CN115292770B - Optimization method and system for fuel cell stack channel structure - Google Patents

Optimization method and system for fuel cell stack channel structure Download PDF

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CN115292770B
CN115292770B CN202211187586.8A CN202211187586A CN115292770B CN 115292770 B CN115292770 B CN 115292770B CN 202211187586 A CN202211187586 A CN 202211187586A CN 115292770 B CN115292770 B CN 115292770B
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薛学良
刘锋
钱伟
张贝贝
林伟鹏
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Foshan Cleanest Energy Technology Co Ltd
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Abstract

The invention relates to the technical field of fuel cells, and particularly discloses an optimization method and an optimization system for a fuel cell stack channel structure, wherein the optimization method comprises the following steps: constructing a single cell-electric pile CFD porous medium numerical calculation model, and distributing a variation coefficient CV by the flow of the fuel cell electric pile, and the total pressure drop of the inlet and the outlet of the fuel cell electric pile
Figure 669637DEST_PATH_IMAGE001
Coefficient of cell flow excess
Figure 559095DEST_PATH_IMAGE002
Unevenness of
Figure 500506DEST_PATH_IMAGE003
And cell voltage drop
Figure 551639DEST_PATH_IMAGE004
And as an optimization condition, realizing efficient optimization of the inlet and outlet common channel structure of the fuel cell stack and the variable flow area structure of the single cell and the common channel of the fuel cell stack based on the simulation calculation result of the single cell-single stack CFD porous medium numerical calculation model.

Description

Optimization method and system for fuel cell stack channel structure
Technical Field
The invention relates to the technical field of fuel cell simulation optimization, in particular to an optimization method and system for a fuel cell stack channel structure.
Background
During the operation of the fuel cell stack, not only the fluid distribution uniformity of each flow channel inside a single cell is related to the cell performance, but also the fluid distribution uniformity flowing into each single cell from a common channel of the stack has a great influence on the operation performance of the stack. The distribution uniformity of the air and hydrogen flow among the single cells is poor, which may cause great difference in performance uniformity among the single cells, and the phenomena of serious water blockage, single low and the like of partial single cells affect the stable operation and the overall performance of the electric pile. The poor uniformity of coolant flow distribution between the monocells may cause that heat generated by part of the cells cannot be taken away in time, so that the temperature is too high, a membrane electrode and even a bipolar plate are burnt out, and the galvanic pile is seriously damaged. Therefore, the optimization work of the common channel structure of the electric pile is very important.
Because the cost of the whole pile of the electric pile is high, and a plurality of rounds of structural changes are possible, if the structure is optimized by adopting an experimental method, the processing time and the cost are very large, and therefore a simulation method is generally adopted in the design stage. The whole pile has complex geometric structure, the number of single cells is hundreds or even more than 400, if the original three-dimensional geometric model is used for simulation calculation, the current hardware calculation resources and capability are difficult to realize, and in addition, the time and cost required by the optimization of multiple rounds are not less than that of the test; if the simplified one-dimensional model is adopted for simulation, the precision of the calculation structure is difficult to ensure.
The prior Chinese patent with application number 2021111572038 and publication number CN114065567A discloses a fuel cell stack common manifold structure optimization method, which utilizes a cuboid structure to simulate and construct a monocell simulation structure according to the size of a flow field runner of a monocell in a stack structure, simplifies the grid amount of the monocell simulation structure when a finite element grid is divided, and reduces the simulation calculation amount. However, the practical application research of the present application finds that the existing patent only uses the flow distribution unevenness of the single cell simulation structure and the total pressure loss of the inlet and outlet areas of the common manifold simulation structure as optimization conditions, and cannot perform efficient simulation optimization on the common channel structure of the fuel cell stack.
Therefore, the prior art is still in need of further improvement and development.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide an optimization method and an optimization system for a fuel cell stack common manifold structure, and aims to solve the problem that the conventional optimization method for the fuel cell stack common manifold structure cannot perform efficient simulation optimization on the fuel cell stack common manifold structure.
The technical scheme of the invention is as follows:
a method for optimizing a channel structure of a fuel cell stack, comprising the steps of:
constructing a single cell CFD numerical calculation model according to a single cell geometric structure of the fuel cell stack;
constructing a single cell CFD porous medium numerical calculation model based on the single cell CFD numerical calculation model according to the variable flow area structure of the single cell and the public channel;
constructing a CFD numerical calculation model of a common channel of the fuel cell stack according to the geometric structure of the common channel of the fuel cell stack;
establishing a single cell-electric pile CFD porous medium numerical calculation model according to the single cell CFD porous medium numerical calculation model and the electric pile common channel CFD numerical calculation model;
optimizing the inlet and outlet common channel structure of the fuel cell stack according to the simulation calculation result of the single cell-stack CFD porous medium numerical calculation model, so that the flow distribution variation coefficient CV of the fuel cell stack meets a first target design value, and the total pressure drop of the inlet and outlet of the fuel cell stack meets a first target design value
Figure DEST_PATH_IMAGE001
Satisfying a second target design value, a cell flow excess coefficient in the fuel cell stack
Figure DEST_PATH_IMAGE002
Unevenness of
Figure DEST_PATH_IMAGE003
Satisfy a third target design valueSingle cell voltage drop in the fuel cell stack
Figure DEST_PATH_IMAGE004
Satisfying a fourth target design value;
after the inlet and outlet common channel structure of the fuel cell stack is optimized and determined, the variable flow area structure of a single cell and a common channel in the fuel cell stack is optimized according to the simulation calculation result of the CFD numerical computation model of the single cell-stack, so that the flow distribution variation coefficient CV of the fuel cell stack meets a fifth target design value, and the total pressure drop of the inlet and outlet of the fuel cell stack
Figure DEST_PATH_IMAGE005
A sixth target design value is satisfied, and a single cell flow excess coefficient in the fuel cell stack
Figure 742703DEST_PATH_IMAGE002
Unevenness of
Figure 128685DEST_PATH_IMAGE003
A single cell voltage drop in the fuel cell stack satisfying a seventh target design value
Figure 111684DEST_PATH_IMAGE004
The eighth target design value is satisfied.
The optimization method of the fuel cell stack channel structure comprises the following steps of calculating a flow distribution variation coefficient CV of the fuel cell stack according to the following formula:
Figure DEST_PATH_IMAGE006
wherein, in the process,
Figure DEST_PATH_IMAGE007
the flow rate of the ith single cell of the fuel cell stack is measured; n is the total number of single cells of the fuel cell stack,
Figure DEST_PATH_IMAGE008
is that theAverage flow rate of each unit cell of the fuel cell stack.
The optimization method of the channel structure of the fuel cell stack is characterized in that the total pressure drop of the inlet and the outlet of the fuel cell stack
Figure 913418DEST_PATH_IMAGE005
Calculated according to the following formula:
Figure DEST_PATH_IMAGE009
wherein, in the process,
Figure DEST_PATH_IMAGE010
calculating an inlet average static pressure value of a model for the single cell CFD porous medium numerical value;
Figure DEST_PATH_IMAGE011
and calculating the outlet average static pressure value of the model for the single cell CFD porous medium numerical value.
