TY - CONF KW - Optimization KW - Chiller plant KW - Modelica Buildings Library KW - District cooling KW - Waterside economizer AU - Kathryn Hinkelman AU - Jing Wang AU - Wangda Zuo AU - Antoine Gautier AU - Michael Wetter AU - Nicholas Long AB -

District cooling (DC) continues to proliferate due to increasing global cooling demands and economies of scale benefits; however, most district-scale modeling has focused on heating, and to the best of our knowledge, researchers have yet to model cooling plants featuring waterside economizers in DC settings. With the Modelica Buildings library expanding its capabilities to district scale, this study is one of the first to demonstrate how the open-source models can be used for detailed energy and control analysis of a DC plant. For a real-world case study, we developed and calibrated high-fidelity models for a DC system central plant at a college campus in Colorado, USA, and we optimized the condenser water supply temperature (CWST) setpoint for a DC plant across multiple time horizons using the Optimization library in Dymola. Results indicate that annual CWST optimization saves 4.7% annual plant energy, with less than 1% of additional energy savings gained through daily optimization. This confirms previous studies' findings that high frequency CWST optimizations are not necessary for the studied system.

BT - 14th International Modelica Conference CY - Linkoping, Sweden DA - 05/2021 DO - https://doi.org/10.31224/osf.io/rfc8p LA - eng N2 -

District cooling (DC) continues to proliferate due to increasing global cooling demands and economies of scale benefits; however, most district-scale modeling has focused on heating, and to the best of our knowledge, researchers have yet to model cooling plants featuring waterside economizers in DC settings. With the Modelica Buildings library expanding its capabilities to district scale, this study is one of the first to demonstrate how the open-source models can be used for detailed energy and control analysis of a DC plant. For a real-world case study, we developed and calibrated high-fidelity models for a DC system central plant at a college campus in Colorado, USA, and we optimized the condenser water supply temperature (CWST) setpoint for a DC plant across multiple time horizons using the Optimization library in Dymola. Results indicate that annual CWST optimization saves 4.7% annual plant energy, with less than 1% of additional energy savings gained through daily optimization. This confirms previous studies' findings that high frequency CWST optimizations are not necessary for the studied system.

PP - Linkoping, Sweden PY - 2021 T2 - 14th International Modelica Conference T3 - 14th International Modelica Conference TI - A Case Study on Condenser Water Supply Temperature Optimization with a District Cooling Plant UR - https://engrxiv.org/index.php/engrxiv/preprint/view/1677 ER -