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알루미늄 플레이트-핀 열교환기의 분배기 형상비에 따른 분배특성에 관한 해석적 연구
이응찬(Eungchan Lee),강훈(Hoon Kang),허재혁(Jaehyeok Heo),김용찬(Yongchan Kim),박재홍(Jaehong Park),조성열(Sungyoul Cho) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.8
알루미늄 플레이트-핀 열교환기는 석유 및 가스 처리공정에서 널리 사용되고 있다. 알루미늄 플레 이트-핀 열교환기의 성능은 각 유체의 헤더 및 분배기에서의 분배 성능에 의하여 크게 영향을 받는다. 본 연구에서는 CFD(Computational fluid dynamics)를 이용하여 알루미늄 플레이트-핀 열교환기의 측면 입구 형태의 분배기를 모델링하고, 입구 조건과 형상비의 변화에 따른 상대 및 절대 불균등 분배도를 고찰하여 최적 분배기 형상비를 제시하였다. Aluminum plate-fin heat exchangers (ALPHEs) are widely used in petroleum and gas-treated processes. The performance of the ALPHE is strongly dependent on the distribution characteristics of the header and the distributors of each fluid. In this paper, we define the aspect ratio in the side-entry type distributor and analyze the distribution characteristics using CFD-based numerical methods. The phenomena of velocity deviation and distribution with the aspect ratio and the inlet Reynolds number were analyzed by applying relative and absolute maldistribution parameters, and an optimum aspect ratio with the inlet Reynolds number was presented.
이응찬(Eungchan Lee),곽정민(Jeongmin Kwak),유지헌(Jiheon Ryu),유병용(Byeongyong Yoo) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
Liquefied hydrogen is the optimal alternative to long distance transportation of hydrogen with large-capacity in a safe and efficient way. The liquefied hydrogen should be stored and transported to –253℃ for a lower than –163℃, which is a storage temperature of LNG at atmospheric pressure. Liquefied hydrogen carriers require a cargo tank with a higher insulation performance than conventional LNG carriers and cargo handling system with minimized the loss of boil-off gas. In this paper, the zero-vent cargo handling system capable of efficiently treating the liquefied hydrogen boil-off gas is introduced by targeting a 20,000 m3-class liquefied hydrogen carrier of KSOE.
이응찬(Eungchan Lee),백창현(Changhyun Baek),강훈(Hoon Kang),김용찬(Yongchan Kim),조홍현(Honghyun Cho),조성욱(Sungwook Cho) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.6
The performance of a CO₂ heat pump water heater was measured with a variation of operating conditions such as refrigerant charge amount, outdoor temperature, compressor frequency, EEV opening, and water mass flow rate. The optimum refrigerant charge amount of the CO₂ system was 1800 g. At water mass flow rates of 75, 85, and 95 ㎏/h, the water heating temperatures were 74, 67, and 62℃ and COPs were 2.6, 2.8, and 3.0, respectively. Besides, the compressor frequency and water mass flow rate were adjusted to maintain the water heating temperature at 60℃ with the decrease of outdoor temperature. As the outdoor temperature decreased by 5 ℃. the compressor frequency increased beyond 60 ㎐ and the water mass flow rate decreased by 16.7%.
손재욱(Jaewook Son),이응찬(Eungchan Lee),강훈(Hoon Kang),김용찬(Yongchan Kim),김정규(Jung-Kyu Kim),조성열(Sung-Youl Cho),박재홍(Jae-Hong Park) 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.6
판형열교환기는 높은 효율로 인하여 다양한 산업 분야에 사용되고 있으며, 판형열교환기의 성능특성을 파악하기 위해 많은 연구가 이루어 졌다. 하지만 세브론 각을 제외한 판형열교환기의 기구적 설계변수에 따른 성능특성 파악은 상대적으로 많이 부족한 실정이다. 본 연구는 판형열교환기의 기구적 설계변수에 따른 열전달 및 압력강하 성능특성을 파악하기 위해서 세브론 각, 전열판 골 깊이, 전열판골 길이, 전열판 개수 등을 변화시키며 실험을 수행하였다. 실험결과를 바탕으로 판형열교환기의 다양한 기구적 설계변수를 반영한 열전달 및 압력강하 성능특성 상관식을 제안하였다. 실험 데이터와 제안된 판형열교환기 상관식을 이용해 예측된 데이터를 비교한 결과 약 95% 이상의 데이터가 ±10% 오차범위 내에 존재함을 알 수 있었다. Plate heat exchangers have been widely used in many industrial applications because of their compactness and high efficiency. Even though plate heat exchangers have been investigated extensively, studies on the effects of geometric parameters other than the chevron angle are very limited in the open literature. In this study, the effects of the chevron angle, corrugation length, corrugation depth, and the number of plates on the heat transfer and pressure drop characteristics of plate heat exchangers were investigated experimentally. Based on the experimental results, empirical correlations were proposed. More than 95% of the predictions made based on the correlations had relative deviations of less than ±10% when compared with the measured data.
판형열교환기의 운전변수 및 설계변수에 따른 난방 성능 특성에 관한 연구
전재명(Jaemyeong Jeon),이응찬(Eungchan Lee),강훈(Hoon Kang),김용찬(Yongchan Kim) 대한설비공학회 2013 대한설비공학회 학술발표대회논문집 Vol.2013 No.11
District heating systems are widely used due to high-efficiency and eco-friendly. A plate heat exchanger is suitable for district heating systems. Even though studies on the plate heat exchangers have been performed by many researchers, the effects of the operation and geometric parameters on the performance of district heating are very limited in open literature. In this study, the effects of the geometric and operation parameters on the heat transfer and pressure drop characteristics of plate heat exchangers were investigated experimentally by varying the chevron angle, hot and cold side flow rate, and inlet temperature. As a result, chevron angle 60˚/60˚ represented the highest pressure drop and heat transfer coefficient. The heat transfer performance increased with increasing the hot side flow rate and inlet temperature.
