure design as the heat exchange plate of the heat exchanger, it is convenient for enterprises and technicians in the field of fuel cell to design the heat exchange plate of the heat exchanger according to the technical accumulation of polar plate design.

[0008] Another advantage of the present application is to provide a fuel cell stack with integrated heat exchanger, wherein the heat exchanger is integrated at the end of the stack body, and the fuel is mixed with recovered fuel after heat exchange in the heat exchanger, and enters the stack body from the middle of the heat exchanger and the stack body to participate in electrochemical reaction, so as to further increase the integration of the fuel cell stack.

[0009] Another advantage of the present application is to provide a fuel cell stack with integrated heat exchanger, wherein the heat exchanger is integrated at the end of the stack body to provide thermal insulation to prevent the temperature of the end of the stack body from being reduced due to excessive heat dissipation to the outside, so as to avoid the influence of external air temperature, so that the stack body no longer needs to be additionally configured with dummy cell.

[0010] Another advantage of the present application is to provide a fuel cell stack with integrated heat exchanger, wherein the heat exchanger is integrated in the stack body, so as to improve the integration of the whole fuel cell system, so as to make the structure of the whole system more compact, further reduce the volume of the fuel cell system, and improve the volume power density of the fuel cell system.

[0011] According to one aspect of the present application, the present application provides a fuel cell stack with integrated heat exchanger, comprising:

[0012] a stack body; and

[0013] a heat exchanger, wherein the heat exchanger is integrated at the end of the stack body, wherein the heat exchanger has multiple heat exchange flow fields, and the multiple heat exchange flow fields comprise fuel flow field and stack heat exchange medium flow field arranged alternately, so that fuel and stack heat exchange medium are heat exchanged and heated to enter the stack body to participate in electrochemical reaction.

[0014] According to some embodiments, when an odd number of layers of heat exchange flow fields of the heat exchanger are the fuel flow fields, an even number of layers of heat exchange flow fields of the heat exchanger are configured to be the fuel cell stack heat exchange medium flow fields; or when an even number of layers of heat exchange flow fields of the heat exchanger are the fuel flow fields, an odd number of layers of heat exchange flow fields of the heat exchanger are configured to be the fuel cell stack heat exchange medium flow fields.

[0015] According to some embodiments, the fuel cell stack with integrated heat exchanger further comprises a separator plate, and the separator plate is positioned between the heat exchanger and the fuel cell stack body, wherein the fuel is allowed to pass through the separator plate into the fuel cell stack body to participate in electrochemical reactions after flowing through the fuel flow fields to exchange heat with the fuel cell stack heat exchange medium, and the oxidant passing through the heat exchanger passes through the separator plate into the fuel cell stack body to participate in electrochemical reactions.

[0016] According to some embodiments, the fuel cell stack forms oxidant inlet and outlet channels that simultaneously pass through the heat exchanger and the fuel cell stack body, so that the oxidant passes through the heat exchanger to the fuel cell stack body to participate in electrochemical reactions.

[0017] According to some embodiments, the heat exchanger comprises a plurality of heat exchange plates, the fuel cell stack body comprises a plurality of single cells, and the fuel cell stack further comprises two current collector plates, wherein the single cells and the heat exchange plates are positioned between the two current collector plates.

[0018] According to some embodiments, the fuel cell stack body comprises a plurality of single cells, and the fuel cell stack further comprises an open end plate and an encapsulation end plate positioned on opposite sides of the plurality of single cells, wherein the heat exchanger is stacked on the open end plate, so that the heat exchanger is integrated into the fuel cell stack body, and the open end plate serves as a separator plate between the heat exchanger and the fuel cell stack body.

[0019] According to some embodiments, the heat exchanger comprises an open end plate having a fuel inlet, an oxidant inlet, a fuel cell stack heat exchange medium inlet, an oxidant outlet, and a fuel cell stack heat exchange medium outlet, and the open end plate further has a fuel cell stack fuel inlet and a fuel cell stack fuel outlet, wherein the oxidant inlet and the oxidant outlet simultaneously serve as inlets and outlets of the oxidant of the heat exchanger and the fuel cell stack body, and the fuel cell stack heat exchange medium inlet and the fuel cell stack heat exchange medium outlet simultaneously serve as inlets and outlets of the fuel cell stack heat exchange medium of the heat exchanger and the fuel cell stack body.

