복사난방패널의 설계 및 운전을 위한 열적 특성 분석

이태원,Lee, T.W. 대한설비공학회 1997 설비공학 논문집 Vol.9 No.2

The theoretical analysis and experiment with simulator were performed to obtain the temperature distributions in radiant heating panel and heat supply from hot water to heating space for the purpose of the development of comfortable living space from a point of view of the improvement of air quality and the enhancement of system efficiency. The relations of various parameters, such as pipe pitch, room temperature as well as flow rate and temperature of hot water and so on, with the rate of heat supplied, mean temperature and maximum temperature difference at panel surface were discussed. The effects of these parameters were also verified on the thermal performance of heating panel using the relations which could be used for the optimal design and operation of the radiant heating panel.

지구환경시대 그린빌딩의 역할

이태원,Lee, T.W. 대한설비공학회 1998 설비저널 Vol.27 No.4

인장변형에 따른 그래핀복합 카본블랙전극의 저항변화연구

이태원,이홍섭,박형호,Lee, T.W.,Lee, H.S.,Park, H.H. 한국마이크로전자및패키징학회 2015 마이크로전자 및 패키징학회지 Vol.22 No.1

Stretchable electrode materials are focused to apply to flexible device such as e-skin and wearable computer. Used as a flexible electrode, increase in electrical resistance should be minimalized under physical strain as bend, stretch and twist. Carbon black is one of candidates, for it has many advantages of low cost, simple processing, and especially reduction in resistivity with stretching. However electrical conductivity of carbon black is relatively low to be used for electrodes. Instead graphene is one of the promising electronic materials which have great electrical conductivity and flexibility. So it is expected that graphene added carbon black may be proper to be used for stretchable electrode. In this study, under stretching electrical property of graphene added carbon black composite electrode was investigated. Mechanical stretching induced cracks in electrode which means breakage of conductive path. However stretching induced aligned graphene enhanced connectivity of carbon fillers and maintained conductive network. Above all, electronic structure of carbon electrode was changed to conduct electrons effectively under stretching by adding graphene. In conclusion, an addition of graphene gives potential of carbon black composite as a stretchable electrode. 신축성 전극소재는 웨어러블 밴드나 전자피부와 같은 플렉서블 제품으로의 적용 때문에 주목 받고 있다. 플렉서블 소자로서 사용하기 위해선 구부리거나 비틀거나 늘리는 등 물리적 변형에도 전기저항의 증가가 최소화되어야 한다. 카본블랙은 저가의 간단한 공정, 특히 인장 시 비저항의 감소라는 장점 때문에 후보소재로 고려되고 있다. 하지만 카본블랙의 전도도는 전극으로 사용되기에 상대적으로 낮다. 이에 비해 그래핀은 뛰어난 전기전도도 및 유연성 때문에 촉망받고 있는 전자소재이다. 따라서 그래핀을 첨가한 카본블랙은 신축성 전극으로 적합한 소재로 예상된다. 본 논문을 통해 인장 시 그래핀을 첨가한 카본전극의 전기적 특성을 연구하였다. 기계적인 인장은 전극 내의 균열(crack)을 형성시켜 도전경로의 파괴를 일으켰다. 하지만 인장으로 정렬된 그래핀은 카본필러 간의 연결성을 강화하고 도전구조를 유지하였다. 무엇보다도 그래핀 첨가로 인하여 인장 시 카본전극의 전자구조가 변화하여 전자를 효과적으로 전도하게 하였다. 결론적으로 그래핀 첨가를 통해 카본블랙 복합체에 신축성 전극으로의 가능성을 부여하였다.

복사 난방 패널의 과도 열전달 해석

이태원,김호영,Lee, T.W.,Kim, H.Y. 대한설비공학회 1992 설비공학 논문집 Vol.4 No.3

To analyze the unsteady heat transfer phenomena in radiant heating panel, a mathematical model was considered. Numerical analysis for solving the governing equations was conducted by using the finite difference method with boundary-fitted meshes. Transient temperature distributions and thermal responses in heating panel were obtained for various design parameters such as pipe pitches, pipe diameters and pipe depths. Experimental results were also obtained to verify the results of calculation.

