• 제목/요약/키워드: Energy Storage Device

검색결과 337건 처리시간 0.033초

Self-Supporting 3D-Graphene/MnO2 Composite Supercapacitors with High Stability

  • Zhaoyang Han;Sang-Hee Son
    • 한국전기전자재료학회논문지
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    • 제36권2호
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    • pp.175-185
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    • 2023
  • A hybrid supercapacitor is a promising energy storage device in view of its excellent capacitive performance. Commercial three-dimensional foam nickel (Ni) can be used as an ideal framework due to an interconnected network structure. However, its application as an electrode material for supercapacitors is limited due to its low specific capacity. Herein, we report a successful growth of MnO2 on the surface of graphene by a one-step hydrothermal method; thus, forming a three-dimensional MnO2-graphene-Ni hybrid foam. Our results show that the mixed structure of MnO2 with nanoflowers and nanorods grown on the graphene/Ni foam as a hybrid electrode delivers the maximum specific capacitance of 193 F·g-1 at a current density 0.1 A·g-1. More importantly, the hybrid electrode retains 104% of its initial capacitance after 1,000 charge-discharge cycles at 1 A·g-1; thus, showing the potential application as a stable supercapacitor electrode.

설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제27권7호
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

한국의 그린 비즈니스/IT 실태분석을 통한 추진전략 우선순위 도출에 관한 연구 (Development of Korean Green Business/IT Strategies Based on Priority Analysis)

  • 김재경;최주철;최일영
    • Asia pacific journal of information systems
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    • 제20권3호
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    • pp.191-204
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    • 2010
  • Recently, the CO2 emission and energy consumption have become critical global issues to decide the future of nations. Especially, the spread of IT products and the increased use of internet and web applications result in the energy consumption and CO2 emission of IT industry though information technologies drive global economic growth. EU, the United States, Japan and other developed countries are using IT related environmental regulations such as WEEE(Waste Electrical and Electronic Equipment), RoHS(Restriction of the use of Certain Hazardous Substance), REACH(Registration, Evaluation, Authorization and Restriction of CHemicals) and EuP(Energy using Product), and have established systematic green business/IT strategies to enhance the competitiveness of IT industry. For example, the Japan government proposed the "Green IT initiative" for being compatible with economic growth and environmental protection. Not only energy saving technologies but energy saving systems have been developed for accomplishing sustainable development. Korea's CO2 emission and energy consumption continuously have grown at comparatively high rates. They are related to its industrial structure depending on high energy-consuming industries such as iron and steel Industry, automotive industry, shipbuilding industry, semiconductor industry, and so on. In particular, export proportion of IT manufacturing is quite high in Korea. For example, the global market share of the semiconductor such as DRAM was about 80% in 2008. Accordingly, Korea needs to establish a systematic strategy to respond to the global environmental regulations and to maintain competitiveness in the IT industry. However, green competitiveness of Korea ranked 11th among 15 major countries and R&D budget for green technology is not large enough to develop energy-saving technologies for infrastructure and value chain of low-carbon society though that grows at high rates. Moreover, there are no concrete action plans in Korea. This research aims to deduce the priorities of the Korean green business/IT strategies to use multi attribute weighted average method. We selected a panel of 19 experts who work at the green business related firms such as HP, IBM, Fujitsu and so on, and selected six assessment indices such as the urgency of the technology development, the technology gap between Korea and the developed countries, the effect of import substitution, the spillover effect of technology, the market growth, and the export potential of the package or stand-alone products by existing literature review. We submitted questionnaires at approximately weekly intervals to them for priorities of the green business/IT strategies. The strategies broadly classify as follows. The first strategy which consists of the green business/IT policy and standardization, process and performance management and IT industry and legislative alignment relates to government's role in the green economy. The second strategy relates to IT to support environment sustainability such as the travel and ways of working management, printer output and recycling, intelligent building, printer rationalization and collaboration and connectivity. The last strategy relates to green IT systems, services and usage such as the data center consolidation and energy management, hardware recycle decommission, server and storage virtualization, device power management, and service supplier management. All the questionnaires were assessed via a five-point Likert scale ranging from "very little" to "very large." Our findings show that the IT to support environment sustainability is prior to the other strategies. In detail, the green business /IT policy and standardization is the most important in the government's role. The strategies of intelligent building and the travel and ways of working management are prior to the others for supporting environment sustainability. Finally, the strategies for the data center consolidation and energy management and server and storage virtualization have the huge influence for green IT systems, services and usage This research results the following implications. The amount of energy consumption and CO2 emissions of IT equipment including electrical business equipment will need to be clearly indicated in order to manage the effect of green business/IT strategy. And it is necessary to develop tools that measure the performance of green business/IT by each step. Additionally, intelligent building could grow up in energy-saving, growth of low carbon and related industries together. It is necessary to expand the affect of virtualization though adjusting and controlling the relationship between the management teams.

