A reversible hydrogen-oxygen fuel cell stack and system based on air cooling

Abstract

The present application provides a reversible hydrogen-oxygen fuel cell stack and system based on air cooling, the stack includes a core unit, the core unit includes a plurality of stacked cells; each of the cells includes a first metal plate, a membrane electrode unit and a second metal plate, the membrane electrode unit is arranged between the first metal plate and the second metal plate; in two adjacent cells, the first metal plate of one cell is welded to the second metal plate of the other cell; a plurality of mutually parallel first airflow channels are arranged on the side of the first metal plate close to the membrane electrode unit; a flow channel ridge is arranged between two adjacent first airflow channels; probe grooves are arranged at both ends of the flow channel ridge, and at least one flow channel ridge is spaced between the adjacent probe grooves at the same end of the first airflow channel. The present application can realize integrated and integrated hydrogen production and fuel cell power generation, with high integration and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a reversible hydrogen-oxygen fuel cell stack and system based on air cooling. Background Art

[0002] A fuel cell is a device that converts chemical energy into electrical energy. It can use a variety of fuel sources and has the advantages of high conversion efficiency, no pollution to the environment, and zero emissions. Among them, the proton exchange membrane (PEM) fuel cell is the most technologically mature fuel cell at present. It uses hydrogen as fuel and has the advantages of high efficiency, fast start-up, and low-temperature start-up. It has been partially commercialized in passenger cars, buses, heavy trucks, drones, two-wheeled vehicles and other transportation fields, and has gradually been used in distributed power generation, household cogeneration, emergency power generation, backup power supply, composite energy systems and other fields.

[0003] In recent years, the market size of 5G communication base station backup power supply has maintained a steady growth trend. For scenarios such as communication base stations, backup power supply is a very important component. The power supply quality and reliability of backup power supply will directly affect the entire communication system and quality.

[0004] At present, lead-acid batteries or lithium-ion batteries are mainly used as backup power sources for 5G communication base stations. However, using lead-acid batteries as backup power sources has disadvantages such as short life, low capacity, short power supply time, high maintenance cost and large size, which are polluting to the environment. If lithium-ion batteries are used, the safety is poor and they are too sensitive to low and high temperature environmental conditions.

[0005] PEM fuel cells are also used in backup power systems for communication base stations. However, if high-purity hydrogen is used as fuel for fuel cells, it is usually stored in high-pressure cylinders. When the hydrogen fuel is consumed, it is difficult to supply new fuel, especially for communication base stations in some harsh geographical conditions, where the fuel supply and maintenance costs are high.

[0006] If a fuel cell using methanol as fuel is used in a backup power system, although the supply of methanol liquid fuel is more convenient and less expensive than high-purity hydrogen, it requires additional methanol reforming equipment and purification modules. At the same time, the required high-temperature fuel cell stack has poor performance and is too expensive, and the entire system is too large, which is not conducive to application.

[0007] The backup power supply for communication base stations can also adopt a three-module integrated system of hydrogen production-hydrogen storage-fuel cell power generation. When the power is normal, hydrogen is produced by water electrolysis technology and stored in hydrogen cylinders or solid-state hydrogen storage devices, and the fuel cell is in a long-term standby state; when the power fails, the backup power supply starts, the hydrogen storage device releases hydrogen, and the fuel cell system is used to generate electricity and supply electricity. However, the whole set of equipment of this three-module integrated system is relatively complex, and the required stack modules and system components are too many, the cost is high, and the volume is large, making it difficult to apply on a large scale. Summary of the invention

[0008] Based on this, an embodiment of the present invention provides a reversible hydrogen-oxygen fuel cell stack and system based on air cooling, which aims to solve the problems of hydrogen supply of hydrogen fuel cell backup power supply required in existing communication base stations and other fields.

