Dynamic Modeling of Target's Cooling Systems

Sammanfattning: The thermal energy generated from the spallation process in the ESS facility must be cooled by cooling systems in order to ensure safe operation of the facility. It is of interest to understand what operating conditions of the cooling systems will ensure this safety for both stationary conditions and transient events. A part of the water cooling system in ESS was modeled in Dymola with the aid of the free Modelica Standard Library and the Buildings Library. Component models such as a pipe segment, a gas and liquid separation tank, a delay tank and a heated component have been constructed. The component models were verified with manufacturer data or known and well-proven mathematical calculations but could not be validated with data from the actual cooling system since it is yet to be in operation. With the system model, normal operation and disturbance cases were simulated. The disturbance cases have been simulated in order to analyze what operating conditions will trigger an alarm and also discern the duration from the introduction of a disturbance to the triggering of an alarm. The temperature transients in the cooling system could be simulated, however the pressure transients could not due to convergence issues.