전기저항식 변형률 게이지를 이용한 콘크리트의 열팽창계수 측정법

남정희,안덕순,김연복 한국도로학회 2013 한국도로학회논문집 Vol.15 No.6

PURPOSES: The purpose of this study is to provide the method of how to measure the coefficient of thermal expansion of concrete using temperature compensation principle of electrical resistance strain gauge. METHODS : The gauge factor compensation method and thermal output(temperature-induced apparent strain) correction method of selftemperature compensation gauge were investigated. From the literature review, coefficient of thermal expansion measurement method based on the thermal output differential comparison between reference material(invar) and unknown material(concrete) was suggested. RESULTS: Thermal output is caused by two reasons; first the electrical resistivity of the grid conductor is changed by temperature variation and the second contribution is due to the differential thermal expansion between gauge and the test material. Invar was selected as a reference material and it、s coefficient of thermal expansion was measured as 2.12×10-6m/m/℃. by KS M ISO 11359-2. The reliability of the suggested measurement method was evaluated by the thermal output measurement of invar and mild steel. Finally coefficient of thermal expansion of concrete material for pavement was successfully measured as 15.45×10-6m/m/℃. CONCLUSIONS: The coefficient of thermal expansion measurement method using thermal output differential between invar and unknown concrete material was evaluated by theoretical and experimental aspects. Based on the test results, the proposed method is considered to be reasonable to apply for coefficient of thermal expansion measurement.

전기저항식 변형률 게이지를 이용한 콘크리트의 열팽창계수 측정법

남정희,안덕순,김연복 한국도로학회 2013 한국도로학회논문집 Vol.15 No.6

PURPOSES: The purpose of this study is to provide the method of how to measure the coefficient of thermal expansion of concrete using temperature compensation principle of electrical resistance strain gauge. METHODS : The gauge factor compensation method and thermal output(temperature-induced apparent strain) correction method of selftemperature compensation gauge were investigated. From the literature review, coefficient of thermal expansion measurement method based on the thermal output differential comparison between reference material(invar) and unknown material(concrete) was suggested. RESULTS: Thermal output is caused by two reasons; first the electrical resistivity of the grid conductor is changed by temperature variation and the second contribution is due to the differential thermal expansion between gauge and the test material. Invar was selected as a reference material and it、s coefficient of thermal expansion was measured as 2.12×10-6m/m/℃. by KS M ISO 11359-2. The reliability of the suggested measurement method was evaluated by the thermal output measurement of invar and mild steel. Finally coefficient of thermal expansion of concrete material for pavement was successfully measured as 15.45×10-6m/m/℃. CONCLUSIONS: The coefficient of thermal expansion measurement method using thermal output differential between invar and unknown concrete material was evaluated by theoretical and experimental aspects. Based on the test results, the proposed method is considered to be reasonable to apply for coefficient of thermal expansion measurement.

상변화물질을 적용한 구체축열시스템 전열 해석 연구

이현화(Lee, Hyun-Hwa),이수진(Lee, Soo-Jin),김수민(Kim, Su-Min),임재한(Lim, Jae-Han),송승영(Song, Seung-Yeong) 한국태양에너지학회 2012 한국태양에너지학회 학술대회논문집 Vol.2012 No.11

TABS(Thermally Activated Building System) has recently applied by huge commercial buildings, airport, and convention center in Europe. The former provide night-time thermal storage by heating or cooling, while the latter embedded water based heating and cooling system, which uses a high thermal inertia of concrete in building construction where a heating or cooling pipe is embedded. The aim of this study is to analyze thermal storage and thermal output of TABS applied with PCM (Phase Change Material). To achieve this paper, prototypes of TABS and PCM were developed, the simualtion program Physibel Voltra 6.0W was used, and thermal strage and thermal output were evaluated according to heating operation schedule.