[0009] To achieve the above-mentioned object, on the one hand, an embodiment of the present invention provides a reversible hydrogen-oxygen fuel cell stack based on air cooling, comprising a core unit, wherein the core unit comprises a plurality of stacked single cells; each of the single cells comprises a first metal plate, a membrane electrode unit and a second metal plate, wherein the membrane electrode unit is arranged between the first metal plate and the second metal plate; in two adjacent single cells, the first metal plate of one single cell is welded to the second metal plate of the other single cell;

[0010] A plurality of mutually parallel first air flow channels are arranged on the side of the first metal electrode plate close to the membrane electrode unit; a flow channel ridge is arranged between two adjacent first air flow channels; probe grooves are respectively arranged at both ends of the flow channel ridge, and at least one flow channel ridge is arranged between adjacent probe grooves at the same end of the first air flow channel.

[0011] As a preferred embodiment, the depth of the probe groove is less than the height of the flow channel ridge; when the reversible hydrogen and oxygen fuel cell stack is in a temperature detection state, a thermocouple of a temperature detector is placed in the probe groove; the probe groove is adapted to be arranged to match the thermocouple.

[0012] As a preferred embodiment, a plurality of second air flow channels parallel to each other are arranged on the side of the second metal electrode plate close to the membrane electrode unit; an air inlet is arranged at one end of the second metal electrode plate, and an exhaust port is arranged at the other end, the air inlet is connected to the air inlet of the second air flow channel, and the exhaust port is connected to the air outlet of the second air flow channel.

[0013] As a preferred embodiment, when the first metal electrode plate is connected to the second metal electrode plate by welding, the gas flow direction of the first air flow channel is arranged perpendicular to the gas flow direction of the second air flow channel.

[0014] The first air flow channel is a straight flow channel, and the second air flow channel is a serpentine flow channel; the first air flow channel is an air flow channel, and the second air flow channel is a hydrogen flow channel.

[0015] As a preferred embodiment, the air-cooled reversible hydrogen-oxygen fuel cell stack also includes an anode current collecting plate, a cathode current collecting plate, a first insulating plate, a second insulating plate, a first end plate, a second end plate and a plurality of stacking screws; the anode current collecting plate is arranged at the anode end of the core unit (i.e., one end on the hydrogen side), and the cathode current collecting plate is arranged at the cathode end of the core unit (i.e., one end on the air side); the first insulating plate is arranged on the side of the anode current collecting plate away from the core unit; the second insulating plate is arranged on the side of the cathode current collecting plate away from the core unit; the first end plate is arranged on the side of the first insulating plate away from the core unit; the second end plate is arranged on the side of the second insulating plate away from the core unit; the stacking screws are symmetrically arranged on both sides of the core unit, and one end of the stacking screw is fixedly connected to the first end plate, and the other end is fixedly connected to the second end plate.

[0016] On the other hand, an embodiment of the present invention further provides a reversible hydrogen-oxygen fuel cell stack system based on air cooling, which is prepared by the above-mentioned reversible hydrogen-oxygen fuel cell stack.

[0017] As a preferred embodiment, the air-cooled reversible hydrogen-oxygen fuel cell stack system comprises a water storage tank, a hydrogen storage tank, a gas-liquid separator, a power supply, a load and the reversible hydrogen-oxygen fuel cell stack;

[0018] The water storage tank is connected to the reversible hydrogen and oxygen fuel cell stack; the reversible hydrogen and oxygen fuel cell stack is respectively connected to the power supply, the load, the gas-liquid separator, and the hydrogen storage tank; the hydrogen storage tank is connected to the gas-liquid separator.

[0019] As a preferred embodiment, the hydrogen storage tank is connected to the gas-liquid separator through a three-way valve; the hydrogen storage tank is connected to the air inlet of the reversible hydrogen and oxygen fuel cell stack through the three-way valve; a pressure reducing valve is provided between the three-way valve and the air inlet of the reversible hydrogen and oxygen fuel cell stack.

[0020] As a preferred embodiment, a hydrogen booster and a dehumidifier are provided between the gas-liquid separator and the three-way valve; the hydrogen booster is provided between the gas-liquid separator and the dehumidifier.

