• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.613-616
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• 2008

Assessment of geothermal resources like other earth resources is a starting point for decision makers or stakeholders to set up basic plan on its development and R&D policies. In this context, there have been various works on world geothermal assessment, to report different estimates from each other. In this paper, we first introduce the definition of geothermal potential mainly adopted from the article by Muffler and Cataldi (1978) and then summarize the estimates made so far referring the work by Bertani (2003). An updated estimates by Stefansson (2005) are also reviewed in terms of identified resources separately for high-temperature resources for power generation and low-temperature ones for direct-use. Recent estimate of US geothermal resources by MIT (2006) using a volumetric method with extensively accumulated data base is discussed. Finally, we introduce the first geothermal assessment in Korea recently made and discuss its importance.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.23-31
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• 2011

The objectives of this study are to analyze the performance of a heat pump system with the various heat source and to carry out economic assessment for the heat pump system. The COP of the river water and ground source heat pump system was 20% higher than that of the air source heat pump system because river water and geothermal provide stable operating temperature compared with air temperature throughout the year. In addition, the economic assessment of a heat pump system using air, river water, and geothermal as a heat source was carried out. The ratio of the life cycle operating cost to the life cycle cost increased with the increase of building capacity. The payback period was found to be less than 3.3 and 4.5 years, respectively when the capacity of the river water and ground source heat pump was larger than 10 RT.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.588-591
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• 2009

Ground source heat pump system; GSHPs is close to most practical use for early stage investment cost and energy efficiency in new renewable energies, and currently considered utilizing to the heat and cooling system of a building. Particularly, the case to utilize 'Standing Column well heat source gathering method' in the open standards process to have the excellent capability of gathering geothermal source is increased. But the research for the optimal design technology and the assessment of a pollution level of the ground to utilize a single well for gathering geothermal is insignificant and the design is insufficient. The heating and cooling system and the equipment to utilize a large size residential development to have over 1000 households have not developed yet. Therefore, our company developed 'geothermal hybrid system' which can construct the heat and cooling system using geothermal energy for a large size residential development of over 1000 households and conducted the evaluation of economic feasibility. Moreover we developed automatic equipment for gathering geothermal source and PLC (Programmable logic controller) to have optimal efficiency and FCU (fan coil unit) considering the floors of large size apartments.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.617-620
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• 2008

지열에너지는 지구 내부의 깊은 곳에서부터 발생하는 열과 상부 지각에서 방사성 동위원소의 붕괴에 의한 열에 의해 발생한다. 지열에너지는 다른 신재생에너지(수력, 풍력, 태양력, 조력, 바이오 매스등)에 비하여 가동효율이 높고, 지속가능한 재활용 자원으로 경제적 효율성이 높아 전 세계적으로 활용도와 잠재성이 높은 신재생에너지의 하나로 각광 받고 있다. 따라서, 지열에너지의 사용은 화석 연료 사용의 상당부분을 대체할 수 있고, 온실가스의 배출도 줄일 수 있다. 현재 우리나라의 지열에너지 이용은 저온성 지열에너지를 이용한 냉난방에 국한되어 있지만, 앞으로의 지열에너지 이용은 Enhanced Geothermal System(EGS) 을 이용한 지열에너지 개발에 초점이 맞추어질 것이다. 현재의 지열에너지 개발을 용이하게 하고, 또한 미래의 지열에너지 개발에 대비하여 우리나라의 이용가능한 지열에너지 부존량을 파악하기 위해 본 연구를 수행하였다. 연구 수행에는1560개 열물성 자료(밀도, 비열, 열전도도), 353개 지표 지열류량 자료, 180개 열생산율 자료와 54개의 지표온도 자료가 사용되었다. 우리나라의 지표에서부터 1 km 깊이 간격별로 5 km 깊이까지 지열에너지 부존량을 산출한 결과 지표에서 부터 5 km 깊이까지의 추출 가능한 지열에너지의 총 부존량은 $1.01{\times}10^{23}$ J로 산출되었다. 지열에너지 부존량을 Toe(석유환산톤) 로 환산하면 $2.40{\times}10^{12}$ Toe 가 된다. 추출한 지열에너지 자원의 2%를 사용한다고 가정 했을때 약 480억 Toe 이다. 이는 2006년 우리나라 전체 1차 에너지 총 소비량(2.33억 Toe)을 고려 했을때 약 200년 동안 사용할 수 있는 양이다.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.4
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• pp.14-20
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• 2017

Refrigerant having high global warming potentials will be phased out due to environmental protection issues. R410A has been widely used in geothermal heat pump. However, it has a little high GWP by 2088 value. One of the recommended substitute for R410A refrigerant is R452B which having a GWP by 698 value. In this paper, the heating and cooling performance of the water-to-water geothermal heat pump unit with R452B was experimentally investigated. The performance of the heat pump adopting R452B was also compared with the system applying R410A. The heating and cooling capacity of R452B heat pump system showed a slightly lower values within 2% comparing with R410A system. However, the R452B system's coefficient of performance was enhanced by 5.2% and 13.7% at heating and cooling mode, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.47-56
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• 2015