The optimization method of the fuel cell stack channel structure is characterized in that each single cell flow excess coefficient in the fuel cell stack
Figure DEST_PATH_IMAGE012
Unevenness of
Figure DEST_PATH_IMAGE013
Calculated according to the following formula:
Figure DEST_PATH_IMAGE014
wherein, in the step (A),
Figure 841972DEST_PATH_IMAGE012
the flow excess coefficient of the ith single cell is obtained; and n is the total number of single cells of the fuel cell stack.
The optimization method of the fuel cell stack channel structure is characterized in that the pressure drop of a single cell in the fuel cell stack
Figure 867697DEST_PATH_IMAGE004
According to the followingThe following formula is calculated:
Figure DEST_PATH_IMAGE015
wherein, in the step (A),
Figure DEST_PATH_IMAGE016
the inlet static pressure value of the ith single cell,
Figure DEST_PATH_IMAGE017
the outlet static pressure value of the ith single cell is shown.
The optimization method of the fuel cell stack channel structure comprises the following steps of constructing a single cell CFD porous medium numerical calculation model based on the single cell CFD numerical calculation model according to the variable flow area structure of a single cell and a common channel, wherein the step comprises the following steps:
the single cell CFD numerical calculation model comprises a bipolar plate with a flow field flow channel structure, a gas diffusion layer, a microporous layer, a catalytic layer and a proton exchange membrane;
setting the cross section size of the single cell CFD porous medium numerical calculation model as the cross section size of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model; and setting the height direction size of the single cell CFD porous medium numerical calculation model as the depth direction size of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model.
The optimization method of the fuel cell stack channel structure further comprises the following steps:
giving corresponding inlet flow to different working conditions of the single cell CFD numerical calculation model to obtain corresponding single cell flow field pressure drop, performing data analysis on a calculated flow resistance curve of the single cell, and fitting a function relation of speed and pressure drop;
obtaining the inertial resistance coefficient of the single cell CFD porous medium numerical calculation model according to the function relation of the speed and the pressure drop of the single cell CFD numerical calculation model
Figure DEST_PATH_IMAGE018
And coefficient of viscous drag
Figure DEST_PATH_IMAGE019
。
The optimization method of the fuel cell stack channel structure comprises the following steps of establishing a single cell-stack CFD porous medium numerical calculation model according to a single cell CFD porous medium numerical calculation model and a stack common channel CFD numerical calculation model:
and setting the single cell CFD porous medium numerical calculation model as a porous medium area, setting the pile common channel CFD numerical calculation model as a fluid area, and establishing a single cell-single pile CFD porous medium numerical model of the fuel cell pile.
A storage medium having one or more programs stored thereon that are executable by one or more processors to implement the steps in the fuel cell stack channel structure optimization method of the present invention.
An optimization system for a channel structure of a fuel cell stack, comprising: a processor, a memory, and a communication bus; the memory has stored thereon a computer readable program executable by the processor;
the communication bus realizes connection communication between the processor and the memory;
the processor, when executing the computer readable program, implements the steps in the fuel cell stack channel structure optimization method of the present invention.
Has the beneficial effects that: the invention provides an optimization method of a fuel cell stack channel structure, which comprises the steps of firstly, respectively establishing a single cell CFD numerical calculation model and a single cell CFD porous medium numerical calculation model based on a single cell geometric structure of a real proton exchange membrane fuel cell and a variable flow area structure of the real proton exchange membrane fuel cell and a public channel; then establishing a CFD numerical calculation model of the common channel of the fuel cell stack based on the geometric structure of the common channel of the fuel cell stack, and further establishing a single cell-single stack CFD porous medium numerical calculation model of the fuel cell stack; finally, the flow distribution variation coefficient CV of the fuel cell galvanic pile is used, and the total pressure drop of the inlet and the outlet of the fuel cell galvanic pile
Figure DEST_PATH_IMAGE020
Coefficient of cell flow excess
Figure DEST_PATH_IMAGE021
Unevenness of
Figure DEST_PATH_IMAGE022
And cell voltage drop
Figure DEST_PATH_IMAGE023
And as an optimization condition, realizing efficient optimization of the inlet and outlet common channel structure of the fuel cell stack and the variable flow area structure of the single cell and the common channel of the fuel cell stack based on the simulation calculation result of the single cell-single stack CFD porous medium numerical calculation model.
Drawings
FIG. 1 is a flow diagram of the connection hole between the common channel and the single cell of the fuel cell stack according to the present invention.
Fig. 2 is a schematic structural diagram of the present invention, in which a bidirectional extension baffle or a unidirectional extension baffle (collectively arranged in a left extension manner or collectively arranged in a right extension manner) is arranged at an air flow inlet of a single cell, so as to reduce the aperture area of the single cell.
Fig. 3 is a schematic structural diagram of a single cell-single pile CFD porous medium numerical calculation model.
Fig. 4 is a schematic view of a variable flow area structure of a single cell and a common channel.
FIG. 5 is a graph illustrating a single cell excess coefficient distribution in a fuel cell stack.
Fig. 6 is a graph illustrating a cell pressure drop profile in a fuel cell stack.
Fig. 7 is a schematic diagram of an optimization system of a channel structure of a fuel cell stack according to the present invention.
Detailed Description
The present invention provides a method and a system for optimizing a fuel cell stack channel structure, and the present invention is further described in detail below in order to make the purpose, technical solution and effect of the present invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Computational Fluid Dynamics (CFD) is an analysis of a system containing related physical phenomena such as Fluid flow and heat conduction by computer numerical calculation and image display, which can be regarded as numerical simulation of flow under the control of a basic equation of flow. Through the numerical simulation and the combination of a graphic processing tool, the structure optimization design can be carried out.
Based on this, the invention provides a method for optimizing a channel structure of a fuel cell stack, which comprises the following steps:
s100, constructing a single cell CFD numerical calculation model according to a single cell geometric structure of the fuel cell stack;
s200, constructing a single cell CFD porous medium numerical calculation model based on the single cell CFD numerical calculation model according to a variable flow area structure of the single cell and the public channel;
s300, constructing a CFD numerical calculation model of the common channel of the fuel cell stack according to the geometric structure of the common channel of the fuel cell stack;
s400, establishing a single cell-electric pile CFD porous medium numerical calculation model according to the single cell CFD porous medium numerical calculation model and the electric pile common channel CFD numerical calculation model;
s500, optimizing a common inlet and outlet channel structure of the fuel cell stack according to a simulation calculation result of the CFD numerical calculation model of the single cell-stack to ensure that the flow distribution variation coefficient CV of the fuel cell stack meets a first target design value and the total inlet and outlet pressure drop of the fuel cell stack meets a first target design value
Figure 915156DEST_PATH_IMAGE020
Satisfying a second target design value, a cell flow excess coefficient in the fuel cell stack
Figure 582898DEST_PATH_IMAGE021
Unevenness of
Figure 517356DEST_PATH_IMAGE022
Satisfying a third target design value, a cell voltage drop in the fuel cell stack
Figure 979561DEST_PATH_IMAGE023
Satisfying a fourth target design value;
s600, after the inlet and outlet common channel structure of the fuel cell stack is optimized and determined, optimizing the variable flow area structure of a single cell and a common channel in the fuel cell stack according to the simulation calculation result of the CFD (computational fluid dynamics) numerical calculation model of the single cell-stack to ensure that the flow distribution variation coefficient CV of the fuel cell stack meets a fifth target design value, and the total pressure drop of the inlet and outlet of the fuel cell stack
Figure 937153DEST_PATH_IMAGE020
A sixth target design value is satisfied, and a single cell flow excess coefficient in the fuel cell stack
Figure 143006DEST_PATH_IMAGE021
Unevenness of
Figure 931971DEST_PATH_IMAGE022
Satisfying a seventh target design value, a cell voltage drop in the fuel cell stack
Figure 565077DEST_PATH_IMAGE023
The eighth target design value is satisfied.