[0021] As a preferred embodiment, the water outlet of the water storage tank is connected to the water inlet of the reversible hydrogen and oxygen fuel cell stack; the water inlet of the water storage tank is connected to the water outlet of the reversible hydrogen and oxygen fuel cell stack.

[0022] As a preferred embodiment, a water valve and a water pump are provided between the water outlet of the water storage tank and the water inlet of the reversible hydrogen and oxygen fuel cell stack; the water valve is provided between the water outlet of the water storage tank and the water pump.

[0023] As a preferred embodiment, the positive electrode of the load is connected to the positive electrode of the reversible hydrogen and oxygen fuel cell stack, and the negative electrode of the load is connected to the negative electrode of the reversible hydrogen and oxygen fuel cell stack.

[0024] As a preferred embodiment, the positive electrode of the power source is connected to the negative electrode of the reversible hydrogen and oxygen fuel cell stack, and the negative electrode of the power source is connected to the positive electrode of the reversible hydrogen and oxygen fuel cell stack.

[0025] As a preferred embodiment, a plurality of fans are further provided on the reversible hydrogen and oxygen fuel cell stack; and an air outlet of the reversible hydrogen and oxygen fuel cell stack is connected to a tail exhaust valve.

[0026] Compared with the prior art, the structure of the present application has the following technical effects: through the present application, hydrogen production and fuel cell power generation are completed by an integrated reversible stack based on air cooling, while saving a large number of system components, and can achieve integrated and integrated hydrogen production and fuel cell power generation, the system is more integrated, the cost is lower, no manual fuel replenishment is required, and the maintenance cost of the backup power supply is effectively reduced. Compared with the traditional three-module integrated solution of hydrogen production-hydrogen storage-fuel cell power generation system, the reversible hydrogen-oxygen fuel cell stack system based on air cooling of the present invention (i.e., hydrogen production-fuel cell integrated stack) has lower cost, more compact structure, and fewer components required for the system. Compared with methanol fuel cell technology, the present application only needs to provide pure water supply for the system, which is safer and more convenient, has better cleanliness than methanol, and has lower fuel replenishment cost. The pole plates of the present application are all titanium substrates coated with precious metals Pt or Ir, which can effectively guarantee the corrosion resistance requirements of fuel cells and the high potential corrosion requirements in the electrolysis water mode, and can be applied to the backup power supply device of communication base stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 This is a schematic diagram of the overall structure of a reversible hydrogen-oxygen fuel cell stack based on air cooling according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1Schematic diagram of the explosion structure of the air-cooled reversible hydrogen-oxygen fuel cell stack;

[0030] Figure 3 for Figure 2 A schematic cross-sectional structure diagram of a model of a single cell of a core unit;

[0031] Figure 4 for Figure 3 A schematic structural diagram of a first metal plate of a single cell;

[0032] Figure 5 for Figure 3 A schematic structural diagram of a second metal plate of a single cell;

[0033] Figure 6 for Figure 3 A schematic diagram of the structure of a membrane electrode unit of a single cell;

[0034] Figure 7 It is a schematic structural diagram of a reversible hydrogen-oxygen fuel cell stack system based on air cooling according to an embodiment of the present invention.

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, top, bottom...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] Specifically, on the one hand, Figures 1 to 6 As shown, an embodiment of the present invention provides a reversible hydrogen-oxygen fuel cell stack based on air cooling, including a core unit 10, wherein the core unit 10 includes a plurality of stacked single cells 11; each of the single cells 11 includes a first metal plate 111, a membrane electrode unit 112, and a second metal plate 113, wherein the membrane electrode unit 112 is arranged between the first metal plate 111 and the second metal plate 113; in two adjacent single cells 11, the first metal plate 111 of one of the single cells 11 is welded to the second metal plate 113 of the other single cell 11;

[0042] A plurality of mutually parallel first airflow channels A are arranged on the side of the first metal electrode plate 111 close to the membrane electrode unit 112; a channel ridge B is arranged between two adjacent first airflow channels A; probe grooves B1 are respectively arranged at both ends of the flow channel ridge B, and at least one flow ridge B is arranged between adjacent probe grooves B1 at the same end of the first airflow channel A.

