An Overview of Sandbox Experiment on Ground Heat Exchangers

As an energy-efficient and low-carbon technology, ground-source heat pumps are promising to contribute carbon neutrality in the building sector. A crucial component of these systems is ground exchanger, which has been extensively studied through sandbox experiments. These experiments play a vital role understanding transfer characteristics validating simulation results. In order facilitate improvement exchangers development heat-pump systems, this article provides comprehensive summary existing The borehole classified into single experiment, group seepage multi-layer soil experiment. It was observed that efficiency spiral tube only 80% compared double tube. Moving on energy-pile experiments, they further divided mechanical performance, thermal thermal-mechanical coupled performance tests. revealed distance U-shaped energy pile radial direction three times greater than vertical direction. For mentioned design, experiment conduction, testing conditions, result analyses summarized. To improve there still some difficulties similarity temperatures small error, controlling boundary conditions accurately, thermophysical properties accurately. Furthermore, perspectives also proposed. under complex environment or with novel composite geo-structures new materials technologies would be investigated. By addressing aspects, review aims provide guidelines for construction, operation, optimization different exchangers, ultimately promoting wider adoption achieving neutrality.