http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 팽진기(Paeng (검색결과 6 건)
- 무료
- 기관 내 무료
- 유료
-
팽진기(Jin Gi Paeng),윤영환(Young Hwan Yoon) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.5
A ceramic monolith heat exchanger is studied to find the performance of heat transfer and pressure drop by numerical computation and ζ-NTU method. The numerical computation was performed throughout the domain including fluid region in exhaust gas-side rectangular ducts, ceramic core and fluid region in air-side rectangular duct with the air and exhaust in cross flow direction. In addition, the heat exchanger was also analyzed to estimate the performance by conventional ζ-NTU method with several Nusselt number correlations for flow in rectangular duct from literature. By comparisons of both performances by the numerical computation and the ζ-NTU method, the effectiveness by ζ-NTU method was closest to the result by numerical computation within a relative error of 2.14% when Stephan's Nusselt number correlation was adopted to the ζ-NTU method among the several correlations.
-
일체형 세라믹 열교환기의 전산 열응력 해석에 관한 연구
팽진기(Jin Gi Paeng),김기철(Ki Chul Kim),윤영환(Young Hwan Yoon) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.11
The thermal stresses of a ceramic heat exchanger were analyzed numerically since the ceramic material is good in heat resistance but weak in the thermal stress. The analysis of thermal stress was conducted in the ceramic core with two boundary conditions depending on bolt jointing. The thermal stresses were computed by applying temperature and pressure distributions obtained from the numerical results of conjugate heat transfer to ANSYS WORKRBENCH. When number of bolt joining halls was reduced from 8 × 2 to 4 × 2, the maximum principal stresses decrease by 47.6~50.5% and increase in safety factors by 2.18~2.5 for ultimate tensile strength. Thus, it can be said that bolt joining halls should be minimized in ceramic heat exchanger to be efficient in reducing thermal stress. In addition, the width of particular gas flow passages were revised from 52 mm to 42 mm to reduce maximum thermal stresses since certain passages experienced high thermal stresses. From the revision, safety factors were increased by 13.8~14.1% for the boundary condition of 4 × 2 bolt joining halls, Therefore, it is suggested that thermal stress can be reduced by changing local geometry of a ceramic heat exchanger.
-
이중진공관형 태양열 집열기의 연간 집열효율에 관한 연구
김기철(Kim Ki-Chul),팽진기(Paeng Ji-Gi),윤영환(Yoon Young-Hwan) 한국태양에너지학회 2008 한국태양에너지학회 논문집 Vol.28 No.4
The Storage efficiency of concentric evacuated tube solar collector is tested for one year from January 1st to December 31st under the real sun condition. The testing equipment is operated continuously for three days without cooling the storage tank. Daily storage efficiency is obtained from dividing stored energy in the storage tank by solar insolation on the solar collector for each day. Daily averaged temperature of the storage tank is lowest in January and highest in August. Monthly averaged storage efficiency is also lowest in November and highest in June. Therefore, it can be said that the storage temperature and the storage efficiency are roughly proportional to outdoor temperature. Furthermore, the daily storage efficiency is reversely proportional to (Ts - Ta)/Ic, where Ts and Ta are daily averaged storage temperature and outdoor temperature from sunrise to sunset, and Ic is total insolation on the solar collector for a day.
-
연료전지용 소형 금속 열교환기의 성능에 대한 실험 및 이론적 연구
윤영환(Yoon,Young-Hwan),팽진기(Paeng,Jin-Gi) 한국태양에너지학회 2011 한국태양에너지학회 논문집 Vol.31 No.4
This study assessed the performance of a compact heat exchanger with staggered tube banks for recuperation of high temperature exhaust thermal energy for SOFC fuel cell system. The compact heat exchanger in this study is two pass system which consists of 315×202.5×48.5㎣ and 132 tubes of 6.0㎜Φ for each heat exchanger. From experiments of the 2 pass heat exchanger system, air temperature was increased from 50~85℃ to 402~482℃ while gas temperature was decreased from 600℃ to 305~402℃ according to mass flow rates of 3.9~7.8 g/s. The experimental heat transfer rates of the heat exchanger were compared with CFD numerical solutions with the conventional ζ-NTU method. From the comparisons, the following conclusions were obtained. For the heat exchanger system, the relative errors of heat transfer rate by CFD solution were from 7.1 to 27%, and those by ζ-NTU method were from 0.6% to 21% compared with experimental data. From the comparisons, it can be said that both of CFD and ζ-NTU method almost simulated to experimental data except specific conditions. Pressure drops through air tubes and gas passages were calculated with both of the CFD computation and head loss equations. The differences between them were from 14 to 22%.
-
-
부분분사에서 작동하는 소형 사류형 터빈에서의 성능특성에 관한 연구
조종현(Chong-Hyun Cho),김재실(Chaesil Kim),팽진기(Jingi Paeng),조수용(Soo-Yong Cho) 한국항공우주학회 2009 韓國航空宇宙學會誌 Vol.37 No.9
본 연구에 적용된 터빈은 사류형 터빈이며 동익의 외경은 108 ㎜ 이다. 터빈은 1.7-2.0%의 낮은 부분분사율에서 작동하므로 익형은 축류형으로 설계되었으며 2단으로 구성되었다. 분사가 축방향으로 형성된 경우와 반경방향으로 형성된 경우에 따른 성능특성의 차이가 연구되었다. 또한 터빈의 단수에 따른 성능특성도 비교 되었다. 터빈의 작동범위에 따른 비교를 위하여 회전수를 변경하면서 성능평가가 이루어졌을 뿐만 아니라 시스템의 평가를 위하여 총 비토오크가 얻어졌다. 사류형 터빈이므로 축방향으로 분사되는 경우가 반경방향으로 분사되어지는 경우보다는 양호한 성능을 얻었으며, 출구단 동익의 효과는 회전수에 의하여 좌우되지만 축방향 분사터빈 경우에 최대 7.8%의 비토오크 상승의 결과를 보여주었다. A mixed-type turbine was adopted and the rotor outer diameter was 108 ㎜. Turbine rotors were designed to the axial-type blade because the turbine operated at a low partial admission rate of 1.7-2.0% with two stages. Performance characteristics were studied when the spouting from the nozzle was toward radially inward or outward direction. Additionally, the effect at each stage of the rotor was measured. For comparing with each turbine performance, properties were measured based on various rotational speeds. Measured net specific torque was used to compare with the turbine system performance. On the mixed-type turbine, better performance was obtained when the operating air spouted toward radially inward direction. The specific torque was increased by 7.8% from using the second stage although its effect depended on the rotational speed.
ScienceON
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