[0043] That is, in the embodiment of the present application, not all flow channel ridges B are provided with the probe groove B1. Generally, a flow channel ridge B without the probe groove B1 is provided between two flow channel ridges B provided with the probe groove B1. This can not only detect the temperature changes in different areas inside the electrode plate in real time and better reflect the temperature changes inside the electrode plate, but also ensure the supporting strength of the electrode plate.

[0044] As a preferred embodiment, the depth of the probe groove B1 is less than the height of the flow channel ridge B; when the reversible hydrogen-oxygen fuel cell stack is in a temperature detection state, a thermocouple of a temperature detector (not marked in the figure) is placed in the probe groove B1; the probe groove B1 is adapted to the thermocouple. In this way, the installation and removal of the temperature detector is convenient. During the temperature test of the stack, the temperature distribution of different numbers of pieces and temperatures in different areas can be monitored and recorded online.

[0045] By setting a probe groove on the flow channel ridge of the first flow channel and controlling the setting method and setting specifications of the probe groove, it is possible to detect the temperature changes in different areas inside the plate and record the distribution of regional temperatures under different working conditions and load changes of the entire stack in real time. At the same time, it can avoid the error caused by inconsistent forces on the battery stack twice before and after each disassembly of the battery stack, providing a basis for optimizing the design of the plate flow channel and formulating the cold start strategy for the fuel cell.

[0046] As a preferred embodiment, a plurality of second air flow channels C parallel to each other are arranged on the side of the second metal electrode plate 113 close to the membrane electrode unit 112; an air inlet D is arranged at one end of the second metal electrode plate 113, and an exhaust port E is arranged at the other end, the air inlet D is connected to the air inlet of the second air flow channel C, and the exhaust port E is connected to the air outlet of the second air flow channel C.

[0047] As a preferred embodiment, when the first metal electrode plate 111 is connected to the second metal electrode plate 113 by welding, the gas flow direction of the first air flow channel A is perpendicular to the gas flow direction of the second air flow channel C.

[0048] The first air flow channel A is a straight flow channel, and the second air flow channel C is a serpentine flow channel; the first air flow channel A is an air flow channel, and the second air flow channel C is a hydrogen flow channel.

[0049] When the reversible hydrogen-oxygen fuel cell stack of the present application is in power generation mode, the first metal plate end (i.e., the cathode end) is open, which can realize both air supply and direct heat exchange with the outside world, and the coolant flow field part can be omitted.

[0050] The first metal plate 111 is a DC field. Air enters the straight flow channel under the action of the fan. The air-cooled flow field plays the role of conveying oxidants on the one hand, and plays the role of conductivity and support on the other hand. The edges of the air inlet and outlet of the second metal plate 113 are provided with rubber ring grooves, and rubber rings can be placed to ensure sealing. Hydrogen enters from the air inlet, and after being blocked by the membrane electrode unit, it passes through the buffer flow channel and enters the active area of ​​the serpentine flow channel to react. The unreacted hydrogen flows out from the outlet and enters the mother pipe.

[0051] In the present application, the first metal plate 111 and the second metal plate 113 are both titanium plates, and the surface of the titanium plate is provided with a Pt coating, which can effectively ensure the corrosion resistance requirements of the fuel cell and the high potential corrosion requirements in the electrolysis water mode; the metal plate is generally prepared by a stamping process, then welded and formed, and finally plated. Compared with traditional graphite plates, titanium plates are easier to process and suitable for batch preparation. The coating can be made of Pt or Ir metal. After the plate welding is completed, the coating is prepared using physical vapor deposition (PVD) and other technologies.

[0052] In the embodiment of the present application, the membrane electrode unit can adopt a commonly used membrane electrode unit structure. The hydrogen side catalytic layer of the membrane electrode unit adopts 1g of commercial Pt / C (Pt mass percentage is 50%) catalyst, a mixed solution of 8g of deionized water and 8g of isopropyl alcohol (IPA) is used as a solvent, and 2.3g of Nafion D2020 (20wt%) is added, and a high-speed disperser is used to disperse it at a speed of 7000rpm for 4h; then it is placed in a vacuum degassing agent for treatment for 0.5h to obtain a Pt / C catalyst slurry; finally, the Pt / C catalyst slurry is coated on the smooth PTFE substrate surface by a doctor blade method, and dried at 50°C for 15 minutes to obtain a hydrogen side catalytic layer.

