평행류와 Interdigitated 유로를 가진 교분자 전해질 연료전지(PEMFC)의 성능특성에 대한 수치해석

이필형,조선아,최성훈,황상순,Lee, Pil-Hyong,Cho, Son-Ah,Choi, Seong-Hun,Hwang, Sang-Soon 한국전기화학회 2006 한국전기화학회지 Vol.9 No.4

고분자 전해질 연료전지의 분리판의 유동채널 설계는 고전류밀도에서 발생하는 농도분극에 직접적인 영향을 줄 뿐 아니라 생성되는 물의 효과적인 전달을 위하여 매우 중요하다. 평행류 유로와 interdigitated 유로의 성능비교를 위하여 연료극과 공기극이 포함된 완전한 형태의 고분자 전해질 연료전지의 3차원 수치해석모델을 개발하였다. 수치해석모델을 사용하여 평행류 유동장과 interdigitated 유동장의 압력강하, 채널간의 물질전달, $H_2O$와 $O_2$의 농도 분포 그리고 i-V 성능을 비교하였다. 그 결과 물질전달에서 채널간의 대류에 의한 물질전할이 더욱 우수한 interdigitated 유동채널에서 성능이 더 높게 나타났으며 압력강하는 보다 크게 나타나 설계시 두가지 성능에 대한 상호보완이 필요함을 알 수 있었다. Optimum design of flow channel in the separation plate of Proton Exchange Membrane Fuel Cell is very prerequisite to reduce concentration over potential at high current region and remove the water generated in cathode effectively. In this paper, fully 3 dimensional computational model which solves anode and cathode flow fields simultaneously is developed in order to compare the performance of fuel cell with parallel and interdigitated flow channels. Oxygen and water concentration and pressure drop are calculated and i-V performance characteristics are compared between flows with two flow channels. Results show that performance of fuel cell with interdigitated flow channel is hi민or than that with parallel flow channel at high current region because hydrogen and oxygen in interdigitated flow channel are transported to catalyst layer effectively due to strong convective transport through gas diffusion layer but pressure drop is larger than that in parallel flow channel. Therefore Trade-off between power gain and pressure loss should be considered in design of fuel cell with interdigitated flow channel.

유동방향 변화에 따른 고분자 전해질 연료전지의 성능 및 전달특성에 대한 3차원 수치해석적 연구

이필형,한상석,황상순,Lee, Pil-Hyong,Han, Sang-Seok,Hwang, Sang-Soon 한국전기화학회 2008 한국전기화학회지 Vol.11 No.1

Many researches for effects of different flow configurations on performance of Proton Exchange Membrane Fuel Cell have extensively been done but the effects of flow direction at the same flow channel shape should be considered for optimal operation of fuel cell as well. In this paper a numerical computational methode for simulating entire reactive flow fields including anode and cathode flow has been developed and the effects of different flow direction at parallel flow was studied. Pressure drop along the flow channel and density distribution of reactant and products and water transport, ion conductivity across the membrane and I-V performance are compared in terms of flow directions(co-flow or counter-flow) using above numerical simulation method. The results show that the performance under counter-flow condition is superior to that under co-flow condition due to higher reactant and water transport resulting to higher ion conductivity of membrane. 고분자 전해질 연료전지의 성능향상을 위한 방법으로 유동채널의 형상을 변경한 많은 연구가 진행되어 왔으나 동일한 유동채널 형상에서 유동방향 변경에 따른 연구는 많이 진행되지 못하였다. 본 연구에서는 동일한 반응면적과 동일한 유동채널의 고분자 전해질 연료전지의 수소와 산소의 유동방향을 Co-flow에서 Counter-flow로 변경될 경우의 연료전지의 성능변화를 분석하기 위하여 연료극과 공기극이 포함된 3차원 수치해석모델을 개발하였다. 개발된 수치해석모델을 활용하여 Co-flow와 Counter-flow의 유동채널 내부의 압력손실, 반응물질의 농도분포, 고분자 전해질 막을 통한 Water Transport, 고분자 전해질 막의 이온전도도 및 I-V 성능곡선을 비교하였다. 그 결과 반응물질의 농도분포, Water Transport, 고분자 전해질 막의 이온전도도가 우수한 Counter-flow 유동조건에서의 성능이 Co-flow 유동조건에 비하여 더욱 우수하였다.

