• Safety and Health at Work
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• 제9권2호
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• pp.149-158
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• 2018

Background: Work comfort studies have been extensively conducted, especially in the underground and meteorological fields resulting in an avalanche of recommendations for their evaluation. Nevertheless, no known or universally accepted model for comprehensively assessing the thermal work condition of the underground mine environment is currently available. Current literature presents several methods and techniques, but none of these can expansively assess the underground mine environment since most methods consider only one or a few defined factors and neglect others. Some are specifically formulated for the built and meteorological climates, thus making them unsuitable to accurately assess the climatic conditions in underground development and production workings. Methods: This paper presents a series of sensitivity analyses to assess the impact of environmental parameters and metabolic rate on the thermal comfort for underground mining applications. An approach was developed in the form of a "comfort model" which applied comfort parameters to extensively assess the climatic conditions in the deep, hot, and humid underground mines. Results: Simulation analysis predicted comfort limits in the form of required sweat rate and maximum skin wettedness. Tolerable worker exposure times to minimize thermal strain due to dehydration are predicted. Conclusion: The analysis determined the optimal air velocity for thermal comfort to be 1.5 m/s. The results also identified humidity to contribute more to deviations from thermal comfort than other comfort parameters. It is expected that this new approach will significantly help in managing heat stress issues in underground mines and thus improve productivity, safety, and health.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.277-279
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• 2003

The study utilizes remote sensing as the main monitoring means. With different spatial high-resolution, multichannel ASTER remote sensing image as the main information in Beijing city zone; with regional border and statistical data as auxiliary factor a study between the thermal space distribution character and the underground medium is analyzed based on the GIS logical algorithm and synthetic analysis technology. Results show thermal forming mechanism and the rule of distribution is mainly related to the underground medium and the change of the city distribution. Different underground medium has different degree and intensity influence on the thermal space distribution. Furthermore, urban greenbelt and water areas can reduce the thermal effect and large-scale greenbelt creates green island effect. In addition, Road net, residential area, population density, heat resources and so on have some positive effect on the thermal distribution, which increase the local temperature and intensity on the other hand. It is important to study the thermal distribution and its related factors, which contributes to the plan, construction and development of the city.

• 한국지열·수열에너지학회논문집
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• 제13권1호
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• pp.14-20
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• 2017

Groundwater heat pump (GWHP) system can achieve higher performance of the system by utilizing heat source of the annual constant groundwater temperature. The performance of GWHP system depends on the ground thermal environment such as groundwater temperature, groundwater flow rate and hydraulic conductivity. In this study, the geothermal environment was analyzed by using numerical simulation for develop the two-well geothermal system. As the result, this paper shows the change of the groundwater level and underground temperature around wells according to the conditions of flow rate and hydraulic conductivity.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2989-2994
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• 2008

The shopping center in underground passage for efficient space utilization is increased in urban area. This study describes operation characteristics of HVAC systems with ventilation and individual heating and cooling unit for shopping center in underground passage. In order to compare energy saving, thermal environment and installation space, etc., an integrated simulator with heat production and distribution system was designed and constructed. Energy delivery efficiency is improved over 20%, and energy saving of the hybrid system is calculated as over 30% compared to conventional all air type in the case of heating. And also the results showed that humidity decreased about $5{\sim}6%$, also characteristics of thermal control is improved over 34%.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.872-878
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• 2006

In recent years the importance of the preservation of cultural artefacts like ancient tombs has been widely accepted domestically and internationally as the quality of life improves. However not much technical attention has been paid for the facilities and systems to preserve those artefacts. Even the general understanding of the preservatory environment of the underground space as tombs is poor. As a part of the present study, the temperature and relative humidity inside a selected artefact, Shinkwan-ri tomb, have been monitored for a year round by the present author to improve the understanding of the indoor thermal environment, is pursued to provide a predictive tool of numerical modelling of Shinkwan-ri tomb the opened underground space thermal environment. In this study, predictive numerical modelling of Shinkwan-ri tomb using the Computational Fluid Dynamics, calculate the velocity and temperature distribution and offer basic data which are necessary for the best fitted design of tomb air-conditioning device.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.901-905
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• 2008

