Introducing the NewLib Library and its application to multi-level, large-scale solar field models

Abstract

Solar thermal technology is a promising solution fordecarbonizing heat production in industrial applicationsand district heating networks. When combined with heatstorage and advanced control strategies, it can cover asignificant share of heat demands. However, designing andoptimizing such systems is complex due to their dynamicbehavior and the interplay of multiple physical phenomena.To better understand and design these systems, modelingtools are essential.Modelica is particularly well-suited for this purpose. AtNewheat, large scale solar thermal field models have beendeveloped in the Modelica language using the Dymolaenvironment. These models represent the thermal andhydraulic behavior of a solar thermal field at twodifferent levels of complexity. Each is designed fordifferent project phases-fast simulations for early-stagefeasibility studies and slower but more detailedsimulations for the engineering phase.To assess the accuracy of both models, comparisons withmeasured data on an operational solar plant were performed.Results indicate that both models achieve high thermalaccuracy, with errors of less than 4% in annual heatproduction. On the hydraulic side, the detailed modelprovides more precise results than the simplified one. Themain drawback of this model being slow simulations in caseof very complex solar field layouts.Moving forward, these models will support variousapplications and enable scalable modeling of complex solarthermal systems, adapting to different project phases andrequirements.