[0053] The oxygen-side catalytic layer of the membrane electrode unit adopts a PtIr alloy catalyst. 0.6 g of the PtIr alloy catalyst is weighed, and a mixed solution of 26 g of deionized water and 26 g of isopropyl alcohol (IPA) is used as a solvent. Then 1.0 g of an ionomer solution Nafion D2020 (20 wt%) is added, and the mixture is dispersed at a speed of 7000 rpm using a high-speed disperser for 4 hours; then it is placed in a vacuum degassing machine for 0.5 hours to obtain a PtIr catalyst slurry; finally, the PtIr slurry is sprayed onto the surface of a proton exchange membrane (Gore 12 μm) with a release membrane by a spraying method, and dried at 50° C. for 15 minutes to obtain an oxygen-side catalytic layer.

[0054] CCM was prepared by hot-pressing transfer, and the specific steps included: removing the release film, placing the PTFE coated with Pt / C on the other side of the proton membrane sprayed with the PtIr catalyst layer, and transferring it by hot-pressing process at a temperature of 120°C, a pressure of 2MPa, and a time of 200s; then removing the PTFE substrate to obtain CCM, with the catalysts on both sides being Pt / C and PtIr alloy respectively.

[0055] The membrane electrode unit adopts a single-frame sealing form, and the membrane electrode frame material can be selected from PEN (polyethylene naphthalate), PI (polyimide), PPS (polyphenylene sulfide) or PEEK (polyetheretherketone). The surfaces on both sides of the frame are coated with adhesive layers, including a first adhesive layer and a second adhesive layer. The first adhesive layer can bond the hydrogen side metal plate and the frame, and the second adhesive layer can bond the frame and the proton exchange membrane. The adhesive layer can be selected from a pressure-sensitive adhesive or a hot-melt adhesive, and finally the double-sided bonding of the proton membrane and the plate is completed. The hydrogen side diffusion layer adopts a carbon paper diffusion layer commonly used in fuel cells, and the hydrogen side diffusion layer adopts one of titanium felt, titanium grid, sintered titanium, etc., and is treated with corrosion-resistant coating, and the coating adopts Au, Pt, Ir, etc.

[0056] As a preferred embodiment, the reversible hydrogen-oxygen fuel cell stack based on air cooling also includes an anode current collector 20, a cathode current collector 30, a first insulating plate 40, a second insulating plate 50, a first end plate 60, a second end plate 70 and a plurality of stacking screws 80; the anode current collector 20 is arranged at the anode end of the core unit 10 (i.e., one end on the hydrogen side), and the cathode current collector 30 is arranged at the cathode end of the core unit 10 (i.e., one end on the air side); the first insulating plate 40 is arranged at the anode collector 20 away from the core unit element 10; the second insulating plate 50 is arranged on the side of the cathode current collecting plate 30 away from the core unit 10; the first end plate 60 is arranged on the side of the first insulating plate 40 away from the core unit 10; the second end plate 70 is arranged on the side of the second insulating plate 50 away from the core unit 10; the stacking screw 80 is symmetrically arranged on both sides of the core unit 10, and one end of the stacking screw 80 is fixedly connected to the first end plate 60, and the other end is fixedly connected to the second end plate 70.

[0057] On the other hand, Figure 7 As shown, an embodiment of the present invention further provides a reversible hydrogen-oxygen fuel cell stack system based on air cooling, which is prepared by the above-mentioned reversible hydrogen-oxygen fuel cell stack 100.

