Self-driven thermal management hydrogen fuel cell
Through the self-driven thermal management system, the capillary pump evaporator and manifold microchannel heat exchanger are used to drive the capillary pump evaporator and the manifold microchannel heat exchanger to form a closed cycle, solving the problem of uneven thermal management of hydrogen fuel cells, and achieving efficient and uniform thermal management and reducing maintenance costs.
Patent Information
- Application Number
- CN202510523158.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-24
- Publication Date
- 2025-07-22
AI Technical Summary
Thermal management problems of hydrogen fuel cells lead to uneven temperatures, which may lead to reduced battery efficiency and damage. The existing heat dissipation technology is complex and difficult to maintain.
The self-driven heat management system is adopted to drive the capillary pump evaporator and manifold microchannel heat exchanger to form a closed cycle, realizing self-driven heating and heat dissipation, and reducing the use of mechanical pumps.
It realizes efficient and uniform thermal management, reduces energy consumption and maintenance costs, improves the reliability and integration of hydrogen fuel cells, and prevents the emergence of internal hot spots.
Smart Images
Figure CN120356973A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of hydrogen fuel cells, in particular to a self-driven thermal management hydrogen fuel cell. Background Art
[0002] As an efficient and environmentally friendly energy conversion device, hydrogen fuel cells are widely used in transportation, energy storage and other fields. However, its thermal management problem has always been one of the key factors limiting its performance and life. Hydrogen fuel cells are mainly composed of multiple battery cells, each of which includes two electrode plates and an electrolyte membrane (PEM) and a gas permeation layer (GDL) located between the two electrode plates, one of the two electrode plates is an anode plate and the other is a cathode plate. During the operation of the hydrogen fuel cell, each battery cell will generate heat, which mainly comes from the electrochemical reaction and the current transport process. The heat generated accounts for about 40%-50% of the output power, of which 20%-30% of the heat is taken away by the raw materials (air, hydrogen) entering the hydrogen fuel cell, and the remaining 70%-80% needs to be dissipated through the heat dissipation system.
[0003] The operating temperature of hydrogen fuel cells is generally between 60-80℃, but when hydrogen fuel cells are working, the temperature inside them may be uneven, and some parts may experience local overheating, which may affect the efficiency of the battery and even cause battery damage. Excessive temperature will cause the membrane to dry or chemically degrade at high temperatures, thereby affecting its ionic conductivity, which in turn leads to an increase in the internal resistance of the battery and a decrease in output power. At the same time, if the temperature of the hydrogen fuel cell is lower than the designed operating temperature, it will also cause performance degradation and difficulty in starting. Specifically, at low temperatures, the rate of electrochemical reactions is significantly reduced, the output power of the battery decreases, and it becomes more difficult to start the battery; lower temperatures will also cause the liquid generated by the reaction to condense quickly and in large quantities, and a large amount of liquid will flood the electrolyte membrane, causing the rate of gas reactions to decrease, and the performance of the battery to decrease. Therefore, how to effectively manage the thermal management of hydrogen fuel cells, achieve efficient and uniform heat dissipation and heating, and maintain their stable operating temperature is of great significance to the safe and reliable operation of hydrogen fuel cells.
[0004] At present, the heat dissipation technologies of hydrogen fuel cells mainly include two methods: liquid cooling and air cooling. The air cooling system is relatively simple. It mainly forces air to flow through a high-power fan, making it pass through the surface of the entire hydrogen fuel cell, thereby taking away the heat generated by it. However, its heat dissipation efficiency is low, the heat dissipation effect on a single battery unit is poor, and the internal temperature of the battery is relatively high. Especially in high-power density applications, it may lead to unstable temperature control. The liquid cooling system mainly uses the channels between two electrode plates as the coolant flow channels. The coolant is transported into each battery unit through a pump. The coolant absorbs the heat generated by each unit in the channels and takes away the heat through circulating flow. This method can dissipate heat from each battery unit, has a high heat dissipation efficiency, and can also effectively control the internal temperature of the fuel cell. However, its complex pipeline design, pump system, and the use of liquid coolant make the entire hydrogen fuel cell structure complex, large in volume and weight, and difficult to maintain. Summary of the Invention
[0005] In view of the above problems, a self-driven thermal management hydrogen fuel cell provided by the present application can not only perform thermal management, achieve efficient and uniform heat dissipation and heating, maintain its stable operating temperature, but also has a simple structure, a high degree of integration, a small volume, and can reduce the maintenance cost of the equipment.
