• 한국주거학회논문집
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• 제25권2호
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• pp.11-18
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• 2014

This study looked at designing, building and operating temporary camp, the first structures that South Korea built in the Antarctica. While there may be differences in accordance with the topography, ground surfaces in the Antarctica are covered broken stones, glaciers and snow. Hence, such topographical characteristics should be taken into account when conducting any construction work. To ensure successful assembly construction in the Antarctica using modules, prior trial assembly work should be done in Korea to identify any possible trouble in the actual construction process. Assuming that the workers will have to spend at least one winter in the temporary camp, the work will be more severely affected by adverse weather conditions and snow drift, resulting in the need to clear snow. This can be by designing roofs with curved surfaces. Also, quantitative effects will need to be verified through simulation and actual measurement. It will also be necessary to assess the camp's thermal environment and examine its air-conditioning methods. To identify the temporary camp's thermal system, the temperatures and humidities were measured, and the heating system was designed not to offer automatic control or desired value selection functions.

• 한국산업융합학회 논문집
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• 제18권1호
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• pp.18-29
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• 2015

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The system was introduced into a real building and was examined by the field measurement. Judging from the measurements during three years(1999~2001), the state of the system operation was very stable through this period and it was clear that the system contributes to reduction of energy consumption for air-conditioning. Futhermore, a simulation model used the simple heat diffusion equation was developed to simulate its thermal characteristics and performances. The simulations resulted in air temperature in good agreement with the measurements. Also, from the result of numerical analysis, it is clear that the amount of heat supply by using this system is more than the amount of energy loss to the room above it. Therefore, it is concluded that this systems is very useful and the proposed numerical model can be used for the prediction of system thermal performance.

• 태양에너지
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• 제11권2호
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• pp.3-8
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• 1991

본 연구는 미국의 태양에너지 연구소(Solar Energy Research Institute)에서 최근에 개발한 건물 열 성능 측정 기법인 PSTAR(Primary and Secondary Terms Analysis and Renormalization) 방법에 따라 대전에 위치한 한 자연형 주택의 열성능 측정 결과를 분석하고 이를 토대로 건물의 종합적인 Thermal Analysis를 수행하였다. 실험 주택은 $156m^2$의 주거 면적을 가지고 있으며 3개의 침실과, 거실 그리고 부엌으로 구성되었으며 아울러 다양한 자연형 시스템을 갖추었다. 본 연구의 목적은 PSTAR 방법을 적용하여 열적으로 massive한 건물의 실제 동적 열성능을 정확히 측정하는 데에 있다. 결과를 분석하여 보면 측정치와 검정치(Renormalized Values)는 대부분의 경우에 있어 잘 일치하나 순수한 도면에 의거한 시뮬레이션치(Audit Values)는 다소 차이를 나타내었다.

• 한국지반공학회논문집
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• 제28권12호
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• pp.5-15
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• 2012

본 연구에서는 일련의 현장 열응답 시험결과를 동일한 지중열교환기와 지반 조건에 대한 CFD(Computational Fluid Dynamics) 수치해석 결과와 비교하고 역해석을 통해 지반의 열전도도를 평가하였다. 총 6개의 보어홀을 원주에 소재하고 있는 시험시공 현장에 설치하였으며 순환 파이프의 형상과 그라우트 재료에 대한 수직 밀폐형 지중열교환기의 성능을 비교하기 위해 일반적인 U형 순환 파이프와 새롭게 개발된 3공형 순환 파이프를 보어홀 내 시공하였다. 수치해석은 CFD 해석 프로그램인 FLUENT를 적용하여 3차원 열전달 거동 해석을 수행하였으며 각각의 보어홀에 대해 시간에 따른 순환수의 유입, 유출 온도 차이와 지반의 깊이별 온도변화를 User Define Function (UDF)을 이용하여 실제 조건을 모사하였다. 주어진 보어홀 조건과 실내시험을 통해 시험시공 현장의 열 물성을 입력치로 적용하여 수치 해석을 수행하였으며, 현장 열응답 시험에서 측정된 시간에 따른 유입, 유출 순환수의 온도 변화를 모사하였다. 수치해석 결과, 지반의 열전도도를 3W/mK로 적용하였을 때 보다 4W/mK일 때 현장 열응답 시험과 유사한 결과를 얻었다.

• 대한기계학회논문집
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• 제9권5호
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• pp.579-589
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• 1985

본 논문의 모의 실험에 사용한 자연순환식 급탕 시스템과 지금까지 발표된 것 과의 차이점은 다음과 같다. 집열기의 집열성능 계산에 Close의 모델은 시스템의 평 균 온도를 이용하였으며, Mertol의 모델은 집열기의 성능을 일정하게 하여 자연순환식 급탕 시스템의 성능을 계산하였다. 그리고, Young의 모델은 집열기 입구 및 출구 유 체의 평균 온도로 집열기의 집열 성능을 계산하였다. Shitzer, Ong의 연구에서 밝혀 진 바와 같이 집열기 집열판의 온도와 유체 온도는 서로 다르므로, 본 논문에서는 이 것들에서 오는 오차를 줄이기 위해 집열기 순환 유체의 평균 온도와 집열판의 온도를 해석적으로 구하여 집열기의 성능과 순환 유체의 성질 계산에 이용하였다.

