• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文OA文献 >Wärmehaushalt einer Karbonat-Brennstoffzelle zur Wasserstoffherstellung für eine Polymerelektrolyt-Brennstoffzelle
【2h】

Wärmehaushalt einer Karbonat-Brennstoffzelle zur Wasserstoffherstellung für eine Polymerelektrolyt-Brennstoffzelle

机译：用于聚合物电解质燃料电池的制氢用碳酸盐燃料电池的热平衡

页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Molten carbonate fuel cells (MCFC) are being used in decentralised power plants, as they can reform hydrocarbon bound fuels internally, e.g. netural gas with a energy density of 10 kWh/m3 at standard conditions, and the efficiency of this mode of operation is around 50%. However in comparison to other fuel cell systems the power density is only 5 kW/m3. The power density of a polymerelectrolyte fuel cell (PEFC) ismuch higher (50 kW/m3). These systems can be run with an efficiency of 50%, too. Therefore they need hydrogen as a fuel, with an energy density of 2,9 kWh/m3 at standard conditions. Efficiency decreases to 35 to 40% using Methane as fuel, because of the reforming losses. The power density than is 6 kW/m3 and therefore as high as for a MCFC-system. Acombination of MCFC and PEFC, the so called CoCell, offers the following advantages:• A highly energetic, hydrocarbon based fuel can be used, e.g. Methane.• A high electrical efciency is achieved.• The power density of this system is higher than for a fuel cell with reformer.In the CoCell the MCFC is working as electricity producing reformer for the PEFC. The offheat of the MCFC is used for reforming, whereby hydrogen is available, being utilised further in the powerdense PEFC. The reforming capacity of the MCFC is limited by the internal heat balance. If the endothermic reforming consumes more heat than supplied by the material streams and the fuel cell waste heat, the stack cools down. The performance of such a combined fuel cell system has been evaluated in this thesis using the thermodynamic simulation software Aspen. Calculations reducing the utilisation in the MCFC by various heating techniques showed, that additional heat is supplied most efficiently by increasing the current density of the MCFC. Thereby the stack is heated electrically and the power density of the system is increased by the improved power density of the MCFC. The reduction of the utilisation is achieved by increasing fuel supply. Thereby the stack is cooled sufficiently at low utilisation and low air supply. In this configuration the current density can be increased up to 350 mA/cm2. This is 2,5 times the value of 140 mA/cm2 of typical, conventional operation. This limitation was explored experimentally. Based on the presented model calculations the power density of the CoCell increases to 14 kW/m3 at a current density in the MCFC of 280 mA/cm2. It is thereby almost three-times as high as for other fuel cell reformer systems (see above). The electrical efficiency accounts for 38% and is as good as a PEFC-Reformer system.
机译：熔融碳酸盐燃料电池（MCFC）正在分散式发电厂中使用，因为它们可以在内部重整碳氢化合物燃料，例如碳氢化合物燃料电池。在标准条件下能量密度为10 kWh / m3的气体，这种操作模式的效率约为50％。但是，与其他燃料电池系统相比，功率密度仅为5 kW / m3。聚合物电解质燃料电池（PEFC）的功率密度更高（50 kW / m3）。这些系统也可以以50％的效率运行。因此，他们需要氢气作为燃料，标准条件下的能量密度为2.9 kWh / m3。由于重整损失，使用甲烷作为燃料的效率降低到35％至40％。功率密度为6 kW / m3，因此与MCFC系统一样高。 MCFC和PEFC的组合，即所谓的CoCell，具有以下优点：•可以使用高能的碳氢化合物燃料，例如：甲烷。•实现了高电效率。•该系统的功率密度高于带有重整器的燃料电池。在CoCell中，MCFC用作PEFC的发电重整器。 MCFC的余热用于重整，从而可利用氢，在功率密集的PEFC中进一步利用氢。 MCFC的重整能力受到内部热量平衡的限制。如果吸热重整所消耗的热量多于物料流所提供的热量，并且燃料电池浪费了热量，则电池组会冷却。本文使用热力学模拟软件Aspen对这种组合式燃料电池系统的性能进行了评估。通过各种加热技术降低MCFC利用率的计算表明，通过增加MCFC的电流密度可以最有效地提供更多热量。由此，堆叠被电加热并且系统的功率密度通过MCFC的改进的功率密度而增加。通过增加燃料供应来实现利用率的降低。因此，在低利用率和低空气供应的情况下，堆被充分冷却。在这种配置下，电流密度可以增加到350 mA / cm2。这是典型常规操作的140 mA / cm2值的2.5倍。通过实验探索了这一局限性。基于提出的模型计算，在280 mA / cm2的MCFC中的电流密度下，CoCell的功率密度增加到14 kW / m3。因此，它几乎是其他燃料电池重整器系统（见上文）的三倍。电气效率占38％，与PEFC-Reformer系统一样好。

著录项

  • 作者

    Adamek Lars;

  • 作者单位
  • 年度 2006
  • 总页数
  • 原文格式 PDF
  • 正文语种 ger
  • 中图分类

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号