Investigation of Applying Technical Measures for Improving Energy Efficiency Design Index (EEDI) for KCS and KVLCC2

  • Jun-Yup Park;Jong-Yeon Jung;Yu-Taek Seo
    • 한국해양공학회지
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    • 제37권2호
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    • pp.58-67
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    • 2023
  • While extensive research is being conducted to reduce greenhouse gases in industrial fields, the International Maritime Organization (IMO) has implemented regulations to actively reduce CO2 emissions from ships, such as energy efficiency design index (EEDI), energy efficiency existing ship index (EEXI), energy efficiency operational indicator (EEOI), and carbon intensity indicator (CII). These regulations play an important role for the design and operation of ships. However, the calculation of the index and indicator might be complex depending on the types and size of the ship. Here, to calculate the EEDI of two target vessels, first, the ships were set as Deadweight (DWT) 50K container and 300K very large crude-oil carrier (VLCC) considering the type and size of those ships along with the engine types and power. Equations and parameters from the marine pollution treaty (MARPOL) Annex VI, IMO marine environment protection committee (MEPC) resolution were used to estimate the EEDI and their changes. Technical measures were subsequently applied to satisfy the IMO regulations, such as reducing speed, energy saving devices (ESD), and onboard CO2 capture system. Process simulation model using Aspen Plus v10 was developed for the onboard CO2 capture system. The obtained results suggested that the fuel change from Marine diesel oil (MDO) to liquefied natural gas (LNG) was the most effective way to reduce EEDI, considering the limited supply of the alternative clean fuels. Decreasing ship speed was the next effective option to meet the regulation until Phase 4. In case of container, the attained EEDI while converting fuel from Diesel oil (DO) to LNG was reduced by 27.35%. With speed reduction, the EEDI was improved by 21.76% of the EEDI based on DO. Pertaining to VLCC, 27.31% and 22.10% improvements were observed, which were comparable to those for the container. However, for both vessels, additional measure is required to meet Phase 5, demanding the reduction of 70%. Therefore, onboard CO2 capture system was designed for both KCS (Korea Research Institute of Ships & Ocean Engineering (KRISO) container ship) and KVLCC2 (KRISO VLCC) to meet the Phase 5 standard in the process simulation. The absorber column was designed with a diameter of 1.2-3.5 m and height of 11.3 m. The stripper column was 0.6-1.5 m in diameter and 8.8-9.6 m in height. The obtained results suggested that a combination of ESD, speed reduction, and fuel change was effective for reducing the EEDI; and onboard CO2 capture system may be required for Phase 5.

