• Title/Summary/Keyword: 에너지 전환

Search Result 1,255, Processing Time 0.031 seconds

Numerical Analysis in a 1 kWe SOFC Stack for the Flow Phenomena (1 kWe 급 고체산화물 연료전지 스택에서의 유동 해석)

  • KUNWOO YI;YOUNG JIN KIM;HAOYUAN YIN;HYEON JIN KIM;KYONG SIK YUN;JI HAENG YU
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.34 no.2
    • /
    • pp.196-204
    • /
    • 2023
  • This study performed the numerical analysis of the internal flow phenomena of 1 kWe-class solid oxide fuel cell (SOFC) stacks with internal manifold type and planar cells using commercial computational fluid dynamics (CFD) software, Star-CCM+. In particular, the locations where the turbulent phenomena occur inside the SOFC stack were investigated. In addition, the laminar flow model and the standard k-ε turbulent model were used to calculate the SOFC stack, separately. And, the calculation results of both laminar and turbulent models were compared. The calculation results showed that turbulent phenomena occurred mainly in the cathode flow. Especially, the turbulent phenomena were found in the cathode inlet/outlet region, and local turbulence occurred in the end plate near the inlet pipe.

The Optimal Energy Mix in South Korea's Electricity Sector for Low Carbon Energy Transition in 2030: In Consideration of INDC and Sequential Shutdown of Decrepit Nuclear Power Plants (저탄소 에너지 전환을 위한 2030년 최적전력구성비: 노후 원전 단계적 폐쇄와 INDC를 고려한 시나리오)

  • Kim, Dongyoon;Hwang, Minsup
    • Journal of Environmental Impact Assessment
    • /
    • v.26 no.6
    • /
    • pp.479-494
    • /
    • 2017
  • After Fukushima incident, negative sentiment towards nuclear power has led to transition in policies that reduce the dependency on nuclear power in some countries. President Moon of Republic of Korea also announced a national plan of decommissioning retired nuclear power plants stage by stage. Therefore, nuclear power that once was considered the critical solution to energy security and climate change is now a limited option. This study aims to find an optimal energy mix in Korea's electricity system from 2016 through 2030 to combat climate change through energy transition with minimum cost. The study is divided into two different scenarios; energy transition and nuclear sustenance, to compare the total costs of the systems. Both scenarios show that electricity generated by wind technology increases from 2018 whereas that of photovoltaic(PV) increases from 2021. However, the total cost of the energy transition scenario was USD 4.7 billion more expensive than the nuclear sustenance scenario.

At the crossroads: An uncertain future facing the electricity-generation sector in South Korea (월드 리포트 - 대한민국 발전산업의 불확실한 미래)

  • Hong, Sanghyun;Brook, Barry W.
    • Nuclear industry
    • /
    • v.38 no.6
    • /
    • pp.21-32
    • /
    • 2018
  • 원자력 발전은 지난 수십 년 동안 대한민국에서 가장 중요하고 청정한 전기 에너지 공급원 역할을 감당해왔다. 그렇지만 한국 정부는 원자력 발전의 점유율을 줄이고 재생에너지의 비중을 높이는 것을 목표로 하는 에너지 전환 정책 로드맵을 발표하였다. 그러나 한국의 높은 인구밀도를 놓고 볼 때, 전력 생산의 최대 에너지원을 재생에너지로 전환하겠다는 구상은 무리일 수밖에 없다. 그 이유는 재생에너지 발전량만으로는 다 감당할 수 없는 원자력 발전량의 감축 부분을 어떻게 보충하겠다는 언급이 한국 정부의 로드맵에는 없기 때문이다. 암묵적으로 받아들여지고 있는 대안은 결국 화석연료인 것 같은데, 한국정부가 어떤 화석연료를 선택하느냐 하는 문제는 온실가스 배출량 감축이라는 문제와 직결되므로 그것이 최종 결정의 핵심적 요소가 될 것이다. 우리는 시나리오 분석 방법을 통해 한 가지 재생에너지를 선택한다는 가정과 함께 두 종류의 화석연료를 주로 사용하게 되는 경우를 분석해 보았다. 아울러 우리는 다른 나라들의 세 가지 에너지계획과 비교 분석한 사항을 바탕으로 원자력 에너지 외에 한국 정부가 선택할만한 에너지원의 타당성과 각 에너지 별 선택에 따른 제약사항을 밝히면서 최악의 결과를 방지하기 위한 기술-경제상의 필수적인 조건들을 제안하려 한다.