• 에너지공학
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• 제24권1호
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• pp.69-77
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• 2015

본 연구에서는 보정된 모델링 건물을 대상으로 PMV 변수에 대한 데이터베이스를 구축하였고, 다중회귀분석을 통하여 PMV 회귀모델을 도출하였다. PMV 회귀모델은 민감도 및 데이터 분석을 통하여 단순화하여 단순 PMV 회귀모델을 제시하였다. 단순 PMV 회귀모델과 Fanger PMV 모델에 대한 MAE 및 RMSE 검증을 통하여 단순 PMV 회귀모델이 Fanger PMV 모델을 대체할 수 있는 것으로 분석되었다. EnergyPlus의 EMS(Energy Management System)를 이용하여 보정된 모델링 건물에 PMV 회귀모델 제어를 적용하였다. 단순 PMV 회귀모델과 Fanger PMV 모델 제어의 온열 쾌적도를 비교한 결과, 두 제어 모두 공조기간 동안 약 90% 이상이 온열쾌적 범위를 만족하였고, 온열 쾌적 제어의 특징인 설정 PMV를 만족하는 설정온도에 의하여 제어되는 것으로 나타났다.

• 설비공학논문집
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• 제12권12호
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• pp.1098-1125
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• 2000

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

• KIEAE Journal
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• 제15권2호
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• pp.123-131
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• 2015

Purpose : Improvement of indoor thermal comfort and reduction of the energy consumption in building can be obtained by applying a double skin facade system. In order to achieve effectively this purpose, design team would have to perform easy and appropriate performance analysis for making better design decision during the design process. Method : This paper focus on the natural ventilation performance of a multi-story type double skin facade with main causes which are pressure difference according to the wind and temperature difference between indoor and outdoor (Buoyancy Effect). Using this main causes, the natural ventilation ratio of wind effect-to-buoyancy effect in cavity of multi-story type double skin facade were analyzed through the performance analysis results of CFD (Computational Fluid Dynamics) simulation. Result : When the wind velocity was 2m/s, the ventilation rate in the cavity was highest. If wind velocity was slower than 2m/s wind velocity, buoyancy effect has more influence on the ventilation rate in the cavity, and if wind velocity was faster than 2m/s wind velocity, wind effect has more influence on the ventilation rate in the cavity.

• 한국농공학회논문집
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• 제50권1호
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• pp.39-47
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• 2008

Most of the broiler houses in Korea have experienced problems on controlling the environmental conditions such as suitability, stability and uniformity of rearing condition inside the broiler house. It is very critical which if not properly controlled, would cause serious stress on the chickens. It is therefore urgent to develop optimum designs of naturally ventilated broiler house which is appropriate to the four seasons of Korea. Field experiment for this matter is very difficult to conduct due to the unpredictable and uncontrollable weather condition. In this study, the heating load of a naturally ventilated broiler house was calculated using TRANSYS 15 BES program while internal climate and thermal condition were computed using Fluent 6.2. The computed resulted of the conventional ventilation system (A) and upgraded ventilation system (B) (Seo et al, 2007) were compared with each other for cold season. The results of the Building Energy Simulation(BES) indicated that the system B, the upgraded ventilation system made 8% lower total heating load and 47% lower at only the broiler zone compared to the conventional broiler house. Considering the entire broiler house, the existence of middle ceiling made the heating energy 11% lower required than without middle ceiling. Accordingly, the system B with middle ceiling was found to save heating energy by 20% in average. This study showed that the BES program can be a very powerful to effectively compute the energy loads of agricultural building while the energy load is very close related to ventilation efficiency.

• 태양에너지
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• 제19권4호
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• pp.71-80
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• 1999

본 연구는 예비실험에서 나타난 평판 및 모서리형 현장 열저항 측정기의 내부공기 온도편차를 줄일 수 있는 방안을 모색하기 위한 것으로 연구결과 다음과 같은 결론을 얻을 수 있었다. 첫째, 측정기의 크기에 따라 기기내의 온도편차는 큰 변화가 없으므로 사용과 운반이 용이한 소형이 적정하며 둘째, 방열판의 위치는 측정기 Casing을 통한 부수적인 손실열량을 최소화하기 위해 측정기 내부 표면과 이격시켜 설치하고 셋째, 방열판의 온도는 측정기내부온도가 실내온도까지 접근하는 도달시간을 고려하여 가능한 한 낮게 설정하고 넷째, 측정기 내부에 설치되는 팬은 측정기의 상부에 설치하여 기류를 하향으로 토출하며 다섯째, 방열판 앞에는 Baffle Plate를 설치하는 것이 기기내의 온도편차를 줄일 수 있는 유효한 방법임을 알 수 있었다.