• 제목/요약/키워드: borehole temperature

검색결과 94건 처리시간 0.024초

광섬유 센서를 이용한 지중 열교환기 시스템 온도 모니터링 (Fiber optic distribution temperature sensing in a borehole heat exchanger system)

  • 심병완;이영민;김형찬;송윤호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.451-454
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    • 2006
  • Fiber optic distributed temperature sensing and thermal line sensor are applied in an observation borehole and a loom deep borehole heat exchanger. For the case of permanently installed system fiber optic DTS is very useful. By comparing with TLS, fiber optic DTS shows good accuracy and reliability. Ground water flow can give influences at heat exchange rate of the heat pump system. According to the hydraulic characteristics and temperature-depth profile, we consider that temperature-depth profile do not seem to be dependent on ground water flow. A permanent installation of fiber optic cable is expected as a reliable temperature measurement technique in a borehole heat exchanger system.

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현지 측정에 의한 남한지역의 지중유효열전도도, 보어홀 전열저항 및 초기온도 분석 (Analysis of Soil Thermal Conductivities, Borehole Thermal Resistances and Initial Soil Temperature with In-Situ Testing in South Korea)

  • 노정근;연광석;송헌
    • 한국태양에너지학회 논문집
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    • 제32권5호
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    • pp.68-74
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    • 2012
  • Investigation of the effective soil thermal conductivity($k$) is the first step in designing the ground loop heat exchanger(borehole) of a geothermal heat pump system. Another important factor is the borehole thermal resistance($R_b$). Thermal response tests offer a good method to determine the ground thermal properties for the total heat transport in the ground. The first step is measured for initial soil temperature. This is done by supplying a only pump power into a borehole heat exchanger. They need to supply into water unload heat power more than 30 minutes. In this study, the initial soil temperature was found to analysis $14.1{\sim}16.0^{\circ}C$,the ratio was 68.7% represented. In this case of $k$, was 2.1~3.0 $W/m{\cdot}k$, $R_b$ was 0.11~0.20 $m{\cdot}K/W$. In this work, it is also shown that the distribution of a soil thermal conductivity and borehole thermal resistance were on the influence of initial soil temperature. And soil thermal conductivity was related with factors of equation by linear least square method, borehole thermal resistance was on the influence of composite factors.

수직형 지열 열교환기(BHE)의 열성능 측정에 관한 실험적 연구 (An Experimental Study on the Thermal Performance Measurement of Vertical Borehole Heat Exchanger(BHE))

  • 임경빈;이상훈;성낙원;이창희
    • 대한기계학회논문집B
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    • 제30권8호
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    • pp.764-771
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    • 2006
  • Knowledge of ground thermal properties is most important for the proper design of large BHE(borehole heat exchanger) systems. Thermal response tests with mobile measurement devices were first introduced in Sweden and USA in 1995. Thermal response tests have so far been used primarily for in insitu determination of design data for BHE systems, but also for evaluation of grout material, heat exchanger types and ground water effects. The main purpose has been to determine insitu values of effective ground thermal conductivity, including the effect of ground-water flow and natural convection in the boreholes. Test rig is set up on a small trailer, and contains a circulation pump, a heater, temperature sensors and a data logger for recording the temperature data. A constant heat power is injected into the borehole through the pipe system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance.

초기 지중온도 측정이 지중 열교환기 설계에 미치는 영향 (Effect of initial ground temperature measurement on the design of borehole heat exchanger)

  • 송윤호;김성균;이강근;이태종
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.600-603
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    • 2009
  • We compared relative importance of thermal conductivity and initial ground temperature in designing borehole heat exchanger network and also we test accuracy of ground temperature estimation in thermal response test using a proven 3-D T-H modeler. The effect of error in estimating ground temperature on calculated total length of borehole heat exchanger was more than 3 times larger than the case of thermal conductivity in maximum 20% error range. Considering 10% of error in estimating thermal conductivity is generally acceptable, we have to define the initial ground temperature within 5% confidence level. Utilizing the mean annual ground surface temperature and the geothermal gradient map compiled so far can be a economic way of estimating ground temperature with some caution. When performing thermal response test for estimating ground temperature as well as measuring thermal conductivity, minimum 100 minutes of ambient circulation is required, which should be even more in case of very cold and hot seasons.

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3중관용 스페이서를 적용한 대구경 지중열교환기의 성능측정에 관한 연구 (An Experimental Study on the Thermal Performance Measurement of Large Diameter Borehole Heat Exchanger(LD-BHE) for Tripe-U Pipes Spacer Apply)

  • 이상훈;박종우;임경빈
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.581-586
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    • 2009
  • Knowledge of ground thermal properties is most important for the proper design of large scale BHE(borehole heat exchanger) systems. The type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for insitu determination of design data for large diameter BHE for triple-U spacer apply. The main purpose has been to determine insitu values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a circulation pump, a inline heater, temperature sensors, flow meter, power analysis meter and a data logger for recording the temperature, fluid flow data. A constant heat power is injected into the borehole through the tripl-U pipes system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance of large diameter BHE for spacer apply.