Energy consumption in buildings is currently a real problem. That is why both assessment of energy performance and effective energy management including renewable energy system are essential. Thus, this paper focuses on a case study to analyze the energy performance and cooling & heating energy saving of a large scale shopping store in Daejeon city. The reference building is simulated by using TRNSYS dynamic simulation tool to examine its annual energy consumption. For annual energy analysis of building, one year energy consumption is surveyed in the field. The related study is carried out in large scale shopping store to investigate the energy consumption and energy use trend of heating, cooling, hot water, lighting, ventilation, equipments and other. The evaluation of energy performance of the geothermal heat pump system installed in a large scale shopping store is also analyzed by TRNSYS tool. From simulation results, it evaluated that the geothermal heat pump system is effective energy savings method in large scale shopping store.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.2
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• pp.16-21
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• 2017

In this study, the flow effect of warming and cooling in the air supply of a pit for air conditioning were evaluated in BS art museum. We simulated the flow temperature for a pit winter and summer seasons using computational fluid dynamics. Consequential, energy saving, energy saving costs and initial payback periods were calculated and the following conclusions were drawn. The warming effect of the winter increased by $18.1^{\circ}C$ and $0.2^{\circ}C/m$ and the cooling effect of the summer decreased by $6.1^{\circ}C$ and dropped to $0.07^{\circ}C/m$. Energy saving appeared to be 19.1 kW in the summer and 54.3 kW in winter. Energy saving costs ranged from 2,567,119 won/year to 5,134,238 won/year and at minimum, initial payback period for initial investment was 3.9 years. As a result, the air supply system using an existing pit without any burden on initial investment costs is believed to contribute to energy saving through warming and cooling of unutilized energy effects.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.144-144
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• 2011

We have estimated power generation potential in Korea following the recently announced EGS protocol. According to the protocol, we calculated the theoretical potential first, which assumes 30 year operation, minimum temperature being surface temperature+$80^{\circ}C$, depth range being from 3 km to 10 km. In this new assessment the in-land area was digitized by 1' by 1' blocks, which is much finer than suggestion of the protocol (5'by 5'). Thus estimated theoretical potential reaches 6,975 GWe which is 92 times of the total power generation capacity in 2010. In the estimation of technical potential, we limited the depth range down to 6.5 km, assumed recovery factor as 0.14 and also counted for temperature drawdown factor of $10^{\circ}C$ following the protocol. Accessible in-land area excluding steep mountains, residence and industrial region, wet area and others covers 40.7% of total area. Finally, we could come up with 19.6 GWe for technical potential, which would be 56 GWe if we do not account for the temperature drawdown factor. These are important results in that we made the first potential assessment for geothermal power generation.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.1
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• pp.7-13
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• 2014

This study intends to analyse the economical aspect of a GSHP(Ground Source Heat Pump) system compared to the conventional system which is consisted with a boiler and a chiller. This study has simulated four systems in Incheon. It developed and analyzed for applications in a residential and an office building which was based on the hourly EPI(Energy Performance Index, $kWh/m^2yr$). Case 1 is utilizing a boiler and a chiller to meet heating and cooling demand of a house. Case 2 is utilizing the same conventional set up as Case 1 of a office. Case 3 is summation of Case 1(house) and 2(office) systems and loads. And Case 4 is utilizing a GSHP to meet the combined loads of the house and office. The method of the economic assessment has been based on IEA ECBCS Annex 54 Subtask-C SPB(Simple Payback) method. The SPB calculated the economic balanced year of the alternative system over the reference system. The SPB of the alternative systems (GSHP) with 10%, 30% and 50% initial incentive has been calculated as 9.38, 6.72 and 4.06 year respectively while the SPB without initial incentive of systems was 10.71 year.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.485-488
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• 2007

Riverbank filtration is a kind of artificial aquifer recharge for the fresh water supply. By construction of several production wells penetrating the riverbank, surface water withdrawn from the river would pass riverbed. This extracted water is well known to be cooler than surface water in summer and warmer than surface water in winter, showing more constant water temperature. This characteristic of extracted water is applied to geothermal energy utilization. Prediction of the annual temperature variation of filtrated water is the major concern in this study. In Daesan-myeon, Changwon-si, Gyeongsangnam-do, South Korea, riverbank filtration facility has been on its operation for municipal water supply and thermal energy utilization since 2006. Appropriate hydraulic and thermal properties were estimated for flow and heat transfer modeling with given pumping rate and location. With the calibrated material properties and boundary conditions, we numerically reproduced measured head and temperature variation with acceptable error range. In the numerical simulation, the change of saturation ratio and river stage caused by rainfall was calculated and the resulting variation of thermal capacity and thermal conductivity was considered. Simulated temperature profiles can be used to assess the possible efficiency of geothermal energy utilization using riverbank filtration facility. Influence of pumping rate, pumping location on the extracted water temperature will be studied.