• 한국지반공학회논문집
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• 제29권10호
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• pp.49-56
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• 2013

최근 들어 경제적이고 친환경적인 에너지 활용을 위하여 지열에너지 필요성이 증대되고 있다. 지반의 열전도도(ground thermal conductivity)와 보어홀 열저항(borehole thermal resistance)은 지열 히트펌프 시스템(geothermal heat pump system)의 설계 과정에서 매우 중요한 변수이다. 본 논문에서는 일반 수직밀폐형에서의 U, W 타입의 지중 열교환기(ground heat exchanger)를 매립지 지반에 설치한 후 100시간 연속 운전 조건으로 현장 열성능 실험(thermal performance test)을 수행하였다. 또한 보어홀 열저항 산정 모델들을 이용하여 열효율을 산정한 후 이를 실험값과 비교하였다. 실험 결과 기존에 주로 적용되고 있는 shape factor(SF) 모델보다 multi-pole과 equivalent diameter(EQD) 모델이 계측값과 잘 일치하였다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2011년도 추계학술대회
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• pp.45-46
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• 2011

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.229-239
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• 2010

Performing a series of in-situ thermal response tests, the effective thermal conductivity of six vertical closed-loop ground heat exchangers was experimentally evaluated and compared each other, which were constructed in a test bed in Wonju. To compare thermal efficiency of the ground heat exchangers in field, the six boreholes were constructed with different construction conditions: grouting materials (cement vs. bentonite), different additives (silica sand vs. graphite) and the shape of pipe-sections (general U-loop type vs. 3 pipe-type). From the test results, it can be concluded that cement grouting has a higher effective thermal conductivity than that of bentonite grouting, and the efficiency of graphite better performs over silica sand as a thermally-enhancing addictive. In addition, a new 3 pipe-type heat exchanger provides less thermal interference between the inlet and outlet pipe than the conventional U-loop type heat exchanger, which results in superior thermal performance.

• 대한환경공학회지
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• 제29권12호
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• pp.1400-1403
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• 2007

• 한국주거학회논문집
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• 제14권1호
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• pp.19-27
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• 2003

This study aims to survey the living spaces of the welfare facilities for the aged to get the objective relationships between the physical thermal environment and the users' subjective responses. The surveys were made twice in winter and once in summer during 2001 and 2002. An ambient temperature, relative humidity, air velocity, globe temperature were measured as physical elements of thermal environment and the ASHRAE Psychophysical Voting Scale were used as an evaluation index for subjective responses. As the results, the aged respond thermally comfortable, in spite of the differences among important factors such as thermal sensations, humidity sensations and air velocity sensations. Also the physical thermal environmental elements and the subjective responses indices exceed thermal comfort range calculated by PMV(Predicted Mean Vote) and PPD(Predicted Percentage Dissatisfied). It shows that the insulation of walls of the facilities is not enough for heating and cooling seasons, and the indoor environmental control is necessary.

• Computers and Concrete
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• 제17권2호
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• pp.173-188
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• 2016

Generally, thermal stress induced by hydration heat causes cracking in mass concrete structures, requiring a thorough control during the construction. The prediction of the thermal stress is currently undertaken by means of numerical analysis despite its lack of reliability due to the properties of concrete varying over time. In this paper, a method for the prediction of thermal stress in concrete structures by adjusting thermal stress measured by a thermal stress device according to the degree of restraint is proposed to improve the prediction accuracy. The ratio of stress in concrete structures to stress under complete restraint is used as the degree of restraint. To consider the history of the degree of restraint, incremental stress is predicted by comparing the degree of restraint and the incremental stress obtained by the thermal stress device. Furthermore, the thermal stresses of wall and foundation predicted by the proposed method are compared to those obtained by numerical analysis. The thermal stresses obtained by the proposed method are similar to those obtained by the analysis for structures with internally as well as externally strong restraint. It is therefore concluded that the prediction of thermal stress for concrete structures with various boundary conditions using the proposed method is suggested to be accurate.

• 공업화학
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• 제21권5호
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• pp.570-574
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• 2010

기존 단열재의 주된 기능은 단지 열전달을 차단하는 기능과 건물로부터 열손실을 줄여주는 기능만을 수행했다. 반면, 축열재는 특정온도 범위 내에서 열에너지를 저장 또는 방출함으로써 건물에너지 사용량을 절감할 수 있다. 축열 건자재는 실내 공기온도 변화주기를 효과적으로 조절하여 일정하게 온도를 유지시킬 수 있다. 결과적으로 냉난방시스템 기능을 효율적으로 향상시킬 수 있다. 본 연구는 건축자재로 많이 이용되고 있는 석고보드에 상변화잠열물질을 축열재로 첨가하여 그 물성과 열환경 특성을 파악하였다. 또한 축열 건자재를 활용할 때 발생가능한 문제점을 확인하였다. 마지막으로 TVOC와 HCHO 함량 분석으로부터 오염물질의 배출가능성을 조사하여 축열 건자재의 환경 친화도를 검토하였다.

• 전기전자학회논문지
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• 제25권2호
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• pp.261-266
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• 2021

이 논문에서는 환경 온도 변화를 고려한 열 적외선 데이터 보정 알고리즘을 설계하는 방법을 제시한다. 첫째, 열 적외선 측정 모델은 적외선 측정 데이터와 모델 환경 매개 변수 간의 관계를 사용하여 매개 변수 종속적인 1차 입력-출력 방정식으로 주어지고, 적외선 데이터에 대한 환경 온도의 영향을 보상하기 위해 보상 함수를 구한다. 실험을 통해 제안된 알고리즘이 적외선 데이터에 대한 환경 온도 변화의 영향을 효과적으로 보상할 수 있음을 보인다.

• Journal of Information Processing Systems
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• 제15권2호
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• pp.386-398
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• 2019

The transmission capacity of transmission lines is affected by environmental parameters such as ambient temperature, wind speed, wind direction and so on. The environmental parameters can be measured by the installed measuring devices. However, it is impossible to install the environmental measuring devices throughout the line, especially considering economic cost of power grid. Taking into account the limited number of measuring devices and the distribution characteristics of environment parameters and transmission lines, this paper first studies the environmental parameter estimating method of inverse distance weighted interpolation and ordinary Kriging interpolation. Dynamic thermal rating of transmission lines based on IEEE standard and CIGRE standard thermal equivalent equation is researched and the key parameters that affect the load capacity of overhead lines is identified. Finally, the distributed thermal rating of transmission line is realized by using the data obtained from China meteorological data network. The cost of the environmental measurement device is reduced, and the accuracy of dynamic rating is improved.

• 설비공학논문집
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• 제13권7호
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• pp.647-652
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• 2001

The thermal comfort of indoor spaces is very important factor in our life. Regions, cultures, climates and individual difference for establishing thermally comfortable environments should be considered carefully because these factors have a large influence on the thermal comfort doing some complicated interactions with environmental, psychological and physical elements. Recently, predicted mean vote(PMV) based on the heat transfer theory between environmental factors and human bodies has evaluated by many researchers and widely used nowadays. The objective of this study is to evaluate the thermal comfort in workspaces with personal air conditioning system using the measurements of environmental comfort parameters and the questionnaire survey of occupant's thermal senses with response to the environment.