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한국의 지중온도를 이용한 기후변화연구 (Climate change in Korea inferred from subsurface temperatures)

  • 이영민;김형찬;송윤호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.442-444
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    • 2006
  • On long time scale and over large areas ground surface temperatures (GSTs) track surface air temperatures (SATs). Additionally, GST changes penetrate into the subsurface and are recorded as transient temperature perturbation to the background thermal filed. Therefore, climate change can be reconstructed from borehole temperature measurements We present GST hi story reconstructed from temperature measurements in a borehole at Pocheon The result shows that GST cold period in the late 19th century and then increased by about 2K to 1990. GST history matches well with surface air temperatures measured from 1907 to 2001 at the Seoul Meteorological Station and GST history reconstructed from temperature measurements in three boreholes at Ulsan.

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우리나라 지표면 온도 분포 (Ground Surface Temperature Distribution of Korea)

  • 구민호;송윤호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.431-433
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    • 2006
  • Accurate information on the ground surface temperature is essential for design of a borehole heat exchanger and thus ensuring the performance of a ground source heat pump system along with knowledge on thermal diffusivity and conductivity of ground. In this study we analyzed the shallow subsurface temperature monitoring data of 58 Korea Meteorological Administration synoptic stations. As a result, we compiled mean annual ground surface temperature distribution map using multiple regression analysis of the monitoring data.

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지중열전달특성 평가에 관한 해석 및 실험적 방법에 관한 연구 - 지중 열물성치 및 보어 홀 열 저항 평가 - (Study on Analytical and Empirical Methods for Assessing Geo-Heat Transfer Characteristics)

  • 박준언;백남춘
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.427-432
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    • 2005
  • This study treats the advantage of in situ line source method measuring the heat transfer capacity of a borehole, using mobile equipment, to determine the thermal properties of the entire borehole system such as thermal conductivity, diffusiveity. volumetric heat capacity, and borehole thermal resistance. The results from the response test include not only the thermal properties of the ground and the borehole, but also conditions that are difficult to estimate, e,g. natural convection in the boreholes, asymmetry in the construction, etc. In this study, 1) theoretical in situ methods for assessing working fluid temperature variation in V-type PE tube have been introduced, and 2) TRTE(Thermal Response Test Equipment) has been built based on these kinds of theoretical in situ methods. Basically TRTE consists of a pump, a heater and temperature sensors for measuring the inlet and outlet temperatures of the borehole. In order to make equipment easily transportable it is set up on a small trailer. Since the response test takes above two days to execute, the test was fully automatic in recording measured data using Labview DAS(Data acquisition system) program. The test was demonstrated in the course of intensive research in this field through the one site at Ulsan city in Korea. From this kind of thermal properties test of borehole systems in situ, the design of the borehole system can be optimized regarding the total geological, hydro-geological and technical conditions at the location.

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상온 및 고온 하 진삼축압축실험을 이용한 시추공의 파괴 거동 기초 연구 (A Basic Study on Borehole Breakout under Room Temperature and High Temperature True Triaxial Compression)

  • 윤정환;민기복;박의섭;정용복
    • 터널과지하공간
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    • 제30권6호
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    • pp.559-572
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    • 2020
  • 본 연구에서는 현지 암반의 진삼축 응력 조건과 온도 변화를 고려한 공벽 안정성 실험을 수행하고, 심부 지하의 응력 조건과 압력 조건에서 암석의 열역학적 거동을 관찰하였다. 중국 황색 사암과 국내 황등 화강암 시료를 이용하여 진삼축압축실험을 진행하였다. 역학 실험은 각각 9가지 구속압 조건에서 수행되었고 열역학 실험은 화강암 시료를 이용하여 6가지 구속압 조건에서 시료를 60℃~100℃로 가열하여 수행하였다. 역학 실험 결과 공벽 파괴가 발생하는 최대 주응력은 중간 주응력에 비례하는 것을 확인하였다. 열역학 실험에서는 온도 증가에 따라 공벽의 응력장에 열응력이 추가되어 공벽 파괴가 추가적으로 발생하는 것을 확인하였다. 실내 실험 결과를 분석하기 위해 모기쿨롱 파괴 기준식을 사용하여 분석하였다. 원통형 시료에 대한 전통적인 삼축압축시험 결과와 진삼축 조건 하의 공벽 파괴 실험 결과가 모두 진삼축 파괴 기준식인 모기쿨롱 파괴 기준식에 잘 부합됨을 확인하였다.

시추공 온도자료를 이용한 고기후 연구에 대한 개관 (A Review on the Paleoclimate Change Inferred from Borehole Temperatures)

  • 이영민;김형찬;송윤호
    • 자원환경지질
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    • 제39권1호
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    • pp.95-102
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    • 2006
  • 19세기말부터 진행된 지구온난화를 규정하기 위해서는 기상관측목적의 지표대기온도(Surface air temperature; SAT) 측정이 시작된 19세기말 이전의 온도 자료가 필요하다. 다행히 과거의 지표온도(Ground surface temperature; GST)가 지중으로 전파되어 기록된 시추공 온도자료로 일반적으로 과거 약 1,000년 전까지의 기온변화에 대한 정보를 얻을 수 있다. 시추공 온도자료로부터 복원된 과거의 기온변화의 정보는 19세기말부터 시작된 지구온난화를 규정하고 또한 그 이전에 있었던 소빙하기(Little Ice Age)와 중세온난기(Medieval Warm Period) 같은 기후변화를 알아내는데 유용하게 사용될 수 있다.