Fuel cells, as devices for direct conversion of the chemical energyof a fuel into electricity by electrochemical reactions, are amongthe key enabling technologies for the transition to a hydrogen-based economy.Among the various types of fuel cells, polymer electrolytemembrane fuel cells (PEMFCs) are considered to be at theforefront for commercialization for portable and transportationapplications because of their high energy conversion efficiency andlow pollutant emission
Components:Fuel cellHydrogen tankElectric motor
What is Fuel Cell?Battery that produces electricityoverall reaction: oxidation of a fuel by oxygen 2H2(g) + O2(g) 2H2O(l) (Hydrogen) Fuel + oxygen waterUnlimited fuel supply: reactants continuously supplied from an external source (open system) Also known as flow batteryUsed as a stack
How fuel cells work ? Chemistry of fuel cell At anode:- 2H 4H + 4e 2 At Cathode:- O + 4H + 4e 2H O 2 2 NET REACTION 2H2 + O2 2H O 2
Overview of a Fuel Cell A fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen over the other, generating electricity, water and heat. A fuel cell system which includes a "fuel reformer" can utilize the hydrogen from any hydrocarbon fuel - from natural gas to methanol, and even gasoline.
Product FC -H2-251C FC-H2-051C FC-H2-251REF FC-H2-051REF FC-H2-501CModelDescriptio Cell 25cm2, Cell 25cm2- Ref., Cell 5cm2- Ref., Cell 50cm2, Cell 5cm2, H2/Airn H2/Air H2/Air H2/Air H2/AirPERFORMANCE*DC 0.7V 0.7V 0.7V 0.7V 0.7VVoltageCurrent 15A 3A 15A 3A 25ANominal 600mA/cm2 at 600mA/cm2 at 600mA/cm2 at 600mA/cm2 at 500mA/cm2 atCurrent 0.7V(Cell) 0.7V(Cell) 0.7V(Cell) 0.7V(Cell) 0.7V(Cell)DensityNominalPower 10W 2W 10W 2W 18WRatingOutputOperation 0 ~ 12W 0 ~ 2.5W 0 ~ 12W 0 ~ 2.5W 0 ~ 20WRangeCell ~45% at 10W ~45% at 2W ~45% at 10W ~45% at 2W ~45% at 18WEfficiencyEffective 25cm2 5cm2 25cm2 5cm2 50cm2area of cellPHYSICALHeight 8cm 9cmWidth 12cm 15cmDepth 12cm 15cmWeight 1kg 2kg
n Carbonate Fuel Cell (MCFC): carbonate salt electrolyte 60 – 80% efficiency ~650˚C operating temp. cheap nickel electrode catalyst up to 2 MW constructed, up to 100 MW designs exist The operating temperature is too hot for many applications. carbonate ions are consumed in the reaction → inject CO 2 to compensate
phoric Acid Fuel Cell (PAFC): phosphoric acid electrolyte 40 – 80% efficiency 150˚C - 200˚C operating temp 11 MW units have been tested sulpher free gasoline can be used as a fuel The electrolyte is very corrosive Platinum catalyst is very expensive
n Exchange Membrane (PEM): thin permeable polymer sheet electrolyte 40 – 50% efficiency 50 – 250 kW 80˚C operating temperature electrolyte will not leak or crack temperature good for home or vehicle use platinum catalyst on both sides of membrane
d Oxide Fuel Cell (SOFC): hard ceramic oxide electrolyte ~60% efficient ~1000˚C operating temperature cells output up to 100 kW high temp / catalyst can extract the hydrogen from the fuel at the electrode high temp allows for power generation using the heat, but limits use SOFC units are very large solid electrolyte won’t leak, but can crack
PEM Fuel Cell: Polymer Electrolyte Membrane FC - consists of an electrolyte membrane sandwiched between an anode (negative electrode) and a cathode (positive electrode). Description - a thin, solid, organic compound, typically the consistency of plastic wrap and about as thick as 2 to 7 sheets of paper. This membrane functions as an electrolyte: allows the solution to conduct electricity Concept PEM fuel cells work with a polymer electrolyte in the form of a thin, permeable sheet and allow hydrogen protons to pass through but prohibit the passage of electrons and heavier gases.
