• 한국지열·수열에너지학회논문집
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• 제16권1호
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• pp.17-25
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• 2020

Ground-coupled heat pump (GCHP) systems have become an efficient alternative to conventional cooling and heating methods due to their higher energy using efficiency. Although some experimental and simulation works related to performance analysis of GCHP systems for commercial buildings have been done, relatively little has been reported on the performance evaluation of GCHP systems for school buildings. The purpose of this simulation study is to evaluate the performance of a hypothetical GCHP system for a school building in Seoul. We collected various data of building specifications and construction materials for the building and then modeled to calculate hourly building loads with SketchuUp and TRNSYS V17. In addition, we used GLD (Ground Loop Design) V2016, a GCHP system design and simulation software, to design the GCHP system for the building and to simulate temperature of circulating water in ground heat exchanger. The variation of entering source temperature (EST) into the system was calculated with different prediction time and then each result was compared. For 20 years of prediction time, EST for baseline design (Case A) based on the hourly simulation results were outranged from the design criteria.

• 설비공학논문집
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• 제18권3호
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• pp.279-286
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• 2006

The present study concerns the annual performance evaluation of a hybrid-renewable energy system with geothermal and solar heat sources for hot water, heating and cooling of the residential buildings. The hybrid energy system consists of ground source heat pump of 2 RT for cooling, solar collectors of $4.8m^2$, storage tank of 250 liters and gas fired backup boiler of 11.6 kW. The averaged coefficients of performance of geothermal heat pump system during cooling and heating seasons are measured as 4.1 and 3.5, respectively. Also solar fraction for hot water is measured as 35 percent. Overall, the results shows that the hybrid-renewable energy system satisfactorily operated under all climatic conditions.

• 한국지반환경공학회 논문집
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• 제8권3호
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• pp.11-18
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• 2007

본 연구에서는 파급효과가 큰 공동주택에서 지열 냉난방 시스템의 경제성을 아파트 분양평형, 운전시간, 냉난방 및 급탕 설치형태별로 구분하여 초기 공사비 증가, 운전비 절감액, 초기 투자비 회수기간등을 산정하였다. 냉난방 및 급탕 운전시간이 많을수록 초기 공사비 증가액에 비해 운전비용 절감액이 커 초기 투자비 회수기간이 단축되었다. 전용면적이 클수록 투자회수 기간이 길었으며 냉난방 및 급탕 설치형태에서는 냉난방을 지열원, 급탕을 폐열회수한 경우가 초기 투자 회수기간이 가장 짧았다. 기존 시스템(패키지 에어콘, LNG 난방 및 급탕)에 비해 냉난방, 급탕을 모두 지열로 이용하는 경우, 냉난방은 지열, 급탕은 폐열을 이용하는 경우, 냉난방은 지열, 급탕은 LNG인 경우에 공사비가 $m^2$당 각각 약 72,000원, 66,900원, 62,300원 정도 증가하였다.

• 신재생에너지
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• 제3권4호
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• pp.31-37
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• 2007

Because of their low operating and maintaining costs, ground-source heat pump(GSHP) systems are an increasingly popular choice for providing heating, cooling and water heating to public and commercial buildings. Despite these advantages and the growing awareness, GSHP systems to residential sectors have not been adopted in Korea until recently. A feasibility study of a residential GSHP system was therefore conducted using the traditional life cycle cost(LCC) analysis within the current electricity price framework and potential scenarios of that framework. As a result, when the current residential electricity costs for running the GSHP system are applied, the GSHP system has weak competitiveness to conventional HV AC systems considered. However, when the operating costs are calculated in the modified price frameworks of electricity, the residential GSHP system has the lower LCC than the existing cooling and heating equipments. The calculation results also show that the residential GSHP system has lower annual prime energy consumption and total pollutant emissions than the alternative HVAC systems considered in this work.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.515-518
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• 2007

