Dynamic model of coaxial ground-source geothermal system for the Smith College field house
Bachelor of Science
Geothermal, Dynamic, Modeling
Nowadays, global warming is an urgent and comprehensive problem. To mitigate the impact of climate change, deep reductions in carbon emission are required. “Decarbonizing” is becoming a challenge for every institution, including Smith College. In 2007, Smith joined the Climate Leadership Network by signing the American College and Universities Presidents’ Carbon Commitment and set a target date, 2030, for achieving carbon neutrality missions. To meet the decarbonization goal, Smith College is considering the conversion of the central steam-based heating and cooling system to a liquid phase geothermal heat exchange system, in which the central heating plant is converted from one that burns fossil fuel to one that exchanges energy with the ground and uses wind or solar electricity to power the system .
A District Energy Master Plan was recently completed to assess opportunities and costs of phasing a geothermal capital project. That master plan necessitated drilling a test well to characterize the subsurface conditions on campus. To demonstrate geothermal technology to the campus and community, a well was designed to serve as a demonstration project at the Smith College Field House, given the buildings proximity to the athletic fields where future geothermal wells are proposed.
In this thesis, a 1D, dynamic control-oriented model of the temperature distribution of the working fluid in the coaxial borehole is developed and calibrated. In order to validate the model, measurements of temperature in the operational borehole were required. As a result, DTS monitoring systems were researched, an appropriate fiber optic cable for the field house application was designed and selected, fiber routing options like splicing were investigated, the cable was installed and the fiber optic interrogator system was deployed in order to measure thermal distribution down the length of the geothermal well. This DTS system was first used to determine the ground temperature when the well is not in operation. Once operational, future work should use the DTS measurements to experimentally validate the proposed model.
2020 Yihui Jiang. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.
Jiang, Yihui, "Dynamic model of coaxial ground-source geothermal system for the Smith College field house" (2020). Honors Project, Smith College, Northampton, MA.
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