[0020] According to some embodiments, the fuel cell stack forms fuel inlet, oxidant inlet, fuel cell stack heat exchange medium inlet, fuel outlet, oxidant outlet, and fuel cell stack heat exchange medium outlet channels that simultaneously pass through the heat exchanger and the fuel cell stack body.

[0021] According to some embodiments, the integrated heat exchanger fuel cell stack further comprises a separator plate, and the separator plate is positioned between the heat exchanger and the stack body, wherein the fuel cell stack forms fuel inlet channels, oxidant inlet channels, stack heat exchange medium inlet channels, fuel outlet channels, oxidant outlet channels and stack heat exchange medium outlet channels that simultaneously pass through the heat exchanger, the stack body and the separator plate.

[0022] According to some embodiments, the fuel that enters the heat exchanger after heat exchange merges into the fuel inlet channels, and the fuel that exits the stack body and is recovered also enters the stack body through the fuel inlet channels.

[0023] According to some embodiments, the fuel cell stack forms fuel inlet channels, oxidant inlet channels, stack heat exchange medium inlet channels, fuel outlet channels, oxidant outlet channels and stack heat exchange medium outlet channels that simultaneously pass through the heat exchanger, the stack body and the separator plate;

[0024] wherein the heat exchanger comprises a plurality of heat exchange plates to form a plurality of the heat exchange flow fields, wherein each of the heat exchange plates 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;

[0025] wherein the separator plate has a separator plate fuel inlet, a separator plate oxidant inlet, a separator plate stack heat exchange medium inlet, a separator plate fuel outlet, a separator plate oxidant outlet and a separator plate stack heat exchange medium outlet;

[0026] wherein the stack body comprises a plurality of unit cells, wherein each of the unit cells has a unit cell fuel inlet, a unit cell oxidant inlet, a unit cell stack heat exchange medium inlet, a unit cell fuel outlet, a unit cell oxidant outlet and a unit cell stack heat exchange medium outlet;

[0027] wherein the fuel inlet channels comprise the heat exchange plate fuel outlets of the heat exchange plates, the separator plate fuel inlets of the separator plates and the unit cell fuel inlets of the unit cell fuel plates that are positionally corresponding and connected;

[0028] wherein the oxidant inlet channels comprise the heat exchange plate oxidant inlets of the heat exchange plates, the separator plate oxidant inlets of the separator plates and the unit cell oxidant inlets of the unit cell oxidant plates that are positionally corresponding and connected;

[0029] wherein the fuel outlet channel comprises the heat exchange plate fuel outlet, the separator fuel outlet, and the polar plate fuel outlet of the polar plate of the single cell in position correspondence and in communication;

[0030] wherein the fuel outlet channel comprises the heat exchange plate fuel outlet, the separator fuel outlet, and the polar plate fuel outlet of the polar plate of the single cell in position correspondence and in communication;

[0031] wherein the oxidant outlet channel comprises the heat exchange plate oxidant outlet, the separator oxidant outlet, and the polar plate oxidant outlet of the polar plate of the single cell in position correspondence and in communication;

[0032] wherein the oxidant outlet channel comprises the heat exchange plate oxidant outlet, the separator oxidant outlet, and the polar plate oxidant outlet of the polar plate of the single cell in position correspondence and in communication.

[0033] According to some embodiments, the heat exchanger and the separator are configured to allow the simultaneous delivery of the stack heat exchange medium into the heat exchanger and the stack body, or the delivery of the stack heat exchange medium into the stack body after the stack heat exchange medium flows through the stack heat exchange medium flow field of the heat exchanger.

[0034] According to some embodiments, the heat exchanger comprises a plurality of heat exchange plates to form a plurality of the fuel flow fields and a plurality of the stack heat exchange medium flow fields, wherein between any two adjacent heat exchange plates, one of the fuel and the stack heat exchange medium is allowed to flow in to form a corresponding fuel flow field or stack heat exchange medium flow field between the two adjacent heat exchange plates.