판형열교환기의 운전 및 설계변수에 따른 파울링 특성에 관한 연구
전재명(Jaemyeong Jeon),이응찬(Eungchan Lee),강훈(Hoon Kang),김용찬(Yongchan Kim) 대한설비공학회 2014 설비공학 논문집 Vol.26 No.4
The plate heat exchanger has been widely used in water heating systems due to high efficiency, simple structure, and easy maintenance. However, the studies on the effects of fouling on the heat transfer performance under various operation and maintenance conditions are very limited in the open literature. The objective of this study is to investigate the effects of fouling with calcium carbonate (CaCO3) on the heat transfer characteristics of the plate heat exchanger under various operating and geometric conditions. The heat transfer coefficient and pressure drop in the plate heat exchangers were measured under accelerated fouling conditions with CaCO3 by varying geometric and operational parameters. The fouling resistance increased with the decrease in the flow rate, and the increase in the chevron angle and the concentration.
판형열교환기 열전달 및 압력강하 성능해석 프로그램 개발
손재욱(Jaewook Son),이응찬(Eungchan Lee),강훈(Hoon Kang),김용찬(Yongchan Kim),박재홍(Jaehong Park),조성열(Sungyoul Cho) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7
Plate heat exchangers have been widely adopted in many industrial applications due to their compactness and high efficiency. In this study, a simulation algorithm was developed using semi-analytical correlations, and the predicted data were compared with the measured data to validate the model. The analytical pressure drop correlation were corrected by comparing with the measured data, and applied to the performance analysis program. In conclusion, the calculated pressure drop data showed the difference less than 5-10%, comparing with the measured data.
운전조건 변화에 따른 이산화탄소 열펌프의 냉난방 성능특성 비교
조홍현(Honghyun Cho),백창현(Changhyun Baek),이응찬(Eungchan Lee),강훈(Hun Kang),김용찬(Yongchan Kim) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.6
Since operating conditions are significantly different for heating and cooling mode operations in a CO₂ heat pump system, it is difficult to optimize the performance of the CO₂ cycle. In addition, the performance of a CO₂ heat pump is very sensitive to outdoor temperature and gascooler pressure. In this study, the cooling and heating performances of a variable speed CO₂ heat pump with a twin-rotary compressor were measured and analyzed with the variations of EEV opening and compressor frequency. As a result, the cooling and heating COPs were 2.3 and 3.0, respectively, when the EEV opening was 22%. When the optimal EEV openings for heating and cooling were 28% and 16%, the cooling and heating COPs increased by 3.3% and 3.9%, respectively, over the COPs at the EEV opening of 22%. Beside, the heating performance was more sensitive to EEV opening than the cooling performance. As the compressor speed decreased by 5 Hz, the cooling COP increased by 2%, while the heating COP decreased by 8%.
항공정찰장비용 환경제어시스템의 냉각특성에 관한 실험적 연구
강훈(Hoon Kang),박형필(Hyungpil Park),이응찬(Eungchan Lee),김용찬(Yongchan Kim),지용남(Yongnam Chi),최희주(Heeju Choi),변영만(Youngman Byeon),김영진(Youngjin Kim),오광윤(Kwangyoon Oh) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.9
Environmental control system is adopted to control the thermal load from the avionic equipment in the reconnaissance pod which is mounted under a fighter aircraft, undergoing large and rapid environmental changes with the variations of flight altitude and velocity. In this study, an environmental control system was designed and built by adopting vapor compression cycle using R-124. The cooling performance characteristics of the system were measured varying operating parameters: thermal load in the pod, air mass flow rate through evaporator, condenser inlet air temperature, and air mass flow rate through condenser. The effects of the experimental parameters on the system performance were analyzed based on the experimental results. The problems on the designed system were also analyzed and the solutions were suggested to improve system efficiency and to obtain stable operation.
이산화탄소 급탕 열펌프의 난방 성능에 관한 실험적 연구
조홍현(Honghyun Cho),조성욱(Sungwook Cho),백창현(Changhyun Baek),이응찬(Eungchan Lee),강훈(Hoon Kang),김용찬(Yongchan Kim) 대한설비공학회 2008 대한설비공학회 학술발표대회논문집 Vol.2008 No.2
In this study, experimental study on the heating performance of a CO₂ heat pump water heater with a variation of operating conditions such as refrigerant charge amount, outdoor temperature, compressor frequency, EEV opening and water mass flow rate. Based on the test results, the optimum charge amount was 1800 g. At the water mass flow rates of 75, 85, 95 ㎏/hr, the water heating temperature was 62, 67, 74℃ and COP was 2.6, 2.8, 3.0, respectively. Besides, the water mass flow rate and compressor frequency were varied to maintain above the water heating temperature of 60℃ with the decrease of outdoor temperature. So, The compressor frequency increased beyond 65 Hz and the water mass flow rate was 45 kg/hr at the outdoor temperature of -13℃, 65 ㎏/hr at -8℃, 75 ㎏/hr at -3℃ and 85 ㎏/hr at 2, 7℃. As the outdoor temperature decreased, the heating COP decreased by 2.5-39.8%.