After a single cell-single stack CFD porous medium numerical calculation model of the fuel cell stack is established, the flow distribution variation coefficient CV of the fuel cell stack and the total pressure drop of the inlet and the outlet of the fuel cell stack are used
Figure 774079DEST_PATH_IMAGE020
Cell flow excess factor
Figure 518044DEST_PATH_IMAGE021
Unevenness of
Figure 427095DEST_PATH_IMAGE022
And cell voltage drop
Figure 965523DEST_PATH_IMAGE023
As an optimization condition, the high-efficiency optimization of the inlet and outlet common channel structure of the fuel cell stack and the variable flow area structure of a single cell and a common channel of the fuel cell stack is realized based on the simulation calculation result of a single cell-single stack CFD porous medium numerical calculation model.
In the present invention, the first target design value, the second target design value, the third target design value and the fourth target design value are designed for optimally adjusting the inlet and outlet common channel structures of the fuel cell stack, the fifth target design value, the sixth target design value, the seventh target design value and the eighth target design value are designed based on further optimizing and adjusting the variable flow area structures of the single cells and the common channels (i.e. the U-shaped necking manner at the connection between the common channels and the single cells) after the inlet and outlet common channel structures are optimally adjusted, and the fifth to eighth target design values are further optimization targets of the same design variable compared with the first to fourth target design values, which are more stringent requirements and can achieve better performance after conditions are satisfied.
The invention uses the flow distribution coefficient of variation CV and total pressure drop of the inlet and outlet of the galvanic pile
Figure 163287DEST_PATH_IMAGE020
As a global evaluation index of the fuel cell stack level, a single cell flow excess coefficient is used
Figure 507680DEST_PATH_IMAGE021
Unevenness of
Figure 208920DEST_PATH_IMAGE022
And single cell voltage drop
Figure 449408DEST_PATH_IMAGE023
As a single cell layerThe evaluation indexes of the key parameter distribution uniformity of the surface optimize the fuel cell stack channel structure from two layer indexes.
In some embodiments, a cell CFD numerical calculation model is constructed from the cell geometry of the fuel cell stack. In this embodiment, the single cell CFD numerical calculation model includes a bipolar plate having a flow field channel structure, a gas diffusion layer, a microporous layer, a catalytic layer, and a proton exchange membrane. The bipolar plate of the single cell CFD numerical calculation model takes the real flow field flow channel structure into consideration, establishes a numerical calculation model taking the actual single cell flow field flow channel structure as a physical model, and can realize the analysis of the influence of the cell structure design on the cell performance. The single cell CFD numerical calculation model considers conservation models of flow, heat transfer, mass transfer, electrochemical reaction, current transmission and the like.
In some embodiments, corresponding flow field pressure drop of the monocell can be accurately obtained by giving corresponding inlet flow to different working conditions of the CFD numerical calculation model of the monocell, data analysis is carried out on a calculated flow resistance curve of the monocell, and a function relation of speed and pressure drop is fitted; calculating and simulating a speed-pressure drop curve of the single cell CFD numerical calculation model to obtain an inertial resistance coefficient of the single cell CFD porous medium numerical model
Figure 665626DEST_PATH_IMAGE018
And coefficient of viscous drag
Figure DEST_PATH_IMAGE024
And conditions are provided for further uniform distribution calculation of the galvanic pile fluid.
Specifically, different excess coefficients are given to the fluid channels (hydrogen, air, water) of the single-cell CFD numerical calculation model
Figure DEST_PATH_IMAGE025
Lower inlet flow
Figure DEST_PATH_IMAGE026
And simulating to obtain the voltage drop of the corresponding single cell CFD numerical calculation model
Figure DEST_PATH_IMAGE027
(non-actual measurement flow resistance), converting the flow into a speed value v under the corresponding inlet structure size, acquiring speed values of different flows, calculating the speed value v of the model according to the single cell CFD numerical value, simulating to obtain the pressure drop of the single cell CFD numerical value calculation model corresponding to the different speed values v, and calculating the functional relation formula of the speed and the pressure drop of the model according to the single cell CFD numerical value
Figure DEST_PATH_IMAGE028
。
In some embodiments, the velocity as a function of pressure drop for the model is calculated from the single cell CFD values
Figure 922033DEST_PATH_IMAGE028
Obtaining the inertial resistance coefficient of the single cell CFD porous medium numerical calculation model
Figure 477779DEST_PATH_IMAGE018
And coefficient of viscous drag
Figure DEST_PATH_IMAGE029
。
Specifically, in fluid calculations, the porous medium region is reduced to a fluid region where the source of resistance is increased, in a manner that provides a velocity-dependent momentum sink in the porous region, expressed as:
Figure DEST_PATH_IMAGE030
in the formula (I), wherein,
Figure DEST_PATH_IMAGE031
a source term of the momentum equation in the ith (x, y, z) direction;
Figure DEST_PATH_IMAGE032
is a speed value; d and C are designated matrixes, and the first term on the right side in the formula is a viscous loss term and the second term is an inertial loss term.
For a homogeneous porous medium, then the rewritables are:
Figure DEST_PATH_IMAGE033
in the formula (I), wherein,
Figure DEST_PATH_IMAGE034
in order to be able to determine the permeability,
Figure DEST_PATH_IMAGE035
in order to be the coefficient of inertial resistance,
Figure 726052DEST_PATH_IMAGE029
is the coefficient of viscous drag. At this time, the matrix D is
Figure 429566DEST_PATH_IMAGE024
. The momentum sink acts on the fluid to create a pressure gradient,
Figure DEST_PATH_IMAGE036
that is to say have
Figure DEST_PATH_IMAGE037
To do so
Figure DEST_PATH_IMAGE038
Is the thickness of the porous media domain. The fluid flows through the single cell CFD numerical calculation model in a function of the speed and the pressure drop,
Figure DEST_PATH_IMAGE039
wherein
Figure DEST_PATH_IMAGE040
。
In some embodiments, the cross-sectional dimension of the single cell CFD porous medium numerical calculation model is set as the cross-sectional dimension of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model; and setting the height direction dimension of the single cell CFD porous medium numerical calculation model as the depth direction dimension of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model.
