Solar Tower용 흡수기의 설치 각도 및 작동 조건 변화에 따른 대류 열손실 분석

강경문(Kang Kyung-Mun),이주한(Lee Ju-Han),김용(Kim Yong),서태범(Seo Tae-Beom),강용혁(Kang Yong-Heack) 한국태양에너지학회 2007 한국태양에너지학회 논문집 Vol.27 No.4

Convective heat loss from solar tower receiver is experimentally investigated in wind tunnel with tilt angles and operating conditions. In order to simulate the receiver, an electric heater, which is made of aluminum (width : 100 ㎜, height : 100㎜) is used and installed in the wind tunnel. The convective heat loss from the receiver is dependent on the direction and the velocity of the wind and the surface temperature of the receiver. The tilt angle and surface temperature of the receiver are varied from 0o(cavity facing straight down) and 90o(cavity aligned horizontally) and from 150℃ to 250℃, respectively. Also, the wind speed is changed from 0 to 4㎧. The convective heat loss is obtained by measuring consumed power to the heater to maintain the desired surface temperature. It is concluded that Nusselt number increases with increasing wind speed for all cases. Especially, it is showed that Nusselt number can be maximized when the tilt angle is 30o.

Experimental Validation of a Direct Methanol Fuel Cells(DMFCs) model with a Operating Temperatures and Methanol Feed Concentrations

강경문(Kang, Kyungmun),고요한(Ko, Johan),이기용(Lee, Giyong),주현철(Ju, Hyunchul) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

In this paper, both theoretical and experimental investigations have been performed to examine the effects of key operating parameters on the cell performance of a DMFCs (i.e., methanol feed concentration and operating temperature). For experiment, the membrane electrode assemblies (MEAs) were prepared using a conventional MEA fabrication method based on a catalyst coated electrode (CCE) and tested under various cell temperatures and methanol feed concentrations. The polarization curve measurements were conducted using in-house-made 25cm² MEAs. The voltage-current density data were collected under three different cell temperatures (50?C, 60?C, and 70?C) and four different methanol feed concentrations (1 M, 2 M, 3 M, and 4 M). The experimental data indicate that the measured I-V curves are significantly altered, depending on these conditions. On the other hand, previously developed one-dimensional, two-phase DMFC model is simulated under the same operating conditions used in the experiments. The model predictions compare well with the experimental data over a wide range of these operating conditions, which demonstrates the validity and accuracy of the present DMFC model. Furthermore, both simulation and experimental results exhibit the strong influences of methanol and water crossover rates through the membrane on DMFC performance and I-V curve characteristics.

전라남도 지역별 스포츠관광자원과 일반관광자원 연계전략

강경문(Kang, Kyoung Moon),전호문(Jun, Ho Moon),김경현(Kim, Kyoung Hyun) 한국스포츠산업경영학회 2021 한국스포츠산업경영학회지 Vol.26 No.2