[0035] According to some embodiments, the heat exchanger comprises a plurality of heat exchange plates to form a plurality of the fuel flow fields and a plurality of the stack heat exchange medium flow fields, wherein each of the heat exchange plates 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, and a heat exchange plate stack fuel outlet, wherein a seal is provided between two adjacent ones of the heat exchange plates, the seal communicating the fuel flow field with the heat exchange plate fuel inlet and the heat exchange plate fuel outlet, and not communicating with the heat exchange plate oxidant inlet, the heat exchange plate oxidant outlet, the heat exchange plate stack heat exchange medium inlet, the heat exchange plate stack heat exchange medium outlet, and the heat exchange plate stack fuel outlet, and the seal communicating the stack heat exchange medium flow field with the heat exchange plate stack heat exchange medium inlet and the heat exchange plate stack heat exchange medium outlet, and not communicating with the heat exchange plate fuel inlet, the heat exchange plate fuel outlet, the heat exchange plate oxidant inlet, the heat exchange plate oxidant outlet, and the heat exchange plate stack fuel outlet. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a block diagram schematic of a fuel cell system of the prior art.

[0037] Figure 2 is a block diagram schematic of a specific example of a fuel cell system according to a preferred embodiment of the present invention.

[0038] Figure 3 is a perspective schematic of a fuel cell stack according to the above preferred embodiment of the present invention.

[0039] Figure 4 is a cross-sectional schematic of a fuel cell stack according to the above preferred embodiment of the present invention.

[0040] Figure 5 is an exploded schematic of a fuel cell stack according to the above preferred embodiment of the present invention.

[0041] Figure 6 is a structural schematic of an open end plate of a heat exchanger of a fuel cell stack according to the above preferred embodiment of the present invention.

[0042] Figure 7 is a structural schematic of a heat exchange plate of a heat exchanger of a fuel cell stack according to the above preferred embodiment of the present invention.

[0043] Figure 8 is a structural schematic of a spacer plate of a fuel cell stack according to the above preferred embodiment of the present invention.

[0044] Figure 9This 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.

[0045] Figure 10 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.

[0046] Figure 11 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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

[0056] 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.

[0057] 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.

[0058] 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 an additional separate fuel heater such as a hydrogen heater.

[0059] 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.

[0060] 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 include one or more fuel flow fields 221 and one or more fuel cell stack heat exchange medium flow fields 223, wherein the fuel flow fields 221 and the fuel cell stack heat exchange medium flow fields 223 are arranged alternately, thereby utilizing the temperature difference between the fuel and the fuel cell stack heat exchange medium for heat exchange, so as to raise the temperature of the fuel and thereby enhance the heat exchange efficiency.

[0061] It is understood that the temperature of the heat exchange medium in the heat exchange medium flow field 223 is higher than the temperature of the fuel in the fuel flow field 221. Thus, before the fuel enters the anode of the fuel stack body 10 (especially before it is mixed with the circulating fuel), it can be heated by the heat exchange medium in the heat exchange medium flow field 223 and adjusted to a suitable temperature to prevent condensation from being generated due to the mixing of low-temperature fuel with high-temperature and humid circulating fuel.

[0062] like Figures 12 to 13 As shown in the diagram, the heat exchanger 20 in this embodiment is schematically configured to have eleven heat exchange flow fields 22, wherein the even-numbered layers of heat exchange flow fields 22 are configured as fuel flow fields 221, and the odd-numbered layers of heat exchange flow fields 22 are configured as fuel stack heat exchange medium flow fields 223. This allows the fuel and fuel stack heat exchange medium to be separately diverted to multiple fuel flow fields 221 and multiple fuel stack heat exchange medium flow fields 223, thereby increasing the heat exchange area between the fuel and the fuel stack heat exchange medium, thus efficiently heating the fuel and improving heat exchange efficiency. It is understood that in another embodiment, the odd-numbered layers of heat exchange flow fields 222 may be the fuel stack heat exchange medium flow fields 223, and the even-numbered layers of heat exchange flow fields 222 may be the fuel flow fields 221.

