Peltier Devices

1
Peltier Devices
David Jones and Michael Wilcox
http//www.penguinslab.com/peltier.htm
2
Basic Function

• Bismuth Telluride cubes carry heat from one
  direction to the other
• Charge comes from DC Voltage

Hot Side
Cool Side
3
?T is the most important

• Increase in Voltage gt Increase in ?T
• At 12 V gt ?T 51C
• Current heat load 0W
• Thot,spec chart 35C, Tcool,spec chart
  -16C

4
Current Setup
Coolant runs between radiator and peltier devices.
Two Peltier Devices connected to stainless steel
plates
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Current Setup

• Coolant is used to keep the Thot down (Troom)
• Pumped through a fan-cooled radiator
• Coolant used for anti-rust, anti-mold, increased
  heat dissipation
• Stainless Steel used
• Easily cleaned
• Resistant to Rusting
• Holds Heat Well
• Stainless Steel k14.9 W/mK

6
Current Setup

• Thermal grease used to bridge the gap
• Stainless Steel
• _at_10,000 kN/m2, R.7-4.0 x10-4 m2K/W
• Thermal grease (_at_ 3500kN/m2), R.04 x10-4 m2K/W

Copper
Stainless
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Purpose

• Measure time constant (t) to reach steady state
• Cooling
• t 86s
• Return to Troom
• t 98.8s

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Analysis (Cooling only)

• Basic Assumption 1-D Transient Conduction
• Governing Equation
• Temperature Distribution
• Additional Assumptions
• h 300 W/(m2K)
• Peltier device neglected, except
• Device modeled by using
• T8 Ti - ?T -27C

9
Analysis (Cooling only)
Time constant t 89.9s