• 대한토목학회논문집
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• 제11권2호
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• pp.99-105
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• 1991

본 연구는 도시폐기물의 성상을 이용하여 에너지회수공정 선택을 위한 기초자료를 얻고자 수행되었다. 폐기물은 서울시 강동구 지역에서 채취하여 물리적조성과 화학적조성이 조사되었으며, 혐기성소화실험을 통해 폐기물내의 생물학적 분해불능물질함량을 결정하였다. 분석결과에 의하면 폐기물의 탄소함량, 수소함량 및 저위발열량은 다음식에 의해 계산되어질 수 있었다; C=0.57VS, H=0.084 VS, HI=49.5VS-(6-0.045 VS)W. 또한 폐기물내의 생물학적 분해불능물질함량은 가연성물질의 58.9%, 전체폐기물의 77.7%로 나타났다. 폐기물의 처리공정중 무게감량이 가장 큰 것은 소각이며 에너지생산량은 연료생산이 가장 큰 것으로 나타났으나 에너지회수공정의 결정시는 폐기물의 연중 발열량변화, 매립지 확보문제 및 추가환경오염여부등의 제반조건이 충분히 고려되어져야 할 것이다.

• 대한기계학회논문집B
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• 제28권11호
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• pp.1368-1375
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• 2004

Measurements of OH chemiluminescence in an atmospheric pressure, laboratory-scale dump combustor at equivalence ratios ranging from 0.63 to 0.89 were reported. The signal from the first electronically excited state of OH to ground state was detected through a band-pass filter with an ICCD. The objectives of this study are two: One is to see the effects of equivalence ratio on global heat release rate and local Rayleigh index distribution. To get the local Rayleigh index distribution, the line-of-sight images were inverted by tomographic method, such as Abel do-convolution. Another aim is to investigate the validity of using OH chemiluminescence acquired with an ICCD as a qualitative measure of local heat release. For constant inlet velocity and temperature, the overall intensities of OH emission acquired at different equivalence ratio showed periodic and higher value at high equivalence ratio. OH intensity averaged over one period of pressure increased exponentially with equivalence ratio. Local Rayleigh index distribution clearly showed the region of amplifying or damping the combustion instability as equivalence ratio increased. It could provide an information/insights on active control such as secondary fuel injection. Finally, local heat release rate derived from reconstructed OH images were presented fur typical locations.

• 대한기계학회논문집B
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• 제35권10호
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• pp.1033-1040
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• 2011

예혼합 버너는 높은 효율과 낮은 배기 때문에 가정용 보일러 버너 시스템에 매우 강력한 버너이다. 일반적으로 가정용 보일러 버너는 내부에 농후한 예혼합 불꽃으로 구성하고 연료는 2차공기의 공급에 의하여 완전연소 되는 분젠 버너를 이용한다. 이것은 상대적으로 긴 불꽃 길이와 높은 과잉공기비에서 작동하기 때문에 높은 효율을 갖는 소형 보일러에 적용하기 어렵다. 이 논문에서 메탈 화이버, 세라믹, SUS 핀과 같은 매질을 사용하는 예혼합 연소 버너의 특징을 실험하였다. 특히, 표면 매질의 비반응 유동 특성은 버너 표면 전체의 유동 속도를 측정하고 조정하였다. 연소 실험은 화염 사진과 화염 온도 측정에 의하여 수행되었다. CO와 NO는 다양한 과잉 공기비와 열량값에 대하여 버너 표면 매질, 연소실, 열교환기의 특성을 측정하고 평가하였다.

• 방사성폐기물학회지
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• 제7권2호
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• pp.115-124
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• 2009

극저온 절단 기술은 절단 과정에서 2차 폐기물이 발생되지 않기 때문에 원자력 시설의 해체기술로 가장 적합한 기술 중 하나이다. 본 논문에서는 SPH 기법과 FEM 기법을 혼합한 하이브리드 기법을 이용한 컴퓨터 시뮬레이션을 통해 극저온 절단 기술의 적용성을 파악하였다. 또한 극저온 절단 시스템의 설계에 활용하기 위해 절단 깊이 예측식을 사용하여 스틸 10 mm 두께를 절단하는데 필요한 설계 변수 및 운전조건을 도출하였다. 마지막으로 도출한 설계변수 및 운전조건을 기반으로 극저온 절단 시스템의 주요 부품을 제작하였다.

