과도응답해석을 이용한 열교환기의 성능평가방법에 관한 연구

박병규,홍택,박상희,Park, B.K.,Hong, T.,Park, S.H. 대한설비공학회 1999 설비공학 논문집 Vol.11 No.1

The performance evaluation technique of a heat exchanger is described by using a transient response analysis for the determination of an average heat transfer coefficient. The model using a finite difference method can accommodate arbitrary inlet fluid temperature as well as longitudinal conduction. Temperature histories are obtained from the experiments at the inlet and outlet of test core. Heat transfer coefficient and friction factor of the plate array are obtained in short times using the data reduction program of transient response analysis in the single-blow method. The results agree very well with theoretical results. It is shown that the rms deviations are very small and the performance evaluation technique gives rapid and accurate results.

변풍량(變風量)시스템의 에너지해석(解析)에 관(關)한 연구(硏究)

박병규,조동우,신현준,Park, B.K.,Cho, D.W.,Shin, H.J. 대한설비공학회 1988 설비저널 Vol.17 No.5

This paper presents an energy analysis on the VAV system of 10-story building in Seoul using DOE-2 program and Modified Bin Method. The use of VAV system is an excellent means of saving energy in new buildings and/or retrofit. The fan control techniques considered are cycling, discharge dampers, inlet vanes, and motor speed control. The monthly and annual energy consumption is calculated for fan control techniques, components, and chiller types. The results of annual fan electricity use are compared using DOE-2 and Modified Bin Method, and show fairly good agreement. In addition, factors affecting energy consumption are also described.

유동방향의 열전도가 전열면의 성능에 미치는 영향

박병규,홍택,박상희,Park, Byung-Kyu,Hong, Taek,Park, Sang-Hee 대한설비공학회 1999 설비공학 논문집 Vol.11 No.5

The effects of longitudinal heat conduction on the performance of heat transfer surfaces are investigated by using a single-blow method. In the transient testing method for determining the heat transfer characteristics, exponential inlet temperature variations are made by using screen-mesh heater with small time constant and low frontal velocities of the test section, and the experimentally determined inlet temperature profile is used as the inlet fluid temperature condition. The effects of longitudinal heat conduction are negligible only if $\gamma^\act<0.05\;and \;N_{tu}\le3$ and should be considered if $N_{tu}\le3$ The test results ate compared with the existing theoretical and experimental data and the validity of this technique is confirmed by the good agreement.

초음속 2유체 분무노즐의 유동 특성

박병규,이준식,Park, Byeong-Gyu,Lee, Jun-Sik 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.7

Twin-fluid atomization has been widely used in combustors and process industries because of its high performance and simple structure. Flow visualization and pressure measurements were conducted to investigate the effects of gas flow in twin-fluid atomization. Schlieren photographs showed that changes in atomizing gas pressure, altered the wave patterns, and the lengths of both recitrculating toroid (impinging stangnation point) nad supersonic flow region in the jet. A longer supersonic wave pattern like net-shape wqas observed as atomizing gas pressure increased. The disintegration phenomenon of liquid delivery tube. The variation of spray angles with gas pressures were obtained by visualization using laser sheet beam. Suction pressuresat the nozzle orifice exit and recirculating region are shown to be used to estimate the stable atomization condition of a twin-fluid atomizer. 공정산업분야 및 분무연소분야에서 많이 사용되고 있는 2유체 분무기에서 출구 초음속유동의 가시화와 하류의 가스압력 측정 결과로부터 다음과 같은 결론을 얻었다. 1) 과소팽창 또는 과대팽창 초음속노즐 유동에서 출구 Mach수가 일정한 경우, 유동이 박리하지 않는다면 가스의 정체압력(유량)이 증가함에 따라 노즐출구에서 충돌정체점까지의 길이와 초음속 유동영역의 길이는 증가한다. 2) 스피팅 현상은 액체공급관 출구의 흡인압력은 분사가스압력이 증가함에 따라 단조증가하지만 분사가스압력이 0.5MPa이상이 되면 증감현상이 커지며 돌출형 노즐에서 유동박리시 급격히 증가한 다음 거의 일정하게 유지된다. 4) 액체공급관 하류축상의 압력변화는 출구의 음압에서 충돌정체점까지 상승한 다음 급강하하고 충격파 세포상의 구조에 따라 진동하면서 대기압에 도달한다.

