Bipolar plate capable of efficiently coping with temperature shock
By introducing a metal heat-conducting layer into the bipolar plate and designing heat exchange paths or closed cavities in the high-temperature and low-temperature zones, the problems of poor heat dissipation and high cost of the bipolar plate are solved, efficient cooling and temperature control are achieved, and the operating efficiency and safety of the fuel cell stack are improved.
Patent Information
- Application Number
- CN202422747014.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-12
AI Technical Summary
The existing bipolar plates have poor heat dissipation effects, resulting in low stack operating efficiency and high costs, especially when faced with temperature shocks, the problem of uneven temperature cannot be effectively controlled.
A metal thermal conductive layer is introduced into the bipolar plate, high-temperature and low-temperature zones are set, and targeted heat exchange paths or closed cavities are designed on the metal thermal conductive layer to achieve efficient cooling and thermal management. Materials with high thermal conductivity, such as aluminum or copper, are used, combined with the economy and lightweight properties of aluminum.
It improves the heat dissipation efficiency of the bipolar plates, reduces manufacturing costs, and can effectively regulate the temperature of the fuel cell stack when facing temperature shocks, ensuring the safety and efficient operation of the fuel cell stack.
Smart Images
Figure CN223373256U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of water electrolysis, in particular to a bipolar plate capable of efficiently coping with temperature shocks. Background Art
[0002] Bipolar plates are key components in hydrogen production by water electrolysis, especially in proton exchange membrane water electrolysis. Bipolar plates include anode flow field plates and cathode flow field plates, and their main functions include current collection and transmission, gas distribution, water management and thermal management, mechanical support, etc. The materials of bipolar plates mainly include titanium and its alloys, stainless steel, graphite, carbon-based composite materials, etc., which makes the material price of bipolar plates relatively high. Among them, titanium has become an ideal material for manufacturing bipolar plates due to its excellent physical and chemical properties. According to statistics, titanium bipolar plates account for up to 24% of the cost of the entire proton exchange membrane electrolyzer system. The main reason is that the price of titanium metal on the market is expensive.
[0003] Furthermore, industrial applications of proton exchange membrane water electrolysis cannot achieve higher installed capacity through the single-cell technology route, so the development of high-power stacks is imperative. However, the stack packaging process has yet to establish a systematic process flow. The main reason is that the stack suffers from uneven stress and difficulty in heat conduction between flow field plates. In particular, excessively high temperatures in the middle flow field plate restrict the electrolysis temperature and cause severe thermal deviations. In actual practice, testing and analysis have shown that when absorbing the fluctuating output of high-proportion wind and solar energy, the load can cause a series of problems such as short-term transient temperature and voltage shocks, necessitating appropriate cooling design.
[0004] Existing cooling designs often employ a holistic approach, failing to penetrate deep into the flow field plates for targeted cooling. This design results in averaged temperatures across different regions, ultimately leading to excessively low temperatures in low-temperature areas and poor cooling in high-temperature areas. Consequently, conventional bipolar stacks, due to the need to maintain a constant temperature of the membrane electrode in the center of the stack, can only operate at around 60°C, resulting in low efficiency. Therefore, optimizing the cooling design to improve cooling efficiency is essential. Utility Model Content
[0005] The utility model discloses a bipolar plate that can effectively cope with temperature shocks. It solves the technical problems of poor heat dissipation and high manufacturing costs of bipolar plates in the prior art. It has a reasonable structure, good heat dissipation effect of the bipolar plate, and is conducive to reducing manufacturing costs. The technical solution adopted is as follows:
[0006] A bipolar plate that efficiently copes with temperature shocks includes an anode flow field plate and a cathode flow field plate, wherein the anode flow field plate is provided with an anode flow channel, and the two ends of the anode flow channel are respectively connected to a first water inlet cavity and a first water outlet cavity that pass through the bipolar plate, the cathode flow field plate is provided with a cathode flow channel, and the two ends of the cathode flow channel are respectively connected to a second water inlet cavity and a second water outlet cavity that pass through the bipolar plate, a metal heat conductive layer is provided between the anode flow field plate and the cathode flow field plate, the thickness of the bipolar plate is 1.2~2.5mm, and the thickness of the metal heat conductive layer accounts for 10~30% of the thickness of the bipolar plate.
