CN-121980712-A - Differential cooling flow passage of proton exchange membrane fuel cell and design method thereof

CN121980712ACN 121980712 ACN121980712 ACN 121980712ACN-121980712-A

Abstract

The invention discloses a differential cooling flow passage of a proton exchange membrane fuel cell and a design method thereof, and relates to the technical field of fuel cell thermal management. The method comprises the steps of obtaining a global heat generation power density distribution diagram of a proton exchange membrane fuel cell based on multi-physical field coupling simulation, identifying extreme values of different temperature characteristic areas, defining geometric parameters of a flow passage section, setting flow passage width and flow passage height to be fixed values, determining an upper limit value and a lower limit value of flow passage spacing according to the extreme values of the different temperature characteristic areas, constructing a flow passage spacing mapping function based on local heat generation power density gradient, and obtaining the flow passage spacing according to the mapping function. The invention realizes the collaborative optimization of heat dissipation efficiency and pressure drop loss by quantifying the heat generation density difference between the center and the edge areas based on the real heat generation distribution data of the proton exchange membrane fuel cell and adopting a differential structure of encryption of the flow passage in the center area and relaxation of the flow passage in the edge area.

Inventors

LU CHENGYI
Lv chong
TAN ZHIYUAN
LI JUCHEN
LIU SIYUAN
LI YUHAN
Luo Silun

Assignees

西北工业大学宁波研究院

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A method for designing differential cooling flow channel of proton exchange membrane fuel cell is characterized in that, an arrangement of cooling flow channels in a cooling layer for a bipolar plate in a proton exchange membrane fuel cell, comprising: S1, acquiring a proton exchange membrane fuel cell global heat generation power density distribution diagram based on multi-physical field coupling simulation, and identifying extreme values of different temperature characteristic areas, wherein the extreme values of the different temperature characteristic areas comprise a maximum value and a minimum value of heat generation power density; s2, defining geometric parameters of a flow channel section, wherein the geometric parameters comprise flow channel width, flow channel height and flow channel spacing, setting the flow channel width and the flow channel height as fixed values, and determining an upper limit value and a lower limit value of the flow channel spacing according to extreme values of different temperature characteristic areas, wherein the upper limit value of the flow channel spacing is set according to a heat generation power density minimum value area, and the lower limit value of the flow channel spacing is set according to a heat generation power density maximum value area; S3, constructing a runner spacing mapping function based on the local heat generation power density gradient based on extreme values of different temperature characteristic areas and upper and lower limit values of the runner spacing, and acquiring the runner spacing according to the mapping function.
2. The method for designing a differential cooling flow path for a proton exchange membrane fuel cell according to claim 1, wherein the mapping function is: In the formula, Is the interval of the flow channels; an average heat generation power density of the flow channel coverage area; Is the upper limit value of the runner spacing; Is the lower limit value of the runner spacing; To identify a maximum value of the generated heat power density; to identify minima of the heat generation power density.
3. The method of claim 1, further comprising determining a thermal management constraint boundary based on physical dimensions of the bipolar plate and a pressure drop threshold for coolant flow prior to defining the geometric parameters of the flow channel cross-section, comprising: setting the upper limit of parasitic power consumption of a cooling system, and reversely calculating the maximum pressure drop of a cooling flow channel by combining rated cooling flow and water pump efficiency, wherein the maximum pressure drop is used as a pressure drop threshold value and is used for restraining the lower limit of parameters of the width and the height of the flow channel; And acquiring the total physical width of the bipolar plate reaction area, and limiting the total sum of the transverse dimensions of all the arranged flow channel widths and the flow channel spacing to the total physical width to form a constraint boundary of geometric space arrangement.
4. The method for designing a differential cooling flow path for a pem fuel cell according to claim 1 wherein determining the upper and lower limits of the flow path spacing from the extremum of the different temperature signature areas comprises: Taking the most densely distributed constraint corresponding to the maximum value of the heat generation power density as the lower limit value of the runner spacing, wherein the value of the lower limit value is determined by the minimum ridge width precision limit and the material fracture resistance strength in the bipolar plate processing technology; And taking the most sparse arrangement constraint corresponding to the minimum value of the heat generation power density as the upper limit value of the runner spacing, wherein the upper limit value is determined by the mechanical support strength requirement of the bipolar plate on the membrane electrode assembly and the transverse thermal resistance limitation so as to prevent the membrane electrode from collapsing and ensure the heat transfer continuity.
5. The method for designing a differential cooling flow path for a pem fuel cell of claim 1 wherein said pem fuel cell global heat generation power density profile comprises: And establishing a three-dimensional multi-physical-field simulation model based on membrane electrode parameters, operation conditions and electrochemical reaction kinetic equation of the target proton exchange membrane fuel cell, and obtaining a global heat production power density distribution cloud image of the cell under rated power through simulation calculation.
6. The method for designing the differential cooling flow channel of the proton exchange membrane fuel cell according to claim 1, wherein after the flow channel spacing is obtained, S4, performing three-dimensional solid model integrated modeling, discretization layout optimization and performance index closed-loop simulation verification of the differential cooling flow channel according to the geometric parameters.
7. The method for designing the differential cooling flow channel of the proton exchange membrane fuel cell according to claim 6, wherein the three-dimensional solid model integrated modeling comprises discretizing and rounding the acquired flow channel spacing along the direction from the center to the edge of the cell to generate a three-dimensional geometric model of the differential flow channel; The discretization layout optimization comprises the steps of carrying out step-like normalization processing on the obtained runner spacing according to the stepping precision of bipolar plate processing equipment, carrying out smooth transition on runner transition areas with adjacent different spacing, and checking the accumulated sum of the widths and the spacing of all arranged runners to enable the integrated geometric dimension boundary of the cooling area of the target bipolar plate to be matched.
8. The method for designing the differential cooling flow channel of the proton exchange membrane fuel cell according to claim 6, wherein the performance index closed-loop simulation verification comprises the steps of importing a three-dimensional geometric model of the differential flow channel into COMSOL software for verification, comparing the highest temperature with a uniform temperature index, and verifying the rationality and the accuracy of the established differential flow channel structure.
9. The method for designing a differential cooling flow channel for a PEM fuel cell according to claim 1, wherein a flat-plate PEM fuel cell of 50mm by 50mm is used as a study object, a lower limit value of a flow channel spacing is set to 0.8mm-1.5mm, an upper limit value of the flow channel spacing is set to 2.5mm-4.0mm, The width of the flow channel is 1.0mm-2.0mm, and the height of the flow channel is 0.5mm-1.5mm.
10. A differential cooling flow channel for a proton exchange membrane fuel cell obtained by the method as claimed in any one of claims 1 to 9, wherein the flow channel is arranged in a cooling layer of a bipolar plate, and the flow channel has a non-uniform distribution structure in a flow field plane.