[0058] As a preferred embodiment, the air-cooled reversible hydrogen-oxygen fuel cell stack system includes a water storage tank 200, a hydrogen storage tank 300, a gas-liquid separator 400, a power supply 500, a load 600 and the reversible hydrogen-oxygen fuel cell stack 100;

[0059] The water storage tank 200 is connected to the reversible hydrogen and oxygen fuel cell stack 100; the reversible hydrogen and oxygen fuel cell stack 100 is respectively connected to the power supply 500, the load 600, the gas-liquid separator 400, and the hydrogen storage tank 300; the hydrogen storage tank 300 is connected to the gas-liquid separator 400.

[0060] As a preferred embodiment, the hydrogen storage tank 300 is connected to the gas-liquid separator 400 through a three-way valve 301; the hydrogen storage tank 300 is connected to the air inlet of the reversible hydrogen and oxygen fuel cell stack 100 through the three-way valve 301; a pressure reducing valve 101 is provided between the three-way valve 301 and the air inlet of the reversible hydrogen and oxygen fuel cell stack 100.

[0061] As a preferred embodiment, a hydrogen booster 700 and a dehumidifier 800 are provided between the gas-liquid separator 400 and the three-way valve 301 ; the hydrogen booster 700 is provided between the gas-liquid separator 400 and the dehumidifier 800 .

[0062] As a preferred embodiment, the water outlet of the water storage tank 200 is connected to the water inlet of the reversible hydrogen and oxygen fuel cell stack 100 ; the water inlet of the water storage tank 200 is connected to the water outlet of the reversible hydrogen and oxygen fuel cell stack 100 .

[0063] As a preferred embodiment, a water valve 201 and a water pump 202 are provided between the water outlet of the water storage tank 200 and the water inlet of the reversible hydrogen-oxygen fuel cell stack 100 ; the water valve 201 is provided between the water outlet of the water storage tank 200 and the water pump 202 .

[0064] As a preferred embodiment, the positive electrode of the load 600 is connected to the positive electrode of the reversible hydrogen and oxygen fuel cell stack 100 , and the negative electrode of the load 600 is connected to the negative electrode of the reversible hydrogen and oxygen fuel cell stack 100 .

[0065] As a preferred embodiment, the positive electrode of the power source 500 is connected to the negative electrode of the reversible hydrogen and oxygen fuel cell stack 100 , and the negative electrode of the power source 500 is connected to the positive electrode of the reversible hydrogen and oxygen fuel cell stack 100 .

[0066] As a preferred embodiment, a plurality of fans 102 are further provided on the reversible hydrogen and oxygen fuel cell stack 100 ; and an air outlet of the reversible hydrogen and oxygen fuel cell stack 100 is connected to a tail exhaust valve 103 .

[0067] When the power is normal, the hydrogen production mode is operated, the water valve is opened, and the pure water in the water storage tank enters the hydrogen flow channel of the reversible hydrogen-oxygen fuel cell stack under the action of the water pump to ensure that the membrane electrode unit is in a wet state. A DC power supply is added on both sides of the anode collector plate and the cathode collector plate, and the high voltage side is connected to the cathode collector plate (i.e., the oxygen side collector plate), and the low voltage side is connected to the anode collector plate (i.e., the hydrogen side collector plate). Oxygen evolution reaction (OER) occurs on the oxygen side, and the generated oxygen is directly discharged into the air. Hydrogen evolution reaction (HER) occurs on the hydrogen side, and the generated hydrogen and pure water are discharged from the outlet. After the water-liquid separation is achieved by the gas-liquid separator, the pure water is transported back to the water storage tank. At the same time, the wet hydrogen is electrochemically pressurized (or mechanically pressurized), and then dehumidified, and enters the hydrogen storage tank (alloy hydrogen storage tank) through the three-way valve. When storing hydrogen, the fan of the hydrogen storage tank runs to dissipate heat for the tank body.

