Model-Based Analysis of Solar Thermal and Heat Pump Systems Using TRNSYS

Abstract

The combination of solar thermal and heat pump (STHP) systems is a promising hybrid concept for the efficient and sustainable energy supply of buildings. In general, the modeling and simulation of such complex energy systems is a challenging task as it requires expert knowledge in modeling as well as in the behavior of the real systems. As an alternative to the complex and lengthy general modeling process, a TRNSYS-based stand-alone tool is presented which enables users to analyze different predefined SHP concepts with hardly any knowledge in modeling and simulation itself. The predefined STHP concepts are explained in detail and the simulation results for a comparison of the performance of different system concepts are presented. The predefined systems are ground or air source heat pump systems with or without parallel integration of solar thermal collectors. In addition to earlier work, these system concepts are extended by solar thermal and ice storage heat pump systems. On the one hand, the simulation results show that in case of moderate climate and new as well as renovated buildings, solar thermal and air source heat pump systems can compete with ground source heat pump systems without solar integration and can achieve the same or even higher values of seasonal performance factors. On the other hand, the results show that solar thermal and ice storage systems are efficient solar thermal heat pump systems, which can achieve higher SPFs than air source heat pump systems and for new buildings even SPFs in the range of ground source heat pump systems. Furthermore, this contribution shows the advantages and the possible performance improvements by parallel integration of solar collectors in different system concepts.