Performance analysis of a solar heating system with the absorption heat pump and oil/water heat exchanger

A solar heating system with the absorption heat pumps (AHPs) and oil/water heat exchanger (OWHE) was set up for space heating. The system was driven by parabolic trough solar collectors (PTCs). In this study, heat transfer models were built and experiments were conducted to evaluate the performance of PTCs. Collector efficiencies of 40-55% were obtained under different weather conditions. For the solar driven AHP system and OWHE system, primary energy ratio (PER) values were calculated and compared. The results showed that in overcast days with low direct normal insolation (DNI), the operation of the PTC system was not cost-effective. In cloudy days with high DNI lasting for a short period (e.g. 2 hours), the operation of OWHE system was better than the operation of AHP system as the AHP system needed more preheating energy before the system operation. While in sunny days with high DNI lasting for a longer period (e.g. 8 hours), the AHP system was suggested to be operated for it owned higher PER values.