In some embodiments, the single cell-single stack CFD porous medium numerical model of the fuel cell stack is established by setting the single cell CFD porous medium numerical calculation model as a porous medium region, setting the stack common channel CFD numerical calculation model as a fluid region; carrying out grid division on a single cell-stack CFD porous medium numerical calculation model of the fuel cell stack; in the single cell-stack CFD porous medium numerical calculation model of the fuel cell stack, resistance pressure drop of each single cell is equivalently replaced by the single cell CFD porous medium numerical model, the single cell CFD numerical calculation model is obtained by an actual single cell real geometric structure (comprising a plurality of flow channels, bridges and other structures), but if the single cell CFD numerical calculation model is directly applied to single cell-stack simulation, the model is complex, so that equivalent replacement and simplification need to be carried out on the single cell CFD numerical calculation model in calculation, and the single cell CFD porous medium numerical model is obtained as a result of replacement and simplification. The connection between the single cell CFD numerical calculation model and the single cell CFD porous medium numerical model is equivalent to a black box, and the same pressure drop can be fed back given the same inlet flow.
Specifically, the invention sets the flow area of the fuel battery single cells and the common channel as 100 percent, optimizes and adjusts the inlet and outlet common channel structure of the fuel battery electric pile so that the flow distribution variation coefficient CV of the fuel battery electric pile meets a first target design value, and the total pressure drop of the inlet and outlet of the fuel battery electric pile meets a first target design value
Figure DEST_PATH_IMAGE041
Satisfying a second target design value, a cell flow excess coefficient in the fuel cell stack
Figure DEST_PATH_IMAGE042
Unevenness of
Figure DEST_PATH_IMAGE043
Satisfying a third target design value, a cell voltage drop in the fuel cell stack
Figure DEST_PATH_IMAGE044
The fourth target design value is satisfied.
And taking the inlet and outlet common channel structures of the fuel cell electric stacks meeting the conditions as the inlet and outlet common channel structures of the target fuel cell electric stacks.
Specifically, the static pressure of the fluid flowing in the common channel is perpendicular to the side walls. And static pressure difference exists between the common channel and the two sides of the single cell connecting hole, and fluid can flow out of the hole in the direction perpendicular to the side wall. According to the theory of hydrodynamics, the flow velocity resulting from the effect of the static pressure difference is:
Figure DEST_PATH_IMAGE045
(1) (ii) a The flow rate of the fluid in the common channel is as follows:
Figure DEST_PATH_IMAGE046
(2) In the formula:
Figure DEST_PATH_IMAGE047
static pressure in the public channel;
Figure DEST_PATH_IMAGE048
is the dynamic pressure in the common channel.
Thus, the actual flow rate and the direction of outflow of the fluid from the orifice are influenced by the flow rate in the utility channel in addition to the flow rate and direction resulting from the static pressure. As shown in fig. 1, the outflow direction in the hole is deflected under the influence of the flow velocity in the common channel, and the actual outlet flow direction from the orifice makes an angle α with the axis of the common channel. Defining the area of the orifice
Figure DEST_PATH_IMAGE049
Projected area of orifice perpendicular to direction of fluid flow
Figure DEST_PATH_IMAGE050
The actual orifice flow rate v, has:
Figure DEST_PATH_IMAGE051
(3) (ii) a The orifice outflow is:
Figure DEST_PATH_IMAGE052
(4) In the formula
Figure DEST_PATH_IMAGE053
Is the orifice flow coefficient. It can be seen from the analysis of equation (4) that to achieve uniform distribution of fluid among the cells, a reduction in orifice area can be adopted
Figure 646921DEST_PATH_IMAGE049
The method (1) is carried out.
The invention only changes the shape and size of the common channel when improving the structure of the common channel of the fuel cell stack, but actually changes the orifice area at the joint of the single cells and the common channel by adopting a U-shaped necking mode, as shown in figure 2, the orifice area is reduced by adopting the U-shaped necking mode to realize the uniform distribution of fluid among the single cells. Specifically, at the connection between the common channel and each single cell airflow inlet, a bidirectional extension baffle or a unidirectional extension baffle (collectively extending leftwards or rightwards) is arranged at the single cell airflow inlet, so that the orifice area of the single cells is reduced, and the fluid entering from the common channel is uniformly distributed among the single cells.
Further, a variable flow area structure of a single cell and a common channel in the fuel cell stack is optimized according to a simulation calculation result of the single cell-stack CFD porous medium numerical calculation model, so that a flow distribution variation coefficient CV of the fuel cell stack meets a fifth target design value, and total pressure drops at an inlet and an outlet of the fuel cell stack meet a fifth target design value
Figure DEST_PATH_IMAGE054
Satisfying a sixth target design value, a cell flow excess coefficient in the fuel cell stack
Figure DEST_PATH_IMAGE055
Unevenness of
Figure DEST_PATH_IMAGE056
Satisfying a seventh target design value, a cell voltage drop in the fuel cell stack
Figure DEST_PATH_IMAGE057
The eighth target design value is satisfied.
Specifically, a structural schematic diagram of the single cell CFD porous medium numerical calculation model is shown in fig. 3, wherein fig. 4 is a structural schematic diagram of a variable flow area of a single cell and a common channel. In the present embodiment, the single cell and common channel variable flow area structure of the fuel cell stack satisfying the above conditions is used as a target single cell and common channel variable flow area structure of the fuel cell stack.
In some embodiments, the flow distribution coefficient of variation CV of the fuel cell stack is calculated as follows:
Figure DEST_PATH_IMAGE058
wherein, in the step (A),
Figure DEST_PATH_IMAGE059
the flow rate of the ith single cell of the fuel cell stack is measured; n is the total number of single cells of the fuel cell stack,
Figure DEST_PATH_IMAGE060
the average flow rate of each single cell of the fuel cell stack.
In some embodiments, the total pressure drop of the inlet and the outlet of the fuel cell stack
Figure DEST_PATH_IMAGE061
Calculated according to the following formula:
Figure DEST_PATH_IMAGE062
wherein, in the process,
Figure DEST_PATH_IMAGE063
calculating an inlet average static pressure value of a model for the single cell CFD porous medium numerical value;
Figure DEST_PATH_IMAGE064
and calculating the outlet average static pressure value of the model for the single cell CFD porous medium numerical value.
In some embodiments, each cell flow excess factor in the fuel cell stack
Figure DEST_PATH_IMAGE065
Unevenness of
Figure DEST_PATH_IMAGE066
Calculated according to the following formula:
Figure DEST_PATH_IMAGE067
wherein, in the step (A),
Figure DEST_PATH_IMAGE068
the flow excess coefficient of the ith single cell is obtained; and n is the total number of single cells of the fuel cell stack.
In some embodiments, the cell voltage drop in the fuel cell stack
Figure DEST_PATH_IMAGE069
Calculated according to the following formula:
Figure DEST_PATH_IMAGE070
wherein, in the step (A),
Figure DEST_PATH_IMAGE071
the inlet static pressure value of the ith single cell,
Figure DEST_PATH_IMAGE072
the outlet static pressure value of the ith single cell is shown.
