• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1497-1502
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• 2009

The present study has been conducted economic analysis of heat storage type ground source heat pump system(HSGSHP) and normal ground source heat pump (GSHP) and central boiler system with individual air conditioning facility which are installed at the same building in the shared an apartment house. Cost items, such as initial construction cost, annual energy cost and maintenance cost of each system are considered to analyze life cycle cost (LCC) and simple payback period (SPP) with initial cost different are compared. The initial cost is a rule to the Government basic unit cost of production. LCC applied present value method is used to assess economical profit of both of them. Variables used to LCC analysis are prices escalation rate and interest rate mean values of during latest 10 years. The LCC result shows that HSGSHP (1,351,000,000won) is more profitable than central boiler system with individual air conditioning facility by 86.7% initial cost. And SPP appeared 8.0 year overcome the different initial cost by different annual energy cost.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.143.2-143.2
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• 2011

Energy foundations and other thermo-active ground structure, energy wells, energy slab, and pavement heating and cooling represent an innovative technology that contributes to environmental protection and provides substantial long-term cost savings and minimized maintenance. This paper focuses on earth-contact concrete elements that are already required for structural reasons, but which simultaneously work as heat exchangers. Pipes, energy slabs, filled with a heat carrier fluid are installed under conventional structural elements, forming the primary circuit of a geothermal energy system. The natural ground temperature is used as a heat source in winter and heat sink in summer season. The system represented very high heating and cooling performance due to the stability of EWT from energy slab. Maximum heat pump unit COP and system COP were 4.9 and 4.3.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.27-32
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• 2008

The present study has been conducted economic analysis of heat storage type ground source heat pump system(HSGSHP) and normal ground source heat pump (GSHP) which are installed at the same building in the shared an apartment house. Cost items, such as initial cost, annual energy cost and maintenance cost of each system are considered to analyze life cycle cost (LCC) and simple payback period (SPP) with initial cost different are compared. The initial cost is a rule to the Government basic unit cost of production. LCC applied present value method is used to assess economical profit of both of them. Variables used to LCC analysis are prices escalation rate and interest rate mean values of during latest 10 years. The LCC result shows that HSGSHP (1,050,910,000won) is more profitable than GSHP by 68.9% initial cost. And SPP appeared 3.0 year overcome the different initial cost by different annual energy cost.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.81-87
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• 2018

Among various types of geothermal heat pump systems, Vertical Closed-Loop Geothermal Heat Pump (VGSHP) has received increasing attention due to a variety of advantages such as the potential to be installed in a relatively small space and improved energy efficiency. In this research, the performance of VGSHP system coupled with heat storage tank was evaluated, by analyzing operational behavior of heat storage tank, the variations of heat pump energy performance due to the connection with heat storage tank, part load ratios characteristics of heat pump and the corresponding energy cost, compared to chiller and boiler based conventional system. The results of this study showed that the VGSHP system coupled with heat storage tank showed an energy saving effect of about 18% for cooling and about 73% for heating, and annual heating/cooling energy cost reduction of 43,000,000 KRW ($ 39,000), compared to the conventional air conditioning system. In addition, after considering both energy cost and initial investment cost including equipment, installation and auxiliary device expenses, payback period of approximately 11.8 years was required.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.143-147
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• 2013

Geothermal energy is easy to take advantage of renewable energy stored in the earth and the heat exchanger can be collected through a heat exchange piping system. In this study, have been developed a heat exchange pipe loop system which it could be installed in tunnel segmental linings to collect geothermal energy around the tunnel. The heat exchange pipe loop system incorporated in the tunnel segments circulate fluid to transport with heat from the surrounding ground and the heat can be used for heating and cooling of nearby structures or districts. The segmental lining incorporating heat exchange pipe loop system are called as ELS (Energy Lining Segment). There are a number of examples incorporating a heat exchange pipe loop system in a tunnel lining in Europe. In this study, a field case using Energy Lining Segment in Germany and applications in urban area are thoroughly examined. In addition, a CFD (Computational Fluid Dynamics) analysis was carried out to investigate heat flow in Energy Lining Segment.

