• 제목/요약/키워드: Dry-bulb temperature

검색결과 114건 처리시간 0.028초

체감온도이론의 비교 연구 (A Comparative Study on the Windchill Indices)

  • 박정환;한욱;박래설
    • 한국지구과학회지
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    • 제23권8호
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    • pp.676-682
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    • 2002
  • 겨울철 체감온도는 온도와 바람에 의해 느끼는 추위의 정도를 정량화한 것이다. Siple-Passel은 최초로 바람에 의한 냉각효과를 이용하여 바람냉각상당온도를 제시하였으나 일반인에게 적합하지 않기 때문에 많은 문제점이 지적되어 왔으므로 이 논문에서 결점들을 비교 분석하였다. Steadman 모델은 열평형(thermal equilibrium) 이론에 근거하여 보다 현실적이지만 추위의 정도를 구분하여 설명하지 못하였다. 최근 캐나다와 미국에서 개발한 JAG/TI-모델은 보다 정확하고 이해하기 쉬우며 인체실험을 반영하였으나 태양복사, 습도, 개인의 신체적 차이 등은 고려하지 않았다. 나이, 사람의 활동, 건강, 신진대사 등이 다르기 때문에 어느 모델이 사람에게 적합한지는 실험 비교가 필요하다. 따라서 우리의 야전환경에 적합한 체감온도모델의 개발이 요구된다.

동계 이중외피와 내부식재에 의한 실내 온도 특성에 관한 연구 (The Characteristics of the winter season window and indoor temperature due to the indoor plant)

  • 윤영일;조주영
    • KIEAE Journal
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    • 제15권5호
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    • pp.107-112
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    • 2015
  • Purpose: This study desires to investigate an effect of indoor temperature, humidity, and illuminance targeting a planting system of double-skin facade and cavity space adjacent to the outside within a certain period of winter. Through this, the study suggests a basic material about an energy conservation effect of double window system using planting to reduce heating load of a building in winter, so desires to contribute to indoor thermal comfort effect and illuminance correction study of double window and indoor plant. Method: Considering effects such as day and night climatic elements and air conditions in winter, illuminance measurement was conducted through a double-skin facade of space, a subject of the measurement, on the basis of practical residence time of a resident, and this study analyzed characteristics of indoor illuminance about this. The study measured and compared a change of insolation, dry-bulb temperature, and relative humidity at each indoor-outdoor measuring point, so measured and compared characteristics of an indoor temperature effect by elements of double-skin facade and indoor plant. Result: Through this study, the researcher could determine that indoor plant within double window in winter not only blocks solar radiation but also photosynthesizes, so is somewhat disadvantageous to winter thermal comfort reducing heating load. In addition, solar radiation going through interior plays a role to bring down somewhat high humidity to about 50% of reasonable humidity, so plays a direct role of maintenance of comfortable indoor space. Although there are effects such as blocking of solar radiation and temperature reduction, this has a positive influence on humidity control and proper illuminance distribution. The researcher could determine that illuminance, temperature, and humidity by solar radiation penetration for the whole measuring time play a role to supplement indoor environment mutually.

동시냉난방 열펌프 시스템의 냉방전용 및 냉방주체 운전모드에서의 실내기온 변화에 따른 성능특성에 관한 실험적 연구 (An Experimental Study on the Performance of a Simultaneous Heating and Cooling Heat Pump in the Cooling-only and Cooling-main Operation Mode with the Variation of the Indoor Air Temperature)

  • 안재환;주영주;강훈;정현준;김용찬;최종민
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2165-2170
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    • 2008
  • The cooling load in winter season is significant in many commercial buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Therefore, the development of a multi-heat pump which can cover heating and cooling simultaneously for each indoor unit is required. In this study, the characteristics and performance of a simultaneous heating and cooling heat pump in the cooling-only and cooling-main operating mode was investigated experimentally with a variation of indoor air dry bulb temperature which is from $21^{\circ}C$ to $35^{\circ}C$. EEV opening was adjusted from 20% to 24% during the tests. When the indoor air temperature varied, the performance in the cooling-only mode was more sensitive to the temperature than in the cooling-main mode. The total capacity and COP were increased by 53.8% and 48.1%, respectively, in the cooling-main, while those were increased by 19.6% and 19.3% in the cooling-only mode. The performance differences between the two operating modes became larger at lower temperatures, especially for the COP.