[0006] The technical solution adopted by the present invention to solve its technical problems is:
[0007] A self-driven thermal management hydrogen fuel cell includes two end plates, and a plurality of battery units are arranged between the two end plates;
[0008] A PTC heater and a capillary pump evaporator are sequentially arranged between one of the end plates and the battery unit along the direction close to the battery unit;
[0009] A manifold microchannel heat exchanger is arranged between the other end plate and the battery unit;
[0010] A manifold microchannel heat exchanger is arranged between two adjacent battery units;
[0011] The capillary pump evaporator and the manifold microchannel heat exchanger are sequentially connected in series through pipelines to form a closed circulation system.
[0012] Furthermore, the capillary pump evaporator includes a main board body and a porous medium core located within the main board body. An inner cavity is provided within the main board body. Along the direction from the evaporator inlet to the evaporator outlet, the inner cavity sequentially includes a liquid chamber, an evaporation chamber, and a steam chamber. Evaporation bosses are respectively provided on both sides of the steam chamber, and a plurality of evaporation channels are provided on the evaporation bosses. Both ends of the evaporation channels are respectively communicated with the liquid chamber and the steam chamber. The porous medium core is located between the two evaporation bosses, and one end extends into the liquid chamber. Protrusion parts are respectively provided on both sides of the porous medium core located within the liquid chamber, and the protrusion parts block the openings of the evaporation channels communicated with the liquid chamber.
[0013] Furthermore, the pore diameter of the porous medium core gradually decreases along the flow direction of the working medium.
[0014] Furthermore, a liquid reservoir is provided on the pipeline on the inlet side of the capillary pump evaporator.
[0015] Furthermore, heat dissipation fins are provided on the pipeline.
[0016] Furthermore, the manifold type microchannel heat exchanger includes a manifold layer. The manifold layer includes an outer frame in a square structure. Along the direction from the heat exchanger inlet to the heat exchanger outlet, the internal space of the outer frame sequentially includes a first confluence area, a heat exchange area, and a second confluence area. A partition is provided within the heat exchange area, and the partition divides the heat exchange area into a plurality of first flow channels and second flow channels arranged at intervals. The open ends of the first flow channels face the first confluence area, and the open ends of the second flow channels face the second confluence area. A plurality of microchannels perpendicular to the first flow channels and the second flow channels are provided on the electrode plate adjacent to the manifold layer, and the working medium within the first flow channels can enter the adjacent second flow channels through the microchannels.
[0017] Furthermore, the ratio of the depth to the width of the microchannels is less than or equal to 2.
[0018] Furthermore, the ratio of the width of the first flow channels and the second flow channels to the width of the microchannels is greater than or equal to 1 and less than or equal to 2.
[0019] Furthermore, the widths of the first flow channels and the second flow channels are equal.
[0020] Furthermore, the ratio of the height of the first flow channels and the second flow channels to the depth of the microchannels is greater than or equal to 6 and less than or equal to 10.
[0021] The beneficial effects of the present invention are:
[0022] 1. A self-driven thermal management hydrogen fuel cell provided by an embodiment of the present application utilizes the capillary driving force generated by the evaporation phase change of the liquid working medium in the porous medium of the capillary pump evaporator caused by the heat generated by the fuel cell itself to drive the circulating flow of the working medium, thereby heating or dissipating heat from the hydrogen fuel cell, and has a self-driven characteristic. The self-driven characteristic can reduce the use of mechanical pumps. On the one hand, it can reduce energy consumption, and on the other hand, it can reduce the risk of system failure caused by mechanical component wear, improve the integration of the entire hydrogen fuel cell, and reduce equipment maintenance costs.
[0023] 2. A self-driven thermal management hydrogen fuel cell provided by an embodiment of the present application adopts a closed system, which can reduce the risk of working medium leakage, reduce the loss of coolant, and improve the reliability of the entire hydrogen fuel cell.
