CN112345202A - Method for evaluating fluid flow of bipolar plate - Google Patents
Method for evaluating fluid flow of bipolar plate Download PDFInfo
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Abstract
The invention provides a bipolar plate fluid flow evaluation method, which is characterized in that the bipolar plate fluid flow is evaluated before electrochemical analysis in the bipolar plate development process, so as to provide a fluid evaluation standard for optimizing a bipolar plate three-dimensional model, so that the optimized bipolar plate has uniform flow and proper pressure drop, and the performance of the bipolar plate is guaranteed; the fluid flow evaluation parameter and method and the multi-parameter evaluation method of the invention make the development of the bipolar plate systematized and scientific. The invention introduces dimensionless parameter flow unevenness and total pressure drop ratio of active area to evaluate the bipolar plate, and reduces the influence of physical and chemical parameters of the bipolar plate on fluid flow evaluation. The invention provides fluid evaluation standard for optimizing the bipolar plate three-dimensional model, is convenient for providing the optimized model for electrochemical analysis, saves project time and cost, and ensures normal development of the bipolar plate.
Description
Technical Field
The invention belongs to the technical field of fuel cells, and particularly relates to a bipolar plate fluid flow evaluation method.
Background
The bipolar plate is used as a core component of the fuel cell, has the functions of gas distribution, electric conduction, heat conduction, cooling, water drainage and the like, and the performance of the bipolar plate directly influences the performance of the fuel cell. The reasonable fluid flow of the bipolar plate can provide uniform fuel and oxidant for the fuel cell, ensure uniform current density and promote effective air exhaust and water drainage. It is important how to assess bipolar plate fluid flow.
The existing proton exchange membrane fuel cell bipolar plate design and numerical simulation method mainly uses a PEMFC module of fluid simulation software Fluent to simulate the electrochemical performance of a fuel cell and output a power density curve in terms of fluid. The bipolar plate flow field of the method adopts a direct-current field, the direct-current field does not need to consider the flow uniformity and has lower pressure drop, and the influence of an inlet and outlet area and a diffusion area on the flow uniformity and the pressure drop is not considered. Therefore, no flow field analysis is needed before electrochemical analysis, and the fluid flow of the bipolar plate is not evaluated.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the bipolar plate fluid flow evaluation method is used for evaluating the bipolar plate fluid flow before electrochemical analysis, and is convenient for providing an optimization model for the electrochemical analysis.
The technical scheme adopted by the invention for solving the technical problems is as follows: a bipolar plate fluid flow evaluation method comprising the steps of:
s1: cfd models are made by using computational fluid dynamics software for the established three-dimensional model of the bipolar plate of the fuel cell; acquiring import and export boundary data for calculating a flow field model;
s2: evaluating the fluid flow condition of the bipolar plate under the rated steady-state working condition of the fuel cell, and calculating five dimensions including total pressure drop, flow unevenness of the ith flow channel in the active region, total pressure drop ratio, total pressure pole difference and total pressure variance;
s3: judging whether the calculated values of the parameters of the five dimensions meet corresponding evaluation preset values or not, dividing the total pressure drop and the flow unevenness of the ith flow channel of the active area into one level according to the weight from high to low, dividing the ratio of the total pressure drop into one level, dividing the total pressure difference and the total pressure variance into one level, and evaluating the fluid flow of the bipolar plate.
According to the scheme, in the step S2, the data of the inlet/outlet boundary includes an inlet flow rate and an outlet pressure.
According to the scheme, in the step S2, the specific steps are as follows:
s21: respectively calculating the total pressure drop Pa of air of the bipolar plate, the total pressure drop Ph of hydrogen of the bipolar plate and the total pressure drop Pc of cooling liquid of the bipolar plate;
s22: respectively calculating the flow unevenness Uai of the ith flow channel of the air active area of the bipolar plate, the flow unevenness Uhi of the ith flow channel of the hydrogen active area of the bipolar plate and the flow unevenness Uci of the ith flow channel of the cooling liquid active area of the bipolar plate;
s23: respectively calculating the air total pressure drop ratio Ra, the hydrogen total pressure drop ratio Rh and the cooling liquid total pressure drop ratio Rc of the active region;
s24: respectively calculating the total pressure pole difference of air in the active area, the total pressure pole difference of hydrogen in the active area and the total pressure pole difference of cooling liquid in the active area, namely delta Pea, delta Peh and delta Pec;
s25: the total pressure variance D (pfa) of air, the total pressure variance D (pfh) of hydrogen, and the total pressure variance D (pfc) of coolant entering the cross-sectional flow channel of the active region were calculated.
Further, in step S21, the specific steps include:
s211: respectively calculating the total pressure Pai of an air inlet, the total pressure Pae of an air outlet, the total pressure Phi of a hydrogen inlet, the total pressure Phe of a hydrogen outlet, the total pressure Pci of a cooling liquid inlet and the total pressure Pce of a cooling liquid outlet of the bipolar plate by using a computational fluid dynamics method according to the boundary data of the inlet and the outlet;
s212: and calculating the total pressure drop Pa of air to be Pai-Pae, calculating the total pressure drop Ph of hydrogen to be Phi-Phe, and calculating the total pressure drop Pc of the cooling liquid to be Pci-Pce.
