Fuel cells are expected to play a major role in the economy of this century and for the foreseeable future. The use of hydrogen and fuel cells can address critical challenges in all energy sectors like commercial, residential, industrial, and transportation. Fuel cells are electrochemical devices that convert energy of a chemical reaction directly into electrical energy by combining hydrogen fuel with oxygen from air. If hydrogen is used as fuel, only byproducts are heat and water.
The objective of this thesis is to investigate the effect of operating temperature and relative humidity (RH) of reactant gases on proton exchange membrane (PEM) fuel cell performance by adjusting the operation temperature of the fuel cell and humidification temperature of the reactant gases.
In this study, the effect of the different operating parameters on the performance of single proton exchange membrane (PEM) fuel cell have been studied experimentally using pure hydrogen on the anode side and air on the cathode side. Experiments with different fuel cell operating temperatures, different air and hydrogen humidification temperatures have been carried out. The experimental results are presented in the form of polarization curves, which show the effects of the various operating parameters on the performance of the PEM fuel cell. The polarization curves data have been fit to a zero dimensional model, and the effect of the fuel cell operation and humidification temperatures on the kinetic parameters and the cell resistance have been determined.
The fuel cell has been operated with 1.2 and 2 stoichiometry ratio for hydrogen and air, respectively. Fuel cell performance was detected at different fuel cell operation temperatures changing from 60 to 80 º / C, and relative humidity of the entering gases changing from 20 to 100 % for air and 50 % and 100 % for hydrogen. Tests were performed in a PEM fuel cell test station.
The highest performance of 275 mA/cm2 at 0.6 V and 650 mA/cm2 at 0.4 V was obtained for 50 % RH air with a constant 100 % relative humidity of hydrogen for working at atmospheric pressure and 60 oC fuel cell temperature. However, the highest performance of 230 mA/cm2 at 0.6 V for 50 % RH of air with a constant 100 % relative humidity of hydrogen and the highest performance of 530 mA/cm2 at 0.4 V for both 70 % RH and 100% RH air with a constant 100 % relative humidity of hydrogen was obtained for working at atmospheric pressure and 70 oC fuel cell temperature. Besides, the highest performance of 200 mA/cm2 at 0.6 V and 530 mA/cm2 at 0.4 V was obtained for 100 % RH air with a constant 100 % RH of hydrogen for working at atmospheric pressure and 80 oC fuel cell temperature.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12614375/index.pdf |
| Date | 01 May 2012 |
| Creators | Ozsan, Burcu |
| Contributors | Eroglu, Inci |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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