Baffle Plate 변화에 따른 다공 원통형 버너의 평면 예혼합 화염특성

이필형(PilHyong Lee),한상석(SangSeok Han),이재영(JaeYoung Lee),박창수(ChangSoo Park),황상순(SangSoon Hwang),이돈형(DonHyung Lee),허정선(JeongSeon Heo) 한국연소학회 2008 KOSCOSYMPOSIUM논문집 Vol.- No.-

다공철판을 활용한 다공 원통형 버너는 금속재질의 Baffle Plate와 화염 염공을 활용하여 원통형버너를 구성하기 때문에 높은 내구성, 강한 취성을 가지고 있어 많은 연구의 대상이 되고 있다. 봉 논문애서는 청동소결 Baffle Plate와 화염지지대를 적용하여 새로운 개념의 원통형버너를 개발하였다. 개발된 다공 원통형 버너의 실험을 통하여 청동소결 Baffle Plate가 연소화염의 안정성에 미치는 영향을 분석하였으며 화염지지대의 설치가 염공의 입구부분과 끝단부분에 발생하는 화염날림 현상에 미치는 영향을 분석하였다. 개발된 다공 원통형 버너의 배기가스 특성을 분석하였으며 분석결과 당량비(Ф)가 0.706-0.775부분에서 7ppm이하의 'Ox배출특성과 57ppm(O' 0% Base)이하의 'O배출특성을 확인하였다.

합성가스를 이용한 역확산버너의 연소 및 복사열전달 특성, Part 1 : 공기-연료 연소

이필형(Pil Hyong Lee),박창수(Chang Soo Park),이재영(Jae Young Lee),박봉일(Bong Il Park),황상순(Sang Soon Hwang),이성호(Sung Ho Lee),안용수(Yong Soo Anh) 한국연소학회 2009 한국연소학회지 Vol.14 No.4

Waste Thermal Pyrolysis Melting process was proposed and has been studied in order to prevent air pollution by dioxin and fly ash generated from combustion process for disposal of waste. In this study, applicability as the fuel of diffusion burner of synthesis gas formed from Waste Thermal Pyrolysis process was addressed. Results showed that there is no big difference in the flame shape between MNDF and SNDF, and lift off was detected in MIDF but flame is more stable in SIDF which contains hydrogen with high combustion velocity as flow rate in first nozzle is increased. And radiation heat flux in inverse diffusion flame of synthesis gas was found to be more by 1.5 times than that in inverse diffusion flame of methane because of higher mole fraction of CO₂ with high emissivity in product gas.

개질기용 예혼합 연소시스템의 화염안정성 분석

이필형(Pil Hyong Lee),이재영(Jae Young Lee),박창수(Chang Soo Park),박봉일(Bong Il Park),황상순(Sang Soon Hwang) 한국연소학회 2009 KOSCOSYMPOSIUM논문집 Vol.- No.38

Fuel processing systems which convert fuel into rich gas need high temperature environment. Generally, anode-off gas or mixture of anode-off gas and LNG used as input gas of fuel reformer. The purpose of this study is to develop a porous premixed flat ceramic burner that can be used for 1-5㎾ fuel cell reformer. Ceramic burner experiments using natural gas, hydrogen gas, anode-off gas were carried out respectively to investigate the flame stability characteristics by heating capacity and equivalence ratio. Results show that the stable flat flames can be established for natural gas, hydrogen gas, anode off gas and mixture of natural & anode off gas as reformer fuel in the porous ceramic burner. For all of fuels, their burning velocities become smaller as the equivalence ratio goes to the lean mixture ratio, and a lift-off occurs at lean limit. Flame length in hydrogen and anode off gas became longer with increasing the heat capacity. In particular, the blue surface flame is found to be very stable at a very lean equivalence ratio at heat capacity and different fuels.

액체연료의 가스화를 통한 예혼합 연소기의 연소특성

이필형(Pil Hyong Lee),차천륜(Chun Loon Cha),황상순(Sang Soon Hwang) 한국연소학회 2014 KOSCOSYMPOSIUM논문집 Vol.2014 No.5

한국부인의 뇨중 Gonardotropin 치, 특히 월경 주기 이상환자, 거세부인의 뇨중 Gonardotropin 치 및 Estrogen 투여전후의 뇨중 Gonardotropin치의 변동