EcoMon: 에코 드라이빙 모니터링 시스템 (EcoMon: A System for Monitoring Eco-Driving)

  • 한동호;김상철
    • 한국산학기술학회논문지
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    • 제15권11호
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    • pp.6830-6837
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    • 2014
  • 최근 지구 온난화와 에너지 고갈 문제가 심각해지면서, 차량의 에코 드라이빙 (에너지 절약형 운행)에 대한 관심이 높다. 본 논문에서는 ISG(공회전 제한 장치)가 장착된 차량의 공회전 제한 사용과 정속 운전을 모니터링하는 시스템을 제안한다. 본 시스템은 차량 운행 정보 수집용 G/W 장치, 에코 드라이빙 모니터링용 스마트폰 앱 및 서버 시스템으로 구성된다. 본 논문의 주요 기여는 공회전 제한을 포함하는 에코 드라이빙의 모니터링 시스템이 제공해야 할 통합적인 기능, 구조 및 동작 원리를 정의한 것이다. 본 시스템을 통해 사용자는 공회전 제한 시간, 운전 속도, 연료 절감량, CO2 배출량 등을 확인해 봄으로써, 에코 드라이빙을 실천하는 좋은 운전 습관을 가지게 될 것이다. 서버 시스템은 운행 정보를 저장 또는 조회하는 기능을 OpenAPI 형태의 웹 서비스로 제공하여, 다양한 응용들을 쉽게 개발할 수 있는 환경을 제공한다.

에너지 저장장치(ESS)의 비상 유도등 동작을 적용한 순간전압강하 보상장치에 관한 연구 (A Study on the Dynamic Voltage Restorer to Application Luminaire for Emergency Exit Sign Operation to the Energy Storage System)

  • 황락훈;나승권;김진선
    • 한국항행학회논문지
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    • 제19권5호
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    • pp.433-439
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    • 2015
  • 최근 컴퓨터, 전기, 전자, 통신, 반도체 장비 등의 전기적 외란에 민감한 부하 설비의 사용이 증가함에 따라 전력 품질에 대한 관심이 높아지고 있다. 더 나아가서는 정밀 부하 장비들에 가장 빈번하게 발생하는 순간 전압 강하는 전력 품질 향상을 위해 적정한 보상이 필요하게 된다. 이를 위해 전기 이중층 커패시터 (EDLC : electric double layer capacitor)를 사용한 순간전압강하 보상장치가 개발되어 적용되고 있다. 본 논문에서는 순간전압강하 보상장치 (DVR : dynamic voltage restorer)에 사용되는 전기 이중층 커패시터(EDLC)에 비해 동일 사이즈 대비 에너지 밀도가 높은 하이브리드 커패시터 (hybrid capacitor)를 적용하는 연구를 하였고, 또한, 유도등의 비상 전원으로써 10년 이상의 수명을 보증할 수 있는 제품으로 하이브리드 커패시터 (hybrid capacitor)의 적용 가능성을 확인하였다.

에너지 저장장치의 계통 연계형 양방향 PCS 기술 (The grid-connected bidirectional PCS technology of the ESS)

  • 고봉운
    • 전기전자학회논문지
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    • 제23권4호
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    • pp.1280-1287
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    • 2019
  • 계통 연계 형 양방향 PCS 기술은 분산 형 신재생 에너지 스마트 그리드를 구현하기 위한 기술이며, 방대한 스마트 그리드 시스템 중 태양광 모듈로부터 수집된 전력 및 상용 계통전원을 이용하여 상시 전력을 충전하였다가 필요시 저장된 전력을 저압 계통 측으로 방출할 수 있도록 하는 하이브리드형 에너지 저장 장치이다. 이를 위해 MPPT 기능이 포함된 PV입력 전력변환기와 배터리 충·방전을 위한 양방향 전력변환기 및 DC Link 전압을 3상 380V AC 계통으로 출력하고 필요할 경우 계통전력을 AC/DC변환하여 양방향 DC/DC컨버터를 통해 배터리로 충전기능을 수행하는 인버터로 구성된 3개의 전력변환기 구조를 갖는 PCS를 설계 및 개발하였다. 현재 이 시스템을 정전 및 화재사고에 취약한 제주의 사이트에 적용하여 실증 및 운영하고 있다.

