Simulations of a solar-assisted block-heating system

Two types of simulation software TRNSYS and Polysun are studied to check their suitability for solar district heating system planning. A reference case, a part of the Vallda Heberg district heating system is modelled in both tools and results are compared with available measured data and with each other. Models are successfully calibrated. TRNSYS and Polysun models have deviations in main key figures compared to the reference case less than 2% and less than 8% respectively. A sensitivity analysis of key parameters shows that the two tools give similar results