My final project for Thermal Fluids Experimentation and Design in Fall 2009 was the design of an electric cooler that could be used on a motorcycle. The cooler is designed to keep two bottles of water cold in a 120 degree C environment without using the refrigeration cycle. In addition, the cooler's only source of power is the motorcycle battery.
Since the refrigeration cycle was not allowed for this project I chose to use thermoelectric modules to draw heat away from the water. I mounted the modules on conductive panels that cradle the water bottles. To maximize surface contact between the bottles and the panels I lined the cradles with conductive foam. The cradles are set in an injected molded shell which is held in a commercially available insulating case.
I coupled each thermomelectric module to a heat sink. To maximize efficiency I selected heat sinks with cylindrical fins. When the motorcycle is in motion the air flowing past the fins keeps them cool. When the bike is stationary the cylindrical fins help create an updraft, drawing heat away from the modules.
I created a detailed CAD model of the cooler to guide decisions on manufacturing and assembly. In addition, each component of the model has the correct thermal and material properties for thermal simulations. Based on these simulations, I found the cooler can keep two bottles of water at just above freezing in a 120 degree C environment.