Stirling Engine Facts and Technology

1. Stirling EngineFacts and Technology Marc Alessandria Ernesto Bosque Jobe Dyson Kirby Little

2. Overview • History • Advantages • Applications • The Stirling Cycle

3. History • Robert Stirling; 1816 • Introduced to engineering by his father • Did not study science in school though • Studied math and Law and decided to become a preacher • Appointed a minister of the Church of Scotland in 1816

4. History • Here he decided to invent a new engine • His parish worked the steam engines • Were very inefficient and often blew up • Wanted to make his parish lives more comfortable and safe

5. History • In 1816 applied for a patent for his “Economiser” • It is the most important part of his engine • The Economiser is responsible for increasing the efficiency of the engine • Sadly his engine was never utilized • It always took a back seat to traditional engines

6. History • 1850; J. Ericsson • Sold nearly 2,000 engines in N. America • 1940’s; Phillips Co • Batteries became the preferred source of power

7. Advantages • External Heat Source • Environmentally friendly • Less Wear and Tear • Minimal emissions • One cycle medium • Simple design • 2 Cylinder • No valves • Minimal maintenance

8. Advantage: Efficiency • Highest thermal efficiency • Difference in temp • Full regeneration, 100% effeciency • Combustion engines lower efficiency

9. Disadvantages • Low Power to weight ratio • Impractical for motion • Internal combustion • Practical for motion • Production costs • No large scale construction

10. USAGES OF THE STIRLING ENGINE • Stirling Engine are used in our everyday lives. • Stirling Engine are used in refrigerators. • Liquefied gases founded in welding supply company are made in Stirling Engine. • The satellite weather channel uses a tiny Stirling cryo-cooler to cool the image sensor to near abolute zero.

11. Disadvantages to using Stirling Engines in Vehicles • In the past 25 years, Stirling Cycling Research Group has directed it interest towards the automotive field. • They are a couple of key characteristics why Stirling Engines are impractical for many applications, including most cars and trucks. • Since the heat source is external, it will take a longer time for the engine to respond to the changes in the amount of heat that is applied to the cylinder.

12. Con’t • In other words, the engine needs to warm up to obtain and produce the useful power. • The engine can not change its power output quickly.

13. Stirling Engines in Aviation • The main reasons these engines are needed in Aviation is because their motor is silent. Smooth torque and lack of vibrations. • Aviation is the last major user of leaded fuel, Stirling Engines produce less pollution. • Altitude performance is the strong reason why these engines are needed. If a plane could hold a constant power, it could cruise twice as fast at 40,000 ft as it can at sea level.

14. Con’t • As a safety precaution, the plane can also fly above the weather instead of through it.

15. The Stirling Cycle Process breakdown For stirling enginewithout regeneration For stirling engine with regeneration

16. Stainless Steal k = 15.9 (W / m*K) α = 16E-6 (°C-1) Brass k = 120 (W / m*K) α = 20.0E-6 (°C-1) DisplacerCylinder DisplacerPiston The Stirling Cycle Materials used in the shop. Q -k A (dT) t dx = Heat Conduction Equation k = Thermal Conductivity α = Coefficient of Thermal Expansion

17. Q -k A (dT) t dx = The Stirling Cycle Materials used utopia. Diamond Displacer Cylinder k = 3150 (W / m-K) and Displacer Piston α = 0.11 - 1.23E-6 (°C-1) Cp= 520 (J / kg-K) Coating of portion of k = 10 (W / m-K) Diamond Cylinder directly above flame. Super Invar α = 0.72E-6 (°C-1)

18. η = 1 - TC ___ TH The Stirling Cycle Materials used utopia.