Further, in step S22, the specific steps include:
s221: setting n flow channels in the bipolar plate active area, calculating the air flow channel flow rate Qa1, Qa2, … and Qan in the bipolar plate active area by computational fluid mechanics method according to the data of the inlet and outlet boundaries,
calculating hydrogen flow channel flow rates Qh1, Qh2, … and Qhn of the active region of the bipolar plate,
calculating the flow rates of cooling liquid flow channels Qc1, Qc2, … and Qcn in the active area of the bipolar plate;
s222: calculating the average flow rate QVa of the air flow channel of the active area as (Qa1+ Qa2+ … + Qan)/n,
calculating the average flow rate QVh ═ Qh1+ Qh2+ … + Qhn)/n,
calculating the average flow rate QVc ═ of (Qc1+ Qc2+ … + Qcn)/n in the cooling liquid flow channel of the active area;
calculating the flow unevenness Uai of the ith air flow channel to be (Qai-QVa)/QVa to be 100 percent,
calculating the flow unevenness Uhi of the ith hydrogen flow channel as (Qhi-QVh)/QVh as 100%,
the ith coolant flow channel flow non-uniformity Uci ═ q i-QVc)/QVc × (100%) was calculated.
Further, in step S23, the specific steps include:
s231: respectively calculating the air total pressure drop delta Pvai, the hydrogen total pressure drop delta Pvhi and the cooling liquid total pressure drop delta Pvci in the ith flow channel active region of the bipolar plate with the total flow channel number n according to the inlet and outlet boundary data, wherein i is 1,2, …, n;
s232: calculating the average total pressure drop of the air in the active area, namely delta Pva1+ Pva2+ … … Pvan)/n,
calculating the average total pressure drop of hydrogen in the active area, namely (delta Pvh1+ Pvh2+ … … Pvhn)/n,
calculating the average total pressure drop of the cooling liquid in the active area, namely (delta Pvc1+ Pvc2+ … … Pvcn)/n;
s233: respectively calculating the total pressure drop delta Pta of air, the total pressure drop delta Pth of hydrogen and the total pressure drop delta Ptc of cooling liquid at the inlet and the outlet of the bipolar plate;
s234: calculating the air total pressure drop ratio Ra of the active area to the air total pressure drop of the active area as delta Pva/delta Pta as 100 percent,
calculating the ratio Rh to Δ Pvh/Δ Pth of the total pressure drop of hydrogen in the active area to 100%,
the total pressure drop ratio Rc ═ Δ Pvc/. DELTA.Ptc × (100%) of the cooling liquid in the active region was calculated.
Further, in step S24, the specific steps include:
s241: selecting a cross section in a direction which is vertical to the flow channels and just enters the active region, and respectively calculating the total air pressure Pzai, the total hydrogen pressure Pzhi and the total cooling liquid pressure Pzci of the ith flow channel of the active region on the cross section;
s242: selecting a maximum value Pzai (max) of total air pressure, a minimum value Pzai (min) of total air pressure, a maximum value Pzhi (max) of total hydrogen pressure, a minimum value Pzhi (min) of total hydrogen pressure, a maximum value Pzci (max) of total coolant pressure, and a minimum value Pzci (min) of total coolant pressure, which enter the cross section of the active region, respectively;
s243: calculating the total pressure pole difference delta Pea ═ Pzai (max) -Pzai (min) in the active area,
calculating the total pressure pole difference delta Peh ═ Pzhi (max) -Pzhi (min) of hydrogen in the active area,
the total pressure difference Δ Pec of the coolant in the active region was calculated as Pzci (max) -Pzci (min).
Further, in step S25, the specific steps include:
s251: based on the data obtained in step S241
Calculating the average value M (Pza) of the total pressure of the air in the n channels on the section, (Pza1+ Pza2+ … + Pza)/n,
calculating the average value M (pzh) of the total pressure of the hydrogen of the n channels on the section, (Pzh1+ Pzh2+ … + Pzhn)/n,
calculating the total pressure average value M (pzc) of the cooling liquid of the n channels on the section, (Pzc1+ Pzc2+ … + Pzcn)/n;
s252: calculating the air total pressure variance of the section of the active region
D(Pfa)＝{[Pza1-M(pza)]2+[Pza2-M(pza)]2+……+[Pzan-M(pza)]2}/n，
Calculating the total pressure variance of hydrogen in the section of the active region
D(Pfh)＝{[Pzh1-M(pzh)]2+[Pzh2-M(pzh)]2+……+[Pzhn-M(pzh)]2}/n，
Calculating total pressure variance of cooling liquid in section of active region
D(Pfc)＝{[Pzc1-M(pzc)]2+[Pzc2-M(pzc)]2+……+[Pzcn-M(pzc)]2}/n。
According to the scheme, in the step S3, the specific steps are as follows:
s31: judging whether the calculated values of the air total pressure drop, the hydrogen total pressure drop, the cooling liquid total pressure drop, the flow unevenness of the ith flow channel in the air active area of the bipolar plate, the flow unevenness of the ith flow channel in the hydrogen active area of the bipolar plate and the flow unevenness of the ith flow channel in the cooling liquid active area of the bipolar plate respectively meet the corresponding evaluation preset value requirements, if not, judging that the evaluation result of the flow of the bipolar plate fluid is unqualified, terminating the evaluation, and re-executing the step after optimizing the three-dimensional model; if so, the evaluation result of the bipolar plate fluid flow is qualified, and the step S32 is executed;
s32: judging whether the calculated values of the air total pressure drop ratio, the hydrogen total pressure drop ratio and the cooling liquid total pressure drop ratio respectively meet the requirements of corresponding evaluation preset values;
s33: and judging whether the calculated values of the total pressure pole difference of the air in the active area, the total pressure pole difference of the hydrogen in the active area, the total pressure pole difference of the cooling liquid in the active area, the total pressure variance of the air in the active area, the total pressure variance of the hydrogen in the active area and the total pressure variance of the cooling liquid in the active area respectively meet the corresponding requirements of the evaluation preset value.
