Report overview the project was carried out by Odelia Ghodsizadeh, Scott Kasper, Sean McGuire, and Brian Robinson for the BME262 design course taught by Dr. Robert Malkin - the team is designing for a 1-2L cavity at 2-8degC for less than $300
- shaker/solar-powered fridge to deliver 6W with an energy storage mechanism
- testing was performed on a small volume "soda-fridge" ($40) that employs a fan to suck air over a heatsink and out the device's back
- initial testing indicates that it takes about ten hours at 16W or five hours at 23W to reach 8degC
- purchased 28W solar panel ($150) able to generate 23W on sunny days; clouds reduced output to 1W
- ran a 19hr test after powering the fridge for 5hrs
- utilized a phase change material from "TCP Reliable, Inc." to (presumably) solidify during the fridge's cooling, and absorb latent heat energy as the box warmed. Melting point was 5degC
- fridge remained below 8degC for 12hrs; ambient temp was 21degC
- team stated desire to add additional insulation to the fridge
- a test involving simulated ambient temperatures of 44degC (via a hair dryer) saw the fridge hold at about 15degC with constant grid power
- team hypothesized that the box could fall below 2degC (their lower temperature bound) on cold days
- sealed the exhaust ducts to bring the temperature back up; the ducts normally carry away latent heat from the box
- report includes extensive list of fridge-related patents
Comments I It was surprised surprising to learn the device only worked with a fan and heatsink. We could easily build one of these devices for a few dollars. The solar decision does not seem like a good idea; the device becomes far more fragile and too susceptible to the weather. They discussed including shaker-flux generators but did not pursue the idea. |