• Nuclear Engineering and Technology
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• 제39권1호
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• pp.9-20
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• 2007

Design study on the Gas Turbine High Temperature Reactor 300-Cogeneration (GTHTR300C) aiming at producing both electricity by a gas turbine and hydrogen by a thermochemical water splitting method (IS process method) has been conducted. It is expected to be one of the most attractive systems to provide hydrogen for fuel cell vehicles after 2030. The GTHTR300C employs a block type Very High Temperature Reactor (VHTR) with thermal power of 600MW and outlet coolant temperature of $950^{\circ}C$. The intermediate heat exchanger (IHX) and the gas turbine are arranged in series in the primary circuit. The IHX transfers the heat of 170MW to the secondary system used for hydrogen production. The balance of the reactor thermal power is used for electricity generation. The GTHTR300C is designed based on the existing technologies of the High Temperature Engineering Test Reactor (HTTR) and helium turbine power conversion and on the technologies whose development have been well under way for IS hydrogen production process so as to minimize cost and risk of deployment. This paper describes the original design features focusing on the plant layout and plant cycle of the GTHTR300C together with present development status of the GTHTR300, IHX, etc. Also, the advantage of the GTHTR300C is presented.

• Nuclear Engineering and Technology
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• 제48권6호
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• pp.1291-1302
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• 2016

This paper presents a new and efficient scheme to determine the optimal neutron source position in a model near-equilibrium pressurized water reactor, which is based on the OPR1000 Hanul Unit 3 Cycle 7 configuration. The proposed scheme particularly assigns importance of source positions according to the local adjoint flux distribution. In this research, detailed pin-by-pin reactor adjoint fluxes are determined by using the Monte Carlo KENO-VI code from solutions of the reactor homogeneous critical adjoint transport equations. The adjoint fluxes at each allowable source position are subsequently ranked to yield four candidate positions with the four highest adjoint fluxes. The study next simulates ex-core detector responses using the Monte Carlo MAVRIC code by assuming a neutron source is installed in one of the four candidate positions. The calculation is repeated for all positions. These detector responses are later converted into an inverse count rate ratio curve for each candidate source position. The study confirms that the optimal source position is the one with very high adjoint fluxes and detector responses, which is interestingly the original source position in the OPR1000 core, as it yields an inverse count rate ratio curve closest to the traditional 1/M line. The current work also clearly demonstrates that the proposed adjoint flux-based approach can be used to efficiently determine the optimal geometry for a neutron source and a detector in a modern pressurized water reactor core.

• 멤브레인
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• 제30권2호
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• pp.79-96
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• 2020

환경오염과 화석연료의 문제로 인한 2차 에너지 변환 및 저장 장치의 개발이 활발하게 진행되고 있다. 이러한 에너지 변환장치들은 전기화학적 시스템을 기본으로 운영되고 있으며 이온교환막은 각 공정의 성능을 결정짓는 중요한 요소이다. 따라서 에너지 시스템의 효율 증대 및 성능 향상을 위해서는 적합한 물성을 갖는 이온교환막 개발이 필요하다. 이러한 이온교환막은 크게 양이온교환막, 음이온교환막, 바이폴라막으로 분류되고 있으며, 이들 막들은 화학적, 물리적, 형태학적 특성에 따라 다양한 용도을 갖고 있다. 본 총설에서는 이온교환막의 주요한 특징과 함께 이들의 제조 방법에 대해 기술했다. 이어서 이온교환막을 이용하여 최근 개발되고 있는 전기화학 시스템에 기반을 둔 역전기 투석, 레독스 흐름 전지, 수전해 공정에 대해서 소개하고, 각 에너지 공정에서 이온교환막이 갖는 역할과 조건에 대해서 설명하였다.

