燃料电池电堆三维温度场分布的研究与优化分析

发布时间：2018-03-26 05:30

本文选题：固体氧化物燃料电池　切入点：3D电堆　出处：《江苏科技大学》2017年硕士论文

【摘要】：固体氧化物燃料电池(SOFC)是具应用前景的电能产生装置之一。由于SOFC有着复杂的工作过程,相比于传统实验方法,模拟仿真的方法会更有优势。SOFC在运作时会有各种复杂的反应过程,包括流动、电化学、传热传质及导电等。电化学反应过程中反应物的生成及消耗会影响到SOFC内的热量的分布、流动以及整个电堆的性能。所以本论文以宁波材料所的新型平板式短堆的结构为原型,实施了电堆的3D模型建立,对电堆进行了优化及分析。并试着建立了3D电堆的全模型(主管道、阳极、阴极、电解质及连接体),包括传热和传质、流动以及化学反应等的综合性多场耦合的全模型。主要研究内容和结论如下:1、首先介绍了10层小型电堆流场优化背景以及关于电堆模型用到的一些理论和具体的优化步骤,第一部分的重点就是对氢气和空气流场均匀度和标准偏差因子的计算,利用计算流体动力学(CFD)对模块化电堆内不同主管道的位置及不同分流器下的气流分布情况进行了对比分析。2、针对10层电堆的流场分析,有以下结论:(1)主管是否穿透SOFC单元平面不会影响电堆层面的电池单元中的燃料和空气流分布质量。对于小型平板式SOFC电堆,在电堆层面的流量分布质量很高。然而,每个SOFC单元表面的流量分布质量应该加以改善;(2)当燃料主管置于SOFC单元区域内并穿过SOFC单元区域时,超过31%的空气将通过燃料主管区域的半圆区域;(3)当空气流主管放置在SOFC单元区域内时,超过14%的燃料将通过空气主管区域的半圆区域;(4)当流量主管穿过电池单元平面时,通过增加额外的分配器或扩大整个出口主管面积,单电池层面上的燃料和空气流分布质量并不会大大改善。3、针对25层带有多孔介质的模块化短堆进行了分流器的优化以及进出口排列的优化分析,对于空气侧模型,包括了空气气道、阴极支撑层、阴极以及电解质;对于燃料模型,包括了燃料气道、电解质、阳极支撑层、阳极,加入了流动、热量以及组分传输等的影响,通过优化的结果分析电堆里的流场分布以及温度和组分的分布情况,最终得出半圆分流器结构改善了原始结构流场及温度场分布的均匀性,而1进2出结构只优化了燃料侧流量分布的均匀性,其余的温度分布及空气侧的流量及温度分布都没有得到改善,所以得出采用半圆分流器结构更能增加电堆系统的使用寿命,降低维修及应用的成本,能很有效的帮助SOFC的商业化发展。
[Abstract]:Solid oxide fuel cell (SOFC) is one of the promising power generation devices. Because of the complex working process of SOFC, compared with the traditional experimental methods, There are many complex reaction processes in the operation of SOFC, including flow, electrochemistry, heat and mass transfer and conduction, etc. The generation and consumption of reactants during electrochemical reaction will affect the distribution of heat in SOFC. Flow and the performance of the whole stack. Therefore, based on the structure of the new type flat short reactor of Ningbo Institute of Materials, the 3D model of the stack is established in this paper. The whole model of 3D stack (main pipe, anode, cathode, electrolytes and connectors, including heat and mass transfer) has been established. The main contents and conclusions of the study are as follows: 1. Firstly, the background of flow field optimization and some theories and specific optimization steps used in the stack model are introduced. The first part focuses on the calculation of the uniformity of hydrogen and air flow field and the standard deviation factor. By using computational fluid dynamics (CFD), the airflow distribution of different main pipeline and different shunt in modularized electric reactor is compared and analyzed, and the flow field of 10 layer reactor is analyzed. The following is the conclusion: 1) whether or not the supervisor penetrates the plane of the SOFC cell does not affect the quality of the fuel and air flow distribution in the battery cell at the stack level. For the small flat SOFC stack, the flow distribution quality at the stack level is very high. However, The quality of flow distribution on the surface of each SOFC cell should be improved when the fuel supervisor is placed in the SOFC cell area and passes through the SOFC cell area, More than 31% of the air will pass through the semicircular area of the fuel charge area.) when the air flow supervisor is placed in the SOFC cell area, more than 14% of the fuel will pass through the semicircular area of the air competent area. By adding additional allocators or expanding the entire export control area, The mass distribution of fuel and air flow on the single cell layer will not be greatly improved. For the 25 layers of modularized short reactor with porous media, the optimization of the shunt and the optimal arrangement of the inlet and outlet are carried out. For the air side model, Including air passage, cathode support layer, cathode and electrolyte; for fuel model, including fuel channel, electrolyte, anode support layer, anode, the effect of adding flow, heat and component transmission, etc. By analyzing the distribution of flow field and temperature and components in the stack, it is concluded that the semi-circular shunt structure improves the uniformity of the flow field and temperature field of the original structure. However, the 1 in 2 output structure only optimizes the uniformity of flow distribution on the fuel side, while the other temperature distribution and the flow rate and temperature distribution on the air side are not improved, so it is concluded that the semi-circular shunt structure can increase the service life of the stack system. Reduce the cost of maintenance and application, can help the commercialization of SOFC very effectively.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM911.4

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