본 연구는 전라남도 11개 시군이 각각 추진하고 있는 스포츠관광자원 및 사업현황을 분석하여, 전라남도를 국제적인 관광지로 발돋움시키기 위한 체계화, 전략화, 집중화한 권역별 스포츠 관광자원의 사업화를 위한 구체적인 마케팅 전략을 제시하는데 목적이 있다. 이와 같은 연구 목적 달성을 위해 관광관련 학회, 공사, 협회 전문가와 전라남도 11개 시·군의 공무원, 현장전문가, 연구자 등을 연구 대상으로 하였으며, 개방형 설문조사와 심층면담, 전문가 회의 등을 통해 범주화 분석을 통해 자료를 수집하였다. 자료 수집은 현황조사를 시작으로 6단계 절차를 거쳐 수행되었다. 자료분석은 주제별로 분류하여 내용 분석을 실시하였다. 도출된 연구결과를 요약하면 다음과 같다. 첫째, 각 지자체에서 활용 가능한 최적의 스포츠관광자원을 도출하기 위하여, 설문조사를 실시하여 지자체별 비교우위 스포츠관광자원과 관련된 일반관광자원을 총 10개(관광지, 대표축제, 음식, 테마파크, 기후환경, 전통민속놀이, 인조 시설물, 캠핑장, 유휴자원)의 범주로 도출하였다. 둘째, 각 지자체 활용 가능한 일반관광자원의 10개 범주를 우선순위 하였으며, 지역의 관광지, 대표축제, 자연환경, 음식, 테마파크, 기후환경 순으로 나타났다. 셋째, 각 지자체가 보유한 스포츠관광자원 현황을 파악한 결과 지자체별로 스포츠관광자원(스포츠이벤트, 스포츠시설, 특화된 스포츠, 대표 프로스포츠, 전지훈련환경, 스포츠테마, 교육시설)을 보유하고 있으며, 지자체별로 스포츠관광자원의 보유 유무와 활용하고 있는지에 대한 결과를 도출하였다. 넷째, 전라남도 스포츠관광자원으로 활용 가능한 일반관광자원을 도출하였다. 다섯째, 전라남도 스포츠관광자원 활용자원에 대한 전략방안을 도출하였다. 여섯째, 전라남도 우수 스포츠관광자원의 종합연계전략을 광주 근교권, 동부권, 서남권, 중남부권 등 4개 권역으로 나누어 지역 특색에 맞는 연계전략을 제시하였다. This study analyzed the current status of sports tourism resources and projects promoted by 11 cities and counties in Jeollanam-do, and proposes a specific marketing strategy for the commercialization of systematized, strategic, and centralized sports tourism resources in order to develop Jeollanam-do into an international tourist destination. Achieving the purpose of the study, two types of research methods that are Delphi survey and open questionnaire survey are adopted, and then the survey results are analysed and classified into three categories and six stages. The results are as follow. First, in order to derive the optimal sports tourism resources that can be used in each local government, a survey was conducted to extract sports tourism resources with comparative advantage by local governments. Second, The analysis of general tourism resources through the advice of experts showed a total of 10 categories and organized into 123 sentences. Third, as a result of grasping the current status of sports tourism resources possessed by each local government, each local government has sports tourism resources and derived the contents used. Fourth, general tourism resources available for sports tourism resources were presented. Fifth, strategic plans for utilization of the sports tourism resources in Jeollanam-do are suggested. Sixth, the comprehensive marketing plans for outstanding sports tourism resources in Jeollanam-do provinces are proposed.

고분자전행질형 연료전지내 마이크로다공층 영향에 대한 수치적 연구

강경문(Kyungmun Kang),주현철(Hyunchul Ju) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

In the fuel cell community it is well-known that a micro-porous layer (MPL) plays a crucial role in the water management of polymer electrolyte fuel cells (PEFCs), and thereby, significantly stabilizes and improves cell performance. In this paper, a numerical MPL model is developed and embodied with comprehensive, multi-dimensional, multi-phase fuel cell models that were developed earlier to discover the exact roles of MPLs,. The effects of different porous properties and liquid-entry pressures between an MPL and a gas diffusion layer (GDL) are examined via fully three-dimensional numerical simulations. Discontinuity in liquid saturation at the GDL/MPL interface is captured by the model when the differences in pore properties and wettability between the MPL and GDL are taken into account without considering variation in the liquid-entry pressures. However, the simulation of this case fails to capture the beneficial effects of an MPL on cell performance, predicting even lower performance than the case of no MPL. On the other hand, when a high liquid-entry pressure in an MPL is additionally considered, the numerical MPL model predicts liquid-free MPL and successfully demonstrates the phenomenon that the high liquid-entry pressure of the MPL prevents any liquid water from entering the MPL. Consequently, it is found from the simulation results that the liquid-free MPL significantly enhances the back-flow of water across the membrane into the anode, which, in turn, helps to avoid membrane dehydration and alleviate the level of GDL flooding. As a result, the model successfully reports the beneficial effects of MPLs on PEFC performance and predicts higher performance in the presence of MPLs (e.g., an increase of 67 ㎷ at 1.5 A ㎝-2). This study provides a fundamental explanation for MPL functions and quantifies the influence of MPL’s porous properties and the liquid-entry pressure on water transport and cell performance.

고분자전해질형 연료전지의 저온시동 모델링 및 시뮬레이션

강경문(Kyungmun Kang),고요한(Johan Ko),주현철(Hyunchul Ju) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

고온 태양열 화학반응기 열전달 성능 평가

강경문(Kyungmun Kang),이주한(Juhan Lee),조현석(Hyunsuk Cho),서태범(Taebeom Seo) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

The objective of this paper is to describe the experimental and numerical investigation of the analysis of the heat transfer in a solar chemical reactor. These are compared about methane steam reforming process in the solar chemical reactor which was a volumetric absorber consisting of honeycomb and a multilayered catalyst supports. With this high operating temperature, convective heat loss, thermal fracture are important features for designing SCR. In order to estimate the system performance and to design the actual solar reactor with various conditions, CFD analysis was used in this study. The nickel oxide porous metal is inserted inside the solar chemical reactor to increase the conversion rate of the reforming reaction. Simulation has been carried out based on the experimental data. According to the simulation results, the optimum methane-steam mole ratio and thickness and numbers of catalyst supports were obtained.