그래핀 첨가에 따른 신축성 카본전극의 전기적 특성 변화

이태원,박형호,Lee, T.W.,Park, H.H. 한국마이크로전자및패키징학회 2014 마이크로전자 및 패키징학회지 Vol.21 No.4

소프트 일렉트로닉스에 대한 많은 수요로 인해 신축성 전극이 주목 받고 있다. 그 후보 중 하나인 카본블랙 복합소재(composite)는 낮은 가격, 용이한 공정성뿐 만 아니라 특정 범위에서 인장에 따라 비저항이 감소하는 장점을 가지고 있다. 하지만 전자소자로 쓰이기엔 전기전도도가 좋지 못 한 단점을 가지고 있다. 그래핀은 2차원 나노구조의 카본 계열 물질로서 뛰어난 전기적 특성과 유연성을 가지고 있으며 그래핀의 첨가로 카본블랙 복합소재의 전도성을 향상시킬 것으로 예상된다. 본 연구에서는 그래핀을 카본블랙 전극에 첨가하여 강화된 전기적 특성을 조사하였다. 그래핀 첨가 카본전극의 전기저항률은 카본블랙 전극과 비교해 감소하였다. 이는 그래핀이 서로 접촉하지 않는 카본블랙 응집체를 연결하여 도전 구조를 강화하였기 때문이다. 또한 그래핀은 인장 시 나타나는 카본블랙 전극의 저항증가를 감소시켰다. 그 원인은 그래핀이 인장 시 멀어지는 카본블랙 응집체 간극을 연결함과 동시에 인장방향으로 정렬되기 때문이다. 결론적으로 그래핀 첨가는 카본블랙 복합소재의 전기적 특성을 향상시켜 신축성 전극으로서 2가지 효과를 부여한다. Stretchable electrodes are focused due to many demands for soft electronics. One of the candidates, carbon black composites have advantages of low cost, easy processing and decreasing resistivity in a certain range during stretching. However, the electrical conductivity of carbon black composites is not enough for electronic devices. Graphene is 2-dimensional nanostructured carbon based material which shows good electrical properties and flexibility. They may help to improve electrical conductivity of the carbon black composites. In this study, graphene was added to a carbon black electrode to enhance electrical properties and investigated. Electrical resistivity of graphene added carbon electrode decreased comparing with that of carbon black electrode because graphene bridged non-contacting carbon black aggregates to strengthen the conductive network. Also graphene reduced an increase in the resistance of the carbon black electrode applied to strain because they connected gap of separated carbon black aggregates and aligned along the stretching direction at the same time. In conclusion, an addition of graphene to carbon black gives two benefits on the electrical properties of carbon black composite as a stretchable electrode.

가압탱크를 이용한 급수시스템의 해석 및 최적화 연구

이태원,김태형,최도혁,김세동,김종필,Lee, T.W.,Kim, T.H.,Choi, D.H.,Kim, S.D.,Kim, J.P. 대한설비공학회 1994 설비공학 논문집 Vol.6 No.2

It is the goal of this study to provide the essential data for design and operation of optimum water supply system. Experimental and theoretical analyses have been conducted for various parameters, for example, volume and air percent of pressurizing tank, pump speed and pressure range inside tank, etc. Pressure inside tank with time, flow rate, energy consumption rate and pump operation time have been obtained for design and operating parameters to optimize the components and to establish the operating method of system, and therefore to contribute to the development of technology from a point of view of the improvement of quality, the enhancement of system efficiency and the reduction of construction cost.

