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2. Team Members  Jeffrey Kung  Richard Sabatini  Steven Ngo  Colton Filthaut 2 Faculty Advisor Jim Mohrfeld Underclassmen Walter Campos Alan Garza Industry Advisor Christopher Keller

3.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 3

4.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 4

5.  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 5

6.  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 6

7.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 7

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9.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 9

10. 10 FuelDensityPracticalityPriceMax Temperature Propane Gas2.01 g/cm³$2.48 per gallon1800˚ C 5435 Electric Burner (1.4 kW) ~16¢ per kWh800˚ C ~152 Gasoline.75 g/cm³$3.504 per gallon1000˚ C 2423

11. 11 Working Fluid Thermal Conductivity Absolute Viscosity Specific Heat Gas Constant Safety/ Practicality Nitrogen.026 W/m °C 0.018 centipoises1040 J/kgK297 J/kgK 13113 Helium.149 W/m °C0.02 centipoises5188 J/kgK2077 J/kgK 34334 Hydrogen 0.182 W/m °C0.009 centipoises14310 J/kgK4126 J/kgK 4154 1

12. 12 MaterialThermal Conductivity Yield Strength PriceMelting Temperature 316 Stainless Steel14 W/(m.K)60,200 psi$74.00/ft1400˚ C 5422 304 Stainless Steel16 W/(m.K)31,200 psi$57.00/ft1450˚ C 2144 4140 Chromoly Steel43 W/(m.K)63,100 psi$70.00/ft1430˚ C 1533 http://www.onlinemetals.com/

13. 13 Ocyaniqueprofessionals.com http://www.mahle.com/  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.

14. BrandVoltageAmpsTorque Req.PriceTotal Mechman14 Volts240A8.092 lb-ft$350.00 434415 Eco-Tech14 Volts325A9.000 lb-ft$1500.00 453110 DC Power14 Volts250A10.924 lb-ft$590.00 442313 https://www.dcpowerinc.com/http://www.ecoair.com/http://www.mechman.com/ 14

15. 15 http://www.mechman.com/images/products-s- curve-big.png

16.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 16

17. Base Engine Requirements (RPM, Power) Engine Calculations (Heat, Dimensions, Pressure, Work) Heat Transfer & Regenerator Calculations Efficiency &Total Work Loss Calculations 17

18.  Variables ◦ Connecting Rod Length (L) ◦ Crankshaft Arm Length (R) ◦ Force on Piston (F) ◦ Mass of Piston (M) ◦ Angular Velocity (ω)  900 rpm required => (ω)= 94.25 rad/s 18 F L R ω M Crank-Slider mechanism Power and Displacer Piston

19. 19  Displacer Piston Diameter: 6.5” (Piston) Connecting Rod Length (L): 8.934” Crankshaft Arm Length (R): 2.625” Mass of Piston (M): 10 lbm 1.625:1 Displacer to Power dia. Ratio  Power Piston Diameter: 4” (Piston) Connecting Rod Length (L): 5.956” Crankshaft Arm Length (R): 1.75” Mass of Piston (M): 1.561 lbm Regenerator Flywheel

20. 20 Piston Acceleration and Force  Power Piston Acceleration  Power Piston Force  Displacer Piston Acceleration  Displacer Piston Force

21. 21 Required Force

22. 22 Work/ Kinetic Energy(N*M) http://cnx.org/content/m32969/latest / KEY POINTS Work being delivered to the system from 0 to 180 degrees (downward direction) Starting pressure when Θ=0: 221 psi Displacer piston dia: 6.5” Power Piston dia: 4” 20% Mechanical Friction loss RPM=900

23. 23 Force Delivered to Force Required Check and Balance

24. 24 Torque ; ;

25. A D E C A B 25 Torque Related to Kinetic Energy Preferred Method WORK delivered from PRESSURE= 208.333 N*M WORK remaining after FRICTION= 166.664 N*M STORE HALF of the energy to be delivered for UPWARD movement of POWER PISTON (=180 to 360)

