Page 165 - Sustainable On-Site CHP Systems Design, Construction, and Operations

138 T h e Fe a s i b i l i t y S t u d y

the DOE 2.E hour-by-hour building energy simulation program along with ORNL CHP
Capacity Optimizer:
1. Development of a building energy model using a forward building energy
simulation program based on the preliminary design documents (architecture,
structural, lighting, plumbing, process, site design criteria, etc.). For equipment
such as chillers, boilers and other plant equipment, automatic sizing and typical
energy efficiency data consistent with local or required energy standards can be
utilized. (Take into account real-time site-specific data and energy costs for
improved predictability.)
2. Retrieve from the output of the energy simulation program, hourly reports for
8760 values for the site electrical requirements (excluding any cooling electrical
energy), thermal energy (space heating, domestic hot water, process heat) and
cooling requirements.
3. Input the hourly data in the ORNL CHP Capacity Optimizer along with the
utility rates and typical electrical efficiency and applicability of waste heat for
the prime mover and the other mechanical equipment. Run the first iterative
simulation to determine prime mover size.
4. Identify a vendor who offers a suitable prime mover, and rerun the ORNL CHP
Capacity Optimizer using published data available from technical data sheets
of the prime mover inputs for electrical efficiency and available waste heat. The
results can be used as a starting point (to size the prime mover) in the building
energy simulation (since the building energy simulation does not calculate the
prime mover size automatically).
5. Return to the building energy simulation and proceed with the conceptual
design.
Chapter 21 provides a case study entitled “Optimal Sizing of Prime Mover and
Absorption Chiller Using Hour-by-Hour Building Simulation Program—New School
Facility” demonstrates the procedure of utilizing hourly load data and optimal sizing of
the prime mover and the absorption chiller.
Although this section discusses new facilities, a similar approach can be used for
existing buildings; in this case, the hourly data that will be inputted to the ORNL CHP
Capacity Optimizer will be generated by an hour by hour calibrated energy model of
the existing building.

References

BEA, 2004. Building Energy Analyzer, InterEnergy Software, available at http://www.
interenergysoftware.com/OrderForms/BEAOrderForm.htm.
Beyene, A., 2002. Combined Heat and Power Sizing Methodology, ASME Turbo Expo
2002, Industrial and Cogeneration, June 3–6, Amsterdam, The Netherlands.
Caton, J. A. and W. D. Turner, 1997. Cogeneration, in Kreider, F. and R. E. West (eds.),
CRC Handbook on Energy Efficiency, CRC Press, Boca Raton, FL, Chapter 17.
CogenPro, 2004. San Diego State University, available at http://www-rohan.sdsu.edu/
~eadc/cogenH.html.