Further, in the step S3, if the calculated values of the parameters in the step S32 and the calculated values of the parameters in the step S33 respectively satisfy the corresponding requirements of the preset evaluation values, the evaluation result of the fluid flow of the bipolar plate is excellent; if the calculated values of the parameters of step S32 and the calculated values of the parameters of step S33 respectively satisfy the corresponding requirements of the preset evaluation values, the evaluation result of the fluid flow of the bipolar plate is good.
The invention has the beneficial effects that:
1. according to the bipolar plate fluid flow evaluation method, before the electrochemical analysis in the bipolar plate development process, a three-dimensional model optimization basis is provided for evaluation of the bipolar plate fluid flow, an optimized model is conveniently provided for the electrochemical analysis, the optimized bipolar plate flows uniformly, the pressure drop is appropriate, and the performance of the bipolar plate is guaranteed.
2. The fluid flow evaluation parameter and method and the multi-parameter evaluation method in the bipolar plate development process established by the invention enable the development of the bipolar plate to be systematized and scientific.
3. The invention introduces dimensionless parameter flow unevenness and total pressure drop ratio of active area to evaluate the bipolar plate, and reduces the influence of physical and chemical parameters of the bipolar plate on fluid flow evaluation.
4. The invention evaluates the fluid flow of the bipolar plate before electrochemical analysis in the development process of the bipolar plate, and only needs to modify the digital-analog when the requirement is not met, and does not need to make a sample piece for testing, thereby shortening the project time, saving the development cost and ensuring the normal development of the bipolar plate.
Drawings
FIG. 1 is a flow chart of an embodiment of the present invention.
Figure 2 is a schematic view of a bipolar plate air flow field of an embodiment of the present invention.
FIG. 3 is a schematic illustration of air flow non-uniformity for an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Referring to fig. 1, a bipolar plate fluid flow evaluation method of an embodiment of the present invention includes the steps of:
s1: acquiring import and export boundary data; the evaluation parameters and process data of the invention are calculated by adopting a Computational Fluid Dynamics method, firstly a bipolar plate three-dimensional digital model is required to be provided, and after the three-dimensional digital model is provided, cfd (Computational Fluid Dynamics) models are made by using Computational Fluid Dynamics software. After the digifax is provided, the import and export boundary data used for calculating the flow field model must be acquired. The inlet and outlet boundary data may specifically include inlet flow, outlet pressure boundary, or other suitable boundaries, and the parameters and process values of the present invention may be calculated after the boundary data is obtained.
S2: calculating five dimensions according to the acquired import and export boundary data; when the bipolar plate fluid flow is evaluated, because the bipolar plate fluid flow under all working conditions of the fuel cell is complex, and parameters such as flow, flow rate, pressure and the like are changed a lot, quantitative evaluation is difficult to carry out, so the rated steady-state working condition of the fuel cell is selected as an evaluation working condition point, and the bipolar plate fluid flow condition is evaluated by steady-state flow.
S21: calculating total pressure drops Pa, Ph and Pc of air, hydrogen and cooling liquid of the bipolar plate; when the bipolar plate fluid flow is evaluated, the evaluation indexes comprise total pressure drop Pa, Ph and Pc of bipolar plate air, hydrogen and cooling liquid; calculating the total pressure Pai of an air inlet, the total pressure Pae of an air outlet, the total pressure Phi of a hydrogen inlet, the total pressure Phe of a hydrogen outlet, the total pressure Pci of a cooling liquid inlet and the total pressure Pce of a cooling liquid outlet of the bipolar plate by using a computational fluid mechanics method according to the acquired boundary data of the inlet and the outlet; the total pressure drop Pa of air is equal to Pai-Pae, the total pressure drop Ph of hydrogen is equal to Phi-Phe, and the total pressure drop Pc of cooling liquid is equal to Pci-Pce. Specific evaluation values Pa, Ph, and Pc are established by each company according to circumstances.
S22: calculating the flow unevenness Uai, Uhi and Uci of the ith flow channel of the air, hydrogen and cooling liquid active region of the bipolar plate; when the fluid flow of the bipolar plate is evaluated, evaluation indexes comprise the flow unevenness Uai, Uhi and Uci of the ith flow channel of the bipolar plate air, hydrogen and a cooling liquid active area. Assuming that the active area has n flow channels, calculating the air flow rate Qa1, Qa2 … … and Qan of the active area of the bipolar plate according to the acquired inlet and outlet boundary data by using a computational fluid dynamics method; calculating hydrogen flow rates Qh1, Qh2 … … and Qhn of the active area of the bipolar plate; the coolant flow rates Qc1, Qc2 … …, Qcn of the active region of the bipolar plate were calculated. Calculating the average flow rate QVa of the air flow channel of the active area as (Qa1+ Qa2+ … … + Qan)/n; calculating the average flow rate QVh ═ Qh1+ Qh2+ … … + Qhn)/n in the hydrogen flow channel of the active region; calculating the average flow rate QVc of the cooling liquid in the active area as (Qc1+ Qc2+ … … + Qcn)/n; calculating the flow unevenness Uai of the ith air flow channel as (Qai-QVa)/QVa as 100%; calculating the flow unevenness Uhi of the ith hydrogen flow channel as (Qhi-QVh)/QVh as 100%; the ith coolant flow channel flow non-uniformity Uci ═ 100% was calculated (Qci-QVc)/QVc.