[0063] 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, an oxidant outlet 235, 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. Understandably, in this embodiment, the fuel inlet 231 and the oxidant inlet 232 are located at the same end of the open end plate 23, meaning that both fuel and oxidant enter the heat exchanger 20 from the same end of the open end plate 23. The fuel then exchanges heat with the fuel cell heat exchange medium entering the heat exchanger 20 from the other end of the open end plate 23. Thus, the low-temperature fuel is adjusted to the desired temperature upon reaching the other end of the heat exchanger 20 before entering the fuel cell stack body 10. The oxidant passes through the heat exchanger 20 and enters the fuel cell stack body 10 to participate in the electrochemical reaction. In another embodiment, the fuel inlet 231 and the oxidant inlet 232 may be located at opposite ends of the open end plate 23, so that the fuel and oxidant enter the heat exchanger 20 from opposite ends of the open end plate 23, respectively. The fuel then exchanges heat with the fuel cell heat exchange medium and is adjusted to the desired temperature upon reaching the same other end of the heat exchanger 20. The heat exchange medium inlet 233 of the electric stack can be located at the same end of the open end plate 23 as the fuel inlet 231 and the oxidant inlet 232, or it can 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 another inlet.

[0064] In this embodiment, the open end plate 23 serves as the inlet and 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. The open end plate 23 also has a fuel cell stack inlet 237 and a fuel cell stack outlet 239.

[0065] Each of the heat exchange plates 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.

[0066] 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 fuel cell stack heat exchange medium outlet 216 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 can exchange heat with the fuel cell stack heat exchange medium in the adjacent fuel cell stack heat exchange medium flow field 223 through the heat exchange plate 21 while flowing, thus ensuring that the fuel in each fuel flow field 221 is heated as uniformly as possible. The oxidant enters the fuel cell stack body from the oxidant inlet 212 of the heat exchange plate through the heat exchanger 20.

[0067] 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.

[0068] like Figures 9 to 11 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 inlet 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.

[0069] 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.

[0070] 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.

[0071] The oxidant inlet 232 of the open end plate 23, the heat exchange plate oxidant inlet 212 of the heat exchange plate 21, the separator oxidant inlet 1322 of the separator 132, and the electrode oxidant inlet 112 of the electrode plate of the single cell 11 are positioned correspondingly and connected to form the oxidant inlet channel 252.

[0072] 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.

[0073] 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.

[0074] The oxidant outlet 235 of the open end plate 23, the heat exchange plate oxidant outlet 215 of the heat exchange plate 21, the separator oxidant outlet 1325 of the separator 132, and the electrode oxidant outlet 115 of the electrode plate of the single cell 11 are positioned correspondingly and connected to form the oxidant outlet channel 255.

[0075] 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.

[0076] like Figure 10 As 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.

[0077] like Figure 9 As shown, an oxidant, such as air, enters the heat exchanger 20 from the oxidant inlet 232 of the open end plate 23 and flows through the oxidant inlet channel 252, passes through the partition oxidant inlet 1322 of the partition 132 and enters the fuel cell stack body 10 to participate in the electrochemical reaction, 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.

[0078] like Figure 11 As shown, the heat exchange medium of the fuel cell stack flows into the heat exchange medium inlet channel 253 through the heat exchange medium inlet 233 of the open end plate 23. Part of the heat exchange medium flows into the heat exchange medium flow field 223 of the heat exchanger 20 for heat exchange with the cryogenic fuel. The rest of the heat exchange medium passes through the partition 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 heat exchange medium that enters the heat exchanger 20 and the fuel cell body 10 flows out of the heat exchanger 20 through the heat exchange medium outlet channel 256.

[0079] The heat exchange medium of the electric stack is in the process of transferring heat from... Figure 11 As 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. 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 the stack body 10, 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 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.

[0080] Furthermore, to ensure that two adjacent heat exchange flow fields 22 form two different flow fields, the corresponding flow fields 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 connected to the oxidant inlet 212, oxidant outlet 215, heat exchange medium inlet 213, heat exchange medium outlet 216, and fuel outlet 219 of the heat exchange plate, thereby forming a fuel flow field 221 between two adjacent heat exchange plates 11 that only allows fuel 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, and the fuel outlet 219 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.

[0081] 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 14 In 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 14The 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.

[0082] 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.

[0083] The oxidant supply system 300 accordingly includes an air filter 310, an air compressor 320, an intercooler 330, and a humidifier 340. Air is filtered by the air filter 310 and compressed by the air compressor 320 before entering the intercooler 330 for cooling. Optionally, it is then humidified by the humidifier 340 and flows directly through the heat exchanger 20 to the fuel cell stack 10 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 10, and includes a temperature regulation module 420 and a pump 430.

[0084] Additionally, the heat exchanger 20 is integrated on the end side of the fuel cell stack body 10, such as... Figure 3 The 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.

