Published: February 28, 2016
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By: Martin Ruiz, Cal Poly Pomona
Category: Mechanical Engineering
Hashtags: #CAD #Cpp #Design #Engineering #MechanicalEngineering #phasechange #Project #Teamwork
This is part of a state funded project that is meant to be a proof of concept that you can pump well water out of the ground and purify it with just the power of the sun. Photo-voltaic panels (picture 4) are used to power the pumps and reverse osmosis membranes that filter the water (picture 2), lead acid batteries are used also to store excess energy for later use when the sunlight diminishes. Concentrated Solar panels (picture 3) are used to heat the water that we pump out of the ground in order to lower the viscosity of the water which makes it easier to pass through the reverse osmosis membranes. The thermal energy storage tank (picture 1 & 5 ) is used to store heat from the sun so that we can continue to heat the water after the sun goes down.
Thermal Energy Tank:
Our design utilizes Phase Change Material in order to store heat for later use. The phase change material used is paraffin wax, which can be thought of as like candle wax except it is much more expensive due to its precise thermal properties. This wax melts at a certain temperature which can vary based on the waxes chemical composition, we decided to go with 53 degrees centigrade for its melting temperature. The hot water that has been heated up by the sun will be pumped through our tank during the day which will melt the wax that is encapsulated inside the tank. When a material changes from solid to liquid it requires heat or energy to do so, likewise when it solidifies it will release heat in the process known as latent heat. This latent heat will be used to heat the water up after the sun goes down and the sun can no longer provide enough energy to keep the incoming water hot enough to maintain the wax as liquid.
Microsoft Excel to compare cost of multiple design ideas and keep track of calculations.
AutoCAD 2016 to model the tank design (can see the rendering in the included PowerPoint file)
Personal skills - Had to reach out to multiple companies to receive quotes on phase change materials, lead times, and discounts!
Critical thinking - Had to overcome cost restrictions, project limitations, and time constraints.