S23: calculating the total pressure drop ratios Ra, Rh and Rc of air, hydrogen and cooling liquid in the active area; when the bipolar plate fluid flow is evaluated, the evaluation indexes comprise active area air, hydrogen and cooling liquid total pressure drop ratios Ra, Rh and Rc. Firstly, respectively calculating the total pressure drop delta Pvai, delta Pvhi and delta Pvci of the air, hydrogen and cooling liquid in the i-th flow channel active area of the bipolar plate with the total flow channel number n according to the acquired inlet and outlet boundary data, and then calculating the average total pressure drop delta Pva of the air in the active area (delta Pva1+ Pva2+ … … Pvan)/n; the average total pressure drop of hydrogen in the active region is (delta Pvh1+ Pvh2+ … … Pvhn)/n; the average total pressure drop Δ Pvc of the cooling liquid in the active region is (Δ Pvc1+ Pvc2+ … … Pvcn)/n; and respectively calculating total pressure drops delta Pta, delta Pth and delta Ptc of air, hydrogen and cooling liquid at the inlet and the outlet of the bipolar plate. The total pressure drop ratios Ra ═ Δ Pva/. DELTA.pta ×, Rh ═ Δ Pvh/. DELTA.pth ×, and Rc ═ Δ Pvc/. DELTA.ptc ×, 100% in the active region air, hydrogen, and coolant are set forth. The specific values of the total pressure drop ratios Ra, Rh and Rc of the air, the hydrogen and the cooling liquid in the active area are set according to the actual conditions of the company.
S24: calculating total pressure pole differences delta Pea, delta Peh and delta Pec of air, hydrogen and cooling liquid in an active area; when the bipolar plate fluid flow is evaluated, the evaluation indexes include active area air, hydrogen and total pressure pole difference delta Pea, delta Peh and delta Pec of the cooling liquid. Selecting a cross section in a direction vertical to the flow channel just entering the active region, wherein the total pressure of air, hydrogen and cooling liquid in the ith flow channel of the active region on the cross section is Pzai, Pzhi and Pzci respectively, the maximum and minimum total pressure of air, hydrogen and cooling liquid entering the cross section of the active region are Pzai (max), Pzai (min), Pzhi (max), Pzhi (min), Pzci (max) and Pzci (min) respectively, and the total pressure difference delta Pea of the air in the active region is Pzai (max) -Pzai (min); the total pressure difference Δ Peh ═ pzhi (max) -pzhi (min) of hydrogen in the active region; total pressure pole difference Δ Pec ═ pzci (max) -pzci (min) in the active region coolant; specific values of total pressure pole differences delta Pea, delta Peh and delta Pec of air, hydrogen and cooling liquid in the active area are set according to actual conditions.
S25: calculating total pressure variances D (pfa), D (pfh) and D (pfc) of air, hydrogen and cooling liquid entering the cross section flow channel of the active area; when the bipolar plate fluid flow is evaluated, the evaluation indexes include air, hydrogen and total pressure variance D (pfa), D (pfh) and D (pfc) of the cooling liquid just after entering the active area cross-section flow channel. Selecting cross section perpendicular to flow channel direction just entering active zone, calculating total pressure of i flow channel air, hydrogen and cooling liquid in active zone on the cross section as Pzai, Pzhi and Pzci respectively, calculating total pressure average value M (Pza) of n flow channel air on cross section as (Pza1+ Pza2+ … + Pza)/n and n cross section asFlow channel hydrogen total pressure average value M (pzh) ═ (Pzh1+ Pzh2+ … + Pzhn)/n, and section n flow channel cooling liquid total pressure average value M (pzc) ═ (Pzc1+ Pzc2+ … + Pzcn)/n. Then, the total pressure variance D (pfa) of the cross section of the active region in air { [ Pza1-M (Pza) ]was calculated]2+[Pza2-M(pza)]2+…+[Pzan-M(pza)]2H/n; total pressure variance of hydrogen in the cross section of the active region D (Pfh) { [ Pzh1-M (pzh)]2+[Pzh2-M(pzh)]2+…+[Pzhn-M(pzh)]2H/n; total pressure variance D (Pfc) of cooling liquid in section of active region { [ Pzc1-M (pzc)]2+[Pzc2-M(pzc)]2+…+[Pzcn-M(pzc)]2H/n; the company determines the total pressure variances D (pfa), D (pfh), D (pfc) of the air, hydrogen and cooling liquid entering the cross-section flow channel of the active area according to actual conditions.
S3: grading the evaluation result; the invention evaluates the fluid flow from five dimensions, each dimension has three parameters, and the bipolar plate fluid flow is evaluated according to whether the evaluation calculation value of each dimension meets the corresponding preset evaluation value.
S31: the total pressure drop of air, hydrogen and cooling liquid of the bipolar plate and the evaluation calculation value corresponding to the flow unevenness of the ith flow channel of the active area of the bipolar plate must reach the corresponding evaluation preset value; in the process of pile development, the matching of an air compressor, a hydrogen pressure adjusting system and a water pump is influenced by the total pressure drop of air, hydrogen and cooling liquid of the bipolar plate, and the air compressor, the hydrogen pressure adjusting system and the water pump cannot be matched by the too large total pressure drop of the air, the hydrogen and the cooling liquid. Therefore, the total pressure drop Pa, Ph and Pc of air, hydrogen and cooling liquid of the bipolar plate must reach evaluation values. In order to ensure the uniform flow of air, hydrogen and cooling liquid in the bipolar plate to achieve the performance of the bipolar plate, the flow of the active area must be uniform, so the flow unevenness Uai, Uhi and Uci of the ith flow channel in the active area of the bipolar plate must also achieve evaluation values.
