Measurement and modelling of a multifunctional solar plus heatpump system from Nilan. Experiences from one year of test operation

摘要

A multifunctional solar and heat pump unit from Nilan has been installed in the Performance Test Facility (PTF) at DTU Byg Denmark. It is part of the IEA Task 44 cooperation. Multifunctional means in this case: Hot water, Air heating, Ventilation, Air heat recovery, Air filtering and Floor heating. Nilan units, with additional air cooling and CO_2 control, are also available. The unit has been in operation for more than one year. The aim has been to stress the system operation to different conditions in the lab, to learn more about the performance, but also to find possible improvements especially concerning advanced control. The operation into extreme states of high hot water demand and low air ventilation rates, has also been done to develop and validate a TRNSYS system model. The model was developed and validated for the first period of operation mainly winter and early spring conditions. Now the system has been in operation during all seasons and a full year model could be developed and validated. The model also includes new possibilities for solar collector loop and heat pump operation control.