Portable Stirling Engine Generator Project

2. Introduction Team Members • Jeffrey Kung • Richard Sabatini • Steven Ngo • Colton Filthaut Faculty Advisor • Jim Mohrfeld Richard Sabatini Steven Ngo Colton Filthaut Underclassmen • Walter Campos • Alan Garza Richard Sabatini Steven Ngo Colton Filthaut

3. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

4. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

5. Goals • To have a working Stirling Engine that will serve as a portable generator capable of producing 2.5 kWh • To be able to run multiple common household appliances simultaneously

6. Household Appliances • Appliances (average): • Refrigerator/Freezer = Start up 1500 Watts • Operating = 500-800 Watts • Toaster Oven = 1200 Watts • Space Heater = 1500 Watts • Lights: Most common are 60 Watt light bulbs • Tools (average): • ½” Drill = 750 Watts • 1” Drill = 1000 Watts • Electric Chain Saw 11”-16” = 1100-1600 Watts • 7-1/4” Circular Saw = 900 Watts

7. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

8. Choice of Configuration • Gamma • Cost efficient • No seal required in the displacer cylinder • More versatile with its design • Easy to isolate the cold and hot pistons

9. Generator Flow http://s3.amazonaws.com/bvsystem_tmp/pages/1296/original/xlibber%20Flickr%20propane%20torch%20plumbing%20tools%20bob%20vila%203257353199_316079a59e_b.jpg http://www.atiracing.com/products/dampers/101/crank2.jpg http://www.whirlpool.com/digitalassets/WRF989SDAM/Standalone_1175X1290.jpg http://www.diversifiedbattery.com/media/graphics/D34-78.jpg http://static.ddmcdn.com/gif/5-signs-alternator-problems-1.jpg

10. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

11. Heat Source

12. Working Gas

13. Hot Cylinder Material Selection http://www.onlinemetals.com/ http://www.onlinemetals.com/ http://www.onlinemetals.com/

14. Cold Cylinder Material Selection http://www.onlinemetals.com/ http://www.onlinemetals.com/ http://www.onlinemetals.com/

15. Piston Materials • Displacer Piston • Forged Steel • High in Strength • Retains Heat • Density of 0.279 lb/cu. in. • Power Piston • Forged Aluminum • Light Weight • High in Strength • Density of 0.101 lb/cu. in. http://www.mahle.com/ Ocyaniqueprofessionals.com

16. Alternator Selection http://www.mechman.com/ http://www.ecoair.com/ https://www.dcpowerinc.com/

17. Alternator Selection Calculation (Mechman) • Selecting an alternator is a key component when designing the stirling engine to reach an output of 2.5kW • Rpms required from engine when using a 3:1 pulley ratio • 900 rpms needed from the engine • 2700 rpms needed from the alternator • 1 hp per 600 watts to run the alternator • To calculate the torque required to spin the shaft http://www.mechman.com/images/products-s-curve-big.png

18. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

19. Calculation Process

20. Mechanical Analysis Power and Displacer Piston Crank-Slider mechanism • Variables • Connecting Rod Length (L) • Crankshaft Arm Length (R) • Force on Piston (F) • Mass of Piston (M) • Angular Velocity (ω) • 571.4 rpm required => (ω)= 6.266 rad/s • ω R L M F http://www.stirlingengine.com/displacer-anim

21. Mechanical Analysis First iteration 1.5:1 Displacer to Piston dia. Ratio • Power Piston • Diameter: 4.5” • Connecting Rod Length (L): 5.956” • Crankshaft Arm Length (R): 1.75” • Mass of Piston (M): 1.561 lbm • Displacer Piston • Diameter: 6” (Box Piston) • Connecting Rod Length (L): 8.934” • Crankshaft Arm Length (R): 2.625” • Mass of Piston (M): 62.238 lbm

22. Mechanical Analysis Piston Positions Relative to Crankshaft • Power Piston • Displacer Piston

23. Mechanical Analysis Piston Velocity • Power Piston • Displacer Piston

24. Mechanical Analysis Piston Acceleration • Power Piston • Displacer Piston

25. Mechanical Analysis Piston Required Force • Power Piston • Displacer Piston

26. Mechanical Analysis Required Force • Displacer Piston

27. Mechanical Analysis Required Force • Power Piston

28. Mechanical Analysis Variables That Will Increase The Required Force • Flywheel • Rotating device that stores and delivers rotational energy when the forces applied to the crankshaft are discontinuous • Will account for the downward forces required to drive the crankshaft with angular momentum • Common formula: KE=½•I•ω2 • Additional forces to drive the flywheel are required • Gravity • Forces in the upward direction will work against gravity, while downward forces will be working with gravity • Additional Masses • Connector rod and crankshaft masses • Alternator • Requires additional torque from the crankshaft

29. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

30. Different Calculation Methods Schmidt Analysis (Isothermal Conditions) • The temperature remains constant under compression and expansion in order for work to be done on the system • Most ideal condition which will output the maximum work that can be obtained by an engine with respect to its volumes • First Order Design Method (Our Current Approach) • Combination of both isothermal and adiabatic processes • Will calculate the change in work with respect to the change in volume, temperature and pressure • Takes into account the dead volumes & and the areas of specific heat • Relates the masses of the working gas through out the system to the crank angle • Second Order Design Method • Builds off of First Order Design method • Takes into account all the heat transfer losses and relates them to variables such as time, material type, and efficiency • Chokes nozzle points and regenerator tube parameters will be taken into effect

31. Isothermal Analysis(Schmidt) • With the “Schmidt Analysis” We get an approximation of our power and pressure output in a perfect isothermal condition • Since our frequency from our crank shaft is 9.18Hz our power output from this calculation is 7532 Watts

32. First Order Design Method (Adiabatic & Isothermal) Th=800K Tc=400K Ideal Heat Efficiency=50% (without heat transfer calculations) http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/carnot.html

33. Ideal & Adiabatic Model

34. First Order Design Method

35. First Order VS. Isothermal • New Variables First Order Took Into Account • Change in the mass of the gas with respect to temperature • Cold & hot dead volumes • Change in energy of the working gas throughout the system • Temperature & pressure drops. • Specific Heat of the different boundaries

36. First Order Design Method

37. First Order Design Method • 1 atm≈100.3 kPa • We have come to the conclusion that we would have to pre pressurized to obtain a higher output to our system.

38. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

39. Cost Analysis

40. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

41. WBS

42. Gantt Chart

43. Agenda • Goals • Choice of Configuration • Component/Material Selection • Design • Mechanical Design • Thermodynamic Design • Cost Analysis • WBS/Gantt Chart • Risk Matrix

44. Risk Matrix

46. Questions? Cot-mect4276.tech.uh.edu/~stngo3