The following further explains the optimization method of the fuel cell stack channel structure according to the present invention by specific embodiments:
example 1 (A: 100% + 100%)
The optimization method is applied to a cell stack consisting of 600 single cells, and the channel structure of the cell stack is subjected to simulation calculation, analysis and evaluation:
s1, constructing a single cell CFD numerical calculation model by using three-dimensional modeling software according to a single cell geometric structure of a fuel cell stack, wherein the three-dimensional modeling software can be CATIA software, but is not limited to the CATIA software;
s2, importing the single cell CFD numerical calculation model constructed in the step S1 into grid division software for grid division to obtain a grid model and ensure grid quality, wherein the grid division software can be ICEM software, but is not limited to ICEM software;
s3, introducing the grid model into fluid calculation software to select a relevant model, determine boundary conditions and set solving parameters, wherein the inlet boundary conditions are set as follows: for different working conditions of the single cell CFD numerical calculation model, corresponding single cell inlet flow under different excess coefficients is given, and single cell inlet flow velocity is obtained through conversion according to the flow area of a common channel and a single cell, wherein the fluid calculation software can be fluent software, but is not limited to the fluent software;
s4, simulating and calculating the corresponding CFD numerical calculation model flow field pressure drop delta P of the single cell, wherein the pressure drop delta P is shown in a table 1:
TABLE 1
Figure DEST_PATH_IMAGE073
S5, performing data analysis on the calculated flow resistance curve of the single cell, and fitting a function relation of the inlet flow velocity and the pressure drop of the CFD numerical calculation model of the single cell;
Figure DEST_PATH_IMAGE074
；
s6, calculating the inlet flow rate and the inlet flow rate of the model according to the single cell CFD numerical value obtained in the step S5Pressure drop function, density of 1.225kg/m for air working operating conditions, kinematic viscosity of 1.79E-05kg/m/s for working operating conditions, effective length of single cell CFD porous medium numerical model
Figure DEST_PATH_IMAGE075
Calculating the inertial resistance coefficient of the single cell CFD porous medium numerical calculation model
Figure DEST_PATH_IMAGE076
And coefficient of viscous drag
Figure DEST_PATH_IMAGE077
The results are shown in Table 2, in which,
Figure DEST_PATH_IMAGE078
，
Figure DEST_PATH_IMAGE079
；
TABLE 2
Figure DEST_PATH_IMAGE080
S7, constructing a single cell CFD porous medium numerical calculation model by using three-dimensional modeling software based on the single cell CFD numerical calculation model constructed in the step S1, and setting the cross section size of the single cell CFD porous medium numerical calculation model as the cross section size of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model; setting the height direction size of the single cell CFD porous medium numerical calculation model as the depth direction size of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model;
s8, constructing a geometric model of a flow field of an air channel of the fuel cell by using three-dimensional modeling software according to the structure of the fuel cell stack, wherein the geometric model is a structural schematic diagram of a numerical calculation model of a single cell-single stack CFD porous medium shown in FIG 3;
s9, 1 in figure 3 is a common inlet channel of the fuel cell stack, which is arranged as a fluidA domain; FIG. 3 shows a fuel cell stack outlet common channel at 3, arranged in the fluid domain; in fig. 3, 2 is a stack of 600 single-cell CFD porous medium numerical calculation models, the geometric structure of which is obtained in step S7 and is set as a porous medium domain, and the parameter viscosity resistance coefficient of the porous medium model of which is set as the porous medium domain
Figure 11886DEST_PATH_IMAGE077
And coefficient of inertial resistance
Figure 390914DEST_PATH_IMAGE076
The obtaining by step S6;
s10, importing the single cell-single pile CFD porous medium numerical calculation model into grid division software for grid division to obtain a single cell-single pile CFD porous medium numerical calculation grid model and ensure grid quality;
s11, introducing the single cell-single pile CFD porous medium numerical calculation grid model into fluid calculation software to select related models, determine boundary conditions and set solving parameters. Wherein the entry boundary conditions are set as follows: for the numerical calculation model of the single cell-single pile CFD porous medium, giving corresponding cell pile inlet flow under the condition that an excess coefficient is 1.7 (or other excess coefficients); the exit boundary conditions were set as follows: a pressure outlet boundary; the operating pressure was set to 101325Pa;
s12, simulating and calculating a corresponding single cell-single pile CFD porous medium numerical calculation model, and performing post-processing on the calculation result to obtain the average flow of 600 single cells:
Figure DEST_PATH_IMAGE081
and then calculating to obtain a flow distribution variation coefficient CV of the fuel cell stack:
Figure DEST_PATH_IMAGE082
through the post-processing analysis of the calculation result, the CV value of the numerical calculation model of the single cell-single pile CFD porous medium before optimization can be obtained to be 5.815%.
Analyzing the result, selecting the inlet boundary surface of the inlet common channel to obtain the average static pressure value of the inlet
Figure DEST_PATH_IMAGE083
(ii) a Selecting the outlet boundary surface of the common channel of the outlet to obtain the average static pressure value of the outlet
Figure DEST_PATH_IMAGE084
Total pressure drop of inlet and outlet of the fuel cell stack
Figure DEST_PATH_IMAGE085
Calculated according to the following formula:
Figure DEST_PATH_IMAGE086
calculating to obtain total pressure drop of inlet and outlet of fuel cell stack
Figure 408156DEST_PATH_IMAGE085
=43.441KPa。
Post-processing the calculation results to obtain the flow excess coefficient of each single battery of 600 single batteries
Figure DEST_PATH_IMAGE088
The minimum excess factor is not 1.602, and the maximum excess factor is 1.920;
fig. 5 is a schematic diagram of a cell excess coefficient distribution curve.
Post-processing and analyzing the calculation result, and respectively selecting the interfaces of the common channel at the inlet of the cell stack and 600 single cells to obtain the inlet static pressure value of each single cell
Figure DEST_PATH_IMAGE089
(ii) a Respectively selecting the interfaces of the common channel at the outlet of the electric pile and 600 single cells to obtain the outlet static pressure value of each single cell
Figure DEST_PATH_IMAGE090
；
The voltage drop of each single cell in the fuel cell stack
Figure DEST_PATH_IMAGE091
Calculated according to the following formula:
Figure DEST_PATH_IMAGE092
；
fig. 6 is a schematic diagram of the pressure drop distribution curve of each unit cell of the fuel cell stack.
Table 3 is the static pressure distribution of the single cell-stack porous medium model of example 1, which includes the inlet average static pressure value of the inlet common channel and the outlet average static pressure value of the outlet common channel; for convenience of calculation, the inlet static pressure value of each 20 single cells, the outlet static pressure value of each 20 single cells and the pressure drop of each 20 single cells are respectively selected for statistical analysis.
TABLE 3
Figure DEST_PATH_IMAGE093
Example 2 (B: 50% + 100%)
And after the inlet and outlet common channel structure of the fuel cell stack is optimized and determined, optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack according to the simulation calculation result of the CFD (computational fluid dynamics) porous medium numerical calculation model of the single cell-stack.
