Leaf vein flow channel bionic air-cooled fuel cell module supporting lung air intake and implementation method thereof

A leaf vein flow channel bionic air-cooled fuel cell module supporting lung air intake, comprising:

• an air inlet, a front fixing plate, a stack, a motor, a sealing volute, an impeller, a rear fixing plate, and an air outlet;
• wherein the sealing volute is a cylindrical structure having no upper bottom but having a lower bottom;
• the air outlet is arranged in a side wall of the sealing volute along a direction parallel to an axis of the sealing volute;
• the impeller is coaxially arranged inside the sealing volute, and the impeller is a cylindrical structure having no upper bottom but having a lower bottom;
• the rear fixing plate is coaxially arranged at a bottom inside the impeller, and the rear fixing plate is a circular flat structure;
• the motor is arranged at a center of the rear fixing plate;
• a transmission shaft of the motor is fixedly connected to a center of a bottom surface of the impeller;
• the stack in a circular columnar structure is coaxially mounted inside the impeller;
• the front fixing plate is coaxially connected at a top portion of the impeller, and a plurality of long screws are axially evenly distributed around the stack, front ends of the long screws are fixedly connected to the front fixing plate, and rear ends of the long screws are fixedly connected to the rear fixing plate, such that the stack is fixedly mounted between the front fixing plate and the rear fixing plate;
• a front end of the sealing volute is fixedly mounted at an edge of the front fixing plate;
• a through hole is arranged at a center of the front fixing plate, and the air inlet is arranged in the through hole;
• wherein
• an area of a cross section, along an air flow direction, of the air inlet progressively decreases along the air flow direction, such that an area at a front end of the air inlet is larger, and an area at a rear end of the air inlet is smaller;
• the stack comprises a plurality of cells successively coaxially stacked, wherein each of the cells comprises from front to rear a bipolar plate, an anode diffusion layer, a proton membrane, and a cathode diffusion layer successively, and each of the cells is in a circular shape, such that the stack formed by stacking the plurality of cells is in a circular shape and a columnar space is defined inside the stack;
• wherein the bipolar plate employs an circular plate-shaped substrate, and a front surface, facing towards the cathode diffusion layer of a previous cell, of the bipolar plate is a cathode surface, and a rear surface, facing towards the anode diffusion layer, of the bipolar plate is an anode surface;
• wherein
• the cathode surface adopts a mesh vein distribution pattern imitating veins of a lotus leaf;
• on the front surface of the circular plate-shaped substrate, arrays of cylinders are arranged like mesh veins to form mesh flow channels;
• a circular inner diffusion flow channel and a circular outer diffusion flow channel are respectively arranged in an inner edge and an outer edge of the front surface of the circular plate-shaped substrate;
• the mesh flow channels between the inner diffusion flow channel and the outer diffusion flow channel are divided by first-stage to Mth-stage flow channels, and the mesh flow channels and the first-stage to Mth-stage flow channels together form a cathode flow channel network;
• a plurality of first-stage flow channels distributed radially and centrosymmetrically are inscribed in an outer edge of the inner diffusion flow channel, and the first-stage flow channels are communicated with the inner diffusion flow channel;
• two communicated ith-stage flow channels are inscribed in a tail end of each of (i−1)th-stage flow channels, and the two ith-stage flow channels each have an included angle with a corresponding (i−1)th-stage flow channel and are symmetrically distributed about the (i−1)th-stage flow channel;
• a tail end of the Mth-stage flow channel is communicated with an inner edge of the outer diffusion flow channel, wherein 2≤i≤M, M is a natural number ≥2;
• and a width of the (i−1)th-stage flow channel is less than a width of the ith-stage flow channel;
• the anode surface adopts a distribution pattern imitating veins of a banana leaf;
• a circular inner non-flow channel region and a circular outer non-flow channel region are respectively arranged in an inner edge and an outer edge of the rear surface of the circular plate-shaped substrate to form contact regions;
• a circular inner air collector flow channel and a circular outer air collector flow channel are respectively inscribed in an outer edge of the inner non-flow channel region and an inner edge of the outer non-flow channel region;
• N air inlet openings and N air outlet openings running through the anode surface and the cathode surface of the bipolar plate are respectively arranged in the anode surface, the air inlets and the air outlets are staggered, a primary air collector flow channel is arranged along a radial direction of the air outlet openings, and the primary air collector flow channel divides, along the radial direction of the air inlet openings, a region between the inner air collector flow channel and the outer air collector flow channel into 2N anode sub-regions symmetrical about a center thereof, N being a natural number greater than or equal to 1;
• in each of the anode sub-regions, a primary flow channel communicating the air inlet with the air outlet is inscribed between the air inlet opening and the air outlet opening, a central line of the primary flow channel is a circular arc, and a width of the primary flow channel progressively decreases from the air inlet to the air outlet;
• an inner branch flow channel and an outer branch flow channel are respectively arranged between the primary flow channel and the inner air collector flow channel and between the primary flow channel and the outer air collector flow channel, a width of the inner branch flow channel progressively decreases from the primary channel to the inner air collector flow channel and a width of the outer branch flow channel progressively decreases from the primary channel to the outer air collector flow channel, central lines of the inner air collector flow channels are parallel to each other, center lines of the outer air collector flow channels are parallel to each other, and an included angle is defined between the inner branch flow channel and the outer branch flow channel;
• the width of the primary flow channel is greater than the width of the inner branch flow channel and the width of the outer branch flow channel;
