• 제목/요약/키워드: Natural ventilation system

검색결과 195건 처리시간 0.026초

배면 통기유로를 가지는 태양광 발전시스템의 발전효율과 열전달의 관계 (Relationships between Electric Power Generation of PV System and Heat Transfer which has Free Air Ventilation Duct)

  • 김명준;채규훈
    • Journal of Advanced Marine Engineering and Technology
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    • 제34권5호
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    • pp.625-631
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    • 2010
  • 최근 몇 년간 에너지 위기에 대한 우려가 급격히 증가하고 있으며, 방대한 에너지소비에 따른 환경오염도 큰 문제로 대두되고 있다. 사회적으로 에너지 위기가 고조되고 있는 가운데 새로운 에너지나 신재생에너지에 대한 관심이 증가하고 있다. 본 연구는 이러한 문제를 해결하는 하나의 수단으로 태양에너지를 적극적으로 이용하기 위한 태양광발전시스템의 발전효율을 상승시키는 일환으로 대류열전달의 향상을 도모한 실험을 수행한 결과를 정리한 논문이다.

전산유체역학을 이용한 표준 오리사 설계안에 대한 환기효율성 분석 (Analysis on Ventilation Efficiency of Standard Duck House using Computational Fluid Dynamics)

  • 여욱현;조예슬;권경석;하태환;박세준;김락우;이상연;이승노;이인복;서일환
    • 한국농공학회논문집
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    • 제57권5호
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    • pp.51-60
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    • 2015
  • In Korea, 69.4 % of duck farms had utilized conventional plastic greenhouses. In this facilities, there are difficulties in controlling indoor environments for raising duck. High rearing density in duct farms also made the environmental control difficult resulting in getting more stressed making their immune system weaker. Therefore, a facility is needed to having structurally enough solidity and high efficiency on the environmental control. So, new design plans of duck house have recently been conducted by National Institute of Animal Science in Korea. As a study in advance to establish standard, computational fluid dynamics (CFD) was used to estimate the aerodynamic problems according to the designs by means of overall and regional ventilation efficiencies quantitatively and qualitatively. Tracer gas decay (TGD) method was used to calculate ventilation rate according to the structural characteristics of duck houses including installation of indoor circulation fan. The results showed that natural ventilation rate was averagely 164 % higher than typically designed ventilation rate, 1 AER ($min^{-1}$). Meanwhile, mechanically ventilated duck houses made 81.2 % of summer ventilation rate requirement. Therefore, it is urgent to develop a new duck house considering more structural safety as well as higher efficiency of environmental control.

CFD 해석을 통한 하이브리드 공조시스템의 인체 온열감의 불균일성에 관한 연구 (Study on Non-uniform Thermal Comfort in Hybrid Air-Conditioning System with CFD Analysis)

  • 남유진;성민기;송두삼
    • 설비공학논문집
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    • 제23권3호
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    • pp.216-222
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    • 2011
  • Recently, hybrid air-conditioning system has been proposed and applied to achieve building energy saving. One example is a system combining radiation panel with natural wind-induced cross-ventilation. However, few research works have been conducted on the non-uniformity of thermal comfort in such hybrid air-conditioning system. In this paper, both thermal environment and non-uniform thermal comfort of human thermal model under various air-conditioning system, including hybrid system, were evaluated in a typical office room using coupled simulation of computation fluid dynamics, radiation model and a human thermal model. The non-uniformity of thermal comfort was evaluated from the deviation of surface temperature of human thermal model. Flow fields and temperature distribution in each case were represented.

새송이버섯 병재배에서 환기방법이 이산화탄소 농도 및 자실체형성에 미치는 영향 (Effects of Various Ventilation Systems on the Carbon Dioxide Concentration and Fruiting Body Formation of King Oyster Mushroom (Pleurotus eryngii) Grown in Culture Bottles)

