• Title/Summary/Keyword: Refrigerating efficiency

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Numerical Analysis of Moisture Ventilation in the Dry Room (Dry room내 수분환기에 대한 수치적 연구)

  • 이관수;임광옥;정영식
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.10
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    • pp.908-916
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    • 2000
  • In this paper, the characteristics of moisture ventilation in the lithium ion battery manufacturing dry room are studied numerically using standard $k-\varepsilon$ turbulence model. Both the steady-state and the unsteady behaviors of moisture ventilation are analyzed by considering local and uniform moisture generation. In order to evaluate the characteristics of moisture ventilation, three scales of ventilation efficiency and characteristic ventilation time are presented from the numerical results. It was shown that moisture distribution was dependent strongly on the flow field. The characteristics of moisture ventilation were improved by 20% and 40% in terms of the 1st scale of ventilation efficiency (SVE1) and the 2nd scale of ventilation efficiency (SVE2), respectively, through the modifications of design variables such as the addition of inlets, outlets and partition. A significant improvement in the characteristic ventilation time and the moisture exhaust efficiency was also made by these modifications.

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Experimental Study on the Cooling seasonal Performance Factor of Room Air-conditioner (에어컨의 냉방기간 에너지 효율 산출을 위한 실험적 연구)

  • Lee, H.W.;Moon, J.H.;Bae, Y.D.;Park, J.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.4 no.3
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    • pp.204-216
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    • 1992
  • In most cases, EER(Energy Efficiency Ratio) is available to present energy efficiency of air-conditioners. But, EER is not adapt to measure energy efficiency at actual life environment because it is based on fixed temperature and humidity contditions. To overcome this disadvantage, there is need to introduce SEER(Seasonal Energy Efficiency Ratio) established at time varient temperature and humidity conditions. In this paper, SEER measurement method and conditions based on actual life environment of the country is introduced, and discussed SEER value about two air-conditioner type, that is, non inverter air-conditioner and inverter air-conditioner. As a result of, inverter air-conditioner was superior to non inverter air-conditioner at cooling seasonal energy efficiency.

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Performance Variation of the Air Curtain for Various Discharge Angles in Feating Space (난방공간에서 에어커튼의 토출각도 변화에 따른 성능 변화)

  • Sung, Sun-Kyung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.2
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    • pp.57-63
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    • 2010
  • Air curtains are widely used for gates of shopping mall, warehouse, cold stores and refrigerated display cabinets. The purpose of the air curtain is to reduce the infiltration of outdoor air and heat loss from the air conditioning space to ambient air. The discharge angle of air curtain is very important as the sealing efficiency is affected by it. This paper presents a performance of single jet air curtain in heating space when the discharge angle of nozzle changes. A numerical simulation is used to study the influence of various parameters on the efficiency of the downward-blowing air curtain device which is installed inside of the wall above the door. The performance of the air curtain is evaluated by sealing efficiency which provides the assessment of the energy savings. A condition of discharge angle that has the highest sealing efficiency is proposed.

Analytical Study on the Performance of a Rotary Vane Compressor (로타리 베인 공기압축기의 성능에 관한 수치해석)

  • Kim Hyun-Jin;Nam Bo-Young;Lee Gyeong-Yong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.4
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    • pp.351-358
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    • 2006
  • This paper presents analytical results of a rotary vane compressor performance when the compressor is used for air supply from underwater. Compression characteristics such as pressure and temperature in a compression chamber are analyzed. Volumetric and adiabatic efficiencies are calculated. Vane dynamics are also performed to give reaction forces on the vane from the cylinder inner surface and from vane slots. Compressor efficiency is about 34.9%, and about 55% of the compressor loss is produced by the friction between the vane nose and the cylinder wall. Volumetric efficiency is about 79.5%, and indicated efficiency is about 77.1%, which are comparable to other displacement type compressors. When roller was introduced between housing inner wall and vane tips, mechanical efficiency could be improved by as much as 24.9%, depending on the roller friction.

An Evaluation for the Quantitative Thermal Performance of High Energy Efficiency Low-e Window (고효율 로이유리 창호의 정량적 단열성능 평가)

  • Choi, Gyoung-Seok;Choi, Hyoun-Joung;Kang, Jae-Sik;Yang, Kwan-Seop;Lee, Seung-Eon
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.970-975
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    • 2006
  • In the high oil prices age, intensification of energy efficiency promotion in the building sector is required. Windows are dominating large percentage whole building loads, and are regarding as the primary target of energy efficiency. The purpose of this study is to draw up a technical counterplan for the intensification of windows energy efficiency and spread promotion by quantitative thermal performance with KS test method for a comparison between the general Pair glass windows and the Low-e pair glass windows.

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