• 제목/요약/키워드: EEV

검색결과 64건 처리시간 0.02초

$CO_2$ 급탕 열펌프의 성능 특성에 관한 실험적 연구 (Experimental Study on the Performance of a $CO_2$ Heat Pump Water Heater)

  • 이응찬;백창현;강훈;김용찬;조홍현;조성욱
    • 설비공학논문집
    • /
    • 제21권6호
    • /
    • pp.367-372
    • /
    • 2009
  • The performance of a $CO_2$ heat pump water heater was measured with a variation of operating conditions such as refrigerant charge amount, outdoor temperature, compressor frequency, EEV opening, and water mass flow rate. The optimum refrigerant charge amount of the $CO_2$ system was 1800 g. At water mass flow rates of 75, 85, and 95 kg/h, the water heating temperatures were 74, 67, and $62^{\circ}C$ and COPs were 2.6, 2.8, and 3.0, respectively. Besides, the compressor frequency and water mass flow rate were adjusted to maintain the water heating temperature at $60^{\circ}C$ with the decrease of outdoor temperature. As the outdoor temperature decreased by $5^{\circ}C$, the compressor frequency increased beyond 60 Hz and the water mass flow rate decreased by 16.7%.

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
    • /
    • 대한기계학회 2008년도 추계학술대회B
    • /
    • pp.2165-2170
    • /
    • 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.

  • PDF

HOW TO DEFINE CLEAN VEHICLES\ulcorner ENVIRONMENTAL IMPACT RATING OF VEHICLES

  • Mierlo, J.-Van;Vereecken, L.;Maggetto, G.;Favrel, V.;Meyer, S.;Hecq, W.
    • International Journal of Automotive Technology
    • /
    • 제4권2호
    • /
    • pp.77-86
    • /
    • 2003
  • How to compare the environmental damage caused by vehicles with different foe]s and drive trains\ulcorner This paper describes a methodology to assess the environmental impact of vehicles, using different approaches, and evaluating their benefits and limitations. Rating systems are analysed as tools to compare the environmental impact of vehicles, allowing decision makers to dedicate their financial and non-financial policies and support measures in function of the ecological damage. The paper is based on the "Clean Vehicles" research project, commissioned by the Brussels Capital Region via the BIM-IBGE (Brussels Institute for the Conservation of the Environment) (Van Mierlo et at., 2001). The VriJe Universiteit Brussel (ETEC) and the universite Libre do Bruxelles (CEESE) have jointly carried out the workprogramme. The most important results of this project are illustrated in this paper. First an overview of environmental, economical and technical characteristics of the different alternative fuels and drive trains is given. Afterward the basic principles to identify the environmental impact of cars are described. An outline of the considered emissions and their environmental impact leads to the definition of the calculation method, named Ecoscore. A rather simple and pragmatic approach would be stating that all alternative fuelled vehicles (LPG, CNG, EV, HEV, etc.) can be considered as ′clean′. Another basic approach is considering as ′clean′ all vehicles satisfying a stringent omission regulation like EURO IV or EEV. Such approaches however don′t tell anything about the real environmental damage of the vehicles. In the paper we describe "how should the environmental impact of vehicles be defined\ulcorner", including parameters affecting the emissions of vehicles and their influence on human beings and on the environment and "how could it be defined \ulcorner", taking into account the availability of accurate and reliable data. We take into account different damages (acid rain, photochemical air pollution, global warming. noise, etc.) and their impacts on several receptors like human beings (e.g., cancer, respiratory diseases, etc), ecosystems, or buildings. The presented methodology is based on a kind of Life Cycle Assessment (LCA) in which the contribution of all emissions to a certain damage are considered (e.g. using Exposure-Response damage function). The emissions will include oil extraction, transportation refinery, electricity production, distribution, (Well-to-Wheel approach), as well as the emission due to the production, use and dismantling of the vehicle (Cradle-to-Grave approach). The different damages will be normalized to be able to make a comparison. Hence a reference value (determined by the reference vehicle chosen) will be defined as a target value (the normalized value will thus measure a kind of Distance to Target). The contribution of the different normalized damages to a single value "Ecoscore" will be based on a panel weighting method. Some examples of the calculation of the Ecoscore for different alternative fuels and drive trains will be calculated as an illustration of the methodology.