S32: the evaluation calculation values corresponding to the total pressure drop ratio of the air, the hydrogen and the cooling liquid reach corresponding evaluation preset values as much as possible; in the development process of the bipolar plate, the total pressure drop of the inlet and outlet area and the transition area is reduced as much as possible, so that the total pressure ratio of the active area is as large as possible, but in order to realize the functions of gas distribution and liquid distribution and make the flow of gas and liquid uniform, the structures of the inlet and outlet area and the transition area cannot be simple, and the pressure drop ratio of the inlet and outlet area and the transition area cannot be too small, which means that the pressure drop ratio of the active area cannot be too large. Therefore, the total pressure drop ratios Ra, Rh and Rc of air, hydrogen and cooling liquid in the active area reach the evaluation parameters as much as possible.
S33: the evaluation calculation values corresponding to the total pressure range difference of the air, the hydrogen and the cooling liquid in the active area and the total pressure variance of the air, the hydrogen and the cooling liquid are only used for reference; when the total pressure drop Pa, Ph and Pc of the air, hydrogen and cooling liquid of the bipolar plate and the flow unevenness Uai, Uhi and Uci of the ith flow channel of the active area of the air, hydrogen and cooling liquid of the bipolar plate reach evaluation values, the total pressure drop ratio Ra, Rh and Rc of the air, hydrogen and cooling liquid of the active area reach evaluation parameters as much as possible. The differences Δ Pea, Δ Peh, and Δ Pec between the total pressures of the air, hydrogen, and cooling liquid in the active area, and the variances d (pfa), d (pfh), d (pfc) of the air, hydrogen, and cooling liquid in the cross-sectional flow channel just before entering the active area are only referred to herein.
Specifically, when the evaluation calculation values of the evaluation parameters 1 (total pressure drop of air, hydrogen and cooling liquid of the bipolar plate) and 2 (flow unevenness of the ith flow channel of the active area of the bipolar plate) do not accord with corresponding evaluation preset values, the evaluation result of the fluid flow of the bipolar plate is determined to be unqualified; and when the evaluation calculated values of the evaluation parameters 1 (total pressure drop of air, hydrogen and cooling liquid of the bipolar plate) and 2 (flow unevenness of the ith flow channel of the active area of the bipolar plate) meet corresponding evaluation preset values, obtaining the evaluation result of the flow of the bipolar plate fluid, wherein the evaluation result is qualified.
Under the scene that corresponding evaluation preset values are met in evaluation calculation values of an evaluation parameter 1 (air, hydrogen and cooling liquid total pressure drop of the bipolar plate) and an evaluation parameter 2 (flow unevenness of the ith flow channel of the active area of the bipolar plate), whether the evaluation parameters 3 (air, hydrogen and cooling liquid total pressure drop ratio of the active area), 4 (air, hydrogen and cooling liquid total pressure pole difference of the active area) and 5 (cross-section flow channel air, hydrogen and cooling liquid total pressure variance) meet the corresponding evaluation preset values or not can be further subdivided, for example, when the evaluation calculation values of the evaluation parameters 3, 4 and 5 meet the corresponding evaluation preset values, the evaluation result of the fluid flow of the bipolar plate is excellent; and when the evaluation parameters 3 accord with the corresponding evaluation preset values, and the evaluation calculation values of the evaluation parameters 4 and 5 do not accord with the corresponding evaluation preset values, the evaluation result of the bipolar plate fluid flow is good.
The specific implementation process of the evaluation method is described by combining with a certain type of stack bipolar plate air flow channel model of Dongfeng automobile company, and the implementation processes of the hydrogen flow and coolant flow evaluation method are similar to the implementation process of the air flow evaluation method and are not described herein again. The air flow path model is shown in figure 2. The number of the air flow channels is 38, and the air flow channels are numbered in sequence. This embodiment will explain only how the bipolar plate air flow evaluation is realized, and a specific evaluation value is not given, and a specific evaluation value is established by each company according to actual conditions. And when the obtained value does not meet the evaluation value, optimizing the digital-to-analog model, and then calculating each parameter value by using a computational fluid dynamics method until the parameter value is optimized to meet the evaluation value.
And (3) obtaining an air flow channel digital model according to the bipolar plate 3D digital model, as shown in figure 2, manufacturing a computational fluid mechanics model by using computational fluid mechanics software, and setting an inlet and outlet boundary for calculation. And calculates the following parameters and process data.
1. The total air pressure drop is calculated.
Calculating the total pressure Pai of an air inlet to be 13.62KPa and the total pressure Pae of an air outlet to be 2.09KPa by using a computational fluid mechanics method; the total pressure drop Pa of the air is 13.62-2.09-11.53 KPa; the air total pressure drop meets the evaluation value of Dongfeng auto company.
2. The core air flow non-uniformity was calculated.
Calculating air flow rate Qa1, Qa2, …, Qa38 of the active region of the bipolar plate by using a computational fluid dynamics method; calculating the average air flow rate QVa ═ 5.8 ═ 10 (Qa1+ Qa2+ … + Qa38)/38 ═ 3-6kg/s; calculating the ith duct air flow non-uniformity Uai ═ 100% of (Qai-QVa)/QVa; the air flow unevenness is shown in figure 3, the factors are more, and the specific process is not carried outThe description is given. The ith duct air flow unevenness Uai each satisfy the eastern wind automobile company evaluation value.
