Recent research and applications of ground source heat pump integrated with thermal energy storage systems: A review

As a renewable energy technology, ground source heat pump (GSHP) system is high efficient for space heating and cooling in buildings. Thermal energy storage (TES) technology facilitates the efficient utilization of renewable energy sources and energy conservation. It is expected to be more prevalent in the future. GSHP application is growing rapidly as it is integrated with TES system. During the last decade, a number of investigators have conducted the studies on the designing, modeling and testing of TES assisted GSHP (GSHP–TES) system. This paper presents a review on the research and applications of GSHP integrated with TES system, including various cooling and heating storage technologies. The studies on the GSHP–TES systems are categorized into five groups including: GSHP integrated with ice storage tank, GSHP integrated with solar collectors, GSHP integrated with soil, GSHP integrated with water tank and GSHP integrated with phase change materials (PCM). However, there are still several challenges for the applications of GSHP–TES systems, such as the mechanisms, thermodynamics and performance of the unsteady and transient heat transfer of underground soil and the thermal storage process as well as control strategies of the GSHP–TES systems. Addressing these problems will strengthen the theoretical and practical understandings and facilitate more extensive applications of GSHP–TES systems.