Description

Differential cooling flow passage of proton exchange membrane fuel cell and design method thereof Technical Field The invention relates to the technical field of fuel cell thermal management, in particular to a differential cooling flow passage of a proton exchange membrane fuel cell and a design method thereof. Background The proton exchange membrane fuel cell has wide application prospect in the fields of new energy automobiles, distributed power generation, portable power sources and the like as an efficient and clean energy conversion device. A large amount of waste heat can be generated in the working process of the battery, if the heat cannot be timely and uniformly dissipated, the problems of overhigh temperature or uneven temperature distribution of the battery, dehydration of a proton exchange membrane, attenuation of catalyst activity, aggravation of local reaction and the like are caused, and the output power, the efficiency and the service life of the battery are seriously influenced. At present, for a high-power proton exchange membrane fuel cell, the optimal cooling mode is liquid cooling, the core of a liquid cooling system is a cooling flow channel, and the structure and the type of the cooling flow channel directly determine the flowing state and the heat exchange efficiency of the cooling liquid, so that the cooling flow channel is the key of the heat management of the proton exchange membrane fuel cell. In the prior art, the cooling flow channels mostly adopt a uniform structure, namely the width and the interval among the flow channels are kept consistent, however, the proton exchange membrane fuel cell has obvious non-uniform heat generation characteristics that the central area of the cell has intense reaction, concentrated heat generation, long heat dissipation path and high heat dissipation difficulty, and the edge area has low reaction intensity, less heat generation, easy heat diffusion to the environment and high heat dissipation speed. The traditional uniform cooling flow channel cannot adapt to the heat generation difference, so that the overheating phenomenon occurs due to insufficient heat dissipation in the central area, the energy consumption waste is caused by excessive heat dissipation in the edge area, and finally, the battery performance attenuation and the service life shortening are caused. Therefore, developing a differential cooling flow channel with 'heat dissipation on demand' based on real heat generation distribution becomes a key technical requirement for solving the thermal management bottleneck of the proton exchange membrane fuel cell. Disclosure of Invention Aiming at the defects in the background technology, the invention mainly solves the defect of the prior art that the adaptability of the non-uniform heat generation characteristics of the traditional uniform cooling flow channel and the proton exchange membrane fuel cell is insufficient. The invention provides a differential cooling flow passage of a proton exchange membrane fuel cell and a design method thereof. The flow channel realizes the cooperative optimization of heat dissipation and energy consumption through a differential flow channel structure, and improves the temperature uniformity and the overall performance of the battery. The cooling flow channel designed by the invention is of a differential structure, and based on the difference of the heat generation density of the heat generation distribution data quantization center and the edge of the proton exchange membrane fuel cell, the structure of encryption of the flow channel in the central area and relaxation of the flow channel in the edge area is designed, the width of the flow channel is kept consistent, and the interval of the flow channel is gradually increased along the center of the cell to the edge, so that 'heat dissipation according to the need' is realized. A first object of the present invention is to provide a method for designing a differential cooling flow channel of a proton exchange membrane fuel cell, for arranging cooling flow channels in a cooling layer of a bipolar plate in a proton exchange membrane fuel cell, comprising: S1, acquiring a proton exchange membrane fuel cell global heat generation power density distribution diagram based on multi-physical field coupling simulation, and identifying extreme values of different temperature characteristic areas, wherein the extreme values of the different temperature characteristic areas comprise a maximum value and a minimum value of heat generation power density; s2, defining geometric parameters of a flow channel section, wherein the geometric parameters comprise flow channel width, flow channel height and flow channel spacing, setting the flow channel width and the flow channel height as fixed values, and determining an upper limit value and a lower limit value of the flow channel spacing according to extreme values of different temperature characteristic areas, wherein t