소형민수헬기 부가형식증명 인증 수행 방안 연구

문경일(Gyung-Il Moon),박상혁(Sang-Hyeok Park),강경철(Kyung-Chul Kang),지준호(Jun-Ho Ji),김성진(Sung-Jin Kim) 한국항공우주학회 2019 한국항공우주학회 학술발표회 논문집 Vol.2019 No.11

ZnO 초박막의 두께 변화에 따른 구조적, 전기적, 광학적 특성 변화 연구

강경문,김민재,이홍섭,박형호,Kang, Kyung-Mun,Wang, Yue,Kim, Minjae,Lee, Hong-Sub,Park, Hyung-Ho 한국마이크로전자및패키징학회 2019 마이크로전자 및 패키징학회지 Vol.26 No.2

원자층 증착법(ALD: atomic layer deposition)으로 $150^{\circ}C$에서 성장된 zinc oxide (ZnO) 초박막의 두께 변화에 따른 구조적, 전기적, 광학적 특성을 조사하였다. ZnO 박막을 증착하기 위해 금속 전구체와 반응물로 각각 diethylzinc와 deionized water를 사용하였다. ALD 사이클 당 성장률은 $150^{\circ}C$에서 약 0.21 nm/cycle로 일정 하였으며, 50 사이클 이하의 샘플들은 초기 ALD 성장 단계에서 상대적으로 얇은 두께로 인하여 비정질 성질을 갖는 것으로 보였다. 100 사이클에서 200 사이클로 두께가 증가함에 따라 ZnO 박막의 결정성이 증가하였고 hexagonal wurtzite 구조를 보였다. 또한, ZnO 박막의 입자 크기가 ALD 사이클의 수의 증가에 따라 증가되었다. 전기적 특성 분석 결과 박막 두께의 증가에 따라서 비저항 값이 감소하였으며, 이는 박막 두께 증가에 따른 입자 크기 증가 및 결정성 개선으로 더 두꺼운 ZnO 박막에서 입자 경계의 농도 감소와 상관 관계가 있음을 알 수 있었다. 광학적 특성 분석 결과 근 자외선 영역 (300 nm~400 nm)에서의 밴드 엣지 흡수가 증가 및 이동되었는데 이 현상은 ZnO 박막 두께의 증가에 따른 캐리어 농도의 증가가 기인 한 것으로, 이 결과는 박막 두께의 증가에 따른 저항률 감소와 잘 일치한다. 결과적으로 박막의 두께가 증가하면 막 면의 응력이 완화되어 밴드 갭이 감소하고 결정성 및 전도성이 향상됨을 알 수 있었다. We investigated the structural, electrical and optical properties of zinc oxide (ZnO) ultra-thin films grown at $150^{\circ}C$ by atomic layer deposition (ALD). Diethylzinc and deionized water were used as metal precursors and reactants, respectively, for the deposition of ZnO thin films. The growth rate per ALD cycle was a constant 0.21 nm/cycle at $150^{\circ}C$, and samples below 50 cycles had amorphous properties due to the relatively thin thickness at the initial ALD growth stage. With the increase of the thickness from 100 cycles to 200 cycles, the crystallinity of ZnO thin films was increased and hexagonal wurtzite structure was observed. In addition, the particle size of the ZnO thin film increased with increasing number of ALD cycles. Electrical properties analysis showed that the resistivity value decreased with the increase of the thin film thickness, which is correlated with the decrease of the grain boundary concentration in the thicker ZnO thin film due to the increase of grain size and the improvement of the crystallinity. Optical characterization results showed that the band edge absorption in the near ultraviolet region (300 nm~400 nm) was increased and shifted. This phenomenon is due to the increase of the carrier concentration with the increase of the ZnO thin film thickness. This result agrees well with the decrease of the resistivity with the increase of the thin film thickness. Consequently, as the thickness of the thin film increases, the stress on the film surface is relaxed, the band gap decreases, and the crystallinity and conductivity are improved.

고칼슘 소각제 치환율에 따른 시멘트 모르타르의 물리적 특성

강경모(Kang, Kyung Mo),김무준(Kim, Mu Jun),문경주(Moon, Kyoung Ju),형원길(Hyung, Won Gil) 한국콘크리트학회 2019 한국콘크리트학회 학술대회 논문집 Vol.31 No.2

상용 RTOS 적응이 가능한 장치제어계 프레임워크 개발 사례

강경순,문성,김형환,임동선,최완,Kang, Gyung-Soon,Moon, Sung,Kim, Hyung-Hwan,Lim, Dong-Sun,Choi, Wan 대한전자공학회 2002 전자공학회지 Vol.29 No.9