The document discusses the effect of relative humidity on polymer electrolyte membrane (PEM) fuel cell performance. It provides an overview of PEM fuel cells, describing their basic components and working principles. The author aims to develop a PEM fuel cell model, investigate how relative humidity affects water management and performance under varying loads, and validate results with literature data. The summary provides context about the author's educational background and current pursuit of a master's degree focused on mechanical engineering and PEM fuel cells.
2. EFFECT OF THE RELATIVE HUMIDITY ON
THE PERFORMANCE OF POLYMER
ELECTROLYTE MEMBRANE FUEL CELLS
SUBMITTED BY :OMAR QASIM SALIH
SUBMITTED TO: DR .ABDULRAZZAK AL-
AKROOT
KARABUK UNIVERSITY - NATURAL AND APPLIED
SCIENCES
ENGINEERING FACULTY - MECHANICAL
ENGINEERING DEPARTMENT
3. Presentation outlines
Overview of the (PEM) fuel cells topic
Basic components of (PEM) fuel cells
(PEM) fuel cells working
The efficiency of the (PEM) fuel cells
Research motivations
Literature review
Problem statement
Research aims
Research methodology
Timeline of research
4. Overview of the (PEM) fuel cells
topic
(PEM) fuel cells are energy conversion devices that
convert the chemical energy in the fuel to electric
energy directly without any combustion processes.
5. Basic components of (PEM) fuel
cells
Polymer Electrolyte
Membrane (PEM)
Catalyst Layers(CLs)
Gas Diffusion Layers(GDLs)
Bipolar Plats (BPs)
6. Polymer Electrolyte Membrane (PEM)
Main roles: Ion transport from the anode to
the cathode.
Thickness: 50 µm
Common material : Sulfonated
tetrafluoroethylene copolymer (Nafion)
Must be
I. Fully moist
II. Mechanical and chemical stability
III. Electronically insulating
IV. Thin as possible
7. Catalyst Layers(CLs)
Main roles: speed up the electrochemical
reaction on both side (anode and cathode)
Thickness: From 3 to 10 mm
Common material: Platinum
Must be
I. High activity to sustain the hydrogen
oxidation and oxygen reduction
II. Gases permeable
III. High durability
IV. Inexpensive
8. Gas Diffusion Layers(GDLs)
Main roles: Distribute the reactant gases
to catalyst surface and transport the
electrons to the current collectors
Thickness: 15-35 µm
Common material: Carbon clothes
(GDLs) Must be :
I. High electronic conductivity
II. porous
III. Thin
IV. Chemical stability
V. preamble for gases
9. Bipolar Plats (BPs)
Main role: Current collection
Thickness: From 2 to 5 mm
Common material :Graphite
(BPs)Must be
I. High conductivity
II. Corrosion resistance
III. Provide thermal management
10. PEMFCs layout and working
Hydrogen Oxidation
reaction (HOR) :
H2 → 2H + 2e –
Oxygen reduction reaction
(ORR) :
½ O2 + 2H + e – → H2O (L)
Net reaction:
H2(g) + ½ O2 (g)→ H2O+HEAT
ANODE
CATHODE
PEMFCs potential = 0.7 V
11. The amount of Heat released from
PEMFCs
Enthalpy of reaction = enthalpy formation of products -
enthalpy formation of reactants
▲H =Hf (H2O) –Hf (H2) – Hf (O2)
▲H=286 KJ/MOL.K
The amount of the reactants and productions stats in the
thermodynamics table below
Reactants/products Hf (kj/mol.k) Hs (kj/mol.k)
Hydrogen(H2) 0 0.13054
Oxygen (O2) 0 0.20514
Water(H2O) liquid -286.02 0.6996
Water(H2O) vapor -214.98 0.018884
12. Calculate the maximum electrical energy
produced from the PEMFCS
In order to calculate the net energy
from the chemical reaction JOSIH
WILLARD GIBBS 1983
Was developed a relationship:
▲G=▲H-T▲S
Where :
▲G=an exchange in the Gibbs free
energy.
▲H=enthalpy of an electrochemical
reaction.
T = electrochemical reaction
temperature
▲S=an exchange in the entropy of
the electrochemical reaction.
▲G= 237 KJ/MOL
JOSIH WILLARD
GIBBS 1983
13. The efficiency of the (PEM) fuel cells
The efficiency of (PEM) fuel cells can be
expressed by the ratio of energy from the
(PEM) fuel cells (Gibbs free energy) to input
energy (enthalpy of the electrochemical
reaction)
ή=▲G / ▲H
= 237 / 286
=83%
14. Literature review
many researchers were focused on the influence
of the relative humidity (RH) of the reactant
gases and water management on the PEMFC
performance.
(Kim and Hong, 2008) investigated the effects
of the humidity and the operating temperature
on the performance of a proton exchange
membrane fuel cell (PEMFC) stack. They
founded that the optimization for operating
conditions including the operating
temperature and humidification are requıred
for high cell performance.
(Ozen, Timurkutluk and Altinisik, 2016) studied
the effect of relative humidity levels on the
performance of proton-exchange membrane
fuel cells.
15. Literature review
(Akroot, A. 2014) studied the effect of heat
and water formation, fuel consumption on the
power output of PEMFCs of the automotive
system the results are showed that sufficient
humidified inlet gases and good water and
heat management leads to better
performance from PEMFCs.
16. Research motivations
(PEMFCs) are :
high efficiency 80%
Low emissions
Safe ,clean and reliable
High Flexibility
high power density
quick start up
17. Problem statement
There is a strong relationship
between PEMFCs performance and
good water management and relative
humidity of inlet gases.
The excessive liquid water may be
blocking the (GDLs) porous and
result in preventing reactants gases
from moving to reaction sites and
cell flooding, finally, flooding cell
leads to decrease in ionic
conductivity hence decrease in
(PEM) fuel cells performance.
performance.
18. Problem statement
no sufficient water leads to membrane
dehydration and leads to a decrease in ionic
conductivity hence a decrease in (PEM) fuel
cell
In both cases, there is a decrease in ionic
conductivity .
In order to obtain high performance from the
fuel cells must be good water management
inside the cells and remove the excess water
to the outside of the cells.
19. Research aims
I. Develop (PEMFCs) model then validate the
model with available experimental data in
the literature.
II. Investigate the effect of the relative
humidity of the inlet gases on the water
formation and (PEMFCs )performance .
III. Analyze the water management
requirements of (PEMFCs) under varying
load conditions.
20. Research methodology
The research will be carried out in three main
steps:
1st step: modeling will be done in two computer
programs SOLDWORK and ANSYS-FLUENT.
2nd step: the effect of the relative humidity of
the inlet gases on the performance of
(PEMFCs)
3rd step: Validation of the results with the
available data from the literature.
22. SHED LIGHT ON THE AUTHOR'S LIFE
OMAR QASIM SALIH AL-HADETHI was born in
1990 in IRAQ-BAGHDAD and he Completed
Primary, middle and high school education in
BAGHDAD city. From 1997 to 2007, he graduated
from MIDDLE TECHNICAL UNIVERSITY -
MECHANICAL ENGINEERING department in the
Automotive Technology branch” in 2014. He
started his master's degree at the KARABUK
UNIVERSITY - MECHANICAL ENGINEERING
department In 2018. He continues his higher
education in the MECHANICAL ENGINEERING
department in the karabuk university.
to contact
(Omarq8176@gmail.Com)