[0007] On the basis of the above technical solution, a closed heat exchange flow path is provided on the metal heat conductive layer, and both ends of the heat exchange flow path can be respectively connected to the heat exchange inlet and the heat exchange outlet that pass through the bipolar plate.
[0008] Based on the above technical solution, the metal heat-conducting layer is divided into at least one high-temperature zone and at least one low-temperature zone according to temperature, and the flow length of the heat exchange flow path in the high-temperature zone is greater than the flow length of the heat exchange flow path in the low-temperature zone.
[0009] On the basis of the above technical solution, the coverage area of the heat exchange flow path gradually decreases from the high temperature zone to the low temperature zone, and the outer envelope formed by the outer edge of the heat exchange flow path is convergent.
[0010] On the basis of the above technical solution, a plurality of closed cavities are provided in the metal heat-conducting layer, so that different areas of the metal heat-conducting layer have different heat transfer efficiencies.
[0011] Based on the above technical solution, the metal heat-conducting layer is divided into at least one high-temperature zone and at least one low-temperature zone according to temperature, and the space occupied by the enclosed cavity in the high-temperature zone is smaller than the space occupied by the enclosed cavity in the low-temperature zone.
[0012] On the basis of the above technical solution, the proportion of the space occupied by the enclosed cavity gradually increases from the high temperature zone to the low temperature zone.
[0013] On the basis of the above technical solution, the volume of each closed cavity gradually increases from the high temperature zone to the low temperature zone.
[0014] On the basis of the above technical solution, the anode flow field plate and the cathode flow field plate are made of titanium material, and the metal heat conductive layer is made of aluminum material or copper material.
[0015] Beneficial effects
[0016] The utility model has a rational structure. A metal heat-conducting layer is provided between the anode flow field plate and the cathode flow field plate. The metal heat-conducting layer can be made of a material with high thermal conductivity to achieve efficient cooling. Furthermore, the metal heat-conducting layer can replace the material layer between the anode flow channel and the cathode flow channel. The economic benefits are particularly significant when the anode and cathode flow field plates are made of titanium. Furthermore, when the metal heat-conducting layer is made of aluminum, it not only has high thermal conductivity but is also lightweight, significantly reducing the load on the supporting components.
[0017] In this application, the thickness of the metal thermal conductive layer accounts for 10-30% of the thickness of the bipolar plate. This ensures that the cathode flow channel and the anode flow channel have sufficient groove depth to ensure sufficient water electrolysis efficiency, while also taking into account good thermal conductivity efficiency.
[0018] In order to deal with temperature shocks more specifically, at least one high-temperature zone and at least one low-temperature zone are divided on the metal heat-conducting layer according to the high-temperature formation zone and the low-temperature formation zone on the bipolar plate. The heat exchange flow path coverage area in the high-temperature zone is larger than that in the low-temperature zone, or the space occupied by the enclosed cavity in the metal heat-conducting layer corresponding to the high-temperature zone is smaller than that in the low-temperature zone. In this way, the bipolar plate can dissipate heat more specifically, so that the temperature and thermal deviation of the battery stack can be fully regulated and alleviated during the operation of the battery stack. Especially when dealing with temperature shocks caused by loading, heat can be effectively exchanged in the high-temperature zone without lowering the temperature of the low-temperature zone, thereby ensuring the safety and efficiency of the peak moment, and providing more reliable safety and efficiency guarantees for connecting to fluctuating working conditions with high proportion of fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other implementation drawings can be derived from the provided drawings without inventive effort.
