• 한국지하수토양환경학회지:지하수토양환경
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• 제14권3호
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• pp.22-31
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• 2009

최근 에너지 위기와 지구 온난화의 영향으로 국내에서 건물의 냉난방에 지열에너지를 비롯한 재생에너지의 사용이 증가하고 있다. 지열히트펌프시스템은 지금까지 지구상에서 가장 환경친화적인 냉난방 공조설비의 하나로 알려져 있다. 그러나 지열히트펌프시스템의 설치 및 운영이 토양 지하수환경에 미칠 수 있는 몇 가지 영향들에 대한 보고가 있다. 이들 영향으로는 주로 지열히트펌프시스템의 부적절한 설치, 운영 및 폐쇄와 관련된다. 본 논문에서는 지열히트 펌프시스템이 토양 지하수환경에 미칠 수 있는 영향에 관하여 고찰하였다.

• 한국지열·수열에너지학회논문집
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• 제15권1호
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• pp.9-17
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• 2019

Reducing global warming potential has become important, and as one of those methods for reducing it, economic evaluation by applying ice thermal storage air conditioning system was performed. The floor area and height of the subject building was assumed $5,000m^2$ and 20 m. Absorption chillerheater system and air source heat pump system was used for comparing to the subject system, and payback period method was used to perform economic evaluation. Although the running cost of ice thermal storage system is reduced compared to two systems, the ratio is not significant compared to the increase of initial construction expenses, and payback period was calculated to be about 7.7 and 79.3 years. However, the heat storage system should be approached from the viewpoint of long term rather than the economic standard in the present standard.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 하계학술발표대회 논문집
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• pp.44-44
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• 2007

• 한국지열·수열에너지학회논문집
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• 제4권2호
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• pp.1-7
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• 2008

GSHP(Ground Source Heat Pump) has been extensively disseminated due to the recent increasing demand over new and renewable energy. However, the system reliability has been key issues and barriers to insure a better system performance as designed originally in ISO (international standard organization) standard. This paper introduces a systematic method to verify its intended design target so called as ISO performance data based commissioning technology for a water to air GSHP system. The commissioning technology starts from are to the international standard ISO performance data of a GSHP model and to compare its installed operation data and to calibrate and tune to the target optimum operation parameters. Results indicated that cooling capacity could be raised up to 76.6% from 46.6% from this proposed commissioning technology.

• 자원환경지질
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• 제43권2호
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• pp.197-205
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• 2010

최근 급격한 기후변화가 세계적 또는 국지적으로 발생하고 있으며, 지구온난화에 대한 대책으로 $CO_2$ 저감 기술들이 중요한 해결책으로 여겨지고 있다. 이 기술들에 대한 한 방법으로서 대체에너지를 개발하고 있는 대부분의 국가에서 천부 지하 열에너지 저장 (UTES: underground thermal energy storage)은 신뢰성 있는 냉난방 기술로 적용되어 왔다. 천부의 토양이나 암반, 대수층내 지하수 및 지하공간내 저장된 유체 등의 열 에너지원을 이용하는 지열 시스템은 일반적으로 열에너지의 회복과 저장의 개념을 기반으로 한다. 아직 국내에서는 이러한 기술 개발이 기초적이지만 지속적인 연구들을 수행한다면 보다 친환경적이며 경제성 및 효율이 높은 시스템을 개발할 수 있을 것으로 본다. 국내 지반은 대수층이 전국적으로 분포하고 있으므로 수리지열학적 특성을 활용한 고효율의 시스템 개발이 용이하다. 그러나 UTES에 대한 이해 부족 및 제도적 문제들로 다양한 시스템이 개발되지 못하고 국내에는 90% 이상이 단편적인 폐회로형 지열시스템으로 보급되고 있다. 비효율적인 지열시스템의 보급 확산을 방지하기 위해서는 지반의 수리 지열학적 특성을 반영한 선진화된 UTES 시스템들을 개발할 필요가 있다. 개선된 시스템 보급을 위하여 국제적인 협력이 필수적이며, 지속적인 UTES 연구를 통하여 천부 지열시스템의 효율을 개선시킬 수 있다.

