• Title/Summary/Keyword: Air-side

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The Effects of N2 Diluent and Preheated Air on Soot Emission in Laminar Diffusion Flames (층류확산화염에서 질소 첨가와 예열온도가 매연 생성에 미치는 영향)

  • Jeong, Yong-Ki;Lee, Jong-Ho;Jeon, Chung-Hwan;Jang, Young-June
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.1
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    • pp.1-8
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    • 2004
  • An study has been performed with axisymmetric coflow diffusion flames to investigate the influence of air-side fuel side dilution and initial preheated temperature on the soot formation in methan/air flames. Soot quantities are determined by using PLII(Planar Laser Induced Incandescence), such a $C_2$H$_2$ major species(CH$_4$, $O_2$, $N_2$) and temperature are simulated by chemkin code. The numerical analysis was performed with transport properties and detailed reaction mechanisms m axisymmetric coflow diffusion flames. The study of how flame temperature and $N_2$ dilution of air and fuel side influence the soot concentrations is focused. Soot concentrations results on PLII show that preheated temperature contributes to an increase in the soot volume fraction, and soot formation Is more productive to air side dilution than to fuel side dilution. $C_2$H$_2$ concentrations have a similar tendency to soot concentrations.

Energy Consumption Analysis based on Filter Differential Pressure when Adopting an Air-side Economizer System for a Data Center (데이터센터에 적용된 외기도입 냉방시스템에서 필터유형별 에너지 소비량 변화)

  • Park, Seonghyun;Seo, Janghoo;Jung, Yong-Ho;Chang, Hyun-Jae;Hwang, Seok-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.7
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    • pp.371-376
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    • 2013
  • Recently, many studies related to reducing the energy consumption in data centers have been conducted. These studies have mainly focused on the air intake and exhaust system of a computer room air handling unit (CRAH) in the server room, diffuser type, suppression and discharge of the heat generated from the server, and the air-side economizer system. In this study, the energy consumption of the conventional central chilled water cooling system is compared with the energy consumption of the air-side economizer system. We also examined how changes of differential pressure by each filter have influenced energy consumption, using the power usage effectiveness (PUE). Results show that the PUE was improved, and energy consumption decreased, by applying the air-side economizer system.

Performance Evaluation of Heat Exchangers due to Air-side Particulate Fouling in the Air Conditioners (공기측 파울링에 의한 에어컨 열교환기의 성능분석 연구)

  • 안영철;조재민;이재근;이현욱;안승표;윤덕현;하삼철;강태욱
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.6
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    • pp.447-453
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    • 2003
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the cooling performance and pressure drop on the air-side particulate fouling of heat exchangers for air conditioners. Air conditioners being used in the field such as inn, restaurant, and office are collected in chronological used order. Test results show 15% decrease of the cooling capacity and 44% increase of the pressure drop for the 7 years air conditioners used in the seaside inn.

Experimental Study on Heating Performance Characteristics of Air Source Heat Pump with Air to Water Type (공기열원 히트펌프의 난방 성능특성에 관한 실험적 연구)

  • Lee, Kwon-Jae;Kwon, Young-Chul;Chun, Chong-Keun;Park, Sam-Jin;Kwon, Jeong-Tae;Huh, Cheol
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.6
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    • pp.400-405
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    • 2011
  • This paper presents the heating performance characteristics of the air source heat pump with air to water type. The heating capacity, COP, P-h diagram were measured at various operating conditions, air-side temperatures, relative humidities, and inlet/outlet water temperature under the standard heating condition of KS B 6275. The experimental data for the heat pump were measured using the air-enthalpy calorimeter and the constant temperature water bath. As the air-side temperature increases, the heating capacity and COP increase. The effect of the air-side relative humidities on the heat pump performance is insignificant. The heat pump performance on inlet and outlet water temperatures and air-side temperatures(-7, -11, $-15^{\circ}C$) were studied. Heating capacity and COP increased about 27~39% with the air-side temperature increasing. Enthalpy between the front and the rear of condenser decreased about 6% by increasing of the inlet water temperature. These results can be utilized in the design of the air source heat pump system with air to water type.

Characteristics of the Air-side Particulate Fouling Materials in Finned-Tube Heat Exchangers of Air Conditioners (공기조화기용 열교환기의 공기측 파울링 입자 분석 연구)

  • 안영철;신희수;황유진;이창건;이재근;이현욱;안승표;윤덕현;하삼철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.7
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    • pp.611-617
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    • 2003
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the characteristics of the air-side particulate fouling materials in finned-tube heat exchangers of air conditioners. Air conditioners being used in the field such as inns, restaurants, and offices are collected in chronological order in use. Typical fouling materials on the heat exchangers include fibers and dusts ranged from 6.6 to 20.9 ${\mu}{\textrm}{m}$ in mass median diameter.

Viability of HVAC System for Energy Conservation in High Density Internal-load Dominated Buildings (고밀도 내부부하 중심 건물의 에너지 절약적 공조방식에 대한 연구)

  • Cho, Jin-Kyun;Jeong, Cha-Su;Kim, Byung-Seon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.8
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    • pp.530-537
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    • 2010
  • With the advancement of technology, the density of IT equipment, heat load and power consumption continue to increase in high density internal-load dominated buildings as datacenters. To improve the HVAC system's energy performance and efficiency, there is a need to find methods of using outside air. Through cooling tower control that is based on outside wet-bulb temperature, the water-side economizer made it possible to achieve a maximum energy performance improvement of about 16.6% over the basic chilled water system, whereas the air-side economizer, through control based on outdoor air enthalpy, made it possible to achieve about 42.4% improvement.