함백산지역 계곡부의 사면방향과 해발고에 따른 산림구조 (Forest Structure in Relation to Slope Aspect and Altitude in valley Forests at Hambaeksan Area)

  • 박인협;최윤호;이석면;최영철;유석봉
    • 한국환경생태학회지
    • /
    • 제15권4호
    • /
    • pp.361-368
    • /
    • 2002
  • 남북으로 뻗어 있는 태백산맥의 함백산지역 사거리재(해발 1,275m)를 중심으로 동향사면인 세곡계곡과 서향사면인 정암사계곡을 대상으로 사면방향과 해발고에 따른 산림구조를 조사분석하였다. 상층임관을 이루는 교목층의 밀도, 평균흉고직경, 흉고단면적은 동향사면과 서향사면간에 별 차이가 없었다. 서향사면은 동향사면에 비하여 피나무, 거제수나무 등의 상대중요치는 높은 반면, 신갈나무, 물푸레나무 등의 상대중요치가 낮았다. 식생층 전체의 종다양도는 서향사면이 1.415로서 동향사면의 1.328보다 높았으며, 이것은 서향사면인 정암사계곡의 경우 천연기념물인 열목어 서식지로서 비교적 보존이 잘 되었기 때문이라고 판단되었다. 해발고에 따른 분석 결과 해발고가 높아짐에 따라 동, 서향사면 모두 교목층의 흉고단면적과 평균수고가 감소하였으며, 식생층 전체의 종수, 종다양도, 균재도가 감소하는 경 향이었다. 해발고가 높아짐에 따라 상대중요치가 증가하는 수종은 신갈나무이었으며, 감소하는 수종은 거제수나무, 다릅나무 등이었다. Cluster분석 결과 서향사면 전체와 동향사면 중, 하부의 활엽수혼효림군집, 동향사면 상부의 신갈나무군집으로 구분되었으며, 활엽수혼효림군집의 경우 동향사면 중, 하부와 서향사면 상부의 신갈나무가 준우점종인 활엽수혼효림군집, 서향사면 중 하부의 신갈나무가 거의 출현하지 않는 활엽수혼효림군집으로 재구분되었다. 신갈나무는 노린재나무, 시닥나무, 물참대와 유의적인 정의 상관이 있었으며 활엽수혼효림군집의 주요 우점종인 거제수나무는 신갈나무 당단풍과 유의적인 부의 상관이 있었다.적이며 신속하고 유연한 프로세스는 기존의 시스템적 어프로치, 계획성 마케팅의 통제적인 과정을 극복하는 대안적 프로세스의 가능성을 가지고 있다. 넷째, 유소년놀이문화의 버내큐러 디자인산물은 과거 순수형태에서 테크노 변형 놀이산물 문화로 변형되어왔는데, 이는 기성적 디자인이 갖지 못한 다양함을 보완하는 대안적 산물이며, 독립적 문화로서 지속성을 가져야 하는 디자인문화이다.성적 : 대상환자 142명중 임상적 효과판정을 평가할 수 있는 환자는 138명이었으며, 이중 116예(84.1%)에서 환치, 8예(5.8%)에서 효험, 14예(10.1%)에서 실패를 보였다. 약리적 부작용 총 14예중 간효소치가 6예 발생하였으며, 피부발진 4예, 어지러움증 3예, 오한 1예가 나타났다. 결론 : 본 다기관 연구에서, teicoplanin은 주요 그람 양성구균에 대해 광범위한 항균력을 갖고 있으며 특히 methicillin에 내성을 가진 포도상구균에 대하여 vancomycin 다음으로 우수한 항균력을 보여 그 임상적 효용성 및 안전성이 높은 것으로 나타났다. 또한, vancomycin에 비하여 부작용이 경미하여 임상의가 항균제를 선택하는데 많은 도움이 될 것으로 사료된다. EV, HEV, etc.) can be considered as ′clean′. Another basic approach is considering as ′clean′ all vehicles satisfying a stringent omission regulation like EURO IV or EEV. Such approaches