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알루미늄반사재의 배치형태에 따른 보온 효과 (Effectiveness of the Aluminum Thermal Screens Depending on the Allocation Type)

  • 김영복;박중춘;허무룡;이시영;정성우
    • 생물환경조절학회지
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    • 제16권4호
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    • pp.284-290
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    • 2007
  • 온실보온을 위한 알루미늄반사단열재의 설치위치와 광택부의 설치방향에 따라 보온효과를 구명하고자 알루미늄반사재와 부직포를 조합하여 모듈을 구성하고, 모듈내 가열량을 각각 100W, 40W로 하여 2차에 걸쳐 처리 건구온도와 흑구온도, 상대습도를 재료의 조합에 따라 분석하였다. 1. 알루미늄반사재가 있는 경우가 부직포만 있는 경우보다 보온효율이 높았으며, 알루미늄을 두 층으로 하면 한 층으로 할 때보다 내부온도가 높았다. 알루미늄반사재를 한 층으로 설치할 때는 알루미늄반사재의 광택부분을 외부로 향하게 하는 것이 내부로 향하게 하는 것보다 모듈내 온도가 높았다. 알루미늄반사재를 두 층으로 할 때는 같은 방향으로 하는 것이 높게 나타났으며 이 경우 광택부를 둘 다 외향으로 배치하는 것이 보온효율이 더 높게 나타났다. 외기온도에 따라 모듈내 건구온도는 전 모듈에서 서서히 상승하며 그 변화의 크기는 외기온도의 변화보다 적었다. 2. 모듈내를 가열하지 않는 경우 모듈내 온도는 모듈간 온도차가 $0.5^{\circ}C$를 넘지 않았으며 그 차이를 인정하기 어려웠다. 3. 모듈내의 흑구온도변화는 건구온도변화와 그 경향이 비슷하였다 흑구온도는 대체적으로 건구온도보다 높았으며, 그 경향은 알루미늄반사재광택부가 내향인 경우가 외향인 경우보다 더 강하게 나타났던 바 복사열영향이 큰 것으로 판단되었다. 모듈내 상대습도는 건구온도가 증가하면 비교적 직선적으로 하강하였다.

국내 기상 측정결과를 이용한 일사량 예측 방법 기초 연구 (A Basic Study to Predict Solar Insolation using Meteorological Observation Data in Korea)

  • 황보성;김하양;김정배
    • 융복합기술연구소 논문집
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    • 제4권2호
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    • pp.27-33
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    • 2014
  • To well design the solar energy system using solar energy, the correlation to calculate solar irradiation is basically needed. So, this study was performed to reveal the relationships between the solar irradiation and four meteorological observation data(dry bulb temperature, relative humidity, sunshine duration, and cloud cover) which are different from previous other researches. And then, we finally proposed the first order non-linear correlation from the measured solar irradiation using four meteorological observation data with MINITAB. To show the deviation of the solar irradiation between measured and calculated, this study compared using the daily total solar irradiance and the maximum peak value. From those results, the calculation error was estimated about maximum 25.4% for the daily total solar irradiance. The error of the solar irradiation between measured and calculated was made from the curve fitting error. So, solar irradiation prediction correlation with higher accuracy can be obtained using 2nd or higher order terms with four meteorological observation data.

분리막 제습공조시스템의 잠열부하 저감효과 예측 (Prediction of Latent Heat Load Reduction Effect of the Dehumidifying Air-Conditioning System with Membrane)

  • 정용호;박성룡
    • 설비공학논문집
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    • 제29권1호
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    • pp.15-20
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    • 2017
  • The summer climate is very hot and humid in Korea. The humidity is an important factor in determining thermal comfort. Recently, the research for dehumidification device development has been attempted to save energy that is required for the operation of the current dehumidifiers on the market. Existing dehumidification systems have disadvantages such as wasting energy to drive a compressor. Meanwhile, dehumidification systems with membranes can dehumidify humid air without increasing the dry bulb temperature so it doesn't have to consume cooling energy. In this paper, the cooling energy savings was studied when a dehumidification system was applied in a model building instead of a chiller. The sensible heat load was almost the same result, but the latent heat load was decreased by 38.9% and the total heat load was decreased by 8.5%. As a result, electric energy used to drive the compressor in a chiller was saved by applying a membrane air-conditioning system instead.

분리막 제습공조시스템의 내부 유동 해석에 관한 연구 (A Study on Air Flow Analysis for the Internal Space of the Dehumidifying Air-Conditioning System with A Membrane)

  • 정용호;박성룡
    • 설비공학논문집
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    • 제27권12호
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    • pp.620-625
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    • 2015
  • The summer climate is very hot and humid in Korea. Humidity is an important factor in determining thermal comfort. Recently, research on dehumidification device development has been attempted to save the energy required for operating the dehumidifier. Existing dehumidification systems have disadvantages such as wasting energy to drive the compressor. Meanwhile, dehumidification systems with membranes can dehumidify humid air without increasing the dry bulb temperature. Therefore. they don't have to consume cooling energy. In this paper, the installation conditions for a membrane system were analyzed to improve the shape and optimum performance of the system. The results showed that the distance between elements was the critical system design factor, and that a distance of 20 mm was the optimal condition for the pressure drop and flow characteristics of the internal air flow.