모터구동 근거리 이동수단의 배터리성능에 관한 연구 (A Study on Battery Performance of a Motor Driven Local Transportation Vehicle)

  • 고지운;고광수;박윤철
    • Journal of Advanced Marine Engineering and Technology
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    • 제36권4호
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    • pp.430-436
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    • 2012
  • 본 연구에서는 납축전지가 장착된 소형 전기자동차의 여러 가지 주행 특성에 따른 배터리의 전압강하를 실증실험을 통하여 측정하였다. 실험을 통하여 2인승의 소형전기자동차의 에너지 소비량을 평가하고 주행거리 등을 점검하기 위하여 속도별 주행특성과 주행 중에 난방장치를 가동하였을 경우에 감소하는 주행거리를 평가하였다. 전기자동차의 주행속도는 10km/h에서 20km/h씩 증가시키면서 히터의 가동유무에 따른 에너지 소비량을 측정하였다. 실험결과 본 실험용 소형 전기자동차의 에너지효율이 가장 높은 경제속도는 35km/h로 나타났으며, 일회 충전으로 경제속도로 주행할 경우에 약 75km의 거리를 주행할 수 있으며, 일반적인 주행의 경우에는 약 58km를 주행할 수 있다. 또한 난방장치를 최대로 가동할 경우에는 약 35%의 에너지 소비가 증가하는 것을 알 수 있다.

소형 풍력발전 적용 풍력자원조사를 위한 데이터로거 개발 (A Development of Dedicated Data Logger for Wind Resource of Small Wind Power Generator)

  • 윤영천;정문선;김상만;김태곤;문채주
    • 한국태양에너지학회 논문집
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    • 제32권3호
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    • pp.146-152
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    • 2012
  • To install a wind power generator, the survey on the wind environment resources must be conducted in advance. The survey on the wind environment resources is to collect and analyze data regarding the wind speed and direction on a data logger. The data logger consists of a sensor, signal processing circuit and storage device. According to the analysis of the stored data, the amount of power generation by the types of generators can be predicted and the most optimal generator including safety grade can be selected, and in case of installing a generator in the future, it can be utilized as basic data regarding supporting base and foundation construction method of survey points. Data logger was developed for a small wind power generator that is suitable for the international standard(IEC 61400) by using DSP-F28335 micro controller in this paper. It was developed to measure the wind speed of 1 [m/s]~17 [m/s], the wind direction of 0 [$^{\circ}$]~359 [$^{\circ}$], and temperature of -30 [$^{\circ}C$]~50 [$^{\circ}C$], and the comparative experiment with other companies' data loggers was conducted, and an error was measured to be less than ${\pm}0.1$ [m/s] for wind speed and less than +1 [$^{\circ}$] for wind direction.

등전환 방법을 이용한 고에너지 물질의 노화 효과 예측 (Characterization of energetic meterials using thermal calorimetry)

  • 김유천;오주영;;여재익
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.547-553
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    • 2017
  • Differential Scanning Calorimetry(DSC)를 이용하여 파이로점화장치에 사용되는 세 가지 고에너지 물질의 열분석 실험을 수행하였다. DSC 실험 데이터를 이용하여 고에너지 물질의 반응속도식을 추출해내는 이론적 방법을 제안하고 반응속도식 추출을 수행하였다. DSC 실험 결과는 Friedman 등전환법으로 분석되었다. 질량분율에 따른 활성화에너지와 빈도인자를 추출해 내어 반응속도식을 완성하였다. 추출된 반응속도식은 고에너지 물질의 화학반응과정을 몇 단계의 주요단계로 가정하는 형태가 아닌 전체 화학 반응 과정을 나타내는 형태를 갖는다. 이는 기존의 열분석 실험을 통해 추출되는 화학반응속도식 형태에 비해 이론적 측면과 정확성 측면에서 상당한 장점을 갖는다. 도출된 반응속도식을 이용하여 실제 추진기관에 운용되는 세 가지 고에너지 물질의 성능변화를 20년에 대하여 예측하였다.

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