In the embodiment 2, the orifice area (50% of the maximum orifice area) at the gas inlet is reduced in a necking mode by changing the interface flow area of the common inlet channel of the fuel cell stack and each single cell, so that the uniform distribution of the fluid among the single cells is realized.
Fig. 4 is a schematic view of a variable flow area structure of a single cell and a common channel.
The simulation calculation procedure was the same as S1 to S11 in example 1.
S12, simulating and calculating a corresponding single cell-single pile CFD porous medium numerical calculation model, and performing post-processing on the calculation result to obtain the average flow of 600 single cells:
Figure DEST_PATH_IMAGE094
and further calculating and obtaining a flow distribution variation coefficient CV of the fuel cell stack:
Figure DEST_PATH_IMAGE095
through the post-processing analysis of the calculation result, the CV value of the numerical calculation model of the single cell-single pile CFD porous medium before optimization is 3.350 percent, and the CV calculation value is reduced compared with that of the example 1.
Analyzing the result, selecting the inlet boundary surface of the inlet common channel to obtain the average static pressure value of the inlet
Figure DEST_PATH_IMAGE096
(ii) a Selecting the outlet boundary surface of the common channel of the outlet to obtain the average static pressure value of the outlet
Figure DEST_PATH_IMAGE097
Then the total pressure drop of the inlet and outlet of the fuel cell stack is reduced
Figure DEST_PATH_IMAGE098
Calculated according to the following formula:
Figure DEST_PATH_IMAGE099
calculating to obtain total pressure drop of inlet and outlet of fuel cell stack
Figure DEST_PATH_IMAGE100
=46.150KPa。
The calculation results are post-processed to obtain the flow excess coefficient of each single battery of 600 single batteries
Figure 762137DEST_PATH_IMAGE088
Minimum excess factor of not 1.650The maximum excess factor was 1.837.
Fig. 5 is a schematic view of a cell excess coefficient distribution curve.
Post-processing and analyzing the calculation result, and respectively selecting the interfaces of the common channel at the inlet of the cell stack and 600 single cells to obtain the inlet static pressure value of each single cell
Figure DEST_PATH_IMAGE101
(ii) a Respectively selecting the interfaces of the common channel at the outlet of the electric pile and 600 single cells to obtain the outlet static pressure value of each single cell
Figure DEST_PATH_IMAGE102
；
The voltage drop of each single cell in the fuel cell stack
Figure DEST_PATH_IMAGE103
Calculated according to the following formula:
Figure DEST_PATH_IMAGE104
；
fig. 6 is a schematic diagram of the pressure drop distribution curve of each unit cell of the fuel cell stack.
Table 4 shows the model static pressure distribution of the single cell-stack porous medium in example 2, including the inlet average static pressure value of the inlet common channel and the outlet average static pressure value of the outlet common channel; for the convenience of calculation, the inlet static pressure value of every 20 single cells, the outlet static pressure value of every 20 single cells and the pressure drop of every 20 single cells are respectively selected for statistical analysis.
TABLE 4
Figure DEST_PATH_IMAGE105
Through comparative analysis, the flow distribution variation coefficient CV, the excess coefficient distribution of each single cell and the pressure drop of each single cell of the fuel cell stack in the embodiment 2 are optimized by optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack
Figure 561334DEST_PATH_IMAGE103
Comparative example 1 was optimized.
Example 3 (C: 100% + 50%)
And after the inlet and outlet common channel structures of the fuel cell stack are optimized and determined, optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack according to the simulation calculation result of the single cell-stack CFD porous medium numerical calculation model.
In the embodiment 2, the orifice area (50% of the maximum orifice area) at the gas outlet is reduced in a necking mode by changing the interface flow area of the common inlet channel of the fuel cell stack and each single cell, so that the uniform distribution of the fluid among the single cells is realized.
The simulation calculation procedure was the same as S1 to S11 in example 1.
S12, simulating and calculating a corresponding single cell-single pile CFD porous medium numerical calculation model, and performing post-processing on the calculation result to obtain the average flow of 600 single cells:
Figure DEST_PATH_IMAGE106
and then calculating to obtain a flow distribution variation coefficient CV of the fuel cell stack:
Figure DEST_PATH_IMAGE107
through the post-processing analysis of the calculation result, the CV value of the numerical calculation model of the single cell-single pile CFD porous medium before optimization is 5.521%, and the CV calculation value is not much different from that of the example 1.
Analyzing the result, selecting inlet boundary surface of inlet common channel to obtain average static pressure value
Figure DEST_PATH_IMAGE108
(ii) a Selecting the outlet boundary surface of the common channel of the outlet to obtain the average static pressure value of the outlet
Figure DEST_PATH_IMAGE109
Total pressure drop of inlet and outlet of the fuel cell stack
Figure DEST_PATH_IMAGE110
Calculated according to the following formula:
Figure DEST_PATH_IMAGE111
calculating to obtain total pressure drop of inlet and outlet of fuel cell stack
Figure 844603DEST_PATH_IMAGE110
=46.839KPa。
The calculation results are post-processed to obtain the flow excess coefficient of each single battery of 600 single batteries
Figure DEST_PATH_IMAGE112
The minimum excess factor is not 1.609 and the maximum excess factor is 1.908.
Fig. 5 is a schematic diagram of a cell excess coefficient distribution curve.
Post-processing and analyzing the calculation result, and respectively selecting interfaces of a common channel of the cell stack inlet and 600 single cells to obtain the inlet static pressure value of each single cell
Figure DEST_PATH_IMAGE113
(ii) a Respectively selecting the interfaces of the common channel at the outlet of the electric pile and 600 single cells to obtain the outlet static pressure value of each single cell
Figure DEST_PATH_IMAGE114
；
The voltage drop of each single cell in the fuel cell stack
Figure DEST_PATH_IMAGE115
Calculated according to the following formula:
Figure DEST_PATH_IMAGE116
；
fig. 6 is a schematic diagram of the pressure drop distribution curve of each single cell of the fuel cell stack.
Through comparative analysis, the purpose of optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack cannot be achieved by reducing the orifice area at the gas outlet in a necking mode, and the flow distribution variation coefficient CV, the excess coefficient distribution of each single cell and the pressure drop of each single cell of the stack in the embodiment 2
Figure 698289DEST_PATH_IMAGE115
Comparative example 1 was not much changed.
Example 4 (D: 40% + 100%)
And after the inlet and outlet common channel structure of the fuel cell stack is optimized and determined, optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack according to the simulation calculation result of the CFD (computational fluid dynamics) porous medium numerical calculation model of the single cell-stack.
In the embodiment 4, the orifice area (40% of the maximum orifice area) at the gas inlet is reduced in a necking mode by changing the interface flow area of the common inlet channel of the fuel cell stack and each single cell, so as to realize uniform distribution of fluid among the single cells.
Fig. 4 is a schematic view of the variable flow area structure of the single cell and the common channel.
The simulation calculation procedure was the same as S1 to S11 in example 1.