[0085] like Figures 15 to 16The 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.

[0086] 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.

[0087] 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 17The 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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; as well as 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 alternating fuel flow fields and fuel cell stack heat exchange medium flow fields, so that the fuel is heated by heat exchange with the fuel cell stack heat exchange medium and then enters the fuel cell stack body to participate in the electrochemical reaction, wherein when the odd-numbered heat exchange flow fields of the heat exchanger are the fuel cell stack heat exchange medium flow fields, the even-numbered heat exchange flow fields of the heat exchanger are configured as the fuel flow fields; or when the even-numbered heat exchange flow fields of the heat exchanger are the fuel cell stack heat exchange medium flow fields, the odd-numbered heat exchange flow fields of the heat exchanger are configured as the fuel flow fields.

2. The fuel cell stack with the integrated heat exchanger according to claim 1, characterized in that, It also includes a baffle, which is positioned between the heat exchanger and the stack body, wherein fuel, after flowing through the fuel flow field to exchange heat with the stack heat exchange medium, is allowed to pass through the baffle into the stack body to participate in the electrochemical reaction, and oxidant passing through the heat exchanger passes through the baffle into the stack body to participate in the electrochemical reaction.

3. The fuel cell stack with the integrated heat exchanger according to claim 1, characterized in that, The fuel cell stack has an oxidant inlet channel and an oxidant outlet channel that simultaneously penetrate the heat exchanger and the stack body, so that the oxidant passes through the heat exchanger to reach the stack body to participate in the electrochemical reaction.

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, an oxidant outlet, and a fuel cell stack heat exchange medium outlet. The open end plate also has a fuel cell stack inlet and a fuel cell stack outlet. The oxidant inlet and the oxidant outlet serve as the oxidant inlet and outlet of the heat exchanger and the fuel cell stack body, respectively. The fuel cell stack heat exchange medium inlet and the fuel cell stack heat exchange medium outlet serve as the fuel cell stack heat exchange medium inlet and outlet of the heat exchanger and the fuel cell stack body, respectively.

7. The fuel cell stack of the integrated heat exchanger according to any one of claims 1 to 2, characterized in that, The fuel cell stack forms a fuel inlet channel, an oxidant inlet 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 and the stack body.

8. The fuel cell stack of the integrated heat exchanger according to any one of claims 1 to 2, 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 inlet 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.

9. The fuel cell stack with the integrated heat exchanger according to claim 8, characterized in that, Fuel enters the heat exchanger and, after heat exchange, 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.

10. The fuel cell stack with the integrated heat exchanger according to claim 2, characterized in that, The fuel cell stack forms a fuel inlet channel, an oxidant inlet 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 electric stack heat exchange medium inlet, a heat exchange plate fuel outlet, a heat exchange plate oxidant outlet, a heat exchange plate electric stack heat exchange medium outlet, and a heat exchange plate electric stack fuel 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 inlet channel includes the heat exchange plate oxidant inlet of the heat exchange plate, the separator oxidant inlet of the separator, and the electrode oxidant inlet 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 oxidant outlet of the heat exchange plate, the separator oxidant outlet of the separator, and the electrode oxidant outlet of the single cell's electrode plate, 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.

11. The fuel cell stack with the integrated heat exchanger according to claim 2, 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.

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 a plurality of heat exchange plates to form a plurality of fuel flow fields and a plurality of electric stack heat exchange medium flow fields, wherein one of the fuel and the electric stack heat exchange medium is allowed to flow between two adjacent heat exchange plates, thereby correspondingly forming a fuel flow field or an electric stack heat exchange medium flow field between the two adjacent heat exchange plates.

13. 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 to form multiple fuel 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, and a fuel outlet. A seal is provided between adjacent heat exchange plates, connecting the fuel flow fields to the fuel inlets and fuel outlets of the heat exchange plates. The heat exchanger is not connected to the oxidant inlet, oxidant outlet, heat exchange medium inlet, heat exchange medium outlet, and fuel outlet of the heat exchange plate, and the seal connects the heat exchange medium flow field of the fuel cell stack to the heat exchange medium inlet and outlet of the heat exchange plate stack, but not to the fuel inlet, fuel outlet, oxidant inlet, oxidant outlet, and fuel outlet of the heat exchange plate stack.

Images