건물 외주부 열쾌적성 향상을 위한 천장복사난방패널의 방열 조건 설정에 관한 연구

조구상,박상훈 한국건축친환경설비학회 2023 한국건축친환경설비학회 논문집 Vol.17 No.2

Due to COVID-19, in office buildings frequented by an unspecified number of people air currents discharged from convective heating systems installed near the ceiling or windows to handle envelope load are believed to be the main cause of the spread of virus. Consequently, the need for radiant ceiling heating panel, which utilize the principle of natural convection, is becoming increasingly significant. To replace convective heating systems and apply radiant ceiling heating panel, it is necessary to examine whether they can promptly respond to changes in the envelope load and secure the thermal output required to handle the heating load without causing discomfort, such as downdraft. In this study, the applicability of radiant ceiling heating panel to the perimeter zone in terms of thermal comfort was evaluated. To achieve this, the thermal characteristics of radiant ceiling heating panel were examined, and a simulation model capable of evaluating the thermal comfort of radiant ceiling heating panel applied to the perimeter zone was constructed. Based on the results of the thermal comfort assessment, thermal output conditions for applying radiant ceiling heating panel to the perimeter zone were proposed.

제로에너지 공동주택에서 바닥복사난방패널의 방열량 설계 기준 평가

임재한 한국건축친환경설비학회 2022 한국건축친환경설비학회 논문집 Vol.16 No.4

This study aims to analyze the thermal output and downward heat loasses according to the pipe pitch of the floor heating panels for the design of a radiant floor heating system in a zero-energy apartment to compare the design heating load in zero-energy apartment housing unit. The thermal output and downward heat losses were analyzed according to the pipe pitches, flooring and pipe materials by using the universial single power function method in ISO 11855-2. The results showed that the heating load could be removed even if the pipe pitch of the existing radiant floor heating system is changed to around 350 mm as the thermal insulation and airtightness in the zero-energy apartment building has been greatly improved. The thermal output in individual heating was about 30% higher than that of district heating. In addition, it was found that it was necessary to consider the thermal resistance of flooring materials for the design of the radiant floor heating panel because it would affect the thermal output through the room air. When the lowerest floor was exposed to the outside air, downward heat losses greatly increased, so it would be necessary to increase the outside thermal insulation thickness for the energy saving during heating operation.

FDM 해석에 의한 구체축열시스템(TABS)의 난방운전시 방열 특성 분석

임 재한(Jae-Han Lim),송진희(Jin-Hee Song),구보경(Bo-Kyoung Koo),송승영(Seung-Yeong Song),성윤복(Yoon-Bok Senog) 대한설비공학회 2012 설비공학 논문집 Vol.24 No.3

This study is focused on the evaluation of thermal output of TABS (Thermally Activated Building System). The aim of this study is to evaluate TABS in terms of the temperature difference between heating medium supply temperature (Ts) and return temperature (Tr), thermal output and the surface temperature distribution according to the design flow rate and the design flow temperature. Through the transient heat transfer simulation using temperature calculation using Crank-Nicolson FDM using Physibel Voltra 6.0 W, the temperature difference between Ts and Tr , thermal output and the surface temperature distribution of specific TABS was calculated and evaluated. The results show that specific thermal output and temperature difference at 60℃ of supply water temperature were about 162 W/㎡, 13.6℃ respectively

RC 네트워크 모델 및 유한차분법에 의한 구체축열시스템의 방열량 해석

송진희(Song Jin-Hee),구보경(Koo Bo-Kyoung),송승영(Song Seung-Yeong),임재한(Lim Jae-Han) 한국건축친환경설비학회 2011 한국건축친환경설비학회 학술발표대회 논문집 Vol.2011 No.10

This study is focused on the evaluation of thermal output of TABS(Thermally Activated Building System) according to the ISO 11866. The aim of this study is to evaluate TABS in terms of the temperature difference between heating medium supply temperature(Ts) and return temperature(Tr), thermal output and the surface temperature distribution according to the design flow rate and the design flow temperature. For this purpose, the RC network model and FDM method in ISO 11866 were firstly reviewed. Through the transient heat transfer simulation using temperature calculation using Cranck-Nicolson FDM using Physibel Voltra 6.0W, the temperature difference between Ts and Tr, thermal output and the surface temperature distribution of specific TABS was calculated and evaluated. The results show that specific thermal output and temperature difference at 60℃ of supply water temperature were about 162 W/m², 13.6℃ respectively.