[0020] Figure 1 : Schematic diagram of the three-dimensional structure of the bipolar plate in Example 1 Figure 1 ;
[0021] Figure 2 : A schematic structural diagram of the front view of the bipolar plate in Example 1;
[0022] Figure 3 : Schematic diagram of the three-dimensional structure of the bipolar plate in Example 1 Figure 2 ;
[0023] Figure 4 : A schematic structural diagram of a rear view of the bipolar plate in Example 1;
[0024] Figure 5 : Figure 1 Schematic diagram of the three-dimensional structure after removing the anode flow field plate;
[0025] Figure 6 : Figure 5 Structural diagram of the main view of the metal heat conducting layer;
[0026] Figure 7 : Schematic diagram of the structure of several bipolar plates arranged in parallel in Example 1;
[0027] Figure 8 : A schematic structural diagram of the front view of the metal heat-conducting layer in Example 2; DETAILED DESCRIPTION
[0028] The following description and accompanying drawings sufficiently illustrate the specific embodiments herein to enable those skilled in the art to practice them. Portions and features of some embodiments may be included in or substituted for portions and features of other embodiments. The scope of the embodiments herein includes the entire scope of the claims, including all available equivalents thereof. Herein, the terms "first," "second," and the like are used solely to distinguish one element from another and do not require or imply any actual relationship or order between these elements. In practice, the first element can also be referred to as the second element, and vice versa. Furthermore, the terms "comprise," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a structure, device, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such structure, device, or apparatus. Without further limitation, an element defined by the phrase "comprising a..." does not preclude the presence of other identical elements in the structure, device, or apparatus comprising the element. The various embodiments herein are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Similar or identical parts between the various embodiments can be referenced to each other.
[0029] The terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like in this document indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this document and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, they can be mechanical or electrical connections, or they can be internal connections between two elements. They can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0030] As used herein, unless otherwise specified, the term "plurality" means two or more.
[0031] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.
[0032] In this article, the term "and / or" is used to describe the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.
[0033] Example 1
[0034] like Figures 1 to 7 A bipolar plate that can efficiently cope with temperature shocks is shown, comprising an anode flow field plate 1 and a cathode flow field plate 2 .
[0035] like Figure 1 and 2 As shown, the anode flow field plate 1 is provided with an anode flow channel 11. The groove depth of the anode flow channel 11 is less than the thickness of the anode flow field plate 1. The anode flow channel 11 is provided on the end surface of the anode flow field plate 1 away from the cathode flow field plate 2. The two ends of the anode flow channel 22 are respectively connected to the first water inlet chamber 4 and the second water outlet chamber 5 that pass through the bipolar plate. In this embodiment, the anode flow channel 11 is simplified and includes a plurality of anode branch flow channels connected end to end. The first water inlet chamber 4 and the first water outlet chamber 5 are arranged vertically and on opposite sides of the bipolar plate. In other embodiments of the present invention, the anode flow channel can also be provided in a zigzag, serpentine, or other special shape.
[0036] like Figure 3 and 4As shown, a cathode flow channel 21 is provided on the cathode flow field plate 2. The groove depth of the cathode flow channel 21 is less than the thickness of the cathode flow field plate 2, and the cathode flow channel 21 is provided on the end face of the cathode flow field plate 2 away from the anode flow field plate 1. The two ends of the cathode flow channel 21 are respectively connected to the second water inlet chamber 6 and the second water outlet chamber 7 that pass through the bipolar plate. The second water inlet chamber 6 and the second water outlet chamber 7 avoid the first water inlet chamber 4 and the first water outlet chamber 7. In this embodiment, the cathode flow channel 21 is simplified in designation, and the cathode flow channel 21 includes several cathode branch flow channels connected end to end. In other embodiments of the present invention, the cathode flow channel 21 can also be provided in the form of a broken line, a serpentine, or a special shape.
[0037] like Figure 1 and 3 As shown, the anode flow field plate 1 and the cathode flow field plate 2 are arranged back to back, and the anode flow channel 11 and the cathode flow channel 21 are arranged back to back to ensure the pressing accuracy of the bipolar plate. Figure 7 As shown, multiple bipolar plates are arranged in parallel, and a membrane electrode assembly is provided between two adjacent bipolar plates. The membrane electrode assembly includes a proton exchange membrane, and catalyst layers are coated on both sides of the proton exchange membrane. Gas diffusion layers are respectively arranged on the outside of the catalyst layers. The membrane electrode assembly is a prior art and will not be described in detail here.
