1. CONSTANT TEMPERATURE AIR BATH Team Members: Mark Campbell Peter Giles Andrew Smith Tom Strapps Nickolay Suther Team Supervisor: Dr. Prabir Basu

2. Presentation Outline What are we doing? What are the options? How do thermoelectrics work? How are we going to solve the problem?

3. What is an Air Bath? Controlled Environment Liquid Baths Research and Calibration http://www.guildline.ca/Datasheet/Guildline503XDatasheet.pdf

4. Project Requirements Temperature Range  +5°C to +25°C Temperature Control  +/- 0.2°C Noise  <40 dB Minimize Vibration

5. Design Features Considered

6. Design Selected Forced Convection Top Loading PID Control Thermistor Sensing Two Thermoelectrics

7. Air Bath Construction Frame  Welded Steel Interior  Fibreglass (25cm) 3 Case  Folded Sheet Metal Insulation  Styrofoam™ SM (5cm Thick)

8. Thermoelectrics Pump heat Small  40mm x 40mm x 4mm Efficiency  COP Refrigerator ~ 4  COP Thermoelectric < 1.5 Reversible http://www.electracool.com/

9. Peltier Effect Source:http://jchemed.chem.wisc.edu/Journal/Issues/1996/Oct/abs940.html

10. Peltier Performance

11. Heat Dissipation Passive Heat Load  q=kA(T 2 -T 1 )/L  q ~ 10W Joule Heat  P=IV  q ~ 70W

12. Heat Sink Assembly

13. Measurement Systems Temperature Sensors  RTD  Thermistor  Thermocouple Overheat Protection  Embedded Thermocouple http://www.veriteq.com/images/thermocouple-thermistor.jpg Thermocouple ThermistorRTD

14. System Control System Control Requires sensing, analysis and power control  On/Off  PID Lumped Parameter Model

15. System Model Lumped Parameter ON/OFF Control Model

16. Simulink Results 25 minutes On/Off Control 1°C Dead band

17. Mock-up Testing

18. The Next Step… Order necessary parts Start construction Continue Mock-up Testing

19. Special Thanks To Greenfield Research Greg Jollimore Dr. Prabir Basu