CN215955330U

CN215955330U - Wave-shaped flow field structure of proton exchange membrane fuel cell

Info

Publication number: CN215955330U
Application number: CN202122623280.XU
Authority: CN
Inventors: 闫法义; 姚健; 卢玉
Original assignee: Shandong Jianzhu University
Current assignee: Shandong Jianzhu University
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2022-03-04
Anticipated expiration: 2031-10-29

Abstract

The utility model provides a wave-shaped flow field structure of a proton exchange membrane fuel cell, which comprises an air inlet hole, a Y-shaped flow channel, a circular flow channel, a horseshoe-shaped rib plate, a rectangular flow channel, a polar plate and an air outlet hole, wherein the circular flow channel and the Y-shaped flow channel are both in wave-shaped structures and are alternately arranged, the air inlet hole is positioned in the center of the flow field structure, and the air outlet hole is uniformly distributed on the outermost side of the flow field. The reaction gas enters the flow field through the gas inlet and diffuses outwards layer by layer through the circular flow channel, the rectangular flow channel and the Y-shaped flow channel. Compared with the existing flow field, the utility model adopts the circular polar plate material to facilitate the uniform distribution of the reaction gas, the rectangular flow channel enhances the drainage performance of the flow field, the occurrence of flooding phenomenon is effectively avoided, the wave-shaped structure leads the gas to be forced to flow in a convection way, the speed division is generated in the vertical direction, and the mass transfer efficiency and the power density of the fuel cell are improved.

Description

Wave-shaped flow field structure of proton exchange membrane fuel cell

Technical Field

The utility model relates to the field of fuel cells, in particular to a proton exchange membrane fuel cell wave-shaped flow field.

Background

A Proton Exchange Membrane Fuel Cell (PEMFC) is a fuel cell that converts chemical energy into electrical energy, and because of its characteristics of high energy conversion efficiency, cleanliness and high efficiency, compared with a heat engine, a fuel cell can directly convert chemical energy into electrical energy without the restriction of carnot cycle, and the energy conversion efficiency can reach 90%.

The bipolar plate is also called as a current collecting plate as one of core components of the fuel cell, and plays roles of distributing gas, collecting current and supporting a cell structure, a flow field is a concave-convex groove processed on the bipolar plate, the performance of the bipolar plate depends on the design of the flow field, and the proton exchange membrane fuel cell has better performance, so that on one hand, sufficient reactant supply is ensured, and on the other hand, water generated in the reaction process is timely discharged.

At present, the common types of fuel cells include a parallel flow field, a serpentine flow field and an interdigitated flow field, and the parallel flow field has the advantages of low manufacturing cost and low total pressure drop. However, when the flow field is too wide, water accumulation is easily formed, which causes a flooding phenomenon.

The serpentine flow field has the advantage of good drainage effect, because the single flow path can effectively promote the transmission of liquid water, but the pressure drop of the serpentine flow field is large, and the gas concentration distribution is easy to cause uneven.

The interdigitated flow field provides better water management than the parallel flow field and the serpentine flow field because the interdigitated flow field causes forced convection of the reactant gases in the diffusion layer, which also results in a large pressure drop.

Aiming at the defects of the prior art, a wave-shaped flow field of a proton exchange membrane fuel cell is provided.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a wave-shaped flow field of a proton exchange membrane fuel cell aiming at the defects of the conventional flow field, solve the defects of uneven distribution of reaction gas and poor drainage effect in the working process of the fuel cell and improve the current density of the proton exchange membrane fuel cell.

The technical scheme adopted by the utility model is as follows: a proton exchange membrane fuel cell wave-shaped flow field is characterized in that: the device comprises an air inlet, a pole plate, a circular flow field, a Y-shaped flow channel, a rectangular flow channel, a horseshoe-shaped rib plate and an air outlet.

Further the inlet may be circular or square in shape and the outlet may be oval or rectangular in shape.

Further air inlets and trapezoidal rib plates are all processed on the polar plate. The air outlets are a plurality of and are distributed on the outermost side of the flow field in an annular mode at equal intervals.

The inner Y-shaped runner and the outer Y-shaped runner are arranged in a delta shape, and the outlet of the inner Y-shaped runner and the inlet of the outer Y-shaped runner are on the same straight line.

Further, rectangular runners are arranged at the bottoms of the trapezoidal rib plates, the rectangular runners under the same trapezoidal rib plate are distributed in parallel, and the number of the rectangular runners is determined according to the area of the polar plate.

The outlet of the Y-shaped flow channel at the outermost side and the outlet channel of the fuel cell are not in the same radial direction and are arranged in a staggered manner.

The longitudinal sections of the circular flow passage and the Y-shaped flow passage are wave-shaped curves, and the wave-shaped curves of the circular flow passage are designed by adopting a sine function Y-1-0.5 sin (pi x). The wave-shaped curve of the Y-shaped flow passage is designed by a sine function Y of 1-0.5 sin (3pi/4 x), and the number ratio of the main flow passage to the branch flow passages in the Y-shaped flow passage is 1: 2.

Compared with the prior art, the utility model has the following advantages:

the utility model relates to a wave-shaped flow field of a proton exchange membrane fuel cell, which adopts a mode that Y-shaped flow channels and circular flow channels are alternately distributed, so that the whole structure is firmer. The Y-shaped flow channel structure has the advantages that the longitudinal section area of the branch flow channel is reduced, the flowing speed of reactants is increased, and the diffusion mass transfer efficiency of the reactants is improved. The circular flow channel is beneficial to redistribution of reactants, and the reactant distribution uniformity is improved.

