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  • Title/Summary/Keyword: Ground heat source

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Application analysis to a shared apartment house of heat storage type GSHP system with dual storage tank (이중 축열조를 갖는 축열식 지열원 히트펌프시스템의 노인공동주택 적용 분석연구)

  • Park, Jong-Woo;Lee, Sang-Hoon;Cho, Sung-Hwan
    • 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.

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Evaluation of Deployment Barriers to Solar Thermal and Ground Source Heat Pump for Buildings (건물용 태양열과 지열의 보급 장벽 평가)

  • Ilhyun Cho;Jaeseok Lee
    • New & Renewable Energy
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    • v.20 no.1
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    • pp.61-69
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    • 2024
  • This study investigates the barriers to the deployment of solar thermal and ground source heat pump (GSHP) from the perspective of consumers and businesses, as well as evaluates priorities for improving the barriers via expert AHP evaluation. From a consumer's perspective, the overall satisfaction with solar thermal is significantly lower than that with PV and needs to be improved at the installation and use stages. GSHP needs to be improved at the prior-information search stage. From a business perspective, the non-distinction between heat and electricity in mandatory installations in public buildings, the difficulty in assessing the value of heat, and high initial costs impede the deployment. Based on the result of AHP analysis, the priorities for improving the barriers to the wide utilization of solar thermal are evaluated in the order of economic feasibility, policy, acceptability, and technology, where high installation cost is shown to be the greatest barrier. Barriers for GSHP are evaluated in the order of policy, acceptability, economic feasibility, and technology, where policy means improvement is evaluated as the most important factor in promoting the deployment of GSHP.

Application textile-type geothermal heat exchanger for tunnel (텍스타일형 지중열교환기의 터널에서의 적용)

  • Lee, Chul-Ho;Lee, Kang-Ja;Gil, Hu-Jeong;Jeoung, Jae-Hyeung;Choi, Hang-Seok
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.604-607
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    • 2009
  • The geothermal energy have been developed as the pro-environmental and the substantial long-term energy. Recently energy foundations and other thermo-active ground structures have been developed to enhance the use of geothermal energy. In this research, a tunnel wall is focused as a source of geothermal energy. If the tunnel wall can be used for geothermal source, it can provide relatively lower cost because it is not necessary to make a deep borehole like in case of closed-loop vertical ground heat exchanger. For analyzing efficiency of heat exchanger in tunnel, laboratory tests and the numerical analyses are performed.

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A Study on the Thermal Characteristics of Horizontal Ground Heat Exchanger using Thermal Response Test (열응답시험을 이용한 수평형 지중열교환기 열특성 연구)

  • Chang, Keun Sun;Kim, Min-Jun;Kim, Young-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.24-30
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    • 2016
  • Vertical and standing column well ground heat exchangers have mostly been installed for ground source heat pump systems (GSHP) and thermal response tests (TRT) have been applied to evaluate the thermal characteristics for these heat exchangers. In this paper, the TRT coupled with a line source method was applied to evaluate the thermal characteristics of the horizontal ground heat exchanger (HGHX). Load tests of a HGHX were also performed to examine the daily variations of the ground and fluid temperatures associated with the daily intermittent operation of GSHP. For this test, the straight HGHX (depth 2 m, length 50 m, 8 line) was installed in Ansan city. The results showed that the variations of ground thermal conductivity of HGHX during one year were relatively small with the range of 1.431.64W/mK, and the maximum and minimum values appeared in December and May, respectively. Load tests with heat injection rate of 6.0 kW for 10 hours per day to HGHX during twelve days were performed in June, September and December, and resulted in a ground initial temperature rise of 4.31C, 3.14C, and 1.21C during these days, respectively.