[0068] When a power failure occurs, the fuel cell power generation mode is started, the valve of the hydrogen storage tank is opened, and the hydrogen enters the hydrogen pipeline of the reversible hydrogen-oxygen fuel cell stack and the corresponding hydrogen flow channel of each single cell, and then passes through the diffusion layer to reach the anode catalyst layer, where a hydrogen oxidation reaction (HOR) occurs under the action of the catalyst; at the same time, the fan of the reversible hydrogen-oxygen fuel cell stack is started, and air enters the oxygen flow channel to reach the cathode catalyst layer, where an oxygen reduction reaction (ORR) occurs under the action of the catalyst, and the fuel cell working mode is performed to realize the power generation function, and the load is started to ensure power supply.

[0069] In the embodiment of the present application, the hydrogen side catalyst layer realizes the dual functions of HOR and HER, and adopts Pt / C, Pt or Pt-M / C catalyst, wherein M is one or two of Co, Ni, Fe, Ru, and Mo. The air side catalyst layer realizes the dual functions of OER and ORR, and adopts PtIr, PtIrRu, Pr-IrO 2 , PtIrPd and other alloy catalysts. The membrane electrode adopts a single-frame sealing method. The membrane electrode frame is bonded to the hydrogen side of the metal plate to form a single cell. At the same time, sealing rubber grooves are designed at the hydrogen inlet and outlet and the periphery of the active area to ensure airtightness.

[0070] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A reversible hydrogen-oxygen fuel cell stack based on air cooling, characterized in that: The invention comprises a core unit, wherein the core unit comprises a plurality of stacked single cells; each of the single cells comprises a first metal plate, a membrane electrode unit and a second metal plate, wherein the membrane electrode unit is arranged between the first metal plate and the second metal plate; in two adjacent single cells, the first metal plate of one single cell is welded to the second metal plate of the other single cell; A plurality of mutually parallel first flow channels are arranged on the side of the first metal electrode plate close to the membrane electrode unit; a flow channel ridge is arranged between two adjacent first flow channels; probe grooves are arranged at both ends of the flow channel ridge, and at least one flow channel ridge is arranged between the adjacent probe grooves at the same end of the first flow channel; When the reversible hydrogen-oxygen fuel cell stack is in a temperature detection state, a thermocouple of a temperature detector is placed in the probe groove; the probe groove is adapted to be arranged with the thermocouple.

2. The air-cooled reversible hydrogen-oxygen fuel cell stack according to claim 1, characterized in that: The depth of the probe groove is smaller than the height of the flow channel ridge.

3. The air-cooled reversible hydrogen-oxygen fuel cell stack according to claim 2, characterized in that: A plurality of second air flow channels parallel to each other are arranged on the side of the second metal electrode plate close to the membrane electrode unit; an air inlet is arranged at one end of the second metal electrode plate, and an exhaust port is arranged at the other end; the air inlet is connected to the air inlet of the second air flow channel, and the exhaust port is connected to the air outlet of the second air flow channel.

4. The air-cooled reversible hydrogen-oxygen fuel cell stack according to claim 3, characterized in that: When the first metal electrode plate is connected to the second metal electrode plate by welding, the gas flow direction of the first gas flow channel is perpendicular to the gas flow direction of the second gas flow channel; The first air flow channel is a straight flow channel, and the second air flow channel is a serpentine flow channel; the first air flow channel is an air flow channel, and the second air flow channel is a hydrogen flow channel.

5. The air-cooled reversible hydrogen-oxygen fuel cell stack according to claim 4, characterized in that: The air-cooled reversible hydrogen-oxygen fuel cell stack also includes an anode current collecting plate, a cathode current collecting plate, a first insulating plate, a second insulating plate, a first end plate, a second end plate and a plurality of stacking screws; the anode current collecting plate is arranged at the anode end of the core unit, and the cathode current collecting plate is arranged at the cathode end of the core unit; the first insulating plate is arranged on the side of the anode current collecting plate away from the core unit; the second insulating plate is arranged on the side of the cathode current collecting plate away from the core unit; the first end plate is arranged on the side of the first insulating plate away from the core unit; the second end plate is arranged on the side of the second insulating plate away from the core unit; the stacking screws are symmetrically arranged on both sides of the core unit, and one end of the stacking screw is fixedly connected to the first end plate, and the other end is fixedly connected to the second end plate.

