http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
응축 풀 내의 비정상 층류 제트의 유동 특성에 관한 연구
최용문,김종보,Choi, Yong Moon,Kim, Chong Bo 대한설비공학회 1988 설비저널 Vol.17 No.4
The pressure suppression pool of BWR(Boiling Water Reactor) is subjected to hydrodynamic impact in the event of a LOCA(Loss of Coolant Accident). The pressure increase in the reactor dry cell would force the existing water of a vent pipe into the suppression pool. When the water is ejected through the pipe opening into the suppression pool, an abrupt downward force is transmitted to the suppression pool floor. Consequently, many structures installed within the pool must be able to withstand these forces. In order to determine the optimum safe locations of the pool structures, numerical analysis have been carried out to investigate the hydrodynamic behavior of the water jet. In the present analysis, a two-dimensional numerical model is utilized to solve transient flow equations.
다공성 물질의 환형수직원통내에서의 자연대류 열전달 수치해석
차기업,김종보,Cha, Ki Up,Kim, Chong Bo 대한설비공학회 1989 설비공학 논문집 Vol.1 No.2
Numerical solutions for two-dimensional, steady, free convection are presented for a cylinder filled with saturated porous media. An annulus is bounded by inner wall with constant heat flux and two adiabatic horizontal walls with outer wall isothermally cooled. Governing equations are numerically solved for the range of Aspect Ratio 1 to 20, Radius Ratio, 1 to 20, and Rayleigh number, 50 to $10^4$ by Finite Difference method utilizing upwind scheme. Results are presented in terms of stream lines and isotherms, temperature distributions and local Nusselt numbers at the heated wall. Average Nusselt numbers are also presented for the comparisons.
천연가스 수송을 위한 가스 하이드레이트의 구조적 특성에 대한 실험적 연구
김남진,김종보,Kim, Nam-Jin,Kim, Chong-Bo 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.2
Natural gas hydrates typically contain 85 wt.% water and 15 wt.% natural gas, and commonly belongs to cubic structure I and II. When referred to standard conditions, 1㎥ solid hydrates contain up to 172N㎥ of methane gas, depending on the pressure and temperature of production. Such large volumes make natural gas hydrates can be used to store and transport natural gas. So, the tests were performed on the formation of natural gas hydrate is governed by the pressure, temperature, gas composition etc. The results show that the formation pressure of structure II is lower about 65% and the solubility is higher about 3 times than that of structure I.
신상호,정동수,김종보,서태범,천원기,오정무,Shin, Sang-Ho,Jung, Dong-Soo,Kim, Chong-Bo,Seo, Tae-Beom,Chun, Won-Gee,Auh, P. Chung-Moo 한국태양에너지학회 1997 한국태양에너지학회 논문집 Vol.18 No.4
본 연구에서는 Rankine 사이클을 이용한 해양 온도차 발전 시스템을 컴퓨터로 모사했고 작동유체를 변화시켜 가면서 그 성능을 비교하였다. 증발기와 응축기는 UA(총괄열전달계수$\times$전열면적)와 LMTD(대수평균온도차) 방법으로 모사하였으며 터빈과 펌프는 등엔트로피 효율로 모사하였다. 작동유체로는 R22, R290, R1270, R134a, R125, R143a, R32, R410A 그리고 암모니아 등을 사용하였다. 모사 결과 OTEC 발전 시스템의 효율은 작동유체에 상관없이 거의 일정한 것으로 드러났다. 한편 증발기 출구에서의 과열도와 응축기 출구에서의 과냉도는 시스템의 성능에 거의 영향을 미치지 않는 것으로 나타났지만 터빈의 효율과 열교환기의 크기는 시스템 성능에 큰 영향을 미치는 것으로 나타났다. 마지막으로 따뜻한 표층수와 차가운 심해수 사이의 온도차가 $20^{\circ}C$이상일 때 실제로 전기를 생산할 수 있다는 사실을 확인했다. In this paper, performance of various working fluids is evaluated for the closed Ocean Thermal Energy Conversion(OTEC) power plant operating on Rankine cycle. The evaporator and condenser are modeled via UA and LMTD method while turbine and pump are modeled by specifying isentropic efficiencies. R22, Propane, Propylene, R134a, R125, R143a, R32, R410A and Ammonia are used as working fluids. Results show that newly developed fluids such as R410A and R32 that do not cause stratospheric ozone layer depletion perform as well as R22 and ammonia. The superheat at the evaporator exit and subcooling at the condenser exit do not affect the performance of the simple OTEC power cycle. Turbine efficiency and heat exchanger size influence greatly the performance of the Rankine cycle. Finally, it was shown that closed OTEC power plants can practically generate electricity when the difference in warm and cold sea water inlet temperatures is greater than $20^{\circ}C$.
SUS - 물을 사용한 2상 밀폐 열싸이폰의 작동특성에 관한 연구
곽희열(Kwak Hee-Youl),김종보(Kim Chong-Bo) 한국태양에너지학회 1994 한국태양에너지학회 논문집 Vol.14 No.3
2상 밀폐 열싸이폰은 용기 내에서 증발과 응축을 반복하면서 많은 양의 열을 수송하는 매우 효과적인 열전달 장치이다. 증발부에서의 증발 현상은 자연대류, 핵비등, 급속한 기포의 주기적인 폭발(Geyser boiling)과 또한 정상상태에서의 국부적인 열전달한계(Dry-out)로 인한 시동 및 작동특성이 매우 복잡하므로, 본 논문에서는 SUS-물을 사용한 열싸이폰의 시동성과 작동 특성을 증발부와 응축부의 열 환경에 따른 액체 풀(Pool)의 높이, 즉 증발부 체적에 대한 작동유체의 충전량과 경사각에 따른 특성을 고찰하였다. The two-phase closed thermosyphon is a heat transfer device capable of transferring large quantities of heat from a source to a sink by taking advantage of the high heat transfer rate associated with the evaporation and condensation of a working fluid within the device. The boiling patterns in the evaporator of thermosyphons are very complicated, considering natural convection in pool, surface evaporation on film, intermittent periodical geyser boiling, and semi-stable froth boiling. Also, heat transfer limit was found in dry-out where some portion of the evaporator ceases to be cooled effectively by the falling film and rivulets, resulting in a wall temperature excursion. In the present investigation, ex periments with a SUS-Water thermosyphon with 1m in length and 19㎜ in outer diameter have been carried out. The unsteady and steady state operations have been investigated for the influence of liquid filling charges and inclination angles of the device.