[0024] 3. A self-driven thermal management hydrogen fuel cell provided by an embodiment of the present application has an adaptive characteristic, and can automatically adjust the size of its heat dissipation power according to the output power of the fuel cell to meet the heating or heat dissipation requirements of the hydrogen fuel cell under various working conditions. That is, the higher the output power of the fuel cell, the more heat is generated by the battery, and the greater the phase change amount of the working medium, thereby increasing the heat dissipation amount.
[0025] 4. A self-driven thermal management hydrogen fuel cell provided by an embodiment of the present application can quickly and effectively dissipate heat from the hydrogen fuel cell, and has a higher heat dissipation efficiency compared with traditional heat dissipation methods. In addition, the microchannel structure can meet the efficient heat dissipation process, and the manifold structure realizes the characteristic of uniform temperature, preventing the occurrence of internal hot spots and avoiding the damage of the electrolyte membrane. Similarly, the heating process, as the reverse process of the heat dissipation process, also has such advantages. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 is a schematic structural diagram of a self-driven thermal management hydrogen fuel cell provided by an embodiment of the present application;
[0027] Figure 2 is a three-dimensional structural diagram of the capillary pump evaporator;
[0028] Figure 3 is a side view of the capillary pump evaporator;
[0029] Figure 4 is Figure 3 the A-A cross-sectional view in
[0030] Figure 5 is Figure 3 the B-B cross-sectional view in
[0031] Figure 6 is the front view of the main board body of the capillary pump evaporator;
[0032] Figure 7 isFigure 6 C-C cross-sectional view in
[0033] Figure 8 Schematic three-dimensional structure diagram of the porous medium core
[0034] Figure 9 Schematic internal structure diagram of the porous medium core
[0035] Figure 10 Schematic three-dimensional structure diagram of the manifold microchannel heat exchanger
[0036] Figure 11 Top view of the manifold microchannel heat exchanger
[0037] Figure 12 is Figure 11 D-D cross-sectional view in
[0038] Figure 13 is Figure 11 E-E cross-sectional view in
[0039] Figure 14 Exploded view of the manifold microchannel heat exchanger
[0040] In the figure: 1. End plate;
[0041] 2. Battery unit; 21. Electrode plate; 211. Microchannel;
[0042] 3. PTC heater;
[0043] 4. Capillary pump evaporator; 41. Main board body; 411. Evaporator inlet; 412. Evaporator outlet; 413. Liquid chamber; 414. Evaporation chamber; 4141. Evaporation boss; 4142. Evaporation channel; 415. Steam chamber; 42. Porous medium core; 421. First attracting part; 422. Second attracting part; 423. Step surface;
[0044] 5. Manifold layer; 51. Outer frame; 52. Partition; 53. Heat exchanger inlet; 54. Heat exchanger outlet; 55. First confluence area; 56. Heat exchange area; 561. First flow channel; 562. Second flow channel; 57. Second confluence area;
[0045] 61. First pipe; 611. First heat dissipation fin; 62. Second pipe; 621. Second heat dissipation fin; 63. Third pipe; 631. Third heat dissipation fin; 64. Fourth pipe; 641. Fourth heat dissipation fin; 65. Fifth pipe; 651. Fifth heat dissipation fin; 66. Sixth pipe; 661. Sixth heat dissipation fin;
[0046] 7. Liquid reservoir. Detailed implementation mode
[0047] To enable those skilled in the art to better understand the technical solutions in this application, the following will describe in detail the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. The described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of this application.
[0048] To facilitate the understanding of the specific implementation manners of this application, a coordinate system is defined as Figure 1 shown, with the left - right direction as the horizontal direction, the front - back direction as the longitudinal direction, and the up - down direction as the vertical direction.
[0049] As Figure 1 shown, a self - driven thermal - management hydrogen fuel cell includes two end plates 1. Between the two end plates 1, a plurality of battery cells 2 are arranged. The battery cell 2 includes two electrode plates 21 and an electrolyte membrane and a gas - permeable layer located between the two electrode plates 21. Between one of the end plates 1 and the battery cell 2, a PTC heater 3 and a capillary pump evaporator 4 are sequentially arranged in the direction close to the battery cell 2. Between the other end plate 1 and the battery cell 2, and between adjacent battery cells 2, a manifold - type microchannel 211 heat exchanger is arranged. A locking mechanism (not shown in the figure) is arranged between the two end plates 1. The battery cell 2, the PTC heater 3, the capillary pump evaporator 4, and the manifold - type microchannel 211 heat exchanger are clamped and fixed between the two end plates 1. The locking mechanism has the same structure as the locking mechanism between the two side end plates 1 of the current hydrogen fuel cell, and thus the specific structure of the locking mechanism will not be elaborated here too much.