• Journal of the Korean Geotechnical Society
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• v.26 no.2
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• pp.33-43
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• 2010

Geothermal energy is gaining wide attention as a highly efficient renewable energy and being increasingly used for heating/cooling systems of buildings. The standing column well (SCW) is especially efficient, cost-effective, and suitable for Korean geological and hydrological conditions. However, a numerical model that simulates the SCW has not yet been developed and applied in Korea. This paper describes the development of the SCW numerical model using a finite-volume analysis program. The model, through hydro-thermal coupled analyses, simulates heat transfer through advection, convection, and conduction. The accuracy of the model was verified through comparisons with field data measured at SCWs in the U.S. and Korea. Comparisons indicated that the SCW numerical model can closely predict the performance of a SCW. The numerical model was used to perform a comprehensive parametric study in the companion paper.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.511-514
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• 2007

This study was performed to construct a geothermal data base about thermal conductivity of ground heat exchanger and thermal properties of grouting material which used to refill the borehole. We have acquired geothermal data sets from 39 sites over wide area of South Korea except to Jeju island. From data analysis, the range of thermal conductivity is $1.5{\sim}4.0$ W/mK. It means that thermal conductivity varies with grouting material as well as regional geology and ground water system.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1136-1137
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• 2008

교토의정서가 발효된 2005년 이후 온실가스를 감축해야 한다는 요구가 급속도로 증대되고 있다. 더군다나 유류가격이 상승하여 '08. 5월 현재 배럴당 130달러를 육박하고 있으며, 몇몇 경제학자들은 올해 말에 150달러를 상회하는 것이 어렵지 않다고 추측하고 있다. 에너지에 대한 관심이 집중되는 가운데, 관련업계는 태양광, 풍력 등 신재생에너지 개발에 힘을 쏟고 있다. 본 고에서는 신재생에너지를 활용하여 온실가스를 줄일 수 있는 지열원 히트펌프시스템의 적용사례와 축냉설비 보급지원 효과를 분석해 보고자 한다.

• 월간 기계설비
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• no.8 s.205
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• pp.28-37
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• 2007

대한설비건설협회는 지난 1989년 협회 창립 이후 설비건설업계의 영역확대를 위해 분리발주를 숙원사업 중 하나로 정하고 그 동안 관계기관에 건의하는 등 끊임없는 노력을 기울여 왔다. 우리협회의 이러한 노력에 힘입어 대한주택공사를 비롯한 정보통신부, 교육인적자원부 등 주요 발주처 및 발주기관에서 분리발주를 시행하고 있다. 최근들어 기계설비공사는 단순한 기계설비에서 벗어나 쓰레기이송설비, 지열냉난방시스템 등 최첨단 기술을 접목한 다양한 시공으로 확대되고 있다. 이 과정에서 업역에 대한 확고한 규정이 없어서 설비•일반•전문건설업자간 치열한 밥그릇 싸움이 예상되고 있다. 따라서 대한설비건설협회는 이러한 신규분야가 우리 설비건설영역이 될 수 있도록 더욱 박차를 가할 계획이다. 또한 지난 5월 17일 공포된 건설산업기본법 개정(안)에는 2개 공종 이상의 소규모 단순복합공사는 전문건설업자에게 원도급을 허용하는 조항이 들어있다. 이로써 오는 2009년 7월 1일부터는 소규모 단순복합공사의 경우 전문건설업자도 전문면허를 복수로 취득하여 원도급 공사 참여 가능하게 됐으며, 분리발주와 동일한 효력을 갖는다. 본지는 앞으로 분리발주 확대를 위한 각오를 새롭게 다지기 위해 대한설비건설협회의 분리발주를 추진 과정 및 분리발주된 공사현황(10억원 이상, 2002년부터)을 살펴본다.

• Journal of the Korean Geotechnical Society
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• v.32 no.7
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• pp.5-14
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• 2016

The use of geothermal energy has increased for economically and environmentally friendly utilization, and a geothermal heat pump (GSHP) system for space heating and cooling is being used widely. As ground thermal properties such as ground thermal conductivity and ground thermal diffusivity are substantial parameters in the design of geothermal heat pump system, ground thermal conductivity should be obtained from in-situ thermal response test (TRT). This paper presents an experimental study of ground thermal properties of U and 2U type ground heat exchangers (GHEs) measured by TRTs. The U and 2U type GHEs were installed in a partially saturated dredged soil deposit, and TRTs were conducted for 48 hours. A method to derive the thermal diffusivity as well as thermal conductivity was proposed from a non-linear regression analysis. In addition, remolded soil samples from different layers were collected from the field, and soil specimens were reconstructed according to the field ground condition. Then equivalent ground thermal conductivity and ground thermal diffusivity were calculated from the lab test results and they were compared with the in-situ TRT results.