초록

현재까지 지열 열펌프 시스템의 지중열교환기는 수직 밀폐형과 개방형 지중열교환기가 주로 설치되어 열응답시험을 이용한 열특성 평가가 수행되어 왔다. 본 논문에서는 열응답시험과 선형열원법을 이용하여 수평형 지중열교환기의 열특성을 분석하였다. 또한 지열 열펌프 시스템은 매일 단속 운전되어지므로 일일부하시험을 수행하여 수평형 지중열교환기의 지중온도 및 순환수 평균온도 일별 변화를 고찰하였다. 시험을 위해 경기도 안산에 직선식 수평형 지중열교환기(심도 2 m, 길이 50 m 8줄)를 설치하였다. 시험결과 수평형 지중열교환기의 지중 열전도율은 연중 $1.43{\sim}1.64W/m{\cdot}K$ 범위로 비교적 큰 변화가 없으며 12월에 최대값을, 5월에 최소값을 갖는 것으로 나타났다. 12일간 지중 열교환기로 하루 10시간동안 6.0 kW의 열량을 투입하는 연속 부하시험을 6월, 9월, 12월에 수행한 결과 지중온도는 이 기간 동안 각각 $4.31^{\circ}C$, $3.14^{\circ}C$, $1.21^{\circ}C$ 상승하는 것으로 나타났다.

Abstract

Vertical and standing column well ground heat exchangers have mostly been installed for ground source heat pump systems (GSHP) and thermal response tests (TRT) have been applied to evaluate the thermal characteristics for these heat exchangers. In this paper, the TRT coupled with a line source method was applied to evaluate the thermal characteristics of the horizontal ground heat exchanger (HGHX). Load tests of a HGHX were also performed to examine the daily variations of the ground and fluid temperatures associated with the daily intermittent operation of GSHP. For this test, the straight HGHX (depth 2 m, length 50 m, 8 line) was installed in Ansan city. The results showed that the variations of ground thermal conductivity of HGHX during one year were relatively small with the range of $1.43{\sim}1.64W/m{\cdot}K$, and the maximum and minimum values appeared in December and May, respectively. Load tests with heat injection rate of 6.0 kW for 10 hours per day to HGHX during twelve days were performed in June, September and December, and resulted in a ground initial temperature rise of $4.31^{\circ}C$, $3.14^{\circ}C$, and $1.21^{\circ}C$ during these days, respectively.

주제어

#Thermal response test(TRT)   #Ground thermal conductivity   #Horizontal ground heat exchanger(HGHX)   #Ground source heat pump system(GSHP)  

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참고문헌 (7)

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