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
Modeling and control of a PEM fuel cell system
Download
index.pdf
Date
2013
Author
Saygılı, Yasemin
Metadata
Show full item record
Item Usage Stats
303
views
176
downloads
Cite This
Polymer electrolyte membrane (PEM) fuel cells attract an extensive interest due to their advantageous properties. To compete with the conventional power generators fuel cell systems should ensure safe and efficient operations at any time. To achieve satisfactory operations, all the process requirements should be determined and implemented within the operational constraints. Thermal management, reactant supply, water management and power management are some of the main issues for which proper and sufficient control strategies should be developed and implemented by the control system. In this study a portable 3kW PEM fuel cell system is modeled to understand the system dynamics. The system model includes the fuel cell stack, humidifier, compressor, inlet and outlet manifolds, and cooling system. Model development is carried out by the mass and energy balances, thermodynamics and kinetics. To define unknown system parameters some experiments are performed on stack and the cooling system and a semi-empirical model is constructed. For the compressor a feedback (PI) controller is combined with a static feed-forward controller. It is observed that the compressor adapts to dynamic changes within small durations. A membrane type, shell and tube structured humidifier is modeled and compared with literature and a reasonable agreement is observed. Two different humidifiers are simulated to see the effect number of tubes involved in humidifier. It is observed that increasing the number of tubes results in better humidification as expected. Three different control strategies are analyzed for the cooling system involving a pump, radiator and fan. The performances of different controllers for thermal management are evaluated in terms of stack temperature, integral time weighted absolute error (ITAE) and the parasitic energy requirements. Minimizing fan usage with an on/off controller while keeping the pump voltage as a variable gives better results. MATLAB Simulink is used for development and implementation of models and controllers.
Subject Keywords
Polymers.
,
Pigments.
,
Emulsions.
URI
http://etd.lib.metu.edu.tr/upload/12616428/index.pdf
https://hdl.handle.net/11511/23072
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Synthesis and charaterization of single hollow opaque polymer pigments
Karakaya, Ekin; Gündüz, Güngör; Maviş, Bora; Department of Chemical Engineering (2013)
In the present work opaque polymer pigments with single hollow structure were synthesized by osmotic swelling method. The hollow pigment is composed of an outer shell and an inner void space which can be filled with air or water. The osmotic swelling process involves synthesizing of a core polymer containing carboxylic acid group on the backbone, and encapsulating it with another polymer which functions as shell. The swelling of the polymer is provided by neutralization of the core with a base. Methyl metha...
Numerical modeling of visco-elasto-plastic hygro-thermal stresses and the effects of operating conditions on the mechanical degradation of PEFC membranes
Mehrtash, Mehdi; Tarı, İlker; YEŞİLYURT, SERHAT (2018-08-31)
Durability of membranes is one of the concerns for widespread commercialization of polymer electrolyte fuel cells. Effects of membrane swelling on the durability pose important challenges for the fabrication of the catalyst-coated membrane. This study provides insight into vulnerable locations of the membrane under hygrothermal loading, mechanical loading due to clamping and realistic conditions where a combination of both of these loadings are imposed. With a half rib-channel model, we simulate a polymer e...
Nanocomposites based on blends of polyethylene
Işık, Fatma; Yılmazer, Ülkü; Department of Chemical Engineering (2005)
In this study the effects of compatibilizer type, organoclay type, and the addition order of components on the morphological, thermal, mechanical and flow properties of ternary nanocomposites based on low density polyethylene, LDPE were investigated. As compatibilizer, ethylene/methyl acrylate/glycidyl methacrylate, ethylene/glycidyl methacrylate, and ethylene/butyl acrylate/maleic anhydride; as organoclay Cloisite? 15A, Cloisite? 25A and Cloisite? 30B were used. All samples were prepared by a co-rotating t...
Synthesis and characterization of polypropylene based ion-exchange resin
Ecevit, Safiye Tuba; Aras, Leyla; Tinçer, Teoman; Department of Polymer Science and Technology (2012)
The synthesis of ion-exchange resin which can be used in various separation and chemical purposes, such as diffusion dialysis, electro dialysis, electrolysis and fuel cells has of considerable interest. For all these applications, the interactions of the ionic groups and the resulted morphologies are critical for establishing the unique properties. Considerable researches have been continued to understand the microstructure of these materials. The aim of this study is to synthesize polypropylene (PP) based ...
Modeling and sensitivity analysis of high temperature PEM fuel cells by using Comsol Multiphysics
Sezgin, Berna; Caglayan, Dilara Gulcin; DEVRİM, YILSER; Steenberg, Thomas; Eroğlu, İnci (2016-06-22)
The objective of this study is to observe the effect of the critical design parameters, velocities of inlet gases (hydrogen and air) and the conductivity of polymer membrane, on the performance of a high temperature PEM fuel cell. A consistent and systematic mathematical model is developed in order to study the effect of these parameters. The model is applied to an isothermal, steady state, three-dimensional PEM fuel cell in order to observe concentration profiles, current density profiles and polarization ...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
Y. Saygılı, “Modeling and control of a PEM fuel cell system,” M.S. - Master of Science, Middle East Technical University, 2013.