• on the front fixing plate, a hydrogen inlet is arranged at a position corresponding to the air inlet opening in the bipolar plate, and the hydrogen inlet is communicated with the air inlet opening in the bipolar plate;
• and on the front fixing plate, a hydrogen outlet is arranged at a position corresponding to the air outlet opening in the bipolar plate, and the hydrogen outlet is communicated with the air outlet opening in the bipolar plate;
• air enters from the air inlet to the cathode surface inside the sealing volute of the fuel cell module while hydrogen enters the anode surface inside the sealing volute of the fuel cell module through the hydrogen inlet, and the motor drives the impeller to rotate;
• the air enters the fuel cell module in a way that imitates an air intake pattern of a lung, wherein the air is compressed at the air inlet to obtain a greater flow rate for flowing through the fuel cell module;
• the motor drives the impeller to rotate, and the impeller provides additional power to the air, such that volume expansion of the air is accelerated and the air quickly passes through the stack;
• upon entry into the sealing volute, the air enters the columnar space inside the circular columnar stack and reaches the cathode surface of each of the cells in the stack, and is transported to the primary flow channel through the inner diffusion flow channel;
• a small amount of the air enters the mesh flow channel in a region near the primary flow channel, and is diffused within the mesh flow channel;
• most of the air is transported through the primary flow channel and enters narrower secondary flow channels successively up to the Mth-stage flow channel, and is diffused to the outer diffusion flow channel in the edge of the cathode flow channel network;
• an air flow rate is greater while being diffused to accommodate an increase in an area of the bipolar plate corresponding to the cell as an radial transportation unit length increases;
• and the air is evenly diffused in the cathode flow channel network while being diffused to the cathode diffusion layer of the previous cell, the region where the air is diffused to the cathode diffusion layer constitutes a reaction region, oxygen in the air participates in reaction to generate cathode water, and the gas not participating in the reaction in the air takes away the generated cathode water and heat and is finally discharged from the air outlet;
• when an amount of the generated cathode water is small, the cathode water gathers at a bottom of the cathode flow channel network and forms a liquid water membrane at the bottom, the water membrane forms a liquid-gas mixed phase with the air, and the air evenly forms a flow field in the cathode flow channel network, which is conducive to the reaction while ensuring a smaller parasitic resistance;
• when the amount of the generated cathode water is over large, widths of the first-stage to Mth-stage flow channels of the cathode flow channel network decrease stage by stage, an additional pressure exerts a capillary effect which automatically cooperates with the air flow to discharge the gas not participating in the reaction along a radial direction, and further under power of the impeller, the cathode water is further radially transported with a transportation direction of the gas and is finally discharged from the air outlet in the side wall of the sealing volute to prevent the stack from being flooded;
• in terms of heat dissipation, heat is evenly generated in the whole reaction region, the heat transferred to the cathode surface is gathered on a surface of the array of cylinders, and since the arrays of cylinders are evenly arranged, the heat is evenly gathered on the surface such that a heat dissipation area is increased;
• further, the heat transferred to the cathode surface is transferred to gas not participating in the reaction in the air, the gas not involved in the reaction in the air comprises gas not intended to participate in the reaction and the oxygen in the air failing to participate in the reaction timely, the oxygen in the air participates in the reaction during transportation and is gradually consumed, and the width of the flow channel decreases during transportation of the gas not participating in the reaction in the air along the first-stage to Mth-stage flow channels, but more heat is accumulated, the heat causes the gas not participating in the reaction in the air to expand, such that the pressure of the gas not participating in the reaction in the air increases in the limited space and is discharged from the air outlet more quickly, making the air pressure inside the sealing volute smaller and causing a pressure difference with the outside of the sealing volute, accelerating the entry of the air from the air inlet, and thus the heat provides the additional pressure for the air entering through the air inlet, which increases the air flow rate, improves an air exchange efficiency, and facilitates quickly taking away the heat by the air;
• and
• the hydrogen enters the anode surface through the air inlet opening and is transferred to the inner branch flow channel and the outer branch flow channel through the primary flow channel;
• since the width of the primary flow channel progressively decreases, the inner branch flow channel and the outer branch flow channel become narrower gradually, and according to the Bernoulli's law, the hydrogen is diffused quickly and evenly to each of anode sub-regions of the anode surface;
• most of the hydrogen is diffused to the anode diffusion layer to participate in the reaction, and a small portion of unreacted hydrogen is gathered in the inner air collector flow channel and the outer air collector flow channel and is transferred to an anode surface of a next cell through the air outlet opening;
• when a temperature sensor set between the stacks detects that a temperature of the cell is too high, a impeller speed is controlled to speed up to accelerate the air flow rate in the cathode flow channel network, and the entry of the hydrogen is controlled to be reduced at the same time;
• since an amount of entered hydrogen is reduced, and a hydrogen consumption rate in the primary flow channel and the inner and outer branch flow channels is accelerated with the air flow in the cathode flow channel network, such that the hydrogen in the main stream channel and the inner and outer branch channels is consumed quickly, and lack of the hydrogen available for the reaction slows down the reaction and slows down generation of the cathode water, but the impeller speed is accelerated, which makes the air flow rate in the cathode flow channel network accelerated to quickly take away the heat and the cathode water remaining on the cathode surface.