空冷型PEMFC启停策略研究

发布时间：2018-04-29 10:27

本文选题：空冷型PEMFC + 启停策略　；参考：《西南交通大学》2017年硕士论文

【摘要】：质子交换膜燃料电池(Proton Exchange Membrane Fuel Cell)是一种新型的电化学发电装置,打破了传统的发电模式。它利用固体电解质,以氢气作为燃料,以空气为氧化剂,通过氢氧化合作用直接将化学能转化为优质的电能。质子交换膜燃料电池由于具有稳定性好、响应速度快、功率密度高、运行温度低等优点,在新能源车辆、便携式移动电源、分布式电站等领域具有非常广阔的应用前景。本文以自己搭建的空冷型质子交换膜燃料电池实验平台为基础,研究了启停控制策略对电堆性能的影响。主要研究成果如下:(1)为了降低燃料电池启动时形成的高电压和缩短高电压维持的时间,我们通过实验研究对比分析了常规启动、联合最低单片电压启动和减小氢气进气压力启动对PEMFC的影响,提出了一种新的PEMFC启动策略。该策略是减小电堆启动时氢气进气压力,当电堆最小单片电压值大于0.3V后立即切入启动负载。结果表明,该策略不仅可以明显降低电堆启动时最大单片电压值,而且缩短了高电压维持的时间,这必然有利于延长电堆寿命和提高电堆耐久性,是一种十分有效的PEMFC启动控制策略。(2)质子交换膜燃料电池停机过程中引起性能衰减的根本原因是阳极侧残留有氢气。为了满足快速消除电堆内残留的氢气,本文提出了利用空冷电堆的风扇对电堆放电和使用辅助负载对电堆中各个单电池单独放电的停机控制策略。通过实验研究对比了直接停机、利用辅助负载整体放电和利用辅助负载对各个单电池单独放电三种停机方式对PEMFC的影响。结果表明,利用辅助负载对各个单电池单独放电的停机策略不仅能缩短燃料电池停机后各个单电池维持在高电位的时间,同时也能防止PEMFC停机放电过程中单电池反极现象的发生,是一种十分有效的质子交换膜燃料电池停机策略。(3)为了快速消除电堆内残留的氢气,本文又通过实验研究对比分析了直接停机、利用辅助负载停机和氮气吹扫停机三种不同的停机方式对PEMFC的影响,并提出了联合辅助负载和氮气吹扫的停机策略。结果表明,该停机策略不仅减短了电堆维持开路高电压的时间,而且避免了燃料电池在启停机过程中氢空界面的形成,这必然有利于延长电堆寿命和提高电堆耐久性,是一种十分有效的燃料电池系统停机控制策略。
[Abstract]:Proton Exchange Membrane Fuel cell (Proton Exchange Membrane Fuel cell) is a new type of electrochemical power generation device, which breaks the traditional power generation mode. It uses solid electrolyte, hydrogen as fuel, air as oxidant, and directly converts chemical energy into high quality electric energy by hydrogen oxidation. Proton exchange membrane fuel cells (PEMFC) have many advantages such as good stability, high response speed, high power density and low operating temperature, so they have a wide application prospect in the fields of new energy vehicles, portable mobile power sources, distributed power stations and so on. Based on the experimental platform of air-cooled proton exchange membrane fuel cell (PEMFC), the effect of startup and stop control strategy on the performance of PEMFC is studied in this paper. The main research results are as follows: (1) in order to reduce the high voltage formed during the fuel cell start-up and shorten the duration of the high voltage maintenance, we have compared and analyzed the conventional start-up through experimental research. A new PEMFC startup strategy is proposed by combining the effects of minimum monolithic voltage startup and reducing hydrogen intake pressure startup on PEMFC. The strategy is to reduce the inlet pressure of hydrogen when the stack is started, and cut into the start-up load immediately when the minimum single chip voltage of the stack is greater than 0.3 V. The results show that the strategy can not only obviously reduce the maximum single chip voltage value at the start of the stack, but also shorten the time of high voltage maintenance, which is bound to prolong the stack life and improve the stack durability. Proton exchange membrane fuel cell (PEMFC) is a very effective PEMFC startup control strategy. The fundamental cause of the performance decay during the shutdown of the proton exchange membrane fuel cell (PEMFC) is the presence of hydrogen on the anode side. In order to rapidly eliminate the residual hydrogen gas in the stack, a shutdown control strategy is proposed in this paper, which uses the fan of the air-cooled stack to discharge electricity and the auxiliary load to separate discharge of each single cell in the stack. The effects of direct shutdown, total discharge of auxiliary load and individual discharge of each single cell on PEMFC were studied and compared. The results show that the strategy of using auxiliary load to discharge each single cell can not only shorten the time of each single cell remaining at high potential after the fuel cell is shut down. At the same time, it can also prevent the phenomenon of single cell reverse during PEMFC shutdown discharge. It is a very effective proton exchange membrane fuel cell shutdown strategy. In this paper, the effects of direct shutdown, auxiliary load shutdown and nitrogen blowing downtime on PEMFC are compared and analyzed, and the strategy of combined auxiliary load and nitrogen purging is put forward in this paper. The results show that the shutdown strategy not only reduces the time of maintaining open circuit high voltage, but also avoids the formation of hydrogen air interface during the start-up and shutdown of fuel cell, which is bound to prolong the stack life and improve the stack durability. It is a very effective control strategy for fuel cell system shutdown.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM911.4

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