26. 26 Flywheel is typically set between.01 to.05 for precision

27. 27 http://enginemechanics.tpub.com/14037/css/14037_90.htm Overview Pressure= 1.5 MPA (220 PSI) 20% Energy Loss= 21.7 N*M K.E.=166.7 N*M Storing Half K.E. @ 0 º to 180 º ) Deliver K.E. @180 º to 360 º= 83.36 N*M Constant Torque= 26.5 N*M

28.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 28

29. First Order Design Method Calculate Ideal Adiabatic & Isothermal Conditions. Analyze changes in temperature, pressure & volume in order to get an estimated power output Calculate initial engine parameters ( Swept Volumes, Dead volumes, Change in mass, Stroke Lengths, & rotational speed) Create a finished first order Design Calculation Sheet allowing us to obtain the previous variables. Second Order Design Method Calculate real life conditions & losses (gas pumping/friction losses, heat transfer rate, porosity, mass flow rate of gas, vibrational forces, principle stress, fatigue rate) Design & Calculate regenerator parameters, tubing dimensions, & Fin parameters. Design & Build a calculation sheet allowing us to obtain several arrays of values for each variable in order to find the best engine operating conditions 29

30. 30 Total Net Work(Joules) Power Output(Watts) Total Volume =MAX(Vexp+Vcomp+Vdead) Total Volume = (7065.3 cm^3)

31.  It was not possible to run a second order analysis by simple calculations & equations because of the enormous amount of unknown variables so we built a program in MATLAB capable of running arrays & guess values to arrive at possible values  Our process for the Second Order Design Method. ◦ Build Calculation Sheet On Excel capable of giving us accurate basic parameters ◦ Designed MATLAB program capable of calculating numerous amount of engine variables at different speeds & pressures ◦ Re-Designed Excel sheet to incorporate data from MATLAB program 31

32. 32 We have picked 15 Hz (900RPM) because we can achieve a high enough torque to up-gear our engine ratio 3:1 giving us 2700(RPM) at a high output power of 3010 (watts) Output values from Stirling Program imported into Excel Freq. (Hz.) Power (Watts) Therm. Eff.% Torque (N.m) Pressure (Pascals)

33. 33 Wout= net work done by entire engine Pe*dVe= The change in expansion volume as a function of expansion space pressure Pc*dVc=The change in compression volume as a function of compression space pressure Work in expansion space= 7162.2(Joules) Work in compression space= -6961.4(Joules) Pout= (7162.2)(J)+(-6961.4)(J) *(15Hz)=3010 Watts

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35. 35 Max Hoop Stress Equals= 14,368 psi Allowable Yield Stress for ChromMolly AISI 4140 at 600C is 60,40psi or (417MPa) Max Operating pressure is 376 psi

36.  Regenerator Design- ◦ The regenerator reduces the heat transferred from expansion cylinder to compression cylinder by incorporating several small tubes & cylinder housing containing a porous mesh material which catches heat ◦ The tubes help dissipate heat by maximizing surface area to help enable the convection of heat. ◦ The tubes also help control the pressure & gas flow by causing a pressure drop which increases the gas velocity 36

37.  As the swept Volume increases by a factor of “x” the # of tubes must also increase by that factor(if you double the volume you double the tubes) 37

38.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 38

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41.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 41

42. Stirling Generator Research Concept & Feasibility Market Research Cost Analysis Project Development Component Selection Intro Design Design Detailed Design & Calculation CAD/CAM Design Components Analysis & Data Results FEA Thermal Analysis FEA Mechanical Analysis Fabrication Mechanical Components Electrical ComponentsWBS 42 100% 61%-99% 31%-60% 100% 1%-30%

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45.  Goals  Prototype Model  Component/Material Selection  Design ◦ Mechanical Design ◦ Thermodynamic Design  Cost Analysis  WBS/Gantt Chart  Risk Matrix 45

46. 46 RiskMatrix

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48. 48 Cot-mect4276.tech.uh.edu/~stngo3