강판 마감형 조립식 벽패널 복사냉난방시스템의 냉난방 방열 특성 평가

임재한(Lim, Jae-Han),구보경(Koo, Bo-Kyoung),김성임(Kim, Sung-Im),송승영(Song, Seung-Yeong) 한국태양에너지학회 2013 한국태양에너지학회 논문집 Vol.33 No.2

Recently the radiant panel heating and cooling system has been regarded as an alternative of low temperature heating and high temperature cooling by applying the renewable energy sources to the heating and cooling of buildings. Especially this system can be used as HVAC system alternatives in super high-rise buildings for energy saving and thermal comfort. Also it can be possible to reduce the plenum space because the minimum ventilation air will be supplied into the space. This study focused on the evaluation the basic characteristics of thermal output in prefabricated steel wall panel system for radiant heating and cooling. In order to evaluate the thermal output according to both various supply water temperatures and supply water flow rates, three-dimensional dynamic heat transfer analysis was performed. As results, for the heating mode, thermal output increased by 26% with the supply temperature increasing by 5℃. The surface temperature of panels range within 1~3℃. For the cooling mode, thermal output decreased by 18.2% with the supply temperature increasing by 2℃. The surface temperature of panels range within 0.5~1℃ and it was shown the even temperature distribution.

벽패널 복사난방시스템의 방열특성에 관한 시뮬레이션 해석 연구

구보경(Koo Bo-Kyoung),송승영(Song Seung-Yeong),임재한(Lim Jae-Han) 한국건축친환경설비학회 2011 한국건축친환경설비학회 학술발표대회 논문집 Vol.2011 No.10

Recently the radiant panel heating and cooling system has been regarded as an alternative of low temperature heating and high temperature cooling by applying the renewable energy sources to the heating and cooling of buildings. Especially this system can be used as HVAC system alternatives in super high-rise buildings for energy saving and thermal comfort. Also it can be possible to reduce the plenum space because the minimum ventilation air will be supplied into the space. This study aimed at evaluating the basic characteristics of thermal output in radiant wall panel heating system. For this purpose, the thermal output of several radiant wall panel types were analysed by 3D dynamic heat transfer simulation. According to the supply water temperature, composition of panel layers and panel dimension, the thermal output characteristics such as surface temperature distribution, temperature difference between supply and return water were analyzed. The results show that we should improve the heat storage performance of wall panel for better distribution of surface temperature and thermal comfort.

Simplified Analytical Model for Investigating the Output Power of Solar Array on Stratospheric Airship

Zhang, Yuanyuan,Li, Jun,Lv, Mingyun,Tan, Dongjie,Zhu, Weiyu,Sun, Kangwen The Korean Society for Aeronautical and Space Scie 2016 International Journal of Aeronautical and Space Sc Vol.17 No.3

Solar energy is the ideal power choice for long-endurance stratospheric airships. The output performance of solar array on stratospheric airship is affected by several major factors: flying latitude, flight date, airship's attitude and the temperature of solar cell, but the research on the effect of these factors on output performance is rare. This paper establishes a new simplified analytical model with thermal effects to analyze the output performance of the solar array. This model consisting of the geometric model of stratospheric airship, solar radiation model and incident solar radiation model is developed using MATLAB computer program. Based on this model, the effects of the major factors on the output performance of the solar array are investigated expediently and easily. In the course of the research, the output power of solar array is calculated for five airship's latitudes of $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$, four special dates and different attitudes of five pitch angles and four yaw angles. The effect of these factors on output performance is discussed in detail. The results are helpful for solving the energy problem of the long endurance airship and planning the airline.