  • 이현욱;안미정;이신우;이철호
    • 생명과학회지
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    • 제17권1호
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    • pp.82-90
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    • 2007
  • 새송이버섯 재배에서 환기방법이 실내의 이산화탄소 농도 및 자실체형성에 미치는 영향을 알아보기 위하여 평압형, 양압형, 음압형, 복합형의 4종의 환기방법을 사용하여 환기효율, 재배효율 및 생리장해발생정도를 포장에서 조사하였다. 그 결과 복합형의 경우, 실내 이산화탄소 농도가 평압형의 경우 1,400 ppm인 것에 비해 800 ppm으로서 현저하게 낮았고, 기류발생정도도 상대적으로 적어 환기효율이 가장 높은 것으로 나타났다. 대의 길이, 갓의 직경, 품질, 수량 등의 재배효율이 복합형에서 가장 높았으며, 수확소요일수가 단축 되었다. 생리장해의 발생에 있어서는, 세균점액증상, 비늘대증상 및 굴곡대증상의 경우에서는 환기방법에 따라 큰 차이를 보이지 않았으나, 오뚝이증상, 진무름증상 및 갈반증상은 이산화탄소 농도가 다른 환기방법에 비해 낮았던 복합형과 음압형에서 현저하게 줄어드는 경향을 보였다. 전체적으로 볼 때, 평압형 환기방법은 환기효율이 낮아 실내 이산화탄소농도를 유효하게 밖으로 배출해 내지 못함으로서 품질과 수량을 현저하게 떨어뜨리고, 생리장해의 발생을 유도하는 결과를 초래하였으며, 양압형 또한 평압형에 비해 효율성이 다소 높은 경향을 보였으나, 이들 2종은 새송이 버섯의 연중재배에 이용되는 환기방법으로 부적절한 것으로 나타났다. 음압형의 경우 상대적으로 효율성이 높은 환기방법으로서 어느 정도 도입의 가능성을 시사하고 있으나, 복합형이 환기효율, 재배효율 및 생리장해억제효과가 가장 우수한 것으로 조사되어, 새송이버섯 재배에서 복합형 환기방법을 도입할 경우, 품질향상과 생산성향상은 물론 연중 안전재배를 기대할 수 있을 것으로 사료된다. 도움이 되리라 생각된다.리고 실험에 사용된 송신부 및 수신부를 사진으로 보였으며, 이것을 이용하여 통신 수신율을 분석하였다. 주파수에서 측정된 Type 1 안테나의 전기적 성능은 원형 도체 배열을 10개 적층(disk10)하였을 때, 15.65 dBi의 최대 안테나 이득과 11.4 dB 이상의 입력 반사 손실 성능을 보여 주었으며, 다층 원형 도체 배열 구조에 의해 약 5 dB의 이득 향상 효과를 얻을 수 있었다. 또한, 원형 도체를 12개 적층하였을 때, 외곽 유전체 링 효과에 의해 Type 1 안테나는 Type 2 안테나보다 상대적으로 약 1.35 dB 만큼 이득이 더 높았으며, 각 안테나의 3 dB 빔 폭은 각각 약 $28^{\circ}$$36^{\circ}$로 측정되었다.. 그러나 기흉 발생 당일은 기흉이 발생하지 않은 날 당일보다 전일 대비 평균 기온이 높고(0.533 vs. $-0.103^{\circ}C$, RR 1.141, Cl $1.038{\sim}l.255$, p=0.006), 기온상승폭도 컸다(9.209 vs. $7.754^{\circ}C$, RR 1.123, Cl $1.061{\sim}1.190$, p=0.000). 결론: 본 연구의 결과를 통해 저자들은 기압이 상승한 뒤 기온이 상승했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수

공기조화, 냉동 분야의 최근 연구 동향 - 1998년 1999년 학회지 논문에 대한 종합적 고찰 - (Recent Progress in Air Conditioning and Refrigeration Research - A Review of papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 1998 and 1999 -)

  • 이재헌;김광우;김병주;이재효;김우승;조형희;김민수
    • 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.

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근대 이상주거 고댕의 사회궁전에 나타나는 건축특성 연구 (A Study on the Architectural Characteristics of Godin's Social Palace System of Modern Ideal Housing)

  • 백승관
    • 한국주거학회논문집
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    • 제25권1호
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    • pp.1-13
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    • 2014
  • This study analyzes the architectural characteristics of Godin's Social Palace system of ideal housing for laborers during the 19th century. Utopian socialists in the first half of the 19th century proposed different solutions to reform their chaotic capitalist society, in response to the maladies of the Industrial Revolution. Fourier designed an ideal housing referred to as the Phalanstere, in which residences coexisted in a cooperative society. His disciples tried in vain to make this ideal housing system real. The only realization of this type of ideal housing was called Godin's Social Palace, which was constructed in Guise, France. The main architectural characteristics of Godin's Social Palace are as follows: dwelling units in consideration of function and expansion are applied basically in the housing. Further, a natural ventilation system is applied between housing and courtyard, and water supply is established in the housing. In Particular, natural lighting and artificial illumination are used in the entire building appropriately. In addition, a device which promotes a community between inhabitants is established. As for such modern facilities and social devices, inhabitants were able to live a more comfortable life. Hence, it is confirmed to have been one of the important factors for sustaining the Social Palace for more than 100 years.