The flow field of the utility model is circular, the air inlet channel is arranged at the center of a circle, and the reaction gas is diffused radially, so that the phenomenon of insufficient reaction gas caused by overlong flow channel when air is fed from one end is prevented, the hydrothermal management can be effectively carried out, the heat is spread from the center of a circle to the periphery, the water flows from the center of a circle to the periphery, and the hydrothermal distribution is more uniform. The air outlet channels are distributed on the outer side of the circular flow channel at equal intervals, so that the distribution uniformity of the reaction gas on the outer side of the polar plate can be effectively improved.

The utility model adopts the wave-shaped flow passage, and the circular flow passage and the Y-shaped flow passage adopt different vibration angular frequencies, thereby avoiding the phenomenon of excessively fast change of gas diffusion speed.

The parallel rectangular flow channels are arranged at the bottoms of the hoof-shaped ribbed plates, so that the water accumulation under the ribs is avoided, the water produced by the ribs is favorably and quickly discharged, and the phenomena of flow channel blockage and water flooding are avoided.

The arc-shaped structure of the horseshoe-shaped rib plate is beneficial to reducing the resistance when gas passes through and reducing the pressure drop, thereby being beneficial to improving the current density.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required in the description will be briefly introduced below.

FIG. 1 is a three-dimensional schematic view of a wave-shaped flow field structure of a PEMFC according to the present invention

FIG. 2 is a three-dimensional schematic view of a wave-shaped flow field rib plate structure of a PEMFC according to the present invention

In the figure: 1. air inlet, 2, Y-shaped flow channel, 4, circular flow channel, 5, hoof-shaped ribbed plate, 3, air outlet 6, rectangular flow channel, 7 and polar plate material

Detailed Description

The present invention will be described in further detail with reference to the following examples and accompanying drawings. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the utility model.

As shown in fig. 1, the corrugated flow field structure of the proton exchange membrane fuel cell is a circular structure and is axially symmetrically distributed, an air inlet (1) is arranged at the center of the flow field, an air outlet (3) is arranged at the outermost side of the flow field, Y-shaped runners and the circular runners are arranged in a staggered manner, one end of the innermost Y-shaped runner is connected with an air inlet channel, the other end of the innermost Y-shaped runner is connected with a circular channel, one end of the outermost circular channel is connected with the Y-shaped runner, and the other end of the outermost circular channel is connected with an air outlet channel.

Furthermore, the longitudinal cross-sectional area of the Y-shaped flow passage is gradually reduced, and the gradually reduced structure is favorable for ensuring the radial diffusion speed of the reaction gas.

And rectangular grooves which are parallel to each other are further formed at the lower ends of the hoof-shaped rib plates, so that the discharge of product water is facilitated, the accumulation of water can be effectively avoided, and the number of the rectangular channels can be determined according to the area of the polar plate.

Furthermore, the upper ends of the Y-shaped flow channel and the circular channel are both in a wave-shaped design, and the connection part of the Y-shaped flow channel and the circular channel is in smooth connection.

The utility model discloses a theory of operation does: reaction gas enters the whole flow field structure from the gas inlet, and begins to diffuse along the Y-shaped flow channel and the rectangular flow channel at the innermost side, and the gas diffuses from the main flow channel into the branch flow channel and then enters the circular flow channel in the Y-shaped flow channel diffusion process. In the rectangular flow passage diffusion process, the reaction gas directly passes through the rectangular flow passage from the gas inlet and is diffused to the circular flow passage. After the reaction gas is diffused into the innermost circular flow channel, the reaction gas is continuously diffused outwards into the adjacent outer Y-shaped channel and the rectangular channel, and the steps are repeated. The reaction gas is gradually diffused from the circle center to the periphery, and the generated liquid water and the residual reaction gas are discharged out of the flow field structure through the air outlet hole connected with the outermost side circular channel.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides a proton exchange membrane fuel cell wave type flow field structure, its characterized in that, the flow field includes inlet port (1), Y type runner (2), circular runner (4), hoof shaped ribbed slab (5) and venthole (3), the distribution of hoof shaped ribbed slab (5) bottom has rectangle runner (6), the inlet port sets up in the centre of utmost point panel (7), the venthole sets up in the outer end of utmost point panel, the Y type flow field is alternate setting with circular flow field, inlet port (1), hoof shaped ribbed slab (5) and venthole (3) all process on utmost point panel and inlet port and venthole are continuous.

2. The pem fuel cell waveform flow field structure of claim 1, wherein said plate (7) is circular in overall shape.

3. The pem fuel cell waveform flow field structure of claim 1, wherein said ribs (5) are horseshoe-shaped.

4. The waveform flow field structure of proton exchange membrane fuel cell according to claim 1, wherein the longitudinal cross-sectional shapes of the Y-shaped flow channels (2) and the circular flow channels (4) are both wave-shaped curves.

5. The waveform flow field structure of proton exchange membrane fuel cell according to claim 1, wherein the maximum height of the Y-shaped flow channels (2) and the circular flow channels (4) is 1mm, the minimum height is 0.5mm, and the height of the rectangular flow channels is 0.2 mm.

6. The waveform flow field structure of proton exchange membrane fuel cell according to claim 1, wherein the number of the Y-shaped flow channels (2) and the number of the circular flow channels (4) increase in a stepwise manner, and the specific number is related to the area of the plate material.

7. The pem fuel cell waveform flow field structure of claim 1, wherein the distance from said inlet to adjacent circular channels is the same as the distance between different adjacent channels.