1. Stirling Refrigeration ME 498 - Senior Laboratory November 16, 2004 Nicholas Taylor

2. Overview Background and theory of the Stirling Cooler Experimental Set-up and Procedure Results

3. Objectives Operate Global Cooling Model 100B Stirling Cooler Use thermodynamic principles to analyze the performance Calculate COP, Q rejected, Q lifted

4. Background Model 100B free piston Stirling Cooler High conversion between mechanical and thermal energy AC linear motor drives the piston Working gas – helium

5. Background

6. Theory Coefficient of Performance

7. Theory Finding Q rejected

8. Experimental Apparatus

9. Procedure Measure flow rate Prepare data acquisition system Increase voltage to the stirling cooler, to begin cooling Record data until the temperature reaches -30°C, activate the heater and reach equilibrium at -20°C Turn off equipment

10. Results Temperature vs. Time COP R for 5°C, 0°C, -10°C, and -23°C Compare COP found to COP from Global Cooling COP R, W stirling, and Q rejected at equilibrium Compare COP at equilibrium with COP carnot Uncertainty Analysis

11. Results

13. Global Cooling TempTimeCpmdT/dtQliftedWstirlingCOPInputCOP% diff. (deg C)(sec)(J/kJ*C)kg (W) 579380.230.27-0.0878.889.220.96362.3358.66 01183790.27-0.0888.9549.20.97352.0652.75 -10219376.420.27-0.0909.1679.111.00631.065.07 -23419372.80.27-0.0969.6339.680.99541.1815.67

14. Results Equilibrium Test Qreject32.318 Qlifted12.204 Wstirling20.114 COP0.607 COP carn.2.809 % difference78.398

15. Uncertainty Uncertainty of COP Uncertainty of Q lifted Uncertainty of Q rejected Uncertainty of Vdot

16. Uncertainty % ωCOP = 1.2% ωQ rejected = 4.61 (32.318) ωVdot = 2.85E-8 ωQ lifted = 0.11 (12.204) ωCOP = 6.18E-3 (.607)

17. Uncertainty Qlifted ComponentValueUncertainty V10.80.01 I1.130.01 ComponentQliftedn(n+dn)Qlifted(n+dn)dQlifted/dn V12.20410.8 12.2041.13 I12.2041.13 12.20410.80 ωQlifted0.11

18. Conclusions Learned a practical use of a Stirling Cooler Found COP, Q rejected, and Q lifted Found the uncertainty in measurements Recommend comparing to a traditional refrigeration cycle

19. References http://www.globalcooling.com http://132.235.18.152/seniorlab