Because of their low operating and maintaining costs, ground-source heat pump(GSHP) systems are an increasingly popular choice for providing heating, cooling and water heating to public and commercial buildings. Despite these ad- vantages and the growing awareness, GSHP systems to residential sectors have not been adopted in Korea until recently. A feasibility study of a residential GSHP system was therefore conducted using the traditional life cycle cost(LCC) analysis within the current electricity price framework and potential scenarios of that framework. As a result, when the current residential electricity costs for running the GSHP system are applied, the GSHP system has weak competitiveness to conven- tional HVAC systems considered. However, when the operating costs are calculated in the modified price frameworks of electricity, the residential GSHP system has the lower LCC than the existing cooling and heating equipments. The calculation results also show that the residential GSHP system has lower annual prime energy consumption and total pollutant emissions than the alternative HVAC systems considered in this work.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.439-444
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• 2002

Geothermal or ground source heat pumps(GSHPs) are electrically powered systems that take advantage of the earth's relatively constant temperature to provide heating, cooling, and hot water for homes and commercial buildings. The buried pipe, or ground loop, is the most recent technical advance in heat pump technology. The idea to bury pipe in the ground to gather heat energy began in the 1940s. Only recently, however, have new heat pump designs and improved buried pipe materials been combined to make GHP systems the most efficient heating and cooling systems available. The aim of the study is application of the GSHP system in korea. Our environments for economy, politics and society are different from other countries. For a case, the progressive tax rate of home electricity is represented.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.460-465
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• 2007

유출지하수는 지하공간이 깊고 넓게 분포하는 건물에서 자연적으로 유출되어 배출되는 낮은 심도의 지하수이다. 본 연구에서는 신축된 교회건물에서 유출되는 지하수를 열원으로 밀폐형태와 개방형태의 열교환기를 활용하여 각각 5RT급 히트펌프시스템을 난방모드로 운전한 결과를 정리하였다. 실험은 난방순환수의 온도를 $43{\sim}49$ $^{\cdot}C$ 범위에서 제어하면서 진행하였으며, 시스템 COP에 있어서 밀폐형은 $4.12{\sim}4.75$, 개방형은 $3.42{\sim}3.98$의 범위에서 측정되었다. 이는 기존의 지열히트펌프시스템의 COP와 대동 소이한 우수한 성능이라고 판단된다. 또한 펌프동력을 제외한 히트펌프 자체 난방COP에 있어서 밀폐형은 $4.69{\sim}5.81$, 개방형은 $4.38{\sim}5.43$의 범위에서 나타났다. 유출지하수의 온도가 겨울철에도 약 $12{\sim}14^{\cdot}C$를 유지하므로 히트펌프와 시스템전체의 COP가 매우 우수한 값을 나타내고 있음이 확인되었다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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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.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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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.

• 신재생에너지
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• 제2권2호
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• pp.86-93
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• 2006

유출지하수나 지표수를 열원으로 지열히트펌프의 지초자료로 활용하기 위하여 Pond Loop형 열교환기를 설계, 제작하여 유동이 없는 수조 내에서 수조의 온도가 변화함에 따라 일정한 열교환기 입구온도를 유지하면서 열전달량을 측정하였다. 그 결과 수조를 Heat Source로 사용하는 경우 $5,500{\sim}4,500kcal/h$의 열량이 전달되었고 수조를 Heat Sink로 사용할 경우 $5,200{\sim}3,500kcal/h$의 열량이 전달되었다. 또한 열교환기 관내 유속이 증가함에 따라 열전달량이 증가하는 경향성을 확인할 수 있었고 이는 동시에 열교환기 입출구의 차압을 증가시킴을 알 수 있었다. 열교환기의 설계단계에서 사용하였던 열전달관계식으로 구한 총괄열전달계수, U와 실험값을 통해 유추한 U값을 비교한 결과 실험에 의해 유추된 U값이 $24{\sim}27%$ 설계치보다 크게 나타났다. 본 연구를 통하여 유출지하수 뿐만 아니라 하수 및 하천수를 이용한 지열히트펌프의 기초자료를 확보할 수 있었다.