Hybrid ground source heat pump system for overcoming soil thermal imbalance: A review

Soil thermal imbalance becomes the main obstacles to the efficient and sustainable operation of ground source heat pump (GSHP) system. There is evidence that hybrid ground source heat pump (HGSHP) system is an advanced alternate to eliminate soil thermal imbalance and improve system performance. Therefore, this paper presents a comprehensive overview of recent developments and applications of hybrid ground source heat pump system, aiming to conclude some valuable remarks and recommendations for the future research in this direction. Based on the difference of cooling or heating load requirements and application areas of GSHP, different types of HGSHP coupled with auxiliary heating source devices, auxiliary cooling source devices, sensible and latent thermal energy storage devices are presented in section 3, section 4 and section 5, respectively. Furthermore, recent progress in control strategies of HGSHP system are summarized and reviewed. Finally, some conclusions and suggestions for the applications of HGSHP system are proposed to provide an overview of HGSHP system and facilitate more extensive applications of HGSHP system.