3. And calculating the air total pressure drop ratio of the active area.
Calculating total pressure drop delta Pva1, delta Pva3, … and delta Pva38 of the flow channel of the active area of the air flow field, wherein the total pressure drop delta Pva1, the delta Pva3, the delta Pva38 and the delta Pva are sequentially 4.19KPa, 4.05KPa, … and 4.21KPa, and calculating the average total pressure drop delta Pva of the active area (delta Pva1 +. delta Pva2+ … +. delta Pvan)/n (4.19+4.05+ … +4.21)/38 ═ 4.13 KPa; and (3) calculating the total air pressure drop Delta Pta of the inlet and the outlet of the bipolar plate to be 13.62-2.09 to be 11.53KPa, and then calculating the total air pressure drop ratio Ra of the active area to be 4.13/11.53 to be 35.82% of 100% of Delta Pva/Delta Pta, wherein the total air pressure drop ratio of the active area to be 35.82% meets the evaluation value of Dongfeng automobile company.
4. And calculating the air total pressure pole difference delta Pea.
Calculating the total pressure Pza1, Pza2, … and Pza38 of each air flow channel which just enters the active area and is vertical to the flow channel section A, and finding out the maximum value Pza 3-10.735 KPa and the minimum value Pza (min) -Pza 37-8.915 KPa, wherein the total pressure difference of the air in the active area is as follows:
△Pea＝Pzai(max)-Pzai(min)＝Pza3-Pza37＝10.735-8.915＝1.82KPa；
this result is incorporated by reference.
5. The total pressure variance d (pfa) of the air in the flow channel of the active zone was calculated.
Referring to fig. 2, a section a is selected in a direction perpendicular to the flow channels of the active region, the total pressure Pzai of the air in the ith flow channel of the active region on the section is calculated, and the average value of the total pressure of the air on the section is calculated:
M(pza)＝(Pza1+Pza2+…+Pzan)/n＝(10.725+10.304+…+8.929)/38＝9.751KPa，
the total pressure variance of the air just entering the section of the active zone is then calculated:
D(Pfa)＝{[Pza1-M(pza)]2+[Pza2-M(pza)]2+…+[Pzan-M(pza)]2}/n＝0.2；
this term is in line with the eastern wind automobile evaluation value.
The above embodiments are only used for illustrating the design idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention accordingly, and the protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes and modifications made in accordance with the principles and concepts disclosed herein are intended to be included within the scope of the present invention.
Claims (10)
1. A bipolar plate fluid flow evaluation method is characterized in that: the method comprises the following steps:
s1: cfd models are made by using computational fluid dynamics software for the established three-dimensional model of the bipolar plate of the fuel cell; acquiring import and export boundary data for calculating a flow field model;
s2: evaluating the fluid flow condition of the bipolar plate under the rated steady-state working condition of the fuel cell, and calculating five dimensions including total pressure drop, flow unevenness of the ith flow channel in the active region, total pressure drop ratio, total pressure pole difference and total pressure variance;
s3: judging whether the calculated values of the parameters of the five dimensions meet corresponding evaluation preset values or not, dividing the total pressure drop and the flow unevenness of the ith flow channel of the active area into one level according to the weight from high to low, dividing the ratio of the total pressure drop into one level, dividing the total pressure difference and the total pressure variance into one level, and evaluating the fluid flow of the bipolar plate.
2. A bipolar plate fluid flow evaluation method as in claim 1, wherein: in step S2, the inlet/outlet boundary data includes inlet flow and outlet pressure.
3. A bipolar plate fluid flow evaluation method as in claim 1, wherein: in the step S2, the specific steps are as follows:
s21: respectively calculating the total pressure drop Pa of air of the bipolar plate, the total pressure drop Ph of hydrogen of the bipolar plate and the total pressure drop Pc of cooling liquid of the bipolar plate;
s22: respectively calculating the flow unevenness Uai of the ith flow channel of the air active area of the bipolar plate, the flow unevenness Uhi of the ith flow channel of the hydrogen active area of the bipolar plate and the flow unevenness Uci of the ith flow channel of the cooling liquid active area of the bipolar plate;
s23: respectively calculating the air total pressure drop ratio Ra, the hydrogen total pressure drop ratio Rh and the cooling liquid total pressure drop ratio Rc of the active region;
s24: respectively calculating the total pressure pole difference of air in the active area, the total pressure pole difference of hydrogen in the active area and the total pressure pole difference of cooling liquid in the active area, namely delta Pea, delta Peh and delta Pec;
s25: the total pressure variance D (pfa) of air, the total pressure variance D (pfh) of hydrogen, and the total pressure variance D (pfc) of coolant entering the cross-sectional flow channel of the active region were calculated.
4. A bipolar plate fluid flow evaluation method as in claim 3, wherein: in the step S21, the specific steps are as follows:
s211: respectively calculating the total pressure Pai of an air inlet, the total pressure Pae of an air outlet, the total pressure Phi of a hydrogen inlet, the total pressure Phe of a hydrogen outlet, the total pressure Pci of a cooling liquid inlet and the total pressure Pce of a cooling liquid outlet of the bipolar plate by using a computational fluid dynamics method according to the boundary data of the inlet and the outlet;
s212: and calculating the total pressure drop Pa of air to be Pai-Pae, calculating the total pressure drop Ph of hydrogen to be Phi-Phe, and calculating the total pressure drop Pc of the cooling liquid to be Pci-Pce.
