COLORADO SPRINGS, Colo. — University of Alabama at Birmingham obtained an annual energy savings of $60,000 after Bernhard TME Engineering (TME) optimized the university’s district chilled water system. The chilled water is distributed to 48 buildings on campus to supply the air conditioning systems in the hot and humid southeastern U.S.

Brandon Smith, commissioning technician, and Wei Guo, energy engineer, at TME, used Applied Flow Technology’s pipe flow modeling software, AFT Fathom, to create a hydraulic model of the existing system.

The system consists of three existing chilled water plants with 38,100 tons of cooling capacity. It operates off of a fixed differential pressure set point based on the combination of dry bulb and wet bulb outside air temperature. The differential pressure set point has been proven to satisfy the chilled water demand of the buildings after years of experience, but is not necessarily the most efficient way to do so.

Smith and Guo were able to run simulations with the chilled water plants’ pumps in several different arrangements in order to determine the most efficient way to run the plants.

A major step to reduce overall energy cost was to determine the most hydraulically remote building and add booster pumps to that building. However, with the size of the campus and the extensiveness of the piping layout, this was no easy feat.

Smith and Guo turned to AFT Fathom to determine which building’s control valve was most open, which indicates poor temperature control of that building. This discovery helped determine the most hydraulically remote building, to which TME added booster pumps and ran several different scenarios to find the best operating condition for the plant. By adding a booster pump to that building, the campus is able to obtain an annual savings of $60,000 a year.

“We were very impressed by how quickly AFT Fathom is able to process and calculate solutions for such a large piping network,” said Smith. “Without the speed of AFT Fathom, this type of modeling project would not have been economically feasible for the university to invest in.”

Smith and Guo submitted the University of Alabama project to AFT’s Platinum Pipe Award Contest and received the 2016 award for the Operational Benefits and Sustainability category. The award recognizes excellence in piping and ducting system modeling using AFT software.

“The application of AFT’s system modeling software at the University of Alabama continues to demonstrate the value of system modeling and the power and versatility of our software products,” said AFT President, Trey Walters. “There is much work to be done to improve the energy efficiency of installed pumping systems and to change the paradigm of how pumping systems are initially designed to reduce their environmental footprint. This application is an important step in that direction.”

Publication date: 2/20/2017

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