• 제목/요약/키워드: Unused energy sources

검색결과 23건 처리시간 0.022초

미이용 산림바이오매스 공급에 있어 수확벌채의 원목 혼입량 추정 (Estimation of the Amount of Round Wood in Unused Forest Biomass Reporting in Forest Clearing)

  • 양지윤;이재정;정한섭;한상훈;이수민
    • 신재생에너지
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    • 제18권4호
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    • pp.70-78
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    • 2022
  • To respond to global warming, there is an increasing interest in eco-friendly alternative energy sources. Therefore, unused forest biomass that has been neglected due to a lack of marketability is attracting attention. With the introduction of the "unused forest biomass certification system" in 2019, ways of determining quantity of unused forest biomass have steadily increased. However, there have been reported cases whereby unused forest biomass weighed more than the amount of harvested trees. It was found that it was possible that forest resources that can be used as round wood were mixed with unused forest biomass. In this context, this study aimed to estimate the amount of mixed round wood in the unused forest biomass supply. The relative expression of growing stock/ha versus the amount of final clearing/ha collected was modeled (y=1.490x-94.341, R2=0.861). As a result, it was found that round wood was mixed into the unused forest biomass, contributing to the disparity observed between the weighted forest biomass and the amount of trees harvested. In conclusion, proper declaration and certification procedures should be carried out for the use of forest resources and promoting unused forest biomass usage.

배관 재질 및 길이에 따른 대규모 시설원예단지용 미활용 에너지 시스템의 성능 평가 (Effects of Pipe Network Materials and Distance on Unused Energy Source System Performance for Large-scale Horticulture Facilities)

  • 이재호;윤여범;현인탁;이광호
    • KIEAE Journal
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    • 제14권4호
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    • pp.119-125
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    • 2014
  • This study investigated the effects of pipe network materials and distance on system performance utilizing unused energy sources in large-scale horticulture facility. For this, the modeling was performed with a 100 m long and 100 m wide rectangular shaped glass house having an area of 1ha ($10,000m^2$) using EnergyPlus software. The heat sources considered were air source, geothermal heat, power plant waste heat, sea water heat, and river water. The temperature variation of the fluid with regard to pipe material and distance from the heat source and the resultant heat pump electricity consumptions were calculated. It turned out that the fluid temperature reaching the heat pump increased as the distance from the heat source increased in case of sea water and river water, which have higher temperatures than the surrounding soil, improving the heat pump efficiency. It was vice versa in case of the power plant waste heat. In addition, pipe material of PVC showed the smallest effect on the system performance variation due to the lowest thermal conductivity, compared to PB and HDPE.

열교환기 용량변화에 따른 하천수열원 열펌프의 성능 변화 (Performance Variations of River Water Source Heat Pump System According to Heat Exchanger Capacity Variations)

  • 박성룡;백영진;김희환;이영수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1530-1535
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    • 2003
  • The utilization of unused energy is important because it can afford to offer a chance to increase energy efficiency of a heat pump system. One of the promising unused energy sources is river water. It can be used as a heat source in both heating and cooling effectively with its superior features as a secondary working fluids. In this study, the performance of a 5HP heat pump system using river water as a heat source is investigated by both experiment and simulation. According to system simulation results, performance improvement of condenser seems more effective than that of evaporator for better $COP_H$. The serial connection is also preferred among several methods to improve plate type heat exchanger performance. The experimental results show that the hot water of $50{\sim}60^{\circ}C$ can be acquired from water heat source of $5{\sim}9^{\circ}C$ with $COP_H$ of $2.7{\sim}3.5$.

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도시 내 지역난방 Heat Pump용 잠재열원 이용에 관한 연구 (A Study on the Utilization of potential heat sources for Heat Pumps to District Heating System in Urban)

  • 오광민;김래현
    • Korean Chemical Engineering Research
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    • 제56권6호
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    • pp.841-855
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    • 2018
  • 본 연구는 도시 내 지역난방 공급지역에 존재하는 Heat Pump용 가용 잠재적 열원을 추정하고자 하였다. 미활용에너지 잠재량은 Open source 기반의 자료를 바탕으로 추정 통합하였다. 특히 수도권 남부에 위치한( 평택시) DH network 내에 대형마트와 공공사우나 시설에 대해 회수 가능한 열에너지 밀도와 열원 지역의 열 수요에 대해 지리적인 공간 분석을 수행하였다. 연구 결과, 연구 대상 DH network 지역에서는 대형마트와 공공사우나 두 가지 열원에 대해 총 1,741.7 toe/year 수준의 잠재 에너지량을 보유하고 있었다. 이 중 57.8%에 해당하는 1,006.9 toe/year를 지역난방용으로 연계할 수 있을 것으로 추정 되었다. 대형마트는 연면적과 에너지 사용량이 0.4937의 양의 상관관계를 보였다. 회수 가능한 에너지 원단위는 상관관계계수를 반영하여 연면적 당 $0.0017toe/m^2$, 저감 가능한 온실가스 배출량은 $0.0069tCO_2/m^2$로 분석되었다. 또한, 공공사우나는 실증사례와 이론 계산 값을 비교하여, 80% 수준의 보수적 추정으로 목욕장 면적당 $0.0315toe/m^2$가 회수 가능한 에너지 원단위로 분석되었으며, 저감 가능한 온실가스 배출량은 $0.1183tCO_2/m^2$로 분석되었다. 이 지역의 총 잠재 에너지량은 행정 구역별 공동주택의 열 수요와 0.5272의 양의 상관관계를 갖고 있었으며, 특히 교통과 상업 중심 지구에서 상대적으로 높은 잠재 에너지량을 가지고 있음을 확인 하였다.