5. A bipolar plate fluid flow evaluation method as in claim 3, wherein: in the step S22, the specific steps are as follows:
s221: setting n flow channels in active area of bipolar plate, and using computational fluid mechanics method according to boundary data of inlet and outlet
Calculating the air flow channel flow rate Qa1, Qa2, … and Qan of the active area of the bipolar plate,
calculating hydrogen flow channel flow rates Qh1, Qh2, … and Qhn of the active region of the bipolar plate,
calculating the flow rates of cooling liquid flow channels Qc1, Qc2, … and Qcn in the active area of the bipolar plate;
s222: calculating the average flow rate QVa of the air flow channel of the active area as (Qa1+ Qa2+ … + Qan)/n,
calculating the average flow rate QVh ═ Qh1+ Qh2+ … + Qhn)/n,
calculating the average flow rate QVc ═ of (Qc1+ Qc2+ … + Qcn)/n in the cooling liquid flow channel of the active area;
calculating the flow unevenness Uai of the ith air flow channel to be (Qai-QVa)/QVa to be 100 percent,
calculating the flow unevenness Uhi of the ith hydrogen flow channel as (Qhi-QVh)/QVh as 100%,
the ith coolant flow channel flow non-uniformity Uci ═ q i-QVc)/QVc × (100%) was calculated.
6. A bipolar plate fluid flow evaluation method as in claim 3, wherein: in the step S23, the specific steps are as follows:
s231: respectively calculating the air total pressure drop delta Pvai, the hydrogen total pressure drop delta Pvhi and the cooling liquid total pressure drop delta Pvci in the ith flow channel active region of the bipolar plate with the total flow channel number n according to the inlet and outlet boundary data, wherein i is 1,2, …, n;
s232: calculating the average total pressure drop of the air in the active area, namely delta Pva1+ Pva2+ … … Pvan)/n,
calculating the average total pressure drop of hydrogen in the active area, namely (delta Pvh1+ Pvh2+ … … Pvhn)/n,
calculating the average total pressure drop of the cooling liquid in the active area, namely (delta Pvc1+ Pvc2+ … … Pvcn)/n;
s233: respectively calculating the total pressure drop delta Pta of air, the total pressure drop delta Pth of hydrogen and the total pressure drop delta Ptc of cooling liquid at the inlet and the outlet of the bipolar plate;
s234: calculating the air total pressure drop ratio Ra of the active area to the air total pressure drop of the active area as delta Pva/delta Pta as 100 percent,
calculating the ratio Rh to Δ Pvh/Δ Pth of the total pressure drop of hydrogen in the active area to 100%,
the total pressure drop ratio Rc ═ Δ Pvc/. DELTA.Ptc × (100%) of the cooling liquid in the active region was calculated.
7. A bipolar plate fluid flow evaluation method as in claim 3, wherein: in the step S24, the specific steps are as follows:
s241: selecting a cross section in a direction which is vertical to the flow channels and just enters the active region, and respectively calculating the total air pressure Pzai, the total hydrogen pressure Pzhi and the total cooling liquid pressure Pzci of the ith flow channel of the active region on the cross section;
s242: selecting a maximum value Pzai (max) of total air pressure, a minimum value Pzai (min) of total air pressure, a maximum value Pzhi (max) of total hydrogen pressure, a minimum value Pzhi (min) of total hydrogen pressure, a maximum value Pzci (max) of total coolant pressure, and a minimum value Pzci (min) of total coolant pressure, which enter the cross section of the active region, respectively;
s243: calculating the total pressure pole difference delta Pea ═ Pzai (max) -Pzai (min) in the active area,
calculating the total pressure pole difference delta Peh ═ Pzhi (max) -Pzhi (min) of hydrogen in the active area,
the total pressure difference Δ Pec of the coolant in the active region was calculated as Pzci (max) -Pzci (min).
8. A bipolar plate fluid flow evaluation method as in claim 7, wherein: in the step S25, the specific steps are as follows:
s251: based on the data obtained in step S241
Calculating the average value M (Pza) of the total pressure of the air in the n channels on the section, (Pza1+ Pza2+ … + Pza)/n,
calculating the average value M (pzh) of the total pressure of the hydrogen of the n channels on the section, (Pzh1+ Pzh2+ … + Pzhn)/n,
calculating the total pressure average value M (pzc) of the cooling liquid of the n channels on the section, (Pzc1+ Pzc2+ … + Pzcn)/n;
s252: calculating the air total pressure variance of the section of the active region
D(Pfa)＝{[Pza1-M(pza)]2+[Pza2-M(pza)]2+……+[Pzan-M(pza)]2}/n，
Calculating the total pressure variance of hydrogen in the section of the active region
D(Pfh)＝{[Pzh1-M(pzh)]2+[Pzh2-M(pzh)]2+……+[Pzhn-M(pzh)]2}/n，
Calculating total pressure variance of cooling liquid in section of active region
D(Pfc)＝{[Pzc1-M(pzc)]2+[Pzc2-M(pzc)]2+……+[Pzcn-M(pzc)]2}/n。
9. A bipolar plate fluid flow evaluation method as in claim 1, wherein: in the step S3, the specific steps are as follows:
s31: judging whether the calculated values of the air total pressure drop, the hydrogen total pressure drop, the cooling liquid total pressure drop, the flow unevenness of the ith flow channel in the air active area of the bipolar plate, the flow unevenness of the ith flow channel in the hydrogen active area of the bipolar plate and the flow unevenness of the ith flow channel in the cooling liquid active area of the bipolar plate respectively meet the corresponding evaluation preset value requirements, if not, judging that the evaluation result of the flow of the bipolar plate fluid is unqualified, terminating the evaluation, and re-executing the step after optimizing the three-dimensional model; if so, the evaluation result of the bipolar plate fluid flow is qualified, and the step S32 is executed;
s32: judging whether the calculated values of the air total pressure drop ratio, the hydrogen total pressure drop ratio and the cooling liquid total pressure drop ratio respectively meet the requirements of corresponding evaluation preset values;
s33: and judging whether the calculated values of the total pressure pole difference of the air in the active area, the total pressure pole difference of the hydrogen in the active area, the total pressure pole difference of the cooling liquid in the active area, the total pressure variance of the air in the active area, the total pressure variance of the hydrogen in the active area and the total pressure variance of the cooling liquid in the active area respectively meet the corresponding requirements of the evaluation preset value.