6. A reversible hydrogen-oxygen fuel cell stack system based on air cooling, characterized in that: It comprises a water storage tank, a hydrogen storage tank, a gas-liquid separator, a power supply, a load and a reversible hydrogen-oxygen fuel cell stack according to any one of claims 1 to 5; The water storage tank is connected to the reversible hydrogen-oxygen fuel cell stack; the reversible hydrogen-oxygen fuel cell stack is respectively connected to the power supply, the load, the gas-liquid separator, and the hydrogen storage tank; the hydrogen storage tank is connected to the gas-liquid separator; When the power is normal, the hydrogen production mode is operated, the water valve is opened, and the pure water in the water storage tank enters the hydrogen flow channel of the reversible hydrogen-oxygen fuel cell stack under the action of the water pump to ensure that the membrane electrode unit is in a wet state; a DC power supply is added on both sides of the anode current collector and the cathode current collector, the high voltage side is connected to the cathode current collector, and the low voltage side is connected to the anode current collector; an oxygen evolution reaction occurs on the oxygen side, and the generated oxygen is directly discharged into the air, and a hydrogen evolution reaction occurs on the hydrogen side, and the generated hydrogen and pure water are discharged from the outlet. After the water-liquid separation is achieved by the gas-liquid separator, the pure water is transported back to the water storage tank, and at the same time, the wet hydrogen is electrochemically pressurized, and then dehumidified, and enters the hydrogen storage tank through the three-way valve; When a power failure occurs, the fuel cell power generation mode is started, the valve of the hydrogen storage tank is opened, and the hydrogen enters the hydrogen pipeline of the reversible hydrogen-oxygen fuel cell stack and the corresponding hydrogen flow channel of each single cell, and then passes through the diffusion layer to reach the anode catalyst layer, where a hydrogen oxidation reaction occurs under the action of the catalyst; at the same time, the fan of the reversible hydrogen-oxygen fuel cell stack is started, and air enters the oxygen flow channel to reach the cathode catalyst layer, where an oxygen reduction reaction occurs under the action of the catalyst, and the fuel cell working mode is carried out to realize the power generation function, and the load is started to ensure power supply.

7. The air-cooled reversible hydrogen-oxygen fuel cell stack system according to claim 6, characterized in that: The hydrogen storage tank is connected to the gas-liquid separator through a three-way valve; the hydrogen storage tank is connected to the air inlet of the reversible hydrogen-oxygen fuel cell stack through the three-way valve; a pressure reducing valve is provided between the three-way valve and the air inlet of the reversible hydrogen-oxygen fuel cell stack; A hydrogen booster and a dehumidifier are arranged between the gas-liquid separator and the three-way valve; the hydrogen booster is arranged between the gas-liquid separator and the dehumidifier.

8. The air-cooled reversible hydrogen-oxygen fuel cell stack system according to claim 7, characterized in that: The water outlet of the water storage tank is connected to the water inlet of the reversible hydrogen and oxygen fuel cell stack; the water inlet of the water storage tank is connected to the water outlet of the reversible hydrogen and oxygen fuel cell stack; A water valve and a water pump are arranged between the water outlet of the water storage tank and the water inlet of the reversible hydrogen-oxygen fuel cell stack; the water valve is arranged between the water outlet of the water storage tank and the water pump.

9. The air-cooled reversible hydrogen-oxygen fuel cell stack system according to claim 8, characterized in that: The positive electrode of the load is connected to the positive electrode of the reversible hydrogen and oxygen fuel cell stack, and the negative electrode of the load is connected to the negative electrode of the reversible hydrogen and oxygen fuel cell stack; The positive electrode of the power source is connected to the negative electrode of the reversible hydrogen and oxygen fuel cell stack, and the negative electrode of the power source is connected to the positive electrode of the reversible hydrogen and oxygen fuel cell stack; The reversible hydrogen-oxygen fuel cell stack is also provided with a plurality of fans; and the air outlet of the reversible hydrogen-oxygen fuel cell stack is connected to the tail exhaust valve.

Images