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06213 – Hydrogen Fuel Cell Test Station
Preliminary Design Review
February 24th, 2006
Group Members• Team Leader: Chad Byler (ME)
• Mechanical Press & Fuel Flow:Dan Upton (ME), Brian Holzberger (ME), &
Sean Ashman (ME)
• Electrical Sensors & Power Supply:Dennis Farley (EE) & Steve Yang (EE)
• Data Acquisition & Software: Shan Hu (CE)
• Process and Safety: Corey Reynolds (ISE)
Project Mentor: Dr. Bailey(ME)
Project Sponsor
• Nanopower Research Laboratory
– Funding• Dr. Rafaelle – Department of Physics at RIT
– Customer Contact• Cory Cress – PhD student in Microsystems
http://www.rit.edu/~physics/Research/nanopower.shtml
Subsystem Topics
• Layering of Fuel Cell• Mechanical Assembly Process• Heating of the Fuel Cell• Humidification of gas• Exhaust/Back Pressure Control• Electrical Sensors and Power Supply• Heating elements• Layout of program logic• Data Acquisition• Budget
But First…
Cathode Reactions:
1/2 O2 + 2e- O-2ion
Porous gas diffusion layer Porous gas diffusion layer2e- 2e-
Reaction Products(H2O only)
Air/O2H2
O2
Catalyst LayersActive Material:Platinum or Platinum/Ruthenium
Thin solid hydrated Membrane as an Electrolyte
Anode Reactions:
H2 2H+ + 2e-
H+ion
proton
2H+ + O-2ion H2O
PEM = Low temperature (80oC) hydrogen fuel cell with polymer electrolyte and precious metal electrodes
Fuel Cell Operation
Cathode = gas diffusion layer + catalyst layer
Anode = gas diffusion layer + catalyst layer
Location - Fuel Cell Assembly
Electrode Plate
–Raised center portion to ensure maximum pressure of electrode with nano-tube catalyst.–Three different sizes for reaction area.
Fuel Cell Assembly
Nano-tube catalyst
PEM
Fuel Cell Stack
Location - Fuel Cell Assembly
Mechanical Assembly
• Ease of Operation•Backing Plate rotates to allow assembly on horizontal surface.•Pegs hold fuel cell assembly in place until it can be compressed.
• Repeatability•Use of power screw in combination with a pressure sensor or a torque wrench will allow for a repeatable mechanical pressure applied to the fuel cell.•The use of the mechanical assembly gives the ability to encapsulate the fuel cell and regulate the temperature.
Mechanical Assembly Animation
Power Screw CalculationsInternal Pressure 120 psi
Surface Area 2.64 in^2
Max Force 316.8 lb
tan() must be less than the coefficient of friction in order to be postitive locking
Screw Type: 1/2" - 10
Lead L= 0.1 in
Root Dia. Dr= 0.45 in
tan()=L/(*Dr)
tan()= 0.071
= 0.3 Coefficient of friction steel to steel
tan() < , therefore the screw is self locking
T=F*Dr/2*((L+**Dr)/(*Dr-*L)
T = 26.999 Lb/in
T = 2.25 Lb/ft
Location - Fuel Cell Heating
Fuel Cell Heating
Steady-State Temperature Distribution without Insulation (O2 side)
-Shows need for cell Insulation
-With insulation all cell components reach 80°C at S.S.
Location - Humidification
Gas Humidification Method
•H2 or O2 inlet in base
•Bubble up through water
•Temperature of water controls the humidity of exit gas
•Resistive heater used to heat water
•Water temperature monitored to ensure safe heating
Expansion Valve
Contains:• Pressure Sensor• Humidity Sensor• Temperature Sensor
Pros:• Interchangeable• Non-Intrusive to flow
Location – Back Pressure
Exhaust/Pressure Regulation
• Constant Upstream Pressure
• Bleeds overpressure• Ability to dry PEM• Bubbles prove flow• Water seal provides
no upstream airflow
Overview Schematic
Important Sensor Parameters
• National Semiconductor LM34 Temperature Sensor:– Maximum Current Draw: 90μA– Maximum Output Current: 160μA– Maximum Output Voltage: 6V– Accuracy: 0.555°C– Operating range: -45°C to 150°C
• Honeywell HIH-3610 Humidity Sensor:– Maximum Current Draw: 200μA– Maximum Output Current: 100μA– Maximum Output Voltage: 3.9V– Accuracy: 2% Relative Humidity– Operating Range: 0 to 100% Relative Humidity in -40°C to 85°C
Important Sensor Parameters Cont.