[0050] As a specific implementation manner, in this embodiment, five battery cells 2 are arranged between the two end plates 1. According to Figure 1 the shown coordinate system, a PTC heater 3 and a capillary pump evaporator 4 are arranged between the left - hand end plate 1 and the left - hand - most battery cell 2, and a manifold - type microchannel 211 heat exchanger is arranged between the right - hand end plate 1 and the right - hand - most battery cell 2.
[0051] The capillary pump evaporator 4 and the manifold - type microchannel 211 heat exchanger are sequentially connected in series through pipes to form a closed circulation system, and heat - dissipating fins are arranged on the pipes.
[0052] As a specific implementation manner, according to Figure 1In the coordinate system shown, in this embodiment, the manifold microchannel 211 heat exchangers are sequentially named the first manifold microchannel 211 heat exchanger, the second manifold microchannel 211 heat exchanger, the third manifold microchannel 211 heat exchanger, the fourth manifold microchannel 211 heat exchanger, and the fifth manifold microchannel 211 heat exchanger from left to right. The outlets of the capillary pump evaporator 4, the second manifold microchannel 211 heat exchanger, and the fourth manifold microchannel 211 heat exchanger are located at the lower end, and the outlets of the first manifold microchannel 211 heat exchanger, the third manifold microchannel 211 heat exchanger, and the fifth manifold microchannel 211 heat exchanger are located at the upper end. Correspondingly, the inlets of the capillary pump evaporator 4, the second manifold microchannel 211 heat exchanger, and the fourth manifold microchannel 211 heat exchanger are located at the upper end, and the inlets of the first manifold microchannel 211 heat exchanger, the third manifold microchannel 211 heat exchanger, and the fifth manifold microchannel 211 heat exchanger are located at the lower end. The outlet of the capillary pump evaporator 4 is connected to the inlet of the first manifold microchannel 211 heat exchanger through a first pipe 61, and a first heat dissipation fin 611 is provided on the first pipe 61. The outlet of the first manifold microchannel 211 heat exchanger is connected to the inlet of the second manifold microchannel 211 heat exchanger through a second pipe 62, and a second heat dissipation fin 621 is provided on the second pipe 62. The outlet of the second manifold microchannel 211 heat exchanger is connected to the inlet of the third manifold microchannel 211 heat exchanger through a third pipe 63, and a third heat dissipation fin 631 is provided on the third pipe 63. The outlet of the third manifold microchannel 211 heat exchanger is connected to the inlet of the fourth manifold microchannel 211 heat exchanger through a fourth pipe 64, and a fourth heat dissipation fin 641 is provided on the fourth pipe 64. The outlet of the fourth manifold microchannel 211 heat exchanger is connected to the inlet of the fifth manifold microchannel 211 heat exchanger through a fifth pipe 65, and a fifth heat dissipation fin 651 is provided on the fifth pipe 65. The outlet of the fifth manifold microchannel 211 heat exchanger is connected to the inlet of the capillary pump evaporator 4 through a sixth pipe 66, and a sixth heat dissipation fin 661 is provided on the sixth pipe 66.
[0053] Further, a liquid storage device 7 is provided on the pipe on the inlet side of the capillary pump evaporator 4, and the liquid storage device 7 is used to store the fluid working medium. That is, a liquid storage device 7 is provided on the sixth pipe 66, and sixth heat dissipation fins 661 are respectively provided on both sides of the liquid storage device 7 on the sixth pipe 66.
[0054] As Figure 2 、 Figure 3 、 Figure 4 and Figure 5As shown, the capillary pump evaporator 4 includes a main board body 41 and a porous medium core body 42 located within the main board body 41. The main board body 41 is made of a metal material with good thermal conductivity.
