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David Jones and Michael Wilcox. Peltier Devices. http://www.penguinslab.com/peltier.htm. Basic Function . Bismuth Telluride cubes carry heat from one direction to the other Charge comes from DC Voltage. Hot Side. Cool Side. Δ T is the most important.
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David Jones and Michael Wilcox Peltier Devices http://www.penguinslab.com/peltier.htm
Basic Function • Bismuth Telluride cubes carry heat from one direction to the other • Charge comes from DC Voltage Hot Side Cool Side
ΔT is the most important • Increase in Voltage => Increase in ΔT • At 12 V => ΔT = 51˚C • Current heat load = 0W • Thot,spec chart = 35˚C, Tcool,spec chart = -16˚C
Current Setup Coolant runs between radiator and peltier devices. Two Peltier Devices connected to stainless steel plates
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: k=14.9 W/m*K
Current Setup • Thermal grease used to bridge the gap • Stainless Steel • @10,000 kN/m2, R=.7-4.0 x10-4 m2*K/W • Thermal grease (@ 3500kN/m2), R=.04 x10-4 m2*K/W Stainless Copper
Purpose • Measure time constant (τ) to reach steady state • Cooling • τ = 86s • Return to Troom • τ = 98.8s
Analysis (Cooling only) Basic Assumption: 1-D Transient Conduction Governing Equation: Temperature Distribution: Additional Assumptions: • h = 300 W/(m^2*K) • Peltier device neglected, except • Device modeled by using T∞= Ti - ΔT = -27˚C
Analysis (Cooling only) • Time constant: τ = 89.9s