Ryerson Engineering Competition 2021

I led my team to build a portable fridge at the Ryerson Engineering Competition's Senior Design Challenge. It can be battery powered and features closed-loop temperature control using a temp sensor and cooling element. We were the runners up.

We were given an assortment of materials and were required to build a portable fridge that could cool the internal volume to 5°C in 25 minutes. The build time was 8 hours, followed by a presentation to a panel of judges the next day. As you can see, we probably placed a little too much focus on functionality over form (ignore the mess of wires!).

The fridge is made out of two layers of styrofoam on all 6 sides with a simple swing out door. Two peltier thermoelectric cooling modules were used along with four fans to provide active cooling. A temperature sensor was placed inside the fridge to measure the internal temperature and provide feedback for the cooling control loop.

A simple PID controller was implemented and tuned to regulate the temperature by varying the fan speeds. The fans were controlled using a L293D motor driver, which was hooked up to an Arduino Uno. The fridge also featured an LCD and a simple user interface consisting of two buttons and a knob so that the user can view and set a desired temperature. While it was supposed to be a portable fridge, we weren't provided with any portable energy sources, so the built model simply features a 360W power supply that can be swapped with battery.