[0055] As Figure 4 , Figure 5 , Figure 6 and Figure 7 shown, an inner cavity is provided within the main board body 41. One end of the main board body 41 in the vertical direction is provided with an evaporator inlet 411 communicating with the inner cavity, and the other end of the main board body 41 in the vertical direction is provided with an evaporator outlet 412 communicating with the inner cavity. Along the direction from the evaporator inlet 411 to the evaporator outlet 412, the inner cavity sequentially includes a liquid chamber 413, an evaporation chamber 414, and a steam chamber 415. Evaporation bosses 4141 extending inward are respectively provided on the left and right side surfaces of the steam chamber 415, and a plurality of evaporation channels 4142 penetrating the evaporation bosses 4141 in the vertical direction are uniformly arranged in the front-rear direction on the evaporation bosses 4141.
[0056] As Figure 4 , Figure 5 and Figure 8 shown, the porous medium core body 42 is located between the two evaporation bosses 4141, and one end of the porous medium core body 42 facing the evaporator inlet 411 extends into the liquid chamber 413 of the inner cavity. Protrusion parts are respectively provided on the left and right sides of the porous medium core body 42 located in the liquid chamber 413 of the inner cavity, and the protrusion parts block the openings of the evaporation channels 4142 communicating with the liquid chamber 413.
[0057] As a specific implementation manner, in this embodiment, the porous medium core body 42 sequentially includes a first attracting part 421 and a second attracting part 422 along the flow direction of the working medium. The first attracting part 421 is inserted between the two evaporation bosses 4141, and the second attracting part 422 is located in the liquid chamber 413 of the inner cavity. The thickness (i.e., the dimension in the left-right direction) of the first attracting part 421 is greater than the thickness (i.e., the dimension in the left-right direction) of the second attracting part 422, and step surfaces 423 are formed on the left and right sides of the porous medium core body 42, and the step surfaces 423 are attached to the end surfaces of the evaporation bosses 4141 facing the evaporator inlet 411.
[0058] During operation, after the capillary pump evaporator 4 is heated, heat is conducted into the porous medium core 42 through the main board body 41 made of metal. The liquid in the pores of the porous medium core 42 is heated and evaporated, forming a gas-liquid two-phase interface in the porous medium core 42 and generating capillary force. Under the action of the capillary force, the gas generated by evaporation enters the steam channel and converges in the steam chamber 415, and flows out of the capillary pump evaporator 4 through the evaporator outlet 412. At the same time, the porous medium core 42 absorbs the liquid entering the liquid chamber 413 from the evaporator inlet 411 through capillary force, enabling continuous generation of steam, taking away heat and maintaining the operating temperature of the capillary pump evaporator 4 stable.
[0059] Further, the end face of the porous medium core 42 facing the evaporator outlet 412 is flush with the end face of the evaporation boss 4141 facing the evaporator outlet 412.
[0060] Further, the size of the steam chamber 415 in the front-back direction gradually increases in the direction close to the evaporation chamber 414, and the steam chamber 415 as a whole has a horn-shaped structure with the large end facing the evaporation chamber 414.
[0061] Further, the liquid chamber 413 includes a confluence part and an avoidance and installation part in sequence in the direction close to the evaporation chamber 414. The size of the confluence part in the front-back direction gradually increases in the direction close to the evaporation chamber 414, and the confluence part as a whole has a horn-shaped structure with the large end facing the evaporation chamber 414. The size of the avoidance and installation part in the front-back direction is the same as that of the evaporation chamber 414 in the front-back direction, and the whole has a square structure.
[0062] Further, as Figure 9 shown, the pore diameter of the porous medium core 42 gradually decreases along the flow direction of the working medium.
[0063] The reason for such a design is that a small pore diameter can provide a large capillary driving force, and the porous medium core 42 is not easily penetrated by steam, while a large pore diameter can reduce the transmission resistance of the liquid in the porous medium core 42. By making the pore diameter of the porous medium core 42 gradually decrease along the flow direction of the working medium, on the one hand, the transmission resistance can be reduced and the capillary driving force can be increased, and on the other hand, the generated steam can smoothly enter the steam chamber 415.
