Campus Chill Water System Design and Operation Improved Through by zku40248


									Customer Profile

       Campus Chill Water System Design and Operation
   Improved Through Hydraulic Modeling With AFT FathomTM

Company:         TME Energy Services Division                        To answer these questions a model of the district
                 TME, Inc.                                        cooling system was developed within AFT Fathom. In
Address:         5800 Evergreen Drive, Suite A                    addition to the ability to model complex and large
                 Little Rock, AR 72205-1757                       networks (the model contains over 3,400 pipes and
Telephone:       501-666-6776                                     junctions), unique capabilities provided by AFT Fathom
Fax:             501-663-8888                                     were critical to the success of the study.

TME, Inc. is a full service mechanical, electrical and               Air conditioning load calculations were developed for
energy engineering firm located in Little Rock, with              average and peak demand periods during winter and
branch offices in Tulsa and Tucson and provides services          summer. Cooling load data was then converted into flow
to clients in over 25 states. TME Energy Services Division        demands for the many heat exchangers in the system.
provides a wide assortment of energy related services             Modifying the input for 358 pumps and control valves
including utility rate analysis, energy audits, wholesale         over the many different load cases studied was greatly
purchasing of natural gas and electricity, and                    facilitated by using AFT Fathom's ExcelTM data import
commissioning.                                                    capability.
                                                                     As James Hess, TME Energy Engineer comments,
    Reducing energy costs is an                                                   "Now that we had a method for quickly
increasingly important consideration for                                          making changes to the models, the real fun
plant owner/operators with an excellent          Annual energy savings            began." A series of runs were made with
example being the energy intensive               of 1.9 million KWHr and varying loads, operating configurations,
district cooling system serving the              $67,000 in pumping               pump characteristics and piping changes.
University of Arkansas at Fayetteville.          power, and $1,200,000 in            In the end, the hydraulic model and
This campus wide system provides air             annual chiller electrical        results achieved by the study were viewed
conditioning for 59 buildings along with                                          very favorably by the University. Benefits
refrigeration heat rejection for laboratories and gas energy savings.             derived from the hydraulic modeling
and laser systems cooling.                                                        include:
    Classified as a primary/secondary/tertiary pump               • Instill confidence in the method as the baseline model
system, the primary circuit circulates water within the                accurately reflected key operating characteristics of
chiller plants, the secondary system distributes cooling               the actual system.
water from the plants to the buildings and other users and        • Confirm selection of the pumps for the Main Plant
the tertiary system consists of pumps within the various               retrofit.
buildings. With a total connected load of 13,600 cooling          • Evaluated piping changes in various buildings to
tons, the system includes a Main Chiller Plant with a                  achieve significantly improved delta-T thereby
pumping capacity of 15,000 gpm, a Southwest Chiller                    lowering required flow rates.
Plant with 9,000 gpm capacity and a North Chiller Plant           • Verify the energy savings benefit that would result
with a capacity of 6,000 gpm. As is the case with many                 from the "Low Flow/High Delta T" project.
growing universities, UAF was undergoing significant              • Identify potential bottlenecks to target areas of
changes that would greatly impact the district cooling                 improvement.
system.                                                           • Determine that operation of the steam turbine driven
    In addition to campus load growth, it was desired to               North Chiller plant as a 'booster' pump could be
evaluate changes to reduce pumping energy costs that                   eliminated realizing substantial energy savings.
would result from supplying colder chilled water to the
                                                                  • Provide the University insight into how to best
campus buildings, converting the buildings to variable
                                                                       operate the plants from a pumping energy
flow using variable speed pump drives and eliminating                  consumption standpoint.
the 'decoupler' at each building allowing it to take
                                                                  • Annual energy savings of 1.9 million KWHr and
advantage of available differential pressure in the
                                                                       $67,000 in pumping power, and $1,200,000 in annual
secondary system. These changes were cumulatively
                                                                       chiller electrical and gas energy savings.
referred to as the "Low Flow/High Delta-T" project.
Finally, an operating strategy for the chiller plants to
                                                                     "Overall, we were quite pleased with what we were
minimize pumping energy was developed. No mean feat
                                                                  able to accomplish using the AFT Fathom software in this
given the complexity of this system.
                                                                  project.", stated Mr. Hess.

Applied Flow Technology Corp. • P.O. Box 6358, 400 W. Hwy. 24, Suite 201, Woodland Park, CO 80866-6358 •
                          Typical Building with circulating pump, heat exchanger and
                          flow control valves.

                                                       Main Chiller Plant

                                     University of Arkansas at Fayetteville
                                     Chilled Water System AFT Fathom

Southwest Chiller Plant

                                             For more information on AFT Fathom, contact
                                             Applied Flow Technology at (800) 589-4943 or
                                             visit our website at

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