PEM Fuel Cell Basics:1 Fuel cells are operationally equivalent to a battery. 4 2 Low temperature; Polymer Electrolyte The reactants or fuel in a fuel cell can Membrane (PEM) type cells are the be replaced unlike a standard standard devices. disposable or rechargeable battery. 5 For automotive applications 3 hydrogen is the fuel choice. Theoretically the maximum voltage that this reaction can generate is 1.2 V. However, in practice the cell usually 6 generates about 0.7 V to 0.9 V and Electrochemical energy comes about 1 W cm-2 of power. from the reaction: ½ H2 + ½ O2 → H2O.
Basic Elements of PEMFC -It conducts the electrons that are freed from the hydrogen molecules so that they can be used in anAnode external circuit. -It has channels etched into it that disperse the hydrogen gas equally over the surface of the catalyst. -has channels etched into it that distribute the oxygen to the surface of the catalyst.Cathode -conducts the electrons back from the external circuit to the catalyst, where they can recombine with the hydrogen ions and oxygen to form water Anode Reaction Cathode Reaction H2 → 2H+ + 2e- O2 + 4H+ + 4e- → 2H2O
Basic Elements of PEMFC -This specially treated material, which looks something Electrolyte like ordinary kitchen plastic wrap, only conducts positively charged ions. - The membrane blocks electrons. - It is usually made of platinum powder very thinly coated onto carbon paper or cloth. - The catalyst is rough and porous so that the Catalyst maximum surface area of the platinum can be exposed to the hydrogen or oxygen. - The platinum-coated side of the catalyst faces the PEM.
The Current PEM Market Portable 63% 2% Large Stationary 16% SmallBuses 3% Stationary Light Duty Niche 10% 6% Devices Transportation Total Number of PEM Units Installed Globally By Application
•Hydrogen tank is used to store the compressed hydrogen gas athigh pressure•Generally four types of hydrogen tanks are being used•Metal tank(steel, (200bar to 2900 psi) , aluminum,(175bar to2538 psi)•Metal tank(aluminum)with filament windings like glass,(263bar to 3814psi) and carbon fiber, (299bar to 4423 psi).•Tank made of composite materials.(305bar to 4423 psi)•Composite tanks such as carbon fiber with a polymer liner.(661bar to 9586psi)
INTRODUCTION:A dc motor is a machine which converts electrical energy into mechanical energy.
3. WORKING PRINCIPLE OF DC MOTOR When ever a current carrying conductor is placed in a magnetic field, it experienced a force whose direction is given by fleming’s left hand rule( also called motor rule)It shows the field set up by the poles.It shows the conductor field due to flow of current in the conductor.
4.TYPES OF DC MOTOR1. Series DC motor2. Shunt DC motor3. Compound DC motor
What is a Mechanism?A mechanism is the part of a machine which containstwo or more pieces arranged so that the motion ofone compels the motion of the others.Generally used to:Change the direction of movementChange the type of movementChange the speed of movementChange the amount of torque or force available to do work
Front-wheel drive .*The FWD platform is used in many reliable vehicles ,such as a Honda Accord or Toyota Camry.* FWD mean that the two forward vehicles are responsible for moving the car .
PARTS OF FWD:1-gear box. it take the motion from the engine and we can modify the received velocity on it2-differential. it is apart mounted by bolts downward the gear box and take the output motion from the gear box and deliver it to the drive shafts (CV joints).3-drive shafts. it take the motion from the differential to the two vehicles.
References (1)FAQ section, fuelcells.org (2) Long Island Power Authority press release: Plug Power Fuel Cell Installed at McDonald’s Restaurant, LIPA to Install 45 More Fuel Cells Across Long Island, Including Homes, http://www.lipower.org/newscent er/pr/2003/feb26.fuelcell.html (3) Proceedings of the 2000 DOE Hydrogen Program Review: Analysis of Residential Fuel Cell Systems & PNGV Fuel Cell Vehicles, http://www.eere.energy.gov/hydroge (2)www.fueelcellenergy.com (3)Figures 1, 3 http://hyperphysics.phy- astr.gsu.edu/hbase/thermo/elec