[0064] As a specific implementation manner, in this embodiment, the pore diameter of the porous medium core 42 gradually decreases from 10 μm to 1 μm along the flow direction of the working medium
[0065] A self-driven thermal management hydrogen fuel cell has two operating modes: heating and heat dissipation.
[0066] The working process of the heat dissipation mode is as follows: When the hydrogen fuel cell operates stably, each battery unit 2 releases heat, causing the temperature to rise. At this time, the liquid working medium in the capillary pump evaporator 4 evaporates and undergoes a phase change, forming a capillary force in the porous medium core 42 inside it, absorbing the liquid working medium in the liquid storage tank 7 and making the generated steam flow unidirectionally into the first pipeline 61. The steam releases heat to the outside through the first heat dissipation fin 611 in the first pipeline 61 and re-condenses into a liquid working medium, then enters the first manifold microchannel 211 heat exchanger, and exchanges heat with the battery units 2 on both sides of the first manifold microchannel 211 heat exchanger. After absorbing the heat released by the battery units 2 on both sides of the first manifold microchannel 211 heat exchanger, the liquid working medium evaporates and undergoes a phase change again, and enters the second pipeline 62. The steam releases heat to the outside through the second heat dissipation fin 621 in the second pipeline 62 and re-condenses into a liquid working medium, then enters the second manifold microchannel 211 heat exchanger. In this way, the working medium flows through the second manifold microchannel 211 heat exchanger, the third pipeline 63, the third manifold microchannel 211 heat exchanger, the fourth pipeline 64, the fourth manifold microchannel 211 heat exchanger, the fifth pipeline 65, the fifth manifold microchannel 211 heat exchanger, and the sixth pipeline 66 in sequence, and finally returns to the liquid storage tank 7 in the form of a liquid working medium. During this process, the working medium completes the heat dissipation of all battery units 2 by continuously absorbing heat between the battery units 2 and releasing heat in the pipeline, forming a closed heat dissipation cycle, and achieving the effect of heat dissipation by the circulation of the working medium in the self-driven loop. When the output power of the hydrogen fuel cell increases, the heat generation of each battery unit 2 increases, the heat absorbed by the liquid working medium in the capillary pump evaporator 4 increases, the evaporation amount of the working medium becomes larger, the flow rate of the condensed liquid entering each manifold microchannel 211 heat exchanger through the pipeline increases, and the heat dissipation capacity is improved; when the output power of the hydrogen fuel cell decreases, the opposite is true, realizing adaptive heat dissipation.
[0067] The working process of the heating mode is as follows: when the working temperature of the fuel cell is relatively low or cold start is required, the PTC heater 3 on one side of the capillary pump evaporator 4 is turned on to quickly apply a large amount of heat to the capillary pump evaporator 4. A large amount of hot steam is instantly generated in the capillary pump evaporator 4. Due to the large amount of steam, the steam cannot condense in the pipeline. Therefore, the steam will pass through each manifold microchannel 211 heat exchanger in sequence to heat each battery unit 2, improving the overall temperature of the hydrogen fuel cell, and finally returning to the liquid reservoir 7 in the form of a liquid working medium to complete the heating cycle, achieving the effect of circulating and heating the working medium in the self-driven loop. As the temperature inside the hydrogen fuel cell rises and reaches the normal working temperature, the high-temperature steam generated and provided in the capillary pump evaporator 4 gradually cannot condense in the manifold microchannel 211 heat exchanger between the battery units 2. A large amount of steam returns to the liquid reservoir 7, which will cause insufficient supply of the liquid working medium in the capillary pump evaporator 4, a decrease in the evaporation amount of the internal working medium, and a continuous rise in the temperature of the capillary pump evaporator 4. As the temperature of the capillary pump evaporator 4 rises, the resistance of the PTC heater 3 in contact with the capillary pump evaporator 4 will increase and the current will decrease due to the influence of the temperature of the capillary pump evaporator 4. When the temperature of the capillary pump evaporator 4 rises to a certain extent, the current of the PTC heater 3 will become zero, thus stopping heating and realizing the adaptive heating of the hydrogen fuel cell.