• 대한기계학회논문집A
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• 제20권4호
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• pp.1123-1132
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• 1996

It has been reported that high temperature structural components represent the phenomenon of material degradation according to a long term service under high temperature and pressure. Especially, fossile power plant components using the fossil fuel and heavy oil are affected by dewpoint corrosion of $H_2SO_4$produced during a combustion. Therefore, the service materials subjected to high temperature and pressure may occur the stress corrosion cracking. The object of this paper is to investigate SCC susceptibility according to the material degradation of the high temperature structural materials in dewpoint corrosive environment-$H_2SO_4$.The obtained results are summarized as follows : 1) In case of secondary superheater tube, the fractograph of dimple is observed at the concentration of $H_2SO_4$-5%. When the concentration of $H_2SO_4$ is above 10%, the fracture mode is shifted from a transgranular fracture to an quasi-intergranular fracture according to the increment of concentration. 2) In the relationship between [$\Delta$DBTT]$_sp$ and SCC susceptibility, it is confirmed that the greater material degradation degree is, the higher SCC susceptibility is. In addition, it can be known that SP test is useful test method to evaluate SCC susceptibility for high temperature structural components. 3) When [$\Delta$DBTT]$_sp$ is above 17$17^{\circ}C$ the SCC fracture behavior is definitely observed with SCC susceptibility of above 0.4.

• 대한건축학회논문집:계획계
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• 제34권2호
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• pp.3-11
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• 2018

Korea has achieved a rapid economic development and with the increase in population and national income and the expansion of social and economic activities, energy consumption has rapidly increased too. Energy consumption per head has constantly increased and currently, power consumption per head is 7.5 times bigger than in 1985. Buildings occupy 25% of total energy consumption and especially, 50% of total energy is consumed for heating and cooling. In this situation, multi-family housing, which has constantly been increased, has an energy saving rate of 1.9%, which is the lowest level and this makes the government's energy policy for sustainable energy system development useless. Besides, energy consumption leads to secondary problems, such as air, water and marine pollution and heat pollution and wastewater/drainage and the increased use of fossil fuel is a fundamental reason for ozone layer destruction and global warming. Therefore, efficient energy consumption plans are required. This study aims to analyze energy performance in each block type of high-rise and diversified multi-family housing that accounts for 60% of all the housing forms, depending on the variations in stories through BIM-based energy simulation. For this study, four representative block types were selected, based on the multi-family floor plan, which is certified for energy performance evaluation and they were applied to the floor plan of a multi-family house that is scheduled to be built. Then BIM modeling was conducted from the fifth story to the 40th story at an intervals of 5 stories and based on the finding, energy characteristics of each block type and energy performance depending on the variations in stories were analyzed. It is considered that this would serve as objective data for block type and block story decision of energy performance-based multi-family housing.

• 자원리싸이클링
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• 제30권3호
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• pp.18-29
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• 2021

백금족 금속(Platinum Group Metals, PGMs)은 화학적 저항성은 물론 전기·열전도성이 뛰어나 촉매, 전자기기, 전극, 전기기기, 연료전지, 고온 소재 등 광범위한 응용 분야에 사용된다. 일반적으로 백금족 금속은 구리와 니켈의 황화광과 관련되어 있으므로 백금족 금속의 상대적인 농도에 따라 주산물로 생산되거나 니켈과 구리의 부산물로 생산된다. 특히 이러한 자원들은 남아프리카와 러시아 같은 나라들에 편재되어 있으며, 백금족 금속의 연간 공급량은 500톤 미만이다. 이와 같은 백금족 금속의 한정된 공급량을 고려하면 향후에 백금족 금속의 공급 리스크가 증가할 것이다. 따라서 폐촉매와 같은 2차 자원으로부터 백금족 금속을 회수하는 것이 매우 중요하다. 본 논문에서는 백금족 금속의 제련 기술과 리사이클링 기술에 대하여 고찰하였다.