This study was conducted to clarify the heat load characteristics and heat and moisture behavior of underground structures. The authors achieved this by carrying out a numerical analysis using simple heat diffusion and simultaneous heat and moisture transfer equations based on measurement data. This paper presents the results of a numerical analysis on the heat load characteristics and heat and moisture behavior of an underground basement and its surrounding ground under a condition of internal heat generation. The authors found it difficult to predict the heat behavior and heat load of the underground basement by simple heat diffusion alone. Accurate prediction of the thermal environment and heat load requires careful consideration of the influences of moisture and precipitation

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.76-81
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• 2007

The shopping center in underground passage increased for efficient space utilization in urban area. This study describes operation characteristics of all air type and hybrid type with local ventilation and fan coil unit fixed to ceiling. In order to compare energy saving, thermal environment and installation space, etc., integrated simulator with heat production and indoor distribution system is designed and constructed. Energy saving of the hybrid system is calculated as over 30% compared to conventional all air type. And also the results showed that humidity decreased about 6%, also indoor thermal distribution is improved as temperature variation of around $1^{\circ}C$.

• 한국터널지하공간학회 논문집
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• 제19권2호
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• pp.121-141
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• 2017

최근 전력구 지중 송전선의 허용 전류용량에 대한 정부규제로 인해 전력구 공사에 현장 되메움재의 열적 거동에 대한 연구가 중요해졌다. 점차 증대되는 고용량 전력공급에 대한 수요와 더불어, 허용 전류용량을 산정하기 위해, 전력 케이블 주변 온도 증가를 유발하는 요인을 예측하고 분석하는 것이 시급하다. 전력구 내부의 과도한 열확산으로 인한 지중 송전선로 주변의 온도 증가는 지중 송전선 자체의 열저항을 증가시켜 절연 파괴 및 열 폭주 현상을 야기한다. 따라서 전력구 설계 및 시공시, 되메움재에 따른 전력구 현장 열거동 메커니즘을 규명하는 것이 매우 중요하다. 본 논문에서는 현장 시험시공을 기반으로, 전력구내부와 주변지반의 온도 변화 및 열저항을 산정하기 위한 수치해석 모델을 개발하였다. 전력구 열거동 파악을 위한 수치해석은 현장시험 시공시 획득한 4개의 다른 종류의 되메움재의 열적 그리고 물리적 물성치를 기반으로 수행되었다. 또한, 실내 시험을 통해 산정한 각 되메움재의 열저항을 수치해석 모델에 입력변수로 적용했다. 전력구 내부에 일정한 열량이 공급될 때, 되메움재의 단위중량, 함수비, 열적 특성 등 여러 변수를 고려한 열거동 메카니즘을 모사할 수 있도록 열거동 수치해석 모델을 구성하고 1년 동안의 수행된 현장계측값과 비교를 통하여 개발된 수치해석 모델을 검증하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.170-175
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• 2009

Apartment housing block has been spreaded according to rapid economic development and urbanization in Korea. A parking lot is located at underground, artificial ground is inevitably created in apartment housing block. Artificial ground creates different thermal environment compared to natural ground, because the composition and coverage of artificial ground are diverse. In this study, the effect of the artificial ground on building thermal environment will be disscussed by simulation. Considering the result of simulation, surface albedo is more important for building energy performance. A purpose of this study is to examine how the characteristic of surface effect to thermal environment, and to develop design method for sustainable outdoor space.

• 전기학회논문지
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• 제67권3호
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• pp.352-357
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• 2018

In this paper, the improvement of the conductor temperature calculation algorithm is studied. The allowable current of the underground transmission line is determined by the conductor temperature limit. Usually to calculate the allowable current limit, the conductor temperature is assumed in the most worst environment condition. It is possible to increase the transmission capacity if the actual burial environment is considered. Therefore, in this paper an algorithm is proposed to calculate the conductor temperature by distinguishing two area of a underground transmission line condition - the manhole where the temperature sensor can be installed and the underground transmission line in which the temperature sensor can not be installed easily. When calculating the conductor temperature by the underground line in the pipeline, the existing standard describes each environment as a single soil heat resistance and one ambient temperature. In order to compensate this situation, thermal resistance model that can take into consideration the ground surface temperature and under ground temperature is proposed. It is shown that the accuracy of the proposed model is increased compared with the existing standard calculation result.