Analysis of Heat Exchange Rate for Low-Depth Modular Ground Heat Exchanger through Real-Scale Experiment

• Published in: Energies (Basel) Vol. 14; no. 7; p. 1893
• Main Authors: Kim, Kwonye, Kim, Jaemin, Nam, Yujin, Lee, Euyjoon, Kang, Eunchul, Entchev, Evgueniy
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-04-2021
• Subjects: ground heat exchanger; heat exchanger rate; low-depth modular GHX; real-scale experiment
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en14071893

A ground source heat pump system is a high-performance technology used for maintaining a stable underground temperature all year-round. However, the high costs for installation, such as for boring and drilling, is a drawback that prevents the system to be rapidly introduced into the market. This study proposes a modular ground heat exchanger (GHX) that can compensate for the disadvantages (such as high-boring/drilling costs) of the conventional vertical GHX. Through a real-scale experiment, a modular GHX was manufactured and buried at a depth of 4 m below ground level; the heat exchange rate and the change in underground temperatures during the GHX operation were tracked and calculated. The average heat exchanges rate was 78.98 W/m and 88.83 W/m during heating and cooling periods, respectively; the underground temperature decreased by 1.2 °C during heat extraction and increased by 4.4 °C during heat emission, with the heat pump (HP) working. The study showed that the modular GHX is a cost-effective alternative to the vertical GHX; further research is needed for application to actual small buildings.