http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
시뮬레이션 모델을 이용한 직팽식 열교환기의 냉각 성능 예측
박성기(Seonggi Park),장동수(Dong Soo Jang),이동찬(DongChan Lee),김용찬(Yongchan Kim) 대한설비공학회 2016 대한설비공학회 학술발표대회논문집 Vol.2016 No.6
With the rise of electric vehicles, the thermal management of the batteries becomes important issue. The technical requirements for high capacity and compactness of the batteries make the thermal management critical. As the overheat of the batteries degrades the performance and durability of the vehicles, an effective cooling device to lower the temperature is needed. In this study, a simplified model of a direct expansion heat exchanger was developed. The direct expansion heat exchanger consists of the large number of lithium-ion battery cells as a heat source, and 4 cooling channels attached to the cells. The cooling fluid was R-134a flowing horizontally through rectangular channels. Using the simulation model, the influence of vapor quality of refrigerant on the cooling performance was examined. In addition, the temperature distribution of the cells was observed and the heat transfer characteristics of the direct expansion heat exchanger were analyzed.
착상조건에서 열교환기 형상 변수에 따른 열전달 성능에 관한 해석적 연구
장동수(Dong Soo Jang),박성기(Seonggi Park),이상헌(Sang Hun Lee),조원희(Wonhee Cho),김용찬(Yongchan Kim) 대한설비공학회 2017 대한설비공학회 학술발표대회논문집 Vol.2017 No.6
This study presents the heat transfer performance according to the heat exchanger type under frosting conditions. The heat transfer performance of the three types of heat exchangers such as plate fin-tube heat exchanger with inline tube alignment, plate fin-tube heat exchanger with staggered tube alignment, and spirally-coiled circular fin-tube heat exchanger was analytically investigated. The heat transfer performance of the heat exchangers according to fin shape, number of tube rows, and tube arrangement was compared and discussed. Initially, the performance of the plate fin-tube heat exchanger was excellent, but the performance of the spirally-coiled circular fin-tube heat exchanger was better after a certain period of time. As the number of tube rows increased, the heat transfer performance increased but the effect of frost growth on the heat transfer decrease increased.
축열조를 이용한 공랭식 모듈 칠러 시스템에 관한 해석적 연구
윤성호(Sungho Yun),박성기(Seonggi Park),서형준(Hyungjoon Seo),배동석(Dongseok Bae),강병하(Byung Ha Kang ),김용찬(YongChan Kim) 대한설비공학회 2017 대한설비공학회 학술발표대회논문집 Vol.2017 No.6
The air-cooled module chiller has the advantages of saving energy and space by combining small units into modules. Combining this air-cooled module chiller system with a thermal storage, it is possible to reduce energy costs by using cheap night-time power at night and reduce power consumption during peak load times in summer. This study was conducted to analyze the economic assessment and the LCCP on the absorption chiller system and the air-cooled module chiller system with the thermal energy storage for an office building. The result showed that the total annual cost decreased with the decrease in the storage tank capacity due to the reduced the initial investment cost. In addition, the total CO2 emissions was decreased with the decrease in the storage tank capacity due to the reduced direct emissions from refrigerant leakage.
R-1234ze(E)를 사용한 브레이징타입 판형열교환기에서의 증발 압력강하 및 열전달 특성 분석
이동찬(DongChan Lee),김동우(Dongwoo Kim),박성기(Seonggi Park),양원석(WonSeok Yang),김용찬(Yongchan Kim) 대한설비공학회 2016 대한설비공학회 학술발표대회논문집 Vol.2016 No.6
This study is to analyze pressure drop and HTC(Heat Transfer Coefficient) in a BPHE(Brazing type Plate Heat Exchanger) using R-1234ze(E) which is known as a substitutional refrigerant of R-134a. The BPHE was installed as a evaporator in the test section and the temperature for evaporating conditions are set to 5, 10 and 15℃. Secondary fluid was used to supply heat to the evaporator and a cooling chiller was used to cool the refrigerant after it has absorbed heat from the test section. Quality of refrigerant entering into the test section was controled by regulating power supplied to the pre-heater that a electricity heater is inserted to copper pipe. The trend of the pressure drop and HTC with respect to average vapor quality has been analyzed to make reasonable explanation for the phenomena. The trend of the pressure drop was varied depending mainly on the mass flux G because dominance of either frictional or gravitational pressure drop was different for each G. The trend of the HTC also depends critically on the mass flux G showing different patterns for each G as the dependance of convective heat transfer and nucleate boiling heat transfer varies for each G.