이필형(PH Lee) 대한산부인과학회 1961 Obstetrics & Gynecology Science Vol.4 No.1

뇨중 하수체성 G를 Crook법으로 정상월경주위를 가진 6예에서 월경기, 난포기, 배란기, 황체기, 4기로 나누어 GA. GB로 분리 측정했던 바 그 성적은 대략 아래와 같다. 1. 월경전주기를 통하여 GA. GB 양자 다 증명할 수 있으며 그 평균은 GA, 197γ/24hrs GB, 197γ/24hrs이다. 2. 배란기에서는 GA, GB 양자 다 peak를 정하며 GA, 360γ/24hrs GB, 142γ/24hrs이다. 3. 전주기를 통하여 GA/GB는 일정한 범위내에 있으며 그 범위는 2~3이다. 월경주기이상환자와 거세부인의 뇨중 G을 화학적인 방법으로 정량해서 정상량과 비교 검토하고 Estrogen투여전후의 변동에 대하여(특히 GA, GB의 소장) 관찰한 바 그 결과는 대략 다음과 같다. 1. 무월경환자의 G은 GA치, GB치, GA/GB가 정상과 다른 pattern을 보인다. 2. 월경불순, (희발성 무경) 환자에서는 GA가 높고 GB가 정상, 혹은 낮아서 GA/GB가 현저히 증가되어 있다. 3. 거세후 1~2개월에 있는 부인에서는 GB가 현저히 증가해 있다. 4. Estrogen 투여가 G에 미치는 영향은 GB에 더 현저하다. 5. Estrogen 10,000 I.U.를 연속투여하면 GA. GB 양자의 방출을 항진시키고 50,000 I.U. 이상 연속투여하면 양자의 방출을 억제한다. 6. Estrogen 20,000 I.U. 연속투여는 GB의 방출을 항진 혹은 억제시킨다. In determination and evaluation of pitiutary gonadotropin, complicated biological methods for the assessment have been employed. However, recent advancement has clarified the physical and chemical nature of the substance. In cope with this advancement, a new quantitative analytical method, Crooke`s method, has been adapted enabling clinical use with the omission of complicacy in the procedure. Furthermore, this procedure has provided fractional analysis of gonado-tropin into GA and GB which correspond to FSH and LH respectively, and the knowledge of interrelationship and of balance between these fractions in various endocrinological environments. It has been well known that this procedure paved the way to establishment of diagnosis and therapeutic measures in case of functional disorders involving hypothalamus-pituitary-ovary system. By this chemical method, the levels of urinary gonadotropin in normal menstrual cycles and various irregular menstrual cycles were measured and the comparison between them were made. So called "feed back mechanism" upon hypothalamus-pituitary system, yet inconclusive, were reviewed from the view point of chage in urinary gonadotropin excretion following the administration of estrogen benzoate. The results are as follows. 1) The presence of gonadotropin in female urine obtained from the individuals with regularity of catamenial cycles and the highest level of gonadotropin were observed during the ovulation time. The average levels in urine were GA, 197γ/24hrs. and GB,80γ/24hrs. GA/GB was 2.5. 2) In comparison with the level of GA, GB, and GA/GB in normal cycles, the amount of GA and GB, also their ratio in patient with abnormal menstrual cycles difference. The levels of GB were especially deviated from normal ranges. 3) The adminaistration of estrogen benzoate were likely to be influential to the level of urinary gonadotropin in abnormally menstruating individuals, especially to GB. In case the estrogenic hormone 10,000 units (I.U.) given daily, increase of GA and GB were observed. On the contrary, administration of a single dose of more than 50,000 units of estrogen showed inhibitory effects. The amount of estrogenic hormone which acted as inhibitor, if given as single dose, would increase the amount of GA and GB in case of the same amount divided.

부분산화법과 초단열화염을 적용한 개질시스템 연구

이필형(Pil Hyong Lee),황상순(Sang Soon Hwang) 한국연소학회 2013 KOSCOSYMPOSIUM논문집 Vol.2013 No.12

열적부분산화법을 적용한 Perforated SiC 관의 개질특성연구

이필형(Pil Hyong Lee),차천륜(Chun Loon Cha),홍성원(Seong Weon Hong),임현진(Hyun Jin Im),황상순(Sang Soon Hwang) 한국연소학회 2012 KOSCOSYMPOSIUM논문집 Vol.- No.44

산소극 가습도 변화에 따른 고분자 전해질 연료전지의 성능변화에 대한 3차원 수치해석적 연구

이필형(Pilhyong Lee),한상석(Sangseok Han),이재영(Jaeyoung Lee),박창수(Changsoo Park),황상순(Sangsoon Hwang) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Flow configuration and operating condition such as cell temperature, humidity at each cell, stoichiometric number is very crucial for improving its performance. Too many flow channels could enhance the performance resulting in high parasite loss. Therefore trade off between pressure drop and efficiency of fuel cell should be considered for optimum design. This work focus on numerical simulation the effects of operating condition, especially cathode humidity, with simple parallel now channel. It is known that humidity at cathode becomes very important for predicting performance of fuel cell because fully humidified condition was normally set at anode. Results show the maximum power density can be obtained under 20~30% humidified condition at cathode where oxygen concentration is moderate high maintaining high thermal conductivity at a membrane.