10. A bipolar plate fluid flow evaluation method as in claim 9, wherein: in the step S3, if the calculated values of the parameters in the step S32 respectively satisfy the corresponding requirements of the preset evaluation values and the calculated values of the parameters in the step S33 respectively satisfy the corresponding requirements of the preset evaluation values, the evaluation result of the fluid flow of the bipolar plate is excellent; if the calculated values of the parameters of step S32 and the calculated values of the parameters of step S33 respectively satisfy the corresponding requirements of the preset evaluation values, the evaluation result of the fluid flow of the bipolar plate is good.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113642265A (en) * | 2021-06-29 | 2021-11-12 | 东风汽车集团股份有限公司 | Method and device for evaluating fluid flow of fuel cell short stack |
| CN114551944A (en) * | 2022-01-07 | 2022-05-27 | 国网浙江省电力有限公司电力科学研究院 | Method and system for rapidly controlling water content in proton exchange membrane fuel cell |
| CN116706151A (en) * | 2023-06-07 | 2023-09-05 | 寰泰储能科技股份有限公司 | Method for estimating average linear velocity of electrolyte flowing in electrode in flow battery |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102089911A (en) * | 2008-07-15 | 2011-06-08 | 戴姆勒股份公司 | Bipolar plate for a fuel cell arrangement, in particular for placement between two adjacent membrane electrode arrangements |
| CN104133965A (en) * | 2014-07-30 | 2014-11-05 | 中国核动力研究设计院 | Transient analysis method applied to two-pass core |
| CN208173710U (en) * | 2017-12-29 | 2018-11-30 | 上海神力科技有限公司 | The bipolar plate structure of fuel cell |
| CN109410659A (en) * | 2018-09-13 | 2019-03-01 | 南京迅猛龙文化传媒有限公司 | The working method of wisdom perception interactive machine |
| CN110911721A (en) * | 2019-11-28 | 2020-03-24 | 东风汽车集团有限公司 | Fuel cell control method and fuel cell control device |
| CN111180767A (en) * | 2020-01-07 | 2020-05-19 | 天津大学 | Fuel cell stack modeling method with fluid uneven distribution effect |
| CN210897482U (en) * | 2019-12-12 | 2020-06-30 | 中国第一汽车股份有限公司 | Fuel cell cooling system, fuel cell and fuel cell automobile |
-
2020
- 2020-11-09 CN CN202011236366.0A patent/CN112345202A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102089911A (en) * | 2008-07-15 | 2011-06-08 | 戴姆勒股份公司 | Bipolar plate for a fuel cell arrangement, in particular for placement between two adjacent membrane electrode arrangements |
| CN104133965A (en) * | 2014-07-30 | 2014-11-05 | 中国核动力研究设计院 | Transient analysis method applied to two-pass core |
| CN208173710U (en) * | 2017-12-29 | 2018-11-30 | 上海神力科技有限公司 | The bipolar plate structure of fuel cell |
| CN109410659A (en) * | 2018-09-13 | 2019-03-01 | 南京迅猛龙文化传媒有限公司 | The working method of wisdom perception interactive machine |
| CN110911721A (en) * | 2019-11-28 | 2020-03-24 | 东风汽车集团有限公司 | Fuel cell control method and fuel cell control device |
| CN210897482U (en) * | 2019-12-12 | 2020-06-30 | 中国第一汽车股份有限公司 | Fuel cell cooling system, fuel cell and fuel cell automobile |
| CN111180767A (en) * | 2020-01-07 | 2020-05-19 | 天津大学 | Fuel cell stack modeling method with fluid uneven distribution effect |
Non-Patent Citations (2)
| Title |
|---|
| 刘洪建: ""燃料电池多通道蛇形流场的设计及优化"", 《内燃机与动力装置》 * |
| 叶强: ""基于高效紧凑设计的液流电池管路优化方法"", 《电源技术》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113642265A (en) * | 2021-06-29 | 2021-11-12 | 东风汽车集团股份有限公司 | Method and device for evaluating fluid flow of fuel cell short stack |
| CN113642265B (en) * | 2021-06-29 | 2024-04-16 | 东风汽车集团股份有限公司 | Method and device for evaluating flow of fuel cell short stack fluid |
| CN114551944A (en) * | 2022-01-07 | 2022-05-27 | 国网浙江省电力有限公司电力科学研究院 | Method and system for rapidly controlling water content in proton exchange membrane fuel cell |
| CN114551944B (en) * | 2022-01-07 | 2023-10-10 | 国网浙江省电力有限公司电力科学研究院 | Method and system for rapidly controlling internal water content of proton exchange membrane fuel cell |
| CN116706151A (en) * | 2023-06-07 | 2023-09-05 | 寰泰储能科技股份有限公司 | Method for estimating average linear velocity of electrolyte flowing in electrode in flow battery |
| CN116706151B (en) * | 2023-06-07 | 2024-03-15 | 寰泰储能科技股份有限公司 | Method for estimating average linear velocity of electrolyte flowing in electrode in flow battery |
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