Pb, Cu, Zn Contaminants and Their Correlation of Soil, Leave and Bark of Ginkgo. B and Ambient Air Adjacent to a Heavy Traffic Road Side (교통량 과밀 도로주변의 토양과 가로수, 대기중 Pb, Cu, Zn 중금속 농도와 그 상관성에 관한 연구)

  • 박기학
    • Journal of Environmental Health Sciences
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    • v.18 no.2
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    • pp.19-25
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    • 1992
  • The study was carried out to investigate the correlation between the heavy metals emitted by the motor vehicles with the heavy traffic road side environment (soil, leave, bark, ambient air). The Pb, Cu, Zn contents in road side soil sand leaves, barks from Ginkgo, biloba and ambient air adjacent to the heavy traffic road side from June to August, 1992 Suwon city were analyzed by Atomic absorption spectrometry and Inductively coupled plasma emission spectrophotometry. The results were as follows: 1) The high levels of heavy metals concentration were Pb, at city-terminal in soil (186 $\mu$g/g), Cu, at city-terminal in soil (221 $\mu$g/g), Zn, at city-terminal in ambient air (252 $\mu$g/m$^{3}$). 2) The low leves of heavy metals concentration were Pb, at North-gate in ambient air (1.65$\mu$g/m$^{3}$), Cu, at North-gate in ambient air (4 $\mu$g/m$^{3}$), Zn, at North-gate in ambient air (15.31$\mu$g/m$^{3}$). 3) The regional distribution of Pb, Cu, Zn in road side soils, leaves and barks from Ginkgo, biloba, ambient air show high levels in turn, city4erminal, Guan Sean Dong, South gate, North gate. 4) The concentration of heavy metals (Pb, Cu, Zn) in soils, leaves, barks, ambient air was highly correlated with the traffic volume of the sampling sites (r=0.64~0.96). To conclude that the high levels of Pb, Cu, Zn contaminations were positively related to motor vehicles-borne pollutants and road side soils, trees, ambient air adjacent to a high density building area with low road coverage and heavy traffic volume were reflected strongly by the hazardous pollutants emitted by motor vehicles.

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Energy Performance of Air-side Economizer System for Data Center Considering Supply Temperature and Design Airflow Rate of CRAH(Computer Room Air Handler) (외기냉방시스템이 적용된 데이터센터 CRAH의 급기온도와 설계 풍량에 따른 에너지성능 분석)

  • Kim, Ji-Hye;Aum, Tae-Yun;Jeong, Cha-Su
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.11
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    • pp.181-188
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    • 2019
  • The purpose of this study is to evaluate the cooling energy saving effects of CRAH supply air temperature(SAT) and design flow rate changes when applying air-side economizer in the data center. MLC(Mechanical Load Component), which is cooling performance indicator of data center, was used to assess the effectiveness of cooling energy savings. It was computed with energy simulation (DesignBuilder) to evaluate the cooling energy performance of 8 different alternatives in a data center. The MLC was 0.31~0.32 regardless of CRAH supply temperature without air-side economizer, and 0.15 to 0.19 value with air-side economizer. That is, cooling energy can be reduced by approximately 40~55% when applying economizer. As the CRAH SAT and design flow rate changed, the MLC values were 0.16 to 0.18 and 0.15 to 0.19, respectively.

Experiments on the Effective Engine Room Ventilation in a Power Car (동력 철도차량 기관실의 효과적인 환기에 관한 실험적 연구)

  • Han, S.Y.;Lee, J.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.2 no.3
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    • pp.166-176
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    • 1990
  • Experimental study was made to find the effective ways for cooling of engine room in a power car through natural ventilation, forced ventilation and wind tunnel test of 1:10 model. Through the measurements of inner temperature of engine room and pressure distribution of model surface for the various opening combinations and the fan locations, the following results are obtained. For natural ventilation, side and top opening combination is more effective than the side openings only and optimal opening combination is all side openings with top center opening. For forced ventilation with fan on the roof, the combination of all sides and top opening is more effective than the combination of side and top opening, and the optimal location of fan is top center. When the model is located in the air stream, the combination of side and top opening is more effective than the side openings only, and the optimal location of top opening is the front opening. With both air stream and forced ventilation, the optimal location of fan is the side region, and the direction of side grill installation is found to have negligible effect on the room ventilation.

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A Numerical Study on the Dynamic Behaviors of Single Vortex in a $CH_4/Air$ Diffusion Flame with Addition of $CO_2$ ($CH_4/Air$ 확산화염에 $CO_2$ 첨가에 따른 단일 와동의 동적 거동에 관한 수치해석)

  • Hwang, Chul-Hong;Oh, Chang-Bo;Lee, Dae-Yup;Lee, Chang-Eon
    • 한국연소학회:학술대회논문집
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    • 2002.06a
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    • pp.68-75
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    • 2002
  • The dynamic behaviors of the single vortex and flame-vortex interaction in a $CH_4/Air$ diffusion flame with addition of $CO_2$ were investigated numerically. The numerical method was based on a predictor-corrector for low Mach number flow. A two-step global reaction mechanism was adopted as a combustion model. Through comparison of results by effect of $CO_2$ added either on the fuel or oxidizer side, it was found that the growth of single vortex and entrainment of surrounding fluid by $CO_2$addition on the fuel side are larger than those by $CO_2$ addition on oxidizer side. Also, when $CO_2$ is added on fuel side, flame-vortex interaction becomes more significant than on air side.

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