Heating Performance of Geothermal Heat Pump System Applied in Cold Climate Region(Mongolia) (한랭지(몽골) 지열 히트펌프 시스템의 난방 성능 분석)

  • Sohn, Byonghu;Choi, Jae Ho;Min, Kyung Chon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.1
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    • pp.31-38
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    • 2015
  • Geothermal heat pump (GHP) systems have become an efficient alternative to conventional cooling and heating methods due to their higher energy using efficiency. These systems use the ground as a heat source in heating mode operation and a heat sink in cooling mode operation. The aim of this study is to evaluate the heating performance of the GHP system for a residential building (420m2) in Ulaanbaatar, Mongolia. In order to demonstrate the feasibility of a sustainable performance of this system, we installed the water-to-water geothermal heat pump with ten vertical ground heat exchangers and measured operation parameters from October 19, 2013 to March 26, 2014. The results showed that the entering source temperature of brine from the ground heat exchangers was in a range of the design target temperature of 10C for heating. For total values of the representative results, the ground heat exchangers extracted heat of 53.51 MWh from the ground. In addition, the GHP system supplied heat of 83.55 MWh to the building and consumed power of 30.27 MWh. Consequently, the average heating seasonal performance factor (SPFh) of the overall system was evaluated to be 2.76 during the measurement period of the heating season.

The Effects of the Installation Conditions of Ground Loop Heat Exchanger to the Thermal Conductivity and Borehole Resistance (지중열교환기 설치 조건이 지중 유효 열전도도와 보어홀 열저항에 미치는 영향)

  • Lim, Hyo-Jae;Kong, Hyoung-Jin;Kang, Sung-Jae;Choi, Jae-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.2
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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%.

Heating Performance Analysis of Building Integrated Geothermal System With Radiant Floor Heating (복사패널이 적용된 건물일체형 지열원 시스템의 난방성능 분석)

  • Jin, Shangzhen;Lee, Jin-Uk;Kim, Taeyeon;Leigh, Seung-Bok
    • Journal of the Korean Solar Energy Society
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    • v.32 no.5
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    • pp.25-30
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    • 2012
  • Ground source heat pumps(GSHPs) are among the most efficient and comfortable heating and cooling technologies currently available, because they use the earth's natural heat to provide heating, cooling, and often, water heating. And Building Integrated Geothermal System(BIGS) is one of GSHPs which install ground heat exchanger(GHE) in energy pile without borehole to save the investment cost. Therefore, the experiment is to evaluate the heating performance of BIGS in Korea. The experimental results indicate that the average heat pump COP and overall system's COP values are approximately 4.4 and 3.0 in one week. This study shows that the BIGS could be used for heating in Korea.

A Study on the Horizontal Ground Source Beat Pump Greenhouse Heating System with Thermal Storage Tank (축열조를 채용한 수평형 지열원 히트펌프 온실 난방 시스템에 관한 연구)

  • Park, Yong-Jung;Kim, Kyoung-Hoon
    • Journal of Energy Engineering
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    • v.15 no.3 s.47
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    • pp.194-201
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    • 2006
  • Greenhouses should be heated during nights and cold days in order to fit growth conditions in greenhouses. Ground source heat pump (GSHP) systems are recognized to be outstanding heating and cooling systems. A horizontal GSHP system with thermal storage tank was installed in greenhouse and investigated the performance characteristics. The reasons for using thermal storage tank were discussed in detail. Thermal storage tank can provide heat for heating load that is larger than GSHP system heating capacity. The results of study showed that the heating coefficient of performance of the heat pump system was 2.69.

Application of the Geothermal Hybrid System for Huge Size Common Structures with Heating & Cooling System (지열 Hybrid System 개발을 통한 대형 공동구조물 지열에너지 적용성 평가)

  • Park, Si-Sam;Na, Sang-Min;Park, Jong-Hun;Rhee, Keon-Joong;Kim, Tae-Won;Kim, Sung-Yub
    • 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.

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

  • Song, Yoon-ho;Kim, Seong-Kyun;Lee, Kang-Kun;Lee, Tae-Jong
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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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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