[0038] In this embodiment, the anode flow field plate 1 and the cathode flow field plate 2 are both made of high-purity titanium. Taking into full consideration the poisoning effect of some impurity ions on the membrane electrode and the acidic environment of electrolysis, the high-purity titanium plates in the processing stage are all stamped once and formed through processes such as turning to ensure the corrosion resistance and structural rigidity of the flow field plates as much as possible.
[0039] like Figure 1 and 3 As shown, a metal heat-conducting layer 3 is provided between the anode flow field plate 1 and the cathode flow field plate 2 to improve heat exchange efficiency. In this embodiment, the metal heat-conducting layer 3 is made of aluminum, which has excellent thermal conductivity, is inexpensive, and lightweight. In other embodiments of the present invention, the metal heat-conducting layer 3 may also be made of copper.
[0040] In this embodiment, the overall thickness of the bipolar plate is 2 mm, wherein the thickness of the cathode flow field plate 2 and the anode flow field plate 1 are the same, and the thickness of the metal heat conductive layer 3 accounts for 20% of the overall thickness of the bipolar plate.
[0041] like Figure 5 and 6As shown, in this embodiment, a heat exchange flow path 31 is provided on the metal heat conductive layer 3. The heat exchange flow path 31 includes a plurality of heat exchange branches connected end to end, wherein the plurality of heat exchange branches are arranged in parallel. In other embodiments of the present invention, the heat exchange flow path 31 may also be configured in a zigzag, serpentine, or other shaped form. The ends of the heat exchange flow path 31 are respectively connected to the heat exchange inlet 9 and heat exchange outlet 10 that pass through the bipolar plate. The heat exchange inlet 9 and heat exchange outlet 10 avoid the first water inlet chamber 4, the first water outlet chamber 5, the second water inlet chamber 6, or the second water outlet chamber 7. Considering the high thermal conductivity of the metal heat conductive layer 3, that is, the metal heat conductive layer 3 has a high heat exchange efficiency with the anode flow field plate 1 and the cathode flow field plate 2, and the metal heat conductive layer 3 also has a high heat exchange efficiency with the coolant in the heat exchange flow path 31, this can further improve the overall heat exchange efficiency of the bipolar plate.
[0042] Among them, the thickness of the heat exchange flow path 31 is less than the thickness of the metal heat conductive layer 3 or penetrates the metal heat conductive layer 3. Since the metal heat conductive layer 3 is sandwiched between the anode flow field plate 1 and the cathode flow field plate 2, the heat exchange flow path 31 forms a closed flow path, which is separated from the electrolyte. At the same time, the two ends of the heat exchange flow path 31 are respectively connected to the heat exchange inlet 9 and the heat exchange outlet 10, and the heat exchange inlet 9 and the heat exchange outlet 10 both penetrate the bipolar plate, so that the heat exchange flow on the two adjacent bipolar plates is connected, which facilitates overall temperature control.
[0043] To address the uneven temperature on the bipolar plate, the metal heat-conducting layer 3 is divided into at least one high-temperature zone and at least one low-temperature zone based on the temperature variation of the bipolar plate. The heat exchange path 31 in the high-temperature zone has a greater length than that in the low-temperature zone. In other embodiments of the present invention, considering that the low-temperature zone cannot be further heated, it is also possible to adopt a solution of not setting the heat exchange path 31 in the low-temperature zone, that is, the heat exchange path is set away from the low-temperature zone, such as Figure 6 shown.
[0044] In addition, considering that there is no large temperature gradient from the high temperature zone to the low temperature zone, and there is also a linear change, in this embodiment, the area covered by the heat exchange flow path 31 gradually decreases from the high temperature zone to the low temperature zone, and the outer envelope formed by the outer edge of the heat exchange flow path 31 is convergent, such as Figure 6 This allows for targeted cooling. Furthermore, by controlling the coolant flow rate and other factors, the cooling efficiency can be precisely regulated. This allows precise control of temperature and thermal deviations during operation of the stack formed by multiple bipolar plates, addressing temperature shocks caused by falls and providing reliable support for high-volume fluctuations in operating conditions.