[0068] As Figure 10 , Figure 11 , Figure 12 , Figure 13 and Figure 14 shown, the manifold microchannel 211 heat exchanger includes a manifold layer 5. The manifold layer 5 includes an outer frame 51 with a square structure. One end of the outer frame 51 in the vertical direction is provided with a heat exchanger inlet 53, and the other end of the outer frame 51 in the vertical direction is provided with a heat exchanger outlet 54. Along the direction from the heat exchanger inlet 53 to the heat exchanger outlet 54, the internal space of the outer frame 51 sequentially includes a first confluence area 55, a heat exchange area 56, and a second confluence area 57. A partition 52 with a serpentine structure is arranged in the heat exchange area 56. The partition 52 divides the heat exchange area 56 into a number of first flow channels 561 and a number of second flow channels 562. The first flow channels 561 and the second flow channels 562 are arranged at intervals. The open end of the first flow channel 561 faces the first confluence area 55, and the open end of the second flow channel 562 faces the second confluence area 57.
[0069] On the plane of the electrode plate 21 adjacent to the manifold layer 5 and facing the manifold layer 5, a plurality of micro-channels 211 extending in the front-back direction are provided. The plurality of micro-channels 211 are uniformly arranged in the upward direction and are perpendicular to the first flow channel 561 and the second flow channel 562. The left side surface of the partition plate 52 is flush with the left side surface of the outer frame 51, and the right side surface of the partition plate 52 is flush with the right side surface of the outer frame 51. When the battery unit 2, the PTC heater 3, the capillary pump evaporator 4, and the manifold micro-channel 211 heat exchanger are clamped and fixed between the two end plates 1, the left side surface of the manifold layer 5 at the right end is sealed and pressed against the electrode plate 21, and the right side surface of the manifold layer 5 at the right end is sealed and pressed against the end plate 1 on the right side. The left side surfaces and the right side surfaces of the remaining manifold layers 5 are all sealed and pressed against the electrode plate 21.
[0070] During operation, the working fluid enters the first confluence area 55 from the heat exchanger inlet 53, enters the first flow channel 561 through the first confluence area 55, then the working fluid in the first flow channel 561 enters the adjacent second flow channel 562 through the micro-channel 211 of the electrode plate 21, and finally converges into the second confluence area 57 through the second flow channel 562 and flows out from the heat exchanger outlet 54. This way can effectively distribute the working fluid in the first flow channel 561, the second flow channel 562, and the micro-channel 211, shorten the flow distance of the working fluid in the micro-channel 211, improve the uniformity and efficiency of heat transfer, reduce the flow resistance of the fluid at the same time, and prevent the capillary pump evaporator 4 from having insufficient capillary driving force provided and resulting in the failure of the system operation.
[0071] Furthermore, for the electrode plate 21 of the battery unit 2, in order to effectively reduce the thickness of the electrode plate 21 and control the overall volume of the entire hydrogen fuel cell, the thickness of the electrode plate 21 should not be too thick. Therefore, the depth Dmc of the micro-channel 211 cannot be too deep. At the same time, in order to ensure its heat transfer efficiency and considering the actual processing ability, the ratio of the depth Dmc to the width Wmc of the micro-channel 211 does not exceed 2, that is, Dmc / Wmc≤2.
[0072] Furthermore, the width Wmmc of the first flow channel 561 and the second flow channel 562 determines the heat transfer efficiency of the entire manifold micro-channel 211 heat exchanger, and its ratio to the width of the micro-channel 211 should not exceed 2, that is, 1≤Wmmc / Wmc≤2.
[0073] Furthermore, the height Hmmc of the first flow channel 561 and the second flow channel 562 mainly determines the distribution uniformity of the fluid in the microchannel 211, and indirectly reflects the heat transfer temperature uniformity in the entire manifold microchannel 211 heat exchanger. Calculations show that when the ratio of the height Hmmc of the first flow channel 561 and the second flow channel 562 to the depth Dmc of the microchannel 211 is between 6 and 10, that is, 6 ≤ Hmmc / Dmc ≤ 10, the temperature uniformity of the entire heat transfer process is relatively good. At the same time, considering the fluid resistance in the manifold microchannel 211 heat exchanger, it is advisable to select a lower Wmmc / Wmc value and a higher Hmmc / Dmc value.
[0074] Based on the embodiments provided in the present application, other embodiments obtained by those skilled in the art through means such as combination, splitting, and recombination of the embodiments of the present application do not exceed the protection scope of the present application.