S12, simulating and calculating a corresponding single cell-single pile CFD porous medium numerical calculation model, and performing post-processing on the calculation result to obtain the average flow of 600 single cells:
Figure 356804DEST_PATH_IMAGE106
and further calculating and obtaining a flow distribution variation coefficient CV of the fuel cell stack:
Figure 37053DEST_PATH_IMAGE107
through the post-processing analysis of the calculation result, the CV value of the numerical calculation model of the single cell-single pile CFD porous medium before optimization is 2.356 percent, and the calculated CV value is obviously reduced compared with the calculated CV value in example 1.
Analyzing the result, selecting the inlet boundary surface of the inlet common channel to obtain the average static pressure value of the inlet
Figure 72005DEST_PATH_IMAGE108
(ii) a Selecting the outlet boundary surface of the common channel of the outlet to obtain the average static pressure value of the outlet
Figure 335190DEST_PATH_IMAGE109
Then the total pressure drop of the inlet and outlet of the fuel cell stack is reduced
Figure 164606DEST_PATH_IMAGE110
Calculated according to the following formula:
Figure 20567DEST_PATH_IMAGE111
calculating to obtain total pressure drop of inlet and outlet of fuel cell stack
Figure 953068DEST_PATH_IMAGE110
=46.478KPa。
The calculation results are post-processed to obtain the flow excess coefficient of each single battery of 600 single batteries
Figure 15702DEST_PATH_IMAGE112
The minimum excess factor is not 1.662 and the maximum excess factor is 1.805.
Fig. 5 is a schematic diagram of a cell excess coefficient distribution curve.
Post-processing and analyzing the calculation result, and respectively selecting the interfaces of the common channel at the inlet of the cell stack and 600 single cells to obtain the inlet static pressure value of each single cell
Figure 827800DEST_PATH_IMAGE113
(ii) a Respectively selecting the interfaces of the common channel at the outlet of the electric pile and 600 single batteries,obtaining the outlet static pressure value of each single cell
Figure 470134DEST_PATH_IMAGE114
；
The voltage drop of each single cell in the fuel cell stack
Figure 746394DEST_PATH_IMAGE115
Calculated according to the following formula:
Figure 917613DEST_PATH_IMAGE116
；
fig. 6 is a schematic diagram of the pressure drop distribution curve of each unit cell of the fuel cell stack.
Through comparative analysis, the flow distribution coefficient of variation CV, the excess coefficient distribution of each single cell and the pressure drop of each single cell of the fuel cell stack of example 4 were obtained by optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack
Figure 279324DEST_PATH_IMAGE115
Compared with the embodiment 1, the method has larger optimization.
Example 5 (E: 33.3% + 100%)
And after the inlet and outlet common channel structure of the fuel cell stack is optimized and determined, optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack according to the simulation calculation result of the CFD (computational fluid dynamics) porous medium numerical calculation model of the single cell-stack.
In the embodiment 5, the orifice area at the gas inlet (which is 33.3 percent of the maximum orifice area) is reduced in a necking mode by changing the interface flow area of the common inlet channel of the fuel cell stack and each single cell so as to realize uniform distribution of the fluid among the single cells.
Fig. 4 is a schematic view of the variable flow area structure of the single cell and the common channel.
The simulation calculation procedure was the same as S1 to S11 in example 1.
S12, simulating and calculating a corresponding single cell-single pile CFD porous medium numerical calculation model, and performing post-processing on the calculation result to obtain the average flow of 600 single cells:
Figure 692725DEST_PATH_IMAGE106
and further calculating and obtaining a flow distribution variation coefficient CV of the fuel cell stack:
Figure 26755DEST_PATH_IMAGE107
through the post-processing analysis of the calculation result, the CV value of the numerical calculation model of the single cell-single pile CFD porous medium before optimization is 1.579%, and the CV calculation value is obviously reduced compared with that of the example 1.
Analyzing the result, selecting the inlet boundary surface of the inlet common channel to obtain the average static pressure value of the inlet
Figure 431191DEST_PATH_IMAGE108
(ii) a Selecting the outlet boundary surface of the common channel of the outlet to obtain the average static pressure value of the outlet
Figure 217882DEST_PATH_IMAGE109
Total pressure drop of inlet and outlet of the fuel cell stack
Figure 936439DEST_PATH_IMAGE110
Calculated according to the following formula:
Figure 187292DEST_PATH_IMAGE111
calculating to obtain total pressure drop of inlet and outlet of fuel cell stack
Figure 239878DEST_PATH_IMAGE110
=46.693KPa。
The calculation results are post-processed to obtain the flow excess coefficient of each single battery of 600 single batteries
Figure 558864DEST_PATH_IMAGE112
The minimum excess factor is not 1.669 and the maximum excess factor is 1.754.
Fig. 5 is a schematic diagram of a cell excess coefficient distribution curve.
Post-processing and analyzing the calculation result, and respectively selecting the interfaces of the common channel at the inlet of the cell stack and 600 single cells to obtain the inlet static pressure value of each single cell
Figure 601907DEST_PATH_IMAGE113
(ii) a Respectively selecting the interfaces of the common channel at the outlet of the electric pile and 600 single cells to obtain the outlet static pressure value of each single cell
Figure 551408DEST_PATH_IMAGE114
；
The voltage drop of each single cell in the fuel cell stack
Figure 109428DEST_PATH_IMAGE115
Calculated according to the following formula:
Figure 933903DEST_PATH_IMAGE116
；
fig. 6 is a schematic diagram of the pressure drop distribution curve of each unit cell of the fuel cell stack.
Through comparative analysis, the flow distribution variation coefficient CV, the excess coefficient distribution of each single cell and the pressure drop of each single cell of the fuel cell stack in example 5 were obtained by optimizing the variable flow area structure of the single cell and the common channel in the fuel cell stack
Figure 831452DEST_PATH_IMAGE115
Comparative example 1 was optimized.
In some embodiments, there is also provided a storage medium storing one or more programs executable by one or more processors to implement the steps in the optimization method of a fuel cell stack channel structure of the present invention.
In some embodiments, there is also provided a fuel cell stack channel structure optimization system, as shown in fig. 7, which includes at least one processor (processor) 20; a display screen 21; and a memory (memory) 22, and may further include a communication Interface (Communications Interface) 23 and a bus 24. The processor 20, the display 21, the memory 22 and the communication interface 23 can communicate with each other through the bus 24. The display screen 21 is configured to display a user guidance interface preset in the initial setting mode. The communication interface 23 may transmit information. Processor 20 may call logic instructions in memory 22 to perform the methods in the embodiments described above.
Furthermore, the logic instructions in the memory 22 may be implemented in software functional units and stored in a computer readable storage medium when sold or used as a stand-alone product.
The memory 22, which is a computer-readable storage medium, may be configured to store a software program, a computer-executable program, such as program instructions or modules corresponding to the methods in the embodiments of the present disclosure. The processor 20 executes the functional applications and data processing, i.e. implements the methods in the above embodiments, by running software programs, instructions or modules stored in the memory 22.
