Presentation on theme: "Pedal Purification University of Notre Dame Senior Design Group A6 November 28, 2006 Team Rallye (from left): Nicole Del Rey Eric Sabelhaus Mike McConnell."— Presentation transcript:
Pedal Purification University of Notre Dame Senior Design Group A6 November 28, 2006 Team Rallye (from left): Nicole Del Rey Eric Sabelhaus Mike McConnell Tim Rodts
Objective 2006 ASME Design Competition requirements: –Allow user to convert 200 mL of ‘polluted’ water into pure drinking water within one hour. –Compact, collapsible, transportable design. Group Requirements: –Robustness - adaptable as power source for emergency applications. –Collapsible – components housed underneath user’s seat when not in operation.
The Concept Pedals and Gears Generator Heating Condensing
Pedals and Gears Generator Heating Condensing Considerations: User comfort (height adjustment with angle-iron) Sustainable user RPM Optimum gear configuration
Generator Pedals and Gears Generator Heating Condensing Considerations: Sprocket mount to 5/16” generator shaft -fitted sleeve and set-screw Exposed wire -wire caps Connection to alternative power sources -fitted to female plug Firm mounting to base -L-brackets mounted to wood base
Heating and Condensing Pedals and Gears Generator Heating Condensing
Packaging Pedals and Gears Generator Heating Condensing Packaging Features: Collapsible chair back Fold-up angle-iron supports All components housed underneath chair on stationary base Concept Realization
Feasibility Issue #1: Energy Requirements P available = 150 W E available = (150 W)(3600 s) = 540 kJ E required = ρcVΔT +mhfg = 523 kJ Question: Can a bicycle pedal system provide enough energy to boil 200 mL water in 1 hour? Answer: YES – at 100% efficiency!
Feasibility Issue #2: Pressure Reduction E required = E heat +E vaporize + E vacuum E max = 523 kJ E min = 510 kJ Question: Would a pressure reduction system be feasible for energy savings, since water boils at lower temperatures under lower pressures? Answer: Energy savings are minimal, hence pressure reduction is infeasible.
Feasibility Issue #3: Maximizing Gear Ratio Question: How can generator power output be fully utilized? Generator: maximum 5,000 rpm at GR = 55.7 Obtained: 460 rpm at GR = 5.13 –Yields ≈ 3.0 W Result: Need 3 sets of sprockets (ratios shown below) to maximize generator power output. Deemed infeasible for prototype due to cost issues related to purchasing/mounting sprockets Answer: For final design, increase gear ratio!
Technical Issue #1: Generator Shaft/ Sprocket Connection Generator can handle radial load, verified by supplier. Sprocket with set-screw in hub necessary. For ANSI Chain #35, minimum ½” bore diameter, generator has 5/16” shaft. Solution: fashion sleeve in sprocket/hub to match shaft diameter.
Technical Issue #2: Compact Packaging Solution: CAD model to verify location/ orientation of components. –21” x 25.5” between chair legs –Condensing unit –Removable Base In disassembled state, all components must be housed underneath chair to meet ASME requirements. –Maximum girth = 165” –Prototype girth = 135”
Technical Issue #3: Material Selection Material Requirements: –Lightweight –Strong –Stiff –Durable σ applied ≈ 3.8 MPa HDPE chosen –Meets all requirements –σ HDPE – UTS ≈ 45 MPa
Use of Prototype Pedaling Demo Voltage Output at 0.2 A Sprockets in Motion Condensing System
Conclusions Prototype shows individual feasibility of: –Mechanical energy transfer –Power Generation –Heating unit –Condensing unit Compact, collapsible and transportable design was achieved. Prototype proves feasibility while satisfying: –$ budget –Design schedule Concept Design is feasible with modification to gear ratio.