Design and Development of a Thermoelectric Beverage Cooler By: Brandon Carpenter Andrew Johnston Tim Taylor Faculty Advisor: Dr. Quamrul Mazumder University of Michigan - Flint Objective • Refrigerator designed for cooling large multiple items • Inefficient if only a single item is to be cooled • Due to size is non-portable • Technology requires coolant, compressor, and cumbersome tubing Objective • Apply concept of refrigerator to a small scale device • Solid-state, eliminate need for coolants • Portability; can be taken wherever needed • Concentrate cooling onto single object to be cooled, eliminate energy waste in cooling empty space Objective Turn This Into This Engineering Approach • Use Peltier thermo cooler to provide cooling • Use tight fitting aluminum sleeve to enhance conductivity • Machine base to match contour of can bottom • Use fans with heat sink to remove heat • Power with drill battery Preliminary Calculations • Initial goal: to cool a can from 700F to 350F approximately 5 minutes. • Required Cooling Rate: q= ρ V c šš šš” q= (1000kg/m3)( 3.54(10-4)m3)( 4.189kJ/kgāK)( .0533 K/second) This gives a value for q of .079 kW, or 79 Watts. Further Calculations • Base: ΔT = 16K kAl = .58W/m•K A= .00383m2 dx= .0051m • q = kA šš šš„ q= (.58)(.00383)(3137) q = 6.99W • Sleeve: ΔT = 16K kAl = .58W/m•K L = .108m r1= .0327m r2= .0349m • q = 2πLk š„š ln š2 q= 2π(.108)(.58) š1 16 .0349 šš.0327 = 95.4W [3] • Total Cooling = 95.4W + 6.99W = 102.4W Main Components • Peltier Cooler Model TEC1-12709 Rated for 90W/ 139W Max Notes on Cooler • While a cooler with a higher rated wattage would theoretically be able to remove more heat, it creates more heat due to resistance and requires a much larger heat sink. • In order to remain portable a smaller cooler was needed, affecting cooling time. Main Components • Sleeve 6061 Aluminum Cut to appropriate length 2.62” Inner Diameter 0.065” Wall Thickness Main Components • Machined Base 6061 Aluminum Designed to accommodate various cans, as dimensions can differ Manufacturing / Assembly • Aluminum tubing was cut into appropriate • lengths to make sections 1. 2. 3. 4. Beverage Compartment Fan Housing (which was not used) Wiring Compartment Battery Compartment Manufacturing / Assembly • Discs were made to serve as plates between sections and for mounting purposes Manufacturing / Assembly • Components were assembled using machine screws and adhesives Manufacturing / Assembly • Insulation was placed around beverage compartment • Thermal paste was applied between thermo cooler, heat sink, top disc, base, and sleeve Testing Procedure Testing Procedure • A 12 oz. pop can is filled with water and placed in the beverage compartment • Initial temperature of the water is recorded • Cooler is turned on, and temperature is recorded in two minute intervals • Additionally, the ambient air temperature, starting battery voltage, and final battery voltage are recorded to check for any correlation Testing Procedure • For each test, the data is entered into an Excel spreadsheet For comparison purposes, a similar test was conducted using a refrigerator Cooling Module Test #1 Time (minutes) Temperature (ā°F) dT/dt (ā°F / min) 0 82.2 2 79.7 1.25 4 77.7 1 6 75.7 1 8 73.9 0.9 10 72.3 0.8 12 70.5 0.9 dT/dt min 0.8 dT/dt max 1.25 dT/dt ave 0.975 Ambient Air: 65.5(ā°F) Starting Voltage: 12.45V Final Voltage: 9.14V Results Data in graph form Discussion • Refrigerator – constant 0.317ā°F / min • Cooler - maximum 0.65ā°F / min - average 0.317ā°F / min šš šš” • In terms of the cooler outperformed the refrigerator • Could only maintain this cooling level for short period due to battery Conclusion • With available technology idea is not yet practical • Current Peltier coolers are not very efficient, require large heat sinks which hinder portability • Also battery power/size ratio insufficient for portability