[0075] The above specific implementation manners have elaborated in detail the objectives, technical solutions, and beneficial effects of the embodiments of the present application. The above are only the specific implementation manners of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. That is, any modifications, equivalent replacements, improvements, etc. made on the basis of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.
Claims
1. A self-driven thermal management hydrogen fuel cell, characterized in that: It includes two end plates (1), and a number of battery cells (2) are arranged between the two end plates (1); Between one of the end plates (1) and the battery cell (2), a PTC heater (3) and a capillary pump evaporator (4) are sequentially arranged in the direction close to the battery cell (2); Between the other end plate (1) and the battery cell (2), a manifold microchannel (211) heat exchanger is arranged; Between two adjacent battery cells (2), a manifold microchannel (211) heat exchanger is arranged; The capillary pump evaporator (4) and the manifold microchannel (211) heat exchanger are sequentially connected in series through pipes to form a closed circulation system.
2. The self-driven thermal management hydrogen fuel cell according to claim 1, wherein: The capillary pump evaporator (4) includes a main board body (41) and a porous medium core body (42) located inside the main board body (41). An inner cavity is arranged in the main board body (41). Along the direction from the evaporator inlet (411) to the evaporator outlet (412), the inner cavity sequentially includes a liquid cavity (413), an evaporation cavity (414), and a steam cavity (415). Evaporation bosses (4141) are respectively arranged on both sides of the steam cavity (415). A plurality of evaporation channels (4142) are arranged on the evaporation bosses (4141). Both ends of the evaporation channels (4142) are respectively communicated with the liquid cavity (413) and the steam cavity (415). The porous medium core body (42) is located between the two evaporation bosses (4141), and one end extends into the liquid cavity (413). Protrusions are respectively arranged on both sides of the porous medium core body (42) located in the liquid cavity (413). The protrusions block the openings of the evaporation channels (4142) communicating with the liquid cavity (413).
3. The self-driven thermal management hydrogen fuel cell according to claim 2, wherein: The pore diameter of the porous medium core body (42) gradually decreases along the flow direction of the working medium.
4. The self-driven thermal management hydrogen fuel cell according to claim 1, characterized in that: A liquid reservoir (7) is arranged on the pipeline on the inlet side of the capillary pump evaporator (4).
5. The self-driven thermal management hydrogen fuel cell according to claim 1, characterized in that: Heat dissipation fins are arranged on the pipeline.
6. The self-driven thermal management hydrogen fuel cell according to claim 1, characterized in that: The manifold microchannel (211) heat exchanger includes a manifold layer (5). The manifold layer (5) includes a square-shaped outer frame (51). Along the direction from the heat exchanger inlet (53) to the heat exchanger outlet (54), the internal space of the outer frame (51) sequentially includes a first confluence area (55), a heat exchange area (56), and a second confluence area (57). A partition plate (52) is arranged in the heat exchange area (56). The partition plate (52) divides the heat exchange area (56) into a number of first flow channels (561) and second flow channels (562) arranged at intervals. The open ends of the first flow channels (561) face the first confluence area (55), and the open ends of the second flow channels (562) face the second confluence area (57). A plurality of microchannels (211) perpendicular to the first flow channels (561) and the second flow channels (562) are arranged on the electrode plate (21) adjacent to the manifold layer (5). The working medium in the first flow channel (561) can enter the adjacent second flow channel (562) through the microchannels (211).
7. The self-driven thermal management hydrogen fuel cell according to claim 6, characterized in that: The ratio of the depth to the width of the microchannel (211) is less than or equal to 2.
8. A self-driven thermal management hydrogen fuel cell according to claim 6, characterized in that: The ratio of the widths of the first flow channel (561) and the second flow channel (562) to the width of the microchannel (211) is greater than or equal to 1 and less than or equal to 2.
9. The self-driven thermal management hydrogen fuel cell according to claim 8, wherein: The widths of the first flow channel (561) and the second flow channel (562) are equal.
10. A self-driven thermal management hydrogen fuel cell according to claim 6, characterized in that: The ratio of the heights of the first flow channel (561) and the second flow channel (562) to the depth of the microchannel (211) is greater than or equal to 6 and less than or equal to 10.