http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오프셋 스트립 휜을 가지는 리큐퍼레이터의 내부 형상 최적화
도규형,한용식,최병일,김명배,Do, Kyu-Hyung,Han, Yong-Shik,Choi, Byung-Il,Kim, Myung-Bae 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.6
In the present study, a recuperator is suggested to improve the thermal efficiency of a micro gas turbine. Primary design parameters of the recuperator are determined from the ideal cycle analysis. The counter flow plate-fin heat exchanger with offset strip fins is chosen as the type of the recuperator. In order to satisfy the design constraints which are the minimum effectiveness and the maximum pressure drop, the optimization for the internal structure of the recuperator is performed with varying the fin spacing and the fin height of offset strip fins. Also the effects of the thermal conductivity of fins and separation plates and the longitudinal heat conduction on the thermal performance of the recuperator are investigated.
태양열/공기열 복합 집열기를 가지는 하이브리드히트펌프 시스템의 열성능에 관한 연구
도규형,최병일,한용식,김명배,김태훈 한국수소및신에너지학회 2016 한국수소 및 신에너지학회논문집 Vol.27 No.2
In the present work, a solar assisted heat pump (SAHP) system with a hybrid collector was analyzed. For this, a simplified thermodynamic model was developed. Based on the proposed model, the heat transfer rate, COP, and the annual operating hour of the SAHP system were estimated. The effect of the variation of system design parameters on the performance of the system was also examined. From the results, the performance was improved with increasing the effectiveness of heat exchangers and decreasing the difference between the evaporation temperature and the outlet brine temperature of the hybrid collector loop. Finally, the performance of SAHP system with a hybrid collector was compared with that of conventional serial and parallel SAHP systems. The SAHP system with a hybrid collector was substantially better than a series system and slightly worse than a parallel system for both the yearly averaged heat transfer rate and COP. However, the annual operating hour of the SAHP system with a hybrid collector was much better than that of a parallel system.
500W 급 마이크로 가스터빈을 위한 파형 휜을 가지는 리큐퍼레이터의 열성능 비교
도규형,김태훈,한용식,최병일,김명배,Do, Kyu Hyung,Kim, Tae Hoon,Han, Yong-Shik,Choi, Byung-Il,Kim, Myung Bae 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.6
In this study, thermal performance of recuperators with plain and offset strip fins is investigated to enhance the thermal efficiency of a micro gas turbine. Thermal cycle analysis is conducted to determine major design parameters of a single-pass counterflow recuperator. In order to evaluate the performance of the recuperator, the effectiveness and the pressure drop in the recuperators are chosen as the objective function and the design constraint, respectively. The optimized geometries for internal structure of the recuperators with plain and offset strip fins are obtained with varying the fin spacing and height. From the result, the recuperator with offset strip fins has better thermal performance when the fin spacing, s, is smaller than 1.45mm and the thermal performance of the recuperator with plain rectangular fins is higher than that with offset strip fins in the region of $s{\geq}1.45mm$. In addition, it is found that the entrance region effect and the longitudinal wall heat conduction effect should be taken into account for accurately predicting the thermal performance of the recuperators with both plain and offset strip fins.
대형 수소 액화 플랜트의 정량적 위험도 평가에 관한 연구
도규형,한용식,김명배,김태훈,최병일 한국수소및신에너지학회 2014 한국수소 및 신에너지학회논문집 Vol.25 No.6
In the present study, the frequency of the undesired accident was estimated for a quantitative riskassessment of a large-scale hydrogen liquefaction plant. As a representative example, the hydrogen liquefactionplant located in Ingolstadt, Germany was chosen. From the analysis of the liquefaction process and operatingconditions, it was found that a LH2 storage tank was one of the most dangerous facilities. Based on the accidentscenarios, frequencies of possible accidents were quantitatively evaluated by using both fault tree analysis and eventtree analysis. The overall expected frequency of the loss containment of hydrogen from the LH2 storage tank was6.83×10-1times/yr (once per 1.5 years). It showed that only 0.1% of the hydrogen release from the LH2 storagetank occurred instantaneously. Also, the incident outcome frequencies were calculated by multiplying the expectedfrequencies with the conditional probabilities resulting from the event tree diagram for hydrogen release. The resultsshowed that most of the incident outcomes were dominated by fire, which was 71.8% of the entire accident outcome. The rest of the accident (about 27.7%) might have no effect to the population.