[0045] Example 2
[0046] The difference between Example 2 and Example 1 is that the heat exchange flow path 31 is not provided. Instead, a plurality of enclosed cavities 32 are provided in the metal heat exchange layer 3. The thermal conductivity of the enclosed cavities 32 is different from that of the aluminum material. The area occupied and the number of the enclosed cavities 32 are adapted to the divided high-temperature and low-temperature zones to meet the heat exchange requirements of different areas.
[0047] like Figure 8 As shown, considering that the low-temperature zone cannot be further heated, in this embodiment, no closed cavity 32 is set in the high-temperature zone, and several closed cavities 32 are set in the low-temperature zone. In addition, from the high-temperature zone to the low-temperature zone, the proportion of the space occupied by the multiple closed cavities 32 gradually increases, and the volume of each closed cavity 32 gradually increases, so that the thermal conductivity of the metal heat exchange layer 3 gradually decreases from the high-temperature zone to the low-temperature zone, and changes roughly linearly.
[0048] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments. Any changes or modifications based on the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A bipolar plate that can effectively cope with temperature shock, characterized in that: The invention comprises an anode flow field plate (1) and a cathode flow field plate (2), wherein the anode flow field plate (1) is provided with an anode flow channel (11), and the two ends of the anode flow channel (11) are respectively communicated with a first water inlet cavity (4) and a first water outlet cavity (5) passing through the bipolar plate, the cathode flow field plate (2) is provided with a cathode flow channel (21), and the two ends of the cathode flow channel (21) are respectively communicated with a second water inlet cavity (6) and a second water outlet cavity (7) passing through the bipolar plate, a metal heat conductive layer (3) is provided between the anode flow field plate (1) and the cathode flow field plate (2), the thickness of the bipolar plate is 1.2-2.5 mm, and the thickness of the metal heat conductive layer (3) accounts for 10-30% of the thickness of the bipolar plate.
2. The bipolar plate capable of efficiently coping with temperature shock according to claim 1, characterized in that: A sealed heat exchange flow path (31) is provided on the metal heat conductive layer (3), and both ends of the heat exchange flow path (31) can be respectively connected to a heat exchange inlet (9) and a heat exchange outlet (10) that pass through the bipolar plate.
3. The bipolar plate capable of efficiently coping with temperature shock according to claim 2, characterized in that: The metal heat-conducting layer (3) is divided into at least one high-temperature zone and at least one low-temperature zone according to temperature, and the flow length of the heat exchange flow path (31) provided in the high-temperature zone is greater than the flow length of the heat exchange flow path (31) in the low-temperature zone.
4. The bipolar plate capable of efficiently coping with temperature shock according to claim 3, characterized in that: From the high-temperature zone to the low-temperature zone, the coverage area of the heat exchange flow path (31) gradually decreases, and the outer envelope formed by the outer edge of the heat exchange flow path (31) is convergent.
5. The bipolar plate capable of efficiently coping with temperature shock according to claim 1, characterized in that: A plurality of sealed cavities (32) are provided in the metal heat-conducting layer (3), so that different areas of the metal heat-conducting layer (3) have different heat transfer efficiencies.
6. The bipolar plate capable of efficiently coping with temperature shock according to claim 5, characterized in that: The metal heat-conducting layer (3) is divided into at least one high-temperature zone and at least one low-temperature zone according to temperature, and the space proportion occupied by the sealed cavity (32) in the high-temperature zone is smaller than the space proportion occupied by the sealed cavity (32) in the low-temperature zone.
7. The bipolar plate capable of efficiently coping with temperature shock according to claim 6, characterized in that: From the high temperature zone to the low temperature zone, the proportion of space occupied by the closed cavity (32) gradually increases.
8. The bipolar plate capable of efficiently coping with temperature shock according to claim 7, characterized in that: From the high temperature zone to the low temperature zone, the volume of each closed cavity (32) gradually increases.
9. The bipolar plate capable of efficiently coping with temperature shock according to any one of claims 1 to 8, characterized in that: The anode flow field plate (1) and the cathode flow field plate (2) are made of titanium material, and the metal heat conductive layer (3) is made of aluminum material or copper material.