식물-미생물전기화학 기반의 미활용 에너지 회수 기초 연구 (Basic Study for Harvesting Unused Energy based on Plant-Microbial Electrochemical Technology)

  • 유재철;신춘환
    • 한국환경과학회지
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    • 제28권2호
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    • pp.219-224
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    • 2019
  • In this study, we evaluated the energy production from plant-microbial fuel cells using representative indoor plants, such as Scindapsus aureus and Clatha minor. The maximum power density of microbial fuel cell (MFC) using S. aureus ($3.36mW/m^2$) was about 2 times higher than that of the MFC using C. minor ($1.43mW/m^2$). It was confirmed that energy recovery is possible using plant-MFCs without fuel. However, further research is needed to improve the performance of plant-MFCs. Nevertheless, plant-MFCs have proved their potential as a novel energy source to overcome the limitations of the conventional renewable energy sources such as wind power and solar cells, and could be employed to a power source for the sensor in charge of the fourth industrial revolution.

에너지 하베스팅을 위한 열전발전 기술의 경제적 타당성 평가 (Economic feasibility of thermoelectric power generation technology for energy harvesting)

  • 문지홍;황정호;양창원;이은도
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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    • pp.323-323
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    • 2015
  • In recent years, increasing concerns of environmental issues of global warming and limitations of conventional energy resources have resulted in extensive researches into energy harvesting from unused energy. Thermoelectric generation (TEG) is a promising technology for waste heat to power, and various kinds of applications are possible if a waste heat source meets the requirements of TEG operation. In terms of commercialization, economic feasibility is important for an emerging technology like TEG. In this study, economic analysis was conducted for the application of TEG on various sources of waste heat.

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온배수를 열원으로 활용하는 생태산업단지 조성에 관한 기초 연구 (Basic study on Eco-industrial Park utilizing thermal effluents as heat source)

  • 김동규;강대석;정용현
    • 수산해양교육연구
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    • 제21권3호
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    • pp.400-408
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    • 2009
  • The purpose of this study is to know the concept of Eco-industrial Park and How to use the thermal effluents from power plants. Thermal effluents, which use sea water for cooling, from power plants have been discharged with about $6{\sim}7^{\circ}C$ higher temperature than near sea area. Therefore, it could effect on the marine ecosystem as a external pressure factor that increase the artificial thermal load in near sea area. The applications of thermal effluents had been surveyed through the several internal and external cases for utilizing heat sources and reducing the thermal load. As the precedence research for applying, the amount of heat sources of thermal effluents was evaluated. When the thermal effluents was fully applied in heat sources and available heat, assume that use heating season by 12 hours a day of demanded available heat, it was possible to calculate total 198 Tcal of energy saving.

열전발전용 Bi-Te module에서 미끄럼에 따른 열응력 완화 특성 (A Effect of Fluid-assisted Sliding on Stress Relaxation of Bi-Te Modules in Thermoelectric Generation System)

  • 서창민;우병철
    • 한국해양공학회지
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    • 제14권4호
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    • pp.62-97
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    • 2000
  • Recently the research for utilization of waste heat produced from electric power plants, casting factories, heat treating factories or commercial are being afforded by the need for energy saving. The objective of this study is to develop a thermoelectric generation system which unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper a thermoelectric technology on a optimum system design method and efficiency and cost effective thermoelectric element on order to extract the maximum power output from energy conversion of waste energy. It is shown that the longitudinal stresses of module contacted with two point constrained Al tubes could be released more than those with a one-point constrained.

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열전발전용 Bi-Te Module에서 미끄럼에 따른 열응력 완화 특성 (A Characteristic of Fluid-Assisted Sliding on Stress Relaxation of Bi-Te Modules in Thermoelectric Generation System)

  • 우병철;이희웅
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권1호
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    • pp.12-18
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    • 2003
  • Recently the research for utilization of waste heat produced from electric power plants, casting factories, heat treating factories or commercial building are being afforded by the need for energy saving. The objective of this study is to develop a thermoelectric generation system which converts unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper presents a thermoelectric technology on a optimum system design method and efficiency and cost effective thermoelectric element on order to extract the maximum power output from energy conversion of waste energy. It is shown that the longitudinal stresses of module contacted with two point constrained AI tubes could be released more than those with a one-point constrained.

광대역 압전 에너지 하베스팅 기술 (Broadband Piezoelectric Energy Harvesting Technology)

  • 이동규;이연정;송현철
    • 세라미스트
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    • 제22권1호
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    • pp.56-69
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    • 2019
  • Recent advances in low-power sensors and transmitters are driving the search for standalone power sources that utilize unused ambient energy. These energy harvesters can alleviate the issues related to the installation and maintenance of sensors. Particularly piezoelectric energy harvesters, with the ability to convert ambient mechanical energy into useful electricity, have received significant attention due to their high energy density, low cost and operational stability over wide temperature and pressure conditions. In order to maximize the generated electrical power, the natural frequency of the piezoelectric energy harvester should be matched with the dominant frequency of ambient vibrations. However, piezoelectric energy harvesters typically exhibit a narrow bandwidth, thus, it becomes difficult to operate near resonance under broadband ambient vibration conditions. Therefore, the resonating of energy harvesters is critical to generate maximum output power under ambient vibration conditions. For this, energy harvesters should have broadband natural frequency or actively tunable natural frequency with ambient vibrations. Here, we review the most plausible broadband energy harvesting techniques of the multi-resonance, nonlinearity, and self-resonance tuning. The operation mechanisms and recent representative studies of each technique are introduced and the advantages and disadvantages of each method are discussed. In addition, we look into the future research direction for the broadband energy harvester.