CPV 냉각용 열분산기 모듈의 열성능에 관한 실험적 연구
도규형,한용식,최병일,김명배 한국태양에너지학회 2011 한국태양에너지학회 논문집 Vol.31 No.4
Inthispaper,thethermalperformanceofaheatspreadermoduleforCPV(ConcentratingPhotovoltaic)cooling isexperimentallyinvestigated.Inordertoevaluatethethermalperformanceoftheheatspreadermodulewhich consistsofaMetalPCB andanaluminum alloyheatspreader,experimentsareconductedwithvaryingthetype ofthemetalPCB,thethicknessoftheheatspreader,theinclinationangle,andtheappliedheatflux.Tovalidate theexperimentaldata,threedimensionalnumericalsimulationsareperformedusingthecommercialsimulationtool inthepresentwork.Theexperimentalresultsarecomparedwiththecorrespondingnumericalresultsandarein closeagreementwiththenumericalresults.From theexperimentalresults,thetemperaturedifferencebetweenthe maximum temperatureandtheambienttemperatureincreaseswithdecreasingthethicknessoftheheatspreader andwith increasing theappliedheatflux.Also,itisfound thattheinclination anglesignificantly affectsthe thermalperformanceoftheheatspreader.themaximum temperaturedifferenceoftheheatspreaderwiththe horizontalorientationismuchlargerthanthatwiththeverticalorientation
500 W 급 마이크로 가스터빈 제너레이터용환형 연소기의 특성에 관한 연구
도규형,김태훈,한용식,김명배,최병일 한국연소학회 2014 한국연소학회지 Vol.19 No.4
In the present study, an annular combustor for a 500 W class micro gas turbine generator was designed andits characteristics were investigated by using both numerical and experimental methods. For this purpose,geometrical configurations of the annular combustor were determined in the aspect of the aerodynamic andchemical consideration. Also, fluid flow and pressure drop characteristics in the combustor were numericallystudied by using commercial tool, FLUENT. Based on the numerical results, the diameter and the angle ofair admission holes in the primary zone were chosen to be 2.5 mm and 30°, respectively. Finally, an integratedtest unit, which consisted of a compressor, combustor, turbine, and motor/generator, was developed in orderto measure the combustor efficiency. As the temperature difference between the combustor inlet and the turbineinlet or the air mass flow rate increased, the combustor efficiency increased and it was over 90% when theair mass flow rate was larger than 7.30 g/s. It was shown that the annular combustor developed in this studymet the design requirement for a 500 W class micro gas turbine generator.
플레이트-휜을 가지는 자연대류 히트싱트의 경사각 변화에 대한 실험적 연구
도규형(Kyu Hyung Do),김태훈(Tae Hoon Kim),한용식(Yong-Shik Han),최병일(Byung-Il Choi),김명배(Myung Bae Kim) 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.6
본 연구에서는 등온 가열 조건 하에서 플레이트-휜을 가지는 자연대류 히트싱크의 열성능을 측정하기 위한 실험적 연구를 수행하였다. 실험은 자연대류 히트싱크의 열입력량, 휜 간격 및 높이를 변화시키면서 수행하였다. 특히, 경사각 변화가 자연대류 히트싱크의 열성능에 미치는 영향에 대해 연구하였다. 기존 연구자들이 제시한 열저항 상관식과 본 연구에서 수행한 실험결과의 비교를 통해 실험결과의 타당성을 검증하였다. 또한 실험결과를 바탕으로 자연대류 히트싱크의 열입력량, 휜 간격 및 높이, 그리고 경사각에 대하여 기존 연구자들이 제시한 상관식의 적용가능 범위를 평가하였다. In this paper, an experimental investigation is performed to estimate the thermal performance of a natural convective heat sink with plate fins subject to the uniform wall temperature condition. Extensive experiments are performed with various input powers, fin spacings, and heights of the natural convective heat sinks with plate fins. In particular, the effect of the inclination angle on the thermal performance of the heat sink is studied. In order to validate the experimental data, the experimental results are compared with results from previous studies. Based on the experimental results, the appropriate ranges of the previous correlations between the input power, the fin spacing, the fin height, and the inclination angle for the natural convective heat sink with plate fins are evaluated.
수직방향 플레이트-휜을 가지는 자연 대류 히트싱크의 열성능에 관한 실험적 연구
도규형(Kyu Hyung Do),김태훈(Tae Hoon Kim),한용식(Yong-Shik Han),최병일(Byung-Il Choi),김명배(Myung-Bae Kim),이유환(Yu-Whan Lee) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11
In this paper, an experimental investigation is performed for estimating the thermal performance of a natural convective heat sink with vertically oriented plate-fins subject to the uniform wall temperature condition. Extensive experiments are performed with various input powers and channel widths and heights of natural convective heat sinks with plate-fins. Numerical simulations are performed to validate experimental results. Also, experimental results are compared with the results obtained from previous correlations. It is shown that the influence of inflow from the front significantly affects the thermal performance of the heat sink and should be considered to accurately predict thermal resistance of the natural convective heat sink with plate-fins.