Simulation Tools for Solar Cooling Systems – Comparison for a Virtual Chilled Water System
Abstract
In the scope of the IEA Task 38 (Solar Air-Conditioning and Refrigeration) a comparative study of different simulation tools for solar cooling system pre-design was conducted. It aimed at identifying a range of uncertainties in simulation results which may be obtained by validated models from market available tools – and simulations performed by different experienced users. Tools applied in the simulation comparison comprise the fast pre-design tool EasyCool and the end-design tools TRNSYS, INSEL, SPARK and the TRNSYS-based TRANSOL. A model of a virtual office building in Palermo climate was used for the generation of a load file that was applied in all simulations. Further, a common system layout, component sizing and specifications, and a control strategy for the more advanced simulation tools were defined. The simulated solar cooling system is a chilled water system applying a 35kW absorption chiller by Yazaki (WFC 10). Results show that a margin of around 6 % deviation of the thermal performance parameters from their mean seems the best possible in the crosscomparison of the three closest baseline simulations – however the upper margin of around 20 % observed for all simulations may be more close to the real margin of variation. This reflects the high uncertainty in results of pre-design simulations and underlines the need of a good technical understanding by the user of simulation tools.