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Experimental Study on Heat Exchange Efficiency of Combined Well & Open-Closed Loops Geothermal System

지하수정호와 결합한 복합지열시스템의 열교환 효율에 대한 실험적 연구

  • Received : 2018.01.19
  • Accepted : 2018.04.24
  • Published : 2018.05.30

Abstract

The temperature of underground water generally remains constant regardless of the season. therefore, it is possible to get plenty of energy if we use characteristics of underground water for both cooling and heating. This study evaluates efficiency of real size coaxial and U-tube type complex geothermal system which is combined with underground water well. This study also evaluates relative efficiency/adaptability through comparison with existing geothermal systems(vertical closed loop system, open loop system(SCW)). The heat exchange capacity of complex geothermal system according to temperature difference between circulating water and underground water shows very high significance by increasing proportionally. The temperature change of underground water according to injection energy, shows very high linear growth aspect as injection thermal volume heightens. As a result of evaluation of heat exchange volume between complex geothermal system and comparative geothermal system, coaxial type has 26.1 times greater efficiency than comparative vertical closed type and 2.8 times greater efficiency than SCW type. U-tube type has 26.5 tims greater efficiency than comparative vertical closed type and 2.8 times greater than SCW type as well. This means complex geothermal system has extremely outstanding performance.

Keywords

Acknowledgement

Supported by : 한국에너지기술평가원(KETEP)

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