Next Generation Heat Exchangers for Atmospheric Water Collection

Abstract

Abdul Raheem Abdul Rasheed Shaik, “Next Generation Heat Exchangers for Atmospheric Water Collection”, M.Sc. Thesis, M.Sc. Mechanical Engineering, Department of Mechanical Engineering Khalifa University of Science and Technology, United Arab Emirates, July 2021.
Water is a staple commodity in our lives. Without it, life cannot exist. In many regions of the world, there is a scarcity of water or processes that are used to generate water are expensive both monetarily and energy wise. As an alternative, the atmosphere has large quantities of water in forms of clouds, fog, and water vapor, ready to be used. Taking this into consideration, a micro bare rod heat exchanger was investigated to condense and collect water present in the atmosphere. For a desired condensation rate of 0.25 liters per hour, a model is created in the Engineering Equation Solver (EES) of the heat exchanger thNext Generation Heat Exchangers for Atmospheric Water Collectionat will perform in Abu Dhabi’s hot and humid climate. Design variables D, Sl, and St are identified which represent the diameter of the rods and the horizontal and vertical spacing between rods respectively. A 2D CFD model of the heat exchanger is created in ANSYS Fluent and the design variables are varied. The CFD results indicate that reducing the diameter increase the rate of heat transfer and reduces pressure drop. Furthermore, reducing Sl and St increase the rate of heat transfer and pressure drop. The micro bare rod heat exchanger design is modified and fabricated via additive manufacturing. The novel heat exchanger is field tested, and results are compared with a fin tube heat exchanger. Results indicate that the novel heat exchanger is able to reach temperatures ranging from 10oC to 15oC, which was approximately 10oC lower than the fin tube heat exchanger. The novel heat exchanger also yields higher daily water collection per unit volume, yielding up to 900 mL/m3-day for days with high moisture content.

Date of Award	Jul 2021
Original language	American English
Supervisor	Ali Al Alili (Supervisor)