Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Second law anlysis of solid oxide fuel cells
Download
index.pdf
Date
2003
Author
Bulut, Başar
Metadata
Show full item record
Item Usage Stats
161
views
0
downloads
Cite This
In this thesis, fuel cell systems are analysed thermodynamically and electrochemically. Thermodynamic relations are applied in order to determine the change of first law and second law efficiencies of the cells, and using the electrochemical relations, the irreversibilities occuring inside the cell are investigated. Following this general analysis, two simple solid oxide fuel cell systems are examined. The first system consists of a solid oxide unit cell with external reformer. The second law efficiency calculations for the unit cell are carried out at 1273 K and 1073 K, 1 atm and 5 atm, and by assuming different conversion ratios for methane, hydrogen, and oxygen in order to investigate the effects of temperature, pressure and conversion ratios on the second law efficiency. The irreversibilities inside the cell are also calculated and graphed in order to examine their effects on the actual cell voltage and power density of the cell. Following the analysis of a solid oxide unit cell, a simple fuel cell system is modeled. Exergy balance is applied at every node and component of the system. First law and second law efficiencies, and exergy loss of the system are calculated.
Subject Keywords
Fuel cells
,
Exergy
,
Solid oxide fuel cell
,
Second law efficiency
URI
http://etd.lib.metu.edu.tr/upload/1219161/index.pdf
https://hdl.handle.net/11511/13804
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Numerical Investigation of thermal management of Solid Oxide Fuel Cells by flow arrangement
Şen, Fırat; Tarı, İlker (null; 2015-05-29)
SolidOxide Fuel Cells (SOFCs) are electrochemical cells working at high temperatures. One of the important problems in planar SOFC designs is the non-uniformtemperature distribution on the plane of the cell due to the waste heat produced by electrochemical reactions. Another important problem of SOFCs is the low fuel utilization ratio. In this study, the effect of the flow arrangement on the temperature distribution, which causes the thermal stresses, and the met...
Numerical investigation of a stand alone solar hydrogen energy system effects of PEFC degradation
Ender, Ozden; Tarı, İlker (null; 2015-08-12)
An existing stand-alone solar energy system producing hydrogen for energy storage is numerically investigated focusing on the degradation of Polymer Electrolyte Fuel Cell (PEFC) and its effects on the overall performance of the system. The system consists of Photovoltaic (PV) panels, polymer electrolyte based electrolyzers, H2 and O2 storage tanks and a commercial PEFC stack. A PEFC is numerically investigated both as new and as degraded (for about two years). Using a variety of observed degradation pattern...
Development of anodes for direct oxidation of methane fuel in solid oxide fuel cells
Akdeniz, Yelda; Timurkutluk, Bora; Timurkutluk, Cigdem (2016-06-22)
In addition to pure hydrogen, solid oxide fuel cells (SOFCs) can utilize hydrocarbons as a fuel. However, conventional Ni-based anodes exhibit an excellent catalytic activity towards the hydrocarbon cracking reaction and thus the carbon deposition occurs in the anode. The deposited carbons quickly deactivate the anode irreversibly by covering the active surface of the anode catalyst. As a result, a significant degradation in the cell performance can be seen. In this study, the anode structure is modified by...
Combinatorial development of LSC-113/LSC-214 cathode materials for intermediate temperature solid oxide fuel cells
Sarı, Doğancan; Öztürk, Tayfur; Kalay, Yunus Eren; Department of Metallurgical and Materials Engineering (2017)
Solid oxide fuel cells are environmentally friendly, efficient and fuel versatile energy conversion devices which suffer from high operating temperatures. For lowering the operating temperatures of solid oxide fuel cells (SOFC), LSC-113/LSC-214 composite cathodes have recently attracted much attention due to their enhanced kinetics. However, the full potential of this novel system is still unknown. In this study, a combinatorial approach was used to develop cathode materials which would reduce operating tem...
MODELING OF BIPOLAR PLATES FOR PROTON EXCHANGE MEMBRANE FUEL CELLS
Ekiz, Ahmet; Camci, Talha; Turkmen, Ibrahim; SANKIR, MEHMET; USLU, SITKI; Baker, Derek Keıth; Agar, Ertan (2011-09-01)
Fuel cell technology is one of the most economic and efficient ways to utilize hydrogen energy. Various types of fuel cells are present regarding the fuel type and amount of power produced. Among these, proton exchange membrane fuel cells (PEMFCs) are very promising. In this work, a 2D proton exchange membrane fuel cell unit cell was modeled using Comsol Multiphysics software. Cell section was taken parallel to flow direction. Obstacles with various geometries were placed in the flow channel in order to for...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
B. Bulut, “Second law anlysis of solid oxide fuel cells,” M.S. - Master of Science, Middle East Technical University, 2003.
