PESCO Solar Water Distillation

As part of the Mechanical Engineering program at NMT, I completed two years of capstone research projects. This included a semester of solar water heater design for a water purification system.

Our team designed a solar-powered collector to heat 500 gallons/day for a membrane distillation unit located near Farmington, NM. Our prototype achieved 300% increase in heat transfer over a previous model, and was approved to code.

My role in this project was prototype modeling, testing, and finite element analysis for model validation.

For a direct contact membrane distillation process designed by PESCO, an intake stream of hot water is necessary for functionality.

Diagram for the Direct Contact Membrane Distillation (DCMD) Process

To maximize distillation efficiency, The complete system had a desired operating load of 500 gallons of water heated from ambient temperature to 50 degrees Celsius for 8 hours each day.

Baffle layout in the solar collector plate for water flow, credit Carl Bolin at NMT

We designed a solar collector plate to be a thin channel with baffles to maximize heat transfer. After the plate was machined, a test plate was created with a plexiglass cover to analyze water flow through the solar collector.

Turbulent water flow between baffles of the solar collector during testing.

Transient heat transfer was experimentally and theoretically calculated through the collector plate, resulting in further iterations of the plate with more baffles.

Inlet and outlet water temperature, including calculation error from NI-DAQ thermocouple setup.

The solar collector was to be installed near Farmington, New Mexico for the DCMD process, so the solar collector frame needed to meet all relevant codes for ground-mounted solar collectors.

Inventor/SkyCiv finite element stress and displacement model under wind and water weight load.

A wooden and steel frame was model in Inventor to be tested for each relevant AISC and ASCE code, with many iterations to each frame to reduce costs and maintain stability.

2×4 wooden model for the experimental setup frame.

After procuring all the materials necessary, our team constructed the following wooden model of the solar collector, equipped with a transfer pump, pressure gauges, and thermostats for experimental measurements.

Completed experimental setup, with a transfer pump and inlet and outlet water feeds.
Section of code adherence document drafted for AISC and ASCE requirements.


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