마이크로 쿨러 증발기의 비등 전 과도열전달 해석

박병규,김근오,Park, Byeong-Gyu,Kim, Geun-O 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.2

It has been investigated for the temperature profile in a planar evaporator of micro-cooler subject to a uniform heat flux prior to tole initiation of boiling. The results of the analysis allow for the determination of applied power levels fur which nucleation is likely to occur only within the vapor grooves of the evaporator while maintaining subcooling in the liquid core, thereby increasing the likelihood of a successful startup. Also, limits are fecund for which additional increases in the applied heat flux do not increase the temperature difference between the vapor grooves and the wick-liquid core interface. This analysis is appropriate for the microscale evaporators of micro-cooler during a fully-flooded startup as well as starter pump designs and micro-CPLs(capillary pumped loops). The results are useful in the initial basic design of microscale heat transfer devices.

액정 스마트윈도우의 신뢰성에 대한 연구

박병규,김순금,이승우,박계춘,이진,Park, Byung-Kyu,Kim, Sun-Geum,Lee, Seung-Woo,Park, Gye-Choon,Lee, Jin 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.6

In recent years, the challenge of higher energy efficiency has emerged as urban buildings have become taller, and the area of window glasses has increased. To address the problem of energy efficiency in buildings, research on smart windows is being actively conducted. In this study, an accelerated experiment for thermal stability was conducted to fabricate a liquid crystal cell applicable to external windows. It was confirmed from the study that the function is maintained even in a high-temperature external environment through the change in transmittance by voltage. Compared with the initial transmittance, after the passage of time, the smart window cell to which the sealant was applied showed a small change in transmittance of 1~2%. This result confirmed the thermal stability of the liquid crystal-based smart window.

Farm-Housing 조성에 관한 지원방안 연구

박병규,Park, Byong-Gyu 한국생태환경건축학회 2013 한국생태환경건축학회 논문집 Vol.13 No.4

There is a rental housing policy in Korea to support low income citizen. However, the living condition of tenants through this rental program is not work for improving, unlike the initial purpose of providing rental housings. Rental housings, which were planned to improve the residential welfare and enhance self-reliance ability of low income groups and the elderly. It's not effective any more in terms of policy purpose. To solve this problem, plans are needed to support for the construction by Farm-Housing(FH) so that the residents of can support their self-reliance by promoting creating jobs and cooperation. This paper analyze and propose some solution in terms of legal system, financing and streamlining of planing process and permission to support FH program. The paper focus purpose to help identify a new area through such proposals and retain a power of leading technology by bridging the gap between the realistic aspect and ideal aspect.

도시 저소득층 주거안정화를 위한 신(新)주거복지 공간연구 - 농장형 주택(Farm Housing)시설 공간 중심으로 -

박병규,Park, Byong-Gyu 한국공간구조학회 2013 한국공간구조학회지 Vol.13 No.2

Korea has been striving for the development of the nation in various aspects. It will also have to make an effort for its continued development in the future. The problems of low-income groups that occur in those processes cannot be simply ignored now. It is needed to provide an equal opportunity to low-income groups so that they can be part of the society. The cycle of economic problem should be disconnected through this process. Farm-Housing is one of the solutions to this problem. Its purposes are not only to provide residence in the complex, but to gain income through various activities, such as production, distribution and consumption, and solve part of the economic problems of the people living in the Farm-Housing. To sell the products of Farm-Housing, the neighboring cities need to be designated as a hinterland. For this reason, Farm-Housing needs to be located in the suburban area of large cities. However, the current laws and policies make it difficult to construct Farm-Housing in suburban areas. Presenting plans to solve such problem is the purpose of this paper.

지수형 온도변화를 이용한 표면 열전달의 측정

박병규,홍택,박상희,Park, Byung Kyu,Hong, Taek,Park, Sang Hee 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.9

A single blow, transient testing method for determining the heat transfer characteristics of heat exchanger surfaces are presented. The exponential inlet temperature variations were made using screen mesh with small time constant and frontal velocities of the test section. The system is used to investigate the usefulness of a model with exponential inlet temperature variations. A data reduction program is developed to calculate the temporally and spatially averaged heat transfer coefficient using the measured disturbance and response of the fluid temperature. The results are compared with the existing theoretical and experimental data for parallel plate stacks. It was recommended to take an average for the time greater than the 99% of the final temperature had reached in order to obtain fairly good results.

지상중계: 중남미 문화와 문화론

박병규,Park, Byong-Kyu 대한건축사협회 2011 建築士 Vol.2011 No.6