분리막 제습공조 시스템의 성능변수 최적화를 위한 실험적 연구 (An Experimental Study on the Optimization of Performance Parameter for Membrane Based Dehumidification and Air Conditioning System)

  • 장재철;강은철;정시영;박성룡
    • 설비공학논문집
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    • 제28권2호
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    • pp.75-80
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    • 2016
  • There are three types of dehumidification systems : refrigeration dehumidification method, desiccant dehumidification method and hybrid dehumidification method. The first method involves removing moisture by condensation below the dew point, the second method involves absorption by a desiccant material and the last is an integration method. However, the refrigeration dehumidification system consumes too much power and controlling the humidity ratio is difficult. The desiccant dehumidification system uses less power but it has problems of environmental pollution. The hybrid dehumidification system has the disadvantage of a high initial cost. On the other hand, the energy consumption of the membrane based dehumidification system is lower than for the refrigeration dehumidification system. Also, it is an environmentally friendly technology. In this study, the performance parameters are evaluated for the dehumidification system using a hollow fiber membrane. Available area, duct side dry-bulb temperature, sweep gas flux (flow rate) and LMPD (Log Mean Pressure Difference) were used as the performance parameters.

동일한 유입온도조건에서 R134a와 R22 적용 응축기의 특성비교 (Comparison of Condenser Characteristics using R134a and R22 under the Same Inlet Temperature Condition)

  • 강신헝;변주석;김창덕
    • 에너지공학
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    • 제15권3호
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    • pp.166-173
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    • 2006
  • 본 연구에서는 상용 냉동 공조기기에서 사용하고 있는 휜-관 열교환기에서 R22와 이의 대체냉매로 채용하고 있는 R134a 압력강하와 열전달 특성에 대해 실험적으로 연구하였다. 실험은 입구온도 $60^{\circ}C$, 질량유량 $150,\;200,\;250\;kg/m^{2}s$의 범위에 대해 수행하였다. 이때 공기의 유입조건은 전구온도 $35^{\circ}C$, 상대습도 40%, 공기유속은 $0.68{\sim}1.6m/s$이다. 실험 결과 응축기 출구의 과냉도를 $5^{\circ}C$로 유지한 경우 Rl34a의 필요공기유속은 R22보다 5.9%작게 나타났으며, R134a의 압력강하는 R22보다 $18.1{\sim}20.4%$의 범위 내에서 크게 나타났다.

흙집의 하절기 실내 물리적 환경 특성과 온열감에 관한 연구 (A Study on the Indoor Climate Characteristics and Thermal Sensation Vote of the Earthen House in Summer Season)

  • 국찬;전지현;신용규
    • 한국주거학회논문집
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    • 제17권5호
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    • pp.9-16
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    • 2006
  • The researches on the environmental friendly buildings have carried out on the materials, environmental property, technical elements and etc., and various buildings with these green materials have built and under construction nowadays and became a new trend of the green building. And recently, new building technique which builds the wall with the soil and wood and very easy to construct (called M Earthen House) was introduced as the green building and rapidly propagated. But the research on the indoor climatic characteristics, the ability to control the environmental comfort and the influence to the human beings of these buildings are not sufficiently identified yet. In this paper, the indoor environmental characteristics and the temperature controlling ability of these buildings in summer season were measured and analysed by the Portable Indoor Air Quality Monitor(BABUC/A, LSI) measuring equipments, ana the subjective test on the thermal environment of the subjects were carried out to evaluate the thermal comfort. The results can be summarized as follows; 1) Compared to the outdoor dry bulb temp.($15.4{\sim}28.7^{\circ}C$), the indoor temp. was $19.5{\sim}26.8^{\circ}C$. It showed the temperature controlling ability of the M earthen house was outstanding. And the indoor relative humidity, compared to the outdoor($45.4{\sim}100%$), was $58.1{\sim}76.4%$, it showed the humidity controlling ability of the M earthen house was also outstanding. 2) The thermal environment was evaluated as 'comfort'(neutral-slightly warm) and the humidity was also evaluated as 'comfort'(neutral-slightly humid). So, the results of the physical and subjective evaluation on the indoor thermal comfort in summer season were 'neutral' and 'comfort' coincidently, it was confirmed that the controlling ability of the indoor temperature and humidity of the M earthen house was very excellent.