• 설비공학논문집
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• 제23권2호
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• pp.95-102
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• 2011

A ground loop heat exchanger in a ground source heat pump system is an important unit that determines the thermal performance of a system and its initial cost. A proper design requires certain site specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This study was performed to investigate the effect of some parameters such as borehole lengths, various grouting materials and U tube configurations on ground effective thermal conductivity and borehole thermal resistance. In this study, thermal response tests were conducted using a testing device to 9 different ground loop heat exchangers. From the experimental results, the length of ground loop heat exchanger affects to the effective thermal conductivity. The results of this experiment shows that higher thermal conductivity of grouting materials leads to the increase effective thermal conductivity from 22 to 32%. Also, mounting spacers have increased by 14%.

• 한국지열·수열에너지학회논문집
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• 제6권2호
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• pp.9-14
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• 2010

The ground source heat pump system is increasingly being considered as an alternative to traditional heating and cooling systems to reduce the emission of ground house gases. In this paper, A series of numerical analysis for energy piles has been performed focusing on heat transfer efficiency, performance and thermal stress. Results of numerical analyses for the W-shape type shows more efficient heat exchange transfer than the coil type. From results of the thermo-mechanical analysis, it is shown that the concentration of thermal stress occurs around the circulating pipe and the interfaces between different materials. The largest deformation caused by thermal stress is observed in the energy pile.

• KIEAE Journal
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• 제17권3호
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• pp.119-124
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• 2017

Purpose: Groundwater heat pump (GWHP) system has high coefficient of performance than conventional air-source heat pump system and closed-loop type geothermal system. However, there is problem in long-term operation that groundwater raise at the diffusion well and reduced at the supply well. Therefore, it is necessary to accurately predict the groundwater flow, groundwater movement and control the groundwater level in the wells. In this research, in consideration of hydrogeological characteristic, groundwater level and groundwater movement were conducted analysis in order to develop the optimal design method of the two-well system using the pairing pipe. Method: For the optimum design of the two-well system, this research focused on the design method of the pairing pipe in the simulation model. Especially, in order to control the groundwater level in wells, pairing pipe between the supply well and diffusion well was developed and the groundwater level during the system operation was analyzed by the numerical simulation. Result: As the result of simulation, the groundwater level increased to -2.65m even in the condition of low hydraulic conductivity and high pumping flow rate. Consequently, it was found that the developed system can be operated stably.

• 한국지열·수열에너지학회논문집
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• 제18권3호
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• pp.1-6
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• 2022

Ground source heat pump (GSHP) system is highly efficient and environment-friendly and supplies heating, cooling and hot water to buildings. For an optimal design of the GSHP system, the ground thermal properties should be determined to estimate the heat exchange rate between ground and borehole heat exchangers (BHE) and the system performance during long-term operating periods. However, the process increases the initial cost and construction period, which causes the system to be hindered in distribution. On the other hand, much research has been applied to the artificial neural network (ANN) to solve problems based on data efficiently and stably. This research proposes the predictive performance model utilizing ANN considering local characteristics and weather data for the predictive performance model. The ANN model predicts the entering water temperature (EWT) from the GHEs to the heat pump for the modular GHEs, which were developed to reduce the cost and spatial disadvantages of the vertical-type GHEs. As a result, the temperature error between the data and predicted results was 3.52%. The proposed approach was validated to predict the system performance and EWT of the GSHP system.

• 한국지열·수열에너지학회논문집
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• 제18권4호
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• pp.45-57
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• 2022

The Ministry of National Defense of the Republic of Korea is showing a lot of interest in net zero-energy buildings (NZEBs) to reduce energy consumption of military facilities and to promote green growth policy in military sector. The application of building passive technologies and renewable energies is essential to achieving NZEBs. This paper analyzed energy performance and energy cost on the conventional heating and cooling system (baseline scenario) and three different alternative scenarios (ALT 1, ALT 2 and ALT 3) applied in a hypothetical military building. A building modeling and simulation software (DesignBuilder V6.1) with EnergyPlus calculation engine was used to calculate the energy consumption for each scenario. Overall, when the GSHPs are applied to both space airconditioning and domestic hot water (DHW) production, Alt-2 and Alt-3, the amount of energy consumption for target building can be greatly reduced. In addition, when the building envelope performance is increased like Alt-3, the energy consumption can be further reduced. The annual energy cost analysis showed that the baseline was approximately 161 million KRW, while Alt-3 was approximately 33 million KRW. Therefore, it was analyzed that the initial construction cost increase could be recovered within about 6.7 years for ALT 3. The results of this study can help decision-makers to determine the optimal strategy for implementing GSHP systems in military buildings through energy performance and initial construction cost assessment.