Journal of the Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회논문집)

Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회)
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Preliminary Analysis of Long-Term Performance of Borefield Connected to Hybrid Sources

하이브리드 열원이 연결된 보어필드 장기 성능의 기초적 분석

  • Young-Joon Park (Graduate School, Department of Architectural Engineering Inha University) ;
  • Eui-Jong Kim (Department of Architectural Engineering Inha University)
  • Received : 2024.05.21
  • Accepted : 2024.06.28
  • Published : 2024.09.01
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Abstract

In this study, the performance of a ground heat exchanger (GHE) for domestic hot water loads was evaluated using an FLS (Finite Line Source) model with various configurations. The evaluation compared two scenarios: using the GHE alone and using a hybrid system combining the GHE with solar thermal modules, operated in both group and individual modes. The results indicated a continuous decrease in ground temperature when only the GHE was used. However, in the group/individual operation modes, the ground temperature showed a slight decrease but maintained a more stable level. Over a long-term operation of 20 years, the hybrid group/individual operation with solar thermal modules showed that the average temperature of the fluid discharged from the GHE was approximately 0.7℃ higher than when only the GHE was used. Providing a higher temperature fluid on the heat source side suggests the potential to improve the COP (Coefficient of Performance) of the heat pump. Moreover, the proposed hybrid group/individual operation mode demonstrated the ability to mitigate ground temperature imbalances caused by load imbalances, and confirmed the possibility of reducing the number of GHE installations by half, thereby lowering initial investment costs. In conclusion, the simulation verified that the group/individual operation mode utilizing hybrid heat sources is an effective alternative for enhancing the performance and cost-efficiency of ground source heat pump systems.

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References

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