Client: City of Beloit/Dan Lutz (fleet manager)Problem: Rising price of gas and new emissions standardsSolution: Investigate the effect of adding hydrogen gas to the air,fuel mixture in an internal combustion engineHypothesis: The addition of H2 gas will produce a more completeburn in the engine, reducing emissions and increasing fueleconomy.
The four “strokes”:1. Intake2. Compression3. Combustion4. Exhaust
Electrolysis of water: Splitting water with electricity to producehydrogen and oxygen2H2O + 2e- H2 + 2OH- 6H2O O2 + H3O+ + 4e- BatteryCathode Anode•Forms H2 •Forms O2•Basic •Acidic•e- flow into solution •e- flow out of solution
• Focused on minimizing parasitic loss of energy to heat and over potential• 21 Nanoparticle coated stainless steel electrodes • 3 positively charged • 2 negatively charged• Rubber gaskets separate plates- Dry Cell• Concentrated NaOH solution acts as an electrolyte• PWM
• Holds about a half gallon of NaOH solution• Solution is pumped to the cell through rubber tubing• Gasses come back into water tank below the water line• Gasses leave the tank and are sent to the engine
• Hydrogen on demand• Gasses are bubbled back through solution to prevent fires• Emergency cap to release if there is a pressure build up due to a flashback
• Started with: • Electrolyzer • Hard Saddlebag• Modifications: • Attached to Harley • Added attachment for air intake • Rewired the system• Began extensive testing and analysis
Started with: •Extra buttons on panel •Extra unlabeled wires •Old tank/fittings •Throttle Position Sensor (TPS)Modifications: •Remove Extra Wiring •Clean Carburetor •Flush electrolyzer •Removed T.P.S. •Installed: Pump, new tank, pulse width modulator •Wired electrolyzer to switch •Re-wired system •Installed new electrolyzer
Goals: • Collect data on flow rate/hydrogen production• Find Correlations between hydrogen production and temperature, amp draw, etc.
•A PWM is a device that controls energy flow by manipulating theduty cycle.•By increasing or decreasing the length of the duty cycle, we canmodify the amount of energy released into the system.
•Previously experiments have shownthat the use of a PWM in an electrolyzersystem reduces corrosion of stainless-steel plates.•The purpose of our experiment wasdetermine the optimum frequency forhydrogen production.
• Concerns about temperature, amp draw• Measures emissions in exhaust• First attempt: Issues/Corrections • Awful data • Harley taking in own exhaust? • Need ventilation • compare results when Harley is at similar running times/temperature
Test 1: 10MPH Test 2: 10MPH CO2 (% CO2 (%emissions) emissions) CO (ppm) CO (ppm) W/O W/O W/ W/NOx (ppm) NOx (ppm) HC (ppm) HC (ppm) 0 50 100 150 0 50 100 150 Test 1: 20MPH Test 2: 20MPH CO2 (% CO2 (% emissions) emissions) CO (ppm) CO (ppm) W/O W/O W/ W/ NOx (ppm) NOx (ppm) HC (ppm) HC (ppm) 0 50 100 150 0 50 100 150
Test 1: 33MPH Test 2: 33MPH CO2 (% CO2 (%emissions) emissions) CO (ppm) CO (ppm) W/O W/O W/ W/NOx (ppm) NOx (ppm) HC (ppm) HC (ppm) 0 50 100 150 0 50 100 150
Hydrogen : Gasoline energy/minute RatioGasoline: 47 kJ/g ( 703 g/L ( X L/minute))= G kJ/minuteHydrogen: 241.818 kJ/mole (.0334 mole/L(364K) ( X L/minute)= H kJ/minute 60 MPH 40 MPH Fuel Hydrogen 20 MPH 0 20 40 60 80 100 120
•Positive Results •Harley: Decrease of HC and CO production up to 30% •Vespa: 33MPH • NOx emission drops by 25% with one electrolyzer and 40% with three • Hydrocarbon output decreases by 5%•Negative Results •Harley: High HC production with electrolyzer above 20mph •Vespa: 10-20MPH • Negligible changes in emissions•Probable Causes •Preignition •Trapped hydrocarbons •Tuning, engine build quality
Dynamometer Testing Didnt Yield Expected ResultsReasons for results: •Method of gas introduction-chance of error with leaking gases •Precise fuel injection systems, air/fuel ratios •Modern engines extremely efficient •Electrolyzer sped up the burn rate •Pressure in the piston uneven(modified piston rings?) •Onboard O2 sensors adjusted to cancel out electrolyzer
•Fuel : air ratio is rich both with and withouthydrogen addition•A decrease in NOx production at higher speeds •indicates a slower or cooler burn with hydrogen•Hydrocarbons are reduced at high speed •Possibly a more complete burn•Emissions are only noticeably effected by hydrogenaddition at higher speeds. •Opposite of hypothesis •Requires more testing
What Can be Improved?Harley •Weight and Balance •More even distribution of weight •Rider could "feel" weight •More weight=negative factor in performance, including cars •Fuel management system/ignition timing adjustmentVespa •Tune carburetorBoth •Prevent irregular burn pattern, preignition •Increase hydrogen addition to find optimal fuel : hydrogen ratioFuture students will want to work on the electrolyzers connection with theengine and the fuel management system
Luce, Ben. “Electrolysis.” Courses in Solar Energy. http://www.nmsea.org/Curriculum/7_12/electrolysis/electrolysis.htm"4 Stroke Engine” 4 Shared Web. 12 Dec. 2011. http://www.4shared.com/photo/Lh-H72sR/4-Stroke-Engine.html>.Photo credit to Dan Lutz and Aevyrie RoesslerSpecial thanks to Dr. Glenn Bower and S&S Cycle