http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Cu-Ca 합금을 이용한 고효율 로터의 반용융성형 공적 적용에 관한 연구
이상용 ( Sang Yong Lee ),문영훈 ( Young Hoon Moon ),이혜경 ( Hyae Kyung Yi ) 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속·재료학회지 Vol.45 No.5
The melting range, electrical conductivity, and microstructure of Cu-Ca alloys and thixoforming process design of developed Cu-Ca alloy were investigated. High purity calcium was added to molten copper up to 1.4% by weight. SIMA(Strain induced melting activated) process has been carried out to modify the copper dendrites to spherical shapes. The semisolid range, grain size and electrical conductivity of Cu-Ca alloy were significantly influenced by the content of calcium and prestrain. Thixoforming experiment of developed Cu-Ca alloy were performed. Efficiency of rotor was negative influenced by internal defects. Thixoformed Cu-Ca rotor shows high efficiency to that of die cast Al rotor by optimization of forming process.
준밀폐형 2상자연순환 회로 내에서의 유동 진동에 관한 실험적 연구
김종문,이상용,Kim, Jong Moon,Lee, Sang Yong 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.12
In the present experimental study, the flow behavior in a semi-closed two-phase natural circulation loop was examined. Water was used as the working fluid. Heat flux, heater-inlet subcooling, and flow restrictions at the heater-inlet and at the expansion-tank-line were taken as the controlling parameters Six circulation modes were identified by changing heat flux and inlet subcooling conditions ; single-phase continuous circulation, periodic circulation (A), two-phase continuous circulation, and periodic circulations (B), (C), and (D). Among these, the single-phase and two-phase continuous-circulation modes exhibit no significant oscillations and are considered to be stable. Periodic circulation (A) is characterized by the large amplitude two-phase f10w oscillations with the temporal single-phase circulation between them, while periodic circulation (B) featured by the flow oscillations with continuous boiling inside the heater section. Periodic circulation (C) appears to be the manometric oscillation with continuous boiling. Periodic circulation (D) has the longer period than periodic circulation (B) and a substantial amount of liquid flow back and forth through the expansion-tank-line periodically ; this mode is considered the pressure drop oscillation. Parametric study shows that the increases of the inlet- and expansion-tank-line- restrictions and the decrease of inlet subcooling broaden the range of the stable two-phase(continuous circulation) mode.
저가형 태양광 발전시스템을 위한 아날로그 MPPT 알고리즘의 특성 해석
김한구(Han-Goo Kim),이상용(Sang-Yong Lee),최문규(Moon-Gyu Choi),김홍성(Hong-Sung Kim),최규하(Gyu-Ha Choe) 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-
In this paper, Simple and inexpensive analog maximum power point tracker (MPPT) algorithm for photovoltaic power system and low power system of doesn't use digital signal processor (DSP). The control circuit is composed such that the actual current and voltage are sensed directly from the PV array. These two signals are then multiplied by a single-chip multiplier. The multiplier output go through different time constants genesis pulse width modulated to switch. Finally those were verified through simulation.