• Honeywell ASDX100G24R Gas Pressure Sensor :– Maximum Current Draw: 10mA– Maximum Output Current: 2mA– Maximum Output Voltage: 5V– Accuracy: 2% of Operating range– Operating range: 0 to 100 PSI in 0°C to 85°C
• Honeywell TD4A Liquid Temperature Sensor:– Maximum Current Draw: 26.3mA– Maximum Output Current: 1mA– Maximum Output Voltage: 2.5V– Accuracy: 1°C– Operating Range: -40°C to 150°C
Worst Case Analysis
Maximum Current Draw:• For Heaters: 0.83A maximum per heater * 3 = 2.5A
maximum• For LM34 Temperature Sensors: 90μA * 3 = 270μA• For HIH-3610 Humidity Sensors: 200μA * 2 = 400μA• For ASDX100G24R Gas Pressure Sensor: 10mA * 2 =
20mA• For Underwater Temp Sensor: 26.3mA * 3 = 78.9mA
• Total Current Draw = 2.51056A
Heater Analysis
• 58200 Joules are needed to heat the water in our largest tank, 0.2317L, from 20°C to 80°C– Using an Omega CIR-3016 (100 Watt)
– Therefore, the longest time needed to heat the water is 9.7 minutes
min7.9sec60
min1sec*582
sec582100
sec)*58200(
W
W
Omega Immersion Cartridge Heater
• 150 Watt Heater
• Incoloy® Sheath - Efficient heat transfer - Sealed tip
- Corrosion resistant.
• Special Insulation - High dielectric strength - Faster heat-up time
• Small size - 1/2 inch diameter
Water Heating Source
Water Temperature Sensor
TD4A - Liquid Temperature Sensor
• RTD (resistance temperature detector) sensors
• Respond rapidly to temperature changes
• Accurate to ± 0.7 °C at 20 °C
• Temp. range: -40 °C to 150 °C (-40 °F to 302 °F)
• Supply Voltage/Current: 10Vdc, 1mA typ.
• Linear outputs.
Power Controllers
Power-IO Solid State Relays
• Surge protection
• DC control input: 4-32VDC
• Operating Voltage: 24-330V
• Max Load Current: 25A
• Affordable price (under $40)
Software Design Flowchart I Start
User input desired testing parameters (Temp/Humidity/Pressure/Duration)and the max pressure, max temperature should be allowed
Test Temperature sensor
Is temp sensor ok?Show error message!
Terminate the program!
End
Set up testing environments
Start testing?
All desired testing parameters are
satisfied?Show violation message!
Timer counts
End test?
Record testing results
Continue without adjustment?
N
Y
Y
Y
Y
Y
N
N
N
N
Software Design Flowchart IISet up testing environments
Heat H2 and O2
water tank
Exceed max water temp?
Show warning!
Desired gas humidity?
Y
N
End set up testing environments
DisplayGas
Temp(H2 and
O2)
Display water temperature
Display gas humidity (H2 and O2)
Desired temp?
Display PEMtemperature
N
Y
Y
N
Y
Desired gaspressure?
Adjust pressure of H2 and O2 gas
Display pressureof H2 and O2 gas line
Heat PEMwater tank
Exceed max water temp?
N
YN
Dangerouslevel?
ShutOff!
YN
Show warning!
Dangerouslevel?
ShutOff!
Y N
Exceed max gas pressure? Y
N Show warning!
Dangerouslevel?
ShutOff!
Y N
USB-1208LS + LabVIEW™ drivers USB-based DAQ module ( $109.00 x 2 + $ 49.00)
•8 Single-Ended or 4 Differential Analog Inputs •12-bit (Diff.)/11-bit (SE) Resolution •Two 10-bit Analog Outputs •One 32-bit External Event Counter •16 Digital I/O Lines •External Trigger Input•Sample Rate 1.2KS/s
Design ProcessOriginal Project Objectives
1. Flow Systems
2. H2 & O2 Electrolysis and Delivery
3. Temperature Systems
4. Pressure Systems
5. Humidity Systems
6. Mechanical Assembly (Optional)
Current Project Objectives
1. Mechanical Assembly
2. H2 & O2 Creation and Delivery
3. Temperature Systems
4. Pressure Systems
5. Humidity Systems
Flow System
Electrolysis System
H2 & O2 Tanks
Flow System
Major Project Scope Changes
Scope Change Impact
Research
Concept Generation
Concept Selection
Feasibility Analysis
Time
Project Schedule
Budget
Questions
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