에너지절감을 도모하는 실내 온열환경 제어논리-Adaptive Model (New approaches of Indoor Environmental Control for Energy Saving-Adaptive Model)

  • 송두삼;가토 신스케
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.838-846
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    • 2006
  • The purpose of this study to develop the air-conditioning system that adopts adaptive model as an indoor climate control logic for energy saving. The adaptive model using the ability of human thermal adaptation could be expected to alleviate the indoor set-point temperature compared with the past heat-balance model. Especially, in case of hybrid air-conditioning system coupled with natural ventilation and heating/cooling system, the adaptive model can be describe the thermal comfort of inhabitant who stay at hybrid system controlled buildings with accuracy. In this paper, the concept of adaptive model will be described and the results of a continuous measurement on the actual thermal experiences and behaviors of thermal adaptation for office worker will be reported.

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현대건축에서 나타나는 중정의 유형 변화에 관한 연구 (A Study on the Typological Alteration of the Courtyard in Modern Architecture)

  • 이정민;김국선;우현용
    • 한국실내디자인학회논문집
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    • 제21권4호
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    • pp.40-47
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    • 2012
  • Courtyard is evolving from the conventional one element of a building far beyond into independent peremeter of urban architecture, of which function has been darmatically upgraded from embedded traditional air fluiding, nutural lighting system into where full fledged function can be experienced so much as your imagimation reaches taking major social responsibility such as intact offline social networking which links people from neighbors, inter / extra buiding openness which allow people can communicate among othewise between themselves and artificial natural environmental emelents supplier where people resort to relaxation and natural healing. Roles of courtyard has been by far streatched out into nearby natural healing space where people can shake off their unavoidable stresses from the modern life relaxing themselves looking at the sky otherwise observe natural surroundigns such as plants, flowers and waters. Thanks to hereonto mentioned its merits, Courtyard building is widely used and seen as a center of modern urban design in residence, public bilding and urban planned buildings. Courtyard biulding is nowadays boasting their morphological diversity brought out from lots of topological variation, type variants, cross section and inter relationship with the other neighboring spaces. Hence, hereby I have been studied how above mentioned three major peremeters of courtyard has been upgraded in modern architecture comparing the period from 1960 to 1990 and the period starting from 1991.

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전산유체역학시뮬레이션을 이용한 도시가스 설비의 폭발위험성 예측 (Prediction of Explosion Risk for Natural Gas Facilities using Computational Fluid Dynamics (CFD))

  • 한상일;이동욱;황규석
    • 한국응용과학기술학회지
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    • 제35권3호
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    • pp.606-611
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    • 2018
  • 산업현장과 열병합발전 등 다양한 장소에 사용되는 도시가스는 산업안전보건법 정의에 따라 인화성 가스에 해당되며 한국산업표준 KS C IEC에 의해 가스 폭발위험장소가 설정되어 안전하게 관리가 되어야 한다. 본 연구에서는 일반 화학공장에 적용되는 KS C IEC 표준을 저압 도시가스 사용설비 폭발위험성 예측에 합리적으로 적용하기 위해누출공 크기, 환기 등급, 환기 유효성 등의 주요 변수를 도입하였다.CFD 시뮬레이션 적용의 타당성을 평가하기 위해 전산유체역학 (CFD) 시뮬레이션, 가스누출실험, KS C IEC 표준 계산 통해 얻어진 폭발하한계가상 체적을 이용하여 네 가지 다른 조건에서 폭발 위험성을 평가하였다.

PIV와 CFD에 의한 LNG선박의 Hood room 환기특성에 관한 연구 (A Study on Ventilation Characteristics of LNG Carrier Hood room by PIV and CFD)

  • 조대환;김동찬;김만응;이영호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.673-679
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    • 2000
  • LNG Carriers are currently known as sole commercial means of shipping natural gas on the sea. They are designed to proven dangerous explosion for shipping a lot of gas over long distance. In this study. In this study, a scaled model chamber was made to investigate ventilation characteristics of the hood room in LNG carrier. Experimental study was performed in model using visualization equipments with laser apparatus and image intensifier CCD camera gated by an AOM controller Twelve different kinds of measuring area were selected as experimental condition. Instant simultaneous velocity vectors at whole field were measured by using 2-D PIV system which software adopts two-frame grey-level cross correlation algorithm. To look into stagnation area of hood room for LNG carrier, a three-dimensional numerical simulation with standard ${\kappa}-{\varepsilon}$ model was carried out by using PHOENICS for three kinds of Reynolds number, $6.5{\times}10^3$, $9.7{\times}10^3\;and\;1.29{\times}10^4$, based on the cavity inlet velocity and cavity height. The flow pattern showed the large scale counter-clockwise forced-vortex rotated at center area, small eddies at each corner and stagnation area located at left-back upper side of model.

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