The memory 22 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal device, and the like. Further, the memory 22 may include a high speed random access memory and may also include a non-volatile memory. For example, a variety of media that can store program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk, may also be transient storage media.
In addition, the specific processes loaded and executed by the storage medium and the instruction processors in the terminal device are described in detail in the above method, and are not stated herein.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.

Claims (6)

1. A method for optimizing a channel structure of a fuel cell stack, comprising the steps of:
constructing a single cell CFD numerical calculation model according to a single cell geometric structure of the fuel cell stack;
constructing a single cell CFD porous medium numerical calculation model based on the single cell CFD numerical calculation model according to the variable flow area structure of the single cell and the common channel;
constructing a CFD numerical calculation model of the common channel of the fuel cell stack according to the geometric structure of the common channel of the fuel cell stack;
establishing a single cell-electric pile CFD porous medium numerical calculation model according to the single cell CFD porous medium numerical calculation model and the electric pile common channel CFD numerical calculation model;
optimizing the inlet and outlet common channel structure of the fuel cell stack according to the simulation calculation result of the single cell-stack CFD porous medium numerical calculation model, so that the flow distribution variation coefficient CV of the fuel cell stack meets a first target design value, and the total pressure drop of the inlet and outlet of the fuel cell stack meets a first target design value
Figure 399818DEST_PATH_IMAGE002
Satisfying a second target design value, and calculating the flow excess coefficient of each single cell in the fuel cell stack
Figure 976293DEST_PATH_IMAGE004
Unevenness of
Figure 902661DEST_PATH_IMAGE006
Satisfying a third target design value, and reducing the voltage drop of each single cell in the fuel cell stack
Figure 248191DEST_PATH_IMAGE008
Satisfy the followingFour target design values, wherein the flow distribution Coefficient of Variation (CV) of the fuel cell stack is calculated according to the following formula:
Figure 601812DEST_PATH_IMAGE010
wherein, in the process,
Figure 400004DEST_PATH_IMAGE012
the flow rate of the ith single cell of the fuel cell stack is shown, n is the total number of single cells of the fuel cell stack,
Figure 130063DEST_PATH_IMAGE014
the average flow rate of each single cell of the fuel cell stack; the total pressure drop of the inlet and the outlet of the fuel cell stack
Figure 854622DEST_PATH_IMAGE002
Calculated according to the following formula:
Figure 140110DEST_PATH_IMAGE018
wherein, in the process,
Figure 408280DEST_PATH_IMAGE020
calculating an inlet average static pressure value of a model for the single cell CFD porous medium numerical value;
Figure 462824DEST_PATH_IMAGE022
calculating an outlet average static pressure value of a model for the single cell CFD porous medium numerical value; flow excess coefficient of each single cell in the fuel cell stack
Figure 423827DEST_PATH_IMAGE004
Unevenness of
Figure 196611DEST_PATH_IMAGE006
Calculated according to the following formula:
Figure 2892DEST_PATH_IMAGE024
wherein, in the step (A),
Figure 177522DEST_PATH_IMAGE004
the flow excess coefficient of the ith single cell is set; n is the total number of single cells of the fuel cell stack; single cell pressure drop in the fuel cell stack
Figure 43847DEST_PATH_IMAGE008
Calculated according to the following formula:
Figure 303927DEST_PATH_IMAGE026
wherein, in the step (A),
Figure 913900DEST_PATH_IMAGE028
the inlet static pressure value of the ith single cell,
Figure 943036DEST_PATH_IMAGE030
the outlet static pressure value of the ith single cell is obtained;
after the inlet and outlet common channel structure of the fuel cell stack is optimized and determined, the variable flow area structure of a single cell and a common channel in the fuel cell stack is optimized according to the simulation calculation result of the CFD numerical computation model of the single cell-stack, so that the flow distribution variation coefficient CV of the fuel cell stack meets a fifth target design value, and the total pressure drop of the inlet and outlet of the fuel cell stack
Figure 245841DEST_PATH_IMAGE002
A sixth target design value is satisfied, and a single cell flow excess coefficient in the fuel cell stack
Figure 462059DEST_PATH_IMAGE004
Unevenness of
Figure 875722DEST_PATH_IMAGE006
Satisfying a seventh target design value, the fuelCell voltage drop in a battery stack
Figure 759365DEST_PATH_IMAGE008
The eighth target design value is met, the variable flow area structure of the single cells and the common channel in the fuel cell stack is improved by changing the orifice area at the joint of the single cells and the common channel in a U-shaped necking mode, and the orifice area of the single cells is reduced by arranging a bidirectional extension baffle or a unidirectional extension baffle at the airflow inlet of the single cells, so that the fluid entering from the common channel is uniformly distributed among the single cells.
2. The method for optimizing the channel structure of the fuel cell stack according to claim 1, wherein the step of constructing the CFD numerical calculation model of the single cell based on the CFD numerical calculation model of the single cell according to the variable flow area structure of the single cell and the common channel comprises the following steps:
the single cell CFD numerical calculation model comprises a bipolar plate with a flow field flow channel structure, a gas diffusion layer, a microporous layer, a catalytic layer and a proton exchange membrane;
setting the cross section size of the single cell CFD porous medium numerical calculation model as the cross section size of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model; and setting the height direction dimension of the single cell CFD porous medium numerical calculation model as the depth direction dimension of a bipolar plate flow field flow channel structure in the single cell CFD numerical calculation model.
3. The method for optimizing the channel structure of the fuel cell stack according to claim 2, further comprising the steps of:
giving corresponding inlet flow to different working conditions of the single cell CFD numerical calculation model to obtain corresponding single cell flow field pressure drop, performing data analysis on a calculated flow resistance curve of the single cell, and fitting a function relation of speed and pressure drop;
calculating the functional relation between the speed and the pressure drop of a model according to the CFD value of the single batteryObtaining the inertial resistance coefficient of the single cell CFD porous medium numerical calculation model
Figure 233071DEST_PATH_IMAGE032
And coefficient of viscous drag
Figure 202164DEST_PATH_IMAGE034
。
4. The method for optimizing the channel structure of the fuel cell stack according to claim 2, wherein the step of establishing the numerical calculation model of the CFD porous medium of the single cell-stack according to the numerical calculation model of the CFD porous medium of the single cell and the numerical calculation model of the CFD porous medium of the common channel of the stack comprises the steps of:
and setting the CFD numerical calculation model of the single cell as a porous medium area, setting the CFD numerical calculation model of the common channel of the fuel cell stack as a fluid area, and establishing a single cell-single stack CFD numerical model of the fuel cell stack.
5. A storage medium storing one or more programs, the one or more programs being executable by one or more processors to perform the steps of the method for optimizing a channel structure of a fuel cell stack according to any one of claims 1 to 4.
6. A system for optimizing a channel structure of a fuel cell stack, comprising: a processor, a memory, and a communication bus; the memory has stored thereon a computer readable program executable by the processor;
the communication bus realizes the connection communication between the processor and the memory;
the processor, when executing the computer readable program, implements the steps in the method for optimizing a channel structure of a fuel cell stack according to any one of claims 1 to 4.
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