  • PDF

Analyses of GHG Reduction Effectiveness and Economic Feasibility in the Wood Pellet Fuel Switching Project (목재 펠릿 연료전환 사업의 온실가스 감축 효과 및 경제성 분석)

  • Lee, Jin-Chul;Kang, Kyu-Young
    • Journal of the Korean Wood Science and Technology
    • /
    • v.41 no.6
    • /
    • pp.594-605
    • /
    • 2013
  • This study was performed to analyze GHG (Greenhouse gas) reduction effectiveness and economic feasibility in the wood pellet fuel switching project using JCDM (Japan Clean Development Mechanism) and KVER (Korea Voluntary Emission Reduction)data. The major data for the analyses consist of investment costs, annual GHG reductions, fuel prices and GHG credit prices. The wood pellet fuel switching projects are the $CO_2$-zero projects. Therefore, these projects are essential to accomplish the GHG mitigation target, especially in Korea. In order to raise the economic feasibility of the wood pellet fuel switching project, the results of this study suggest that the Korean government should reduce the price of wood pellet through the supply on a large scale and raise the KCER price of wood pellet fuel switching project.

An Investigation of Elementary School Students' Conception on Energy (에너지에 대한 초등학생들의 개념 탐색)

  • Lim, Soo-min;Yoon, Heojeong;Bang, Dami
    • Journal of Science Education
    • /
    • v.43 no.3
    • /
    • pp.284-299
    • /
    • 2019
  • The purpose of this study is to investigate elementary school students' conceptions about the energy represented in the integrated theme 'Energy and life' of the 2015 revised science curriculum. The instruments were developed to grasp students' understanding about 'the concepts of energy,' 'forms of energy,' 'conversion of energy,' and 'energy use of plants and animals.' The surveys were conducted on 92 elementary school students in Seoul. The students' answers were analyzed by descriptive statistics, clouds and semantic network analysis. The results are as follows: 'Electricity' and 'electric energy' were most frequently mentioned as the associated concepts to energy and forms of energy, respectively. Also, the daily use of energy was mixed to the use in science. According to conceptual hierarchy, understanding of energy conversion was dependent on the understanding of energy forms. Although students have basic concepts about the energy use of plants and animals, they had some misconceptions and lack of understanding. The educational implications were discussed to teach 'Energy and Life' as integrated theme in new elementary school curriculum.

Explaining One Less Nuclear Energy Policy from Governance Perspective: Energy Transition and Effectiveness of Urban Energy Policy (대안적 에너지 정책에 대한 탐색: 서울시 원전하나 줄이기 정책과 거버넌스의 역할)

  • Lee, Joo Hun
    • Korean Journal of Legislative Studies
    • /
    • v.23 no.1
    • /
    • pp.151-185
    • /
    • 2017
  • Seoul's One Less Nuclear Power Plant is the major urban energy policy launched in April 2012. Its effort to respond to climate change and energy crisis in the aftermath of the Fukushima nuclear accident turned out very successful, considering huge decrease of energy consumption. However, the question of how the cut of energy consumption was possible remains unanswered. This paper introduces the concept of urban governance capacity as the cause of the success. It is the managing and governing capability to maintain the logical consistency policy system, comprising of policy perception, goals, policy tools and evaluation. Without this logical correspondence between the policy factors, any system including energy regime easily falls apart during the systemic transitional period. Governance capacity provides the integrating framework, so that the system as a whole maintains the internal homeostasis.

Thermochemical conversion of biomass in a fluidized bed pyrolyzer (유동층 열분해로에서의 바이오매스 열화학적 전환)

  • Lee Seehoon;Kim Younggu;Hong JaeChang;Yoon Sangjun;Choi Youngchan;Lee Jaegoo
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2005.06a
    • /
    • pp.467-470
    • /
    • 2005
  • 지구온난화 현상과 화석연료의 고갈에 대한 두려움 때문에 재생에너지에 대한 관심이 지속적으로 증가하고 있다. 이에 따라 대체에너지, 합성가스, 화학 원료, 오일 등으로 전환할 수 있는 바이오매스 활용에 대한 연구도 활발히 진행되고 있다. 바이오매스의 열화학적 전환 공정에는 열분해, 연소, 가스화 등이 이용되고 있다. 특히 열분해는 syringol, levoglucosan, guaiacol등의 고부가가치 물질들을 생산하기에 적합한 기술로 인정받고 있다. 본 연구에서는 국내에서 쉽게 구할 수 있는 톱밥, 폐목재 등의 바이오매스의 열화학적 전환 특성을 분석하였다. 사용된 바이오매스의 열분해 특성은 열중량 분석기 및 열천칭 반응기를 통해 분석하였으며 이를 통해 유동충 반응기(지름 0.2m, 높이 2m)를 설계 및 제작하였다. 반응온도 및 산소 농도가 증가할수록 levoglucosan 등의 고부가가치 물질들의 수율이 낮아지며 페놀류가 급격히 증가함을 알 수 있었다. 회재 성분이 높은 왕겨의 바이오오일 수율은 톱밥보다 $30\%$이상 낮게 나타났다

  • PDF