[디젤엔진부문] 이종연료 층상분사를 이용한 디젤엔진의 NOx와 soot 동시 저감에 관한 연구

강병무(B.M. Kang),김종률(J.Y. Kim),이태원(T.W. Lee),정성식(S.S Chung),하종률(J.Y. Ha) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

<br/> ~~.A\-%7}t'--c:j-~ 2000\15:. ~;>jI~t:1J~<br/> 2000-03-2041<br/> 01<br/> 3S. 91 ~ ~A~~<br/> A<br/> L.s:.<br/> OI<br/> Ho~<br/> c:"~.n. C::>C>c r2. C:::>L ;<br/> C/~2!!~~ NOx$ soot ~AI AI~OU ~~ eF?<br/> 7J'!!-';'-, 7,J'6-it(%ottJI-o:}jj! tJI~~), 01I11~(~~ ~~tJI-O:}), '\J'\J-6j, "6J-'6-iH%ottJI-o:}jj!)<br/> A Study on the Simultaneous Reduction of :>iOx and Soot<br/> with Dual Fuel Stratified Injection System in a Diesel Engine<br/> B. 1\1. Kang, ]. Y. Kim(Graduated School of Dong- A L'niv'>, T. W. Lee(Changwon CQUage), S. S. Chung, ]. Y. Ha(Dong-A Univ,)<br/> ABSTRACT<br/> To investigate the method of the simultaneous reduction of Soot and NOx, we developed a new conception for dual fuel stratified injection system in a Diesel Engine.<br/> Some parts of the injection system, ie. nozzle holder, delivery vale. were remodeled to inject diesel and methanol in order from one injector. The Quantity of diesel and methanol was controled precisely by micrometers that were mounted at control lack of injection pump.<br/> The real injection Quantity ratio of dual fuel was certificated by volumetric ratio at injection Quantity experiment. We could confirm the capability that soot and NOx simultaneously were reduced by diesel-methanol stratified injection from the results of combustion and exhaust characteristic.<br/>

[디젤엔진] 디젤엔진의 Cavity Shape에 따른 KL치의 변화에 관한 연구

이태원(T.W. Lee),이선봉(S.B. Lee),하종률(J.Y. Ha) 한국자동차공학회 1999 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The present study deals with the effect of combusion chamber shape on in-cylinder soot oxidation characteristics of direct injection diesel engine. The anaylsed combustion chambers were a toroidal and a reentrant a reentrant with a projection(Complex). The two-color method was used to measure in-cylinder flame temperature and KL valve which is approximately proportional to the soot amount along the optical path. In addition, heat release rate was calculated from the in-cylinder pressure data. From this study, the soot oxidation of the reentrant and the complex which were strengthen squish flows went worse in late combustion period under heavy-load operation compared to that of the toroidal at retared fuel injection timing. It might be cause of the flame holding that squish lip depress the outflow of flame from the bowl to the entire combustion space.

볼 소켓 피봇을 갖는 틸팅 패드의 유한 요소 해석을 통한 강성 계산과 Hertzian Contact 모델 해석 결과 비교

이태원(T. W. Lee),김태호(T. H. Kim) 한국트라이볼로지학회 2014 한국트라이볼로지학회 학술대회 Vol.2014 No.4

점화에너지특성이 예혼합기의 착화와 연소에 미치는 영향

이태원(T.W.Lee),이중순(J.S.Lee),정성식(S.S.Chung),하종률(J.Y.Ha) 한국자동차공학회 1994 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1994 No.11_1

Studied in this paper is effect of the factors, participating in the combustion as the initial conditions, such as the flow characteristics of the mixture and the initial temperature, pressure and equivalence ratio in the chamber on the ignitability of the mixture, the combustion duration and the maximum combustion- pressure.<br/> The experiment was performed in a constant-volume combustion chamber, with turbulent flow inside, equivalent to the actual engine at TDC.<br/> Used in the experiment are three ignition devices, which differ from each other in the distribution and the magnitude of discharge energy.<br/>