• 제목/요약/키워드: Humidity effectiveness

검색결과 88건 처리시간 0.025초

운전조건에 따른 제습로터의 제습특성과 유용도에 관한 실험적 연구 (An Experimental Study on the Dehumidification Characteristics and the Effectiveness for Operating Conditions of a Desiccant Rotor)

  • 강병하;이진주;김석현
    • 설비공학논문집
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    • 제24권1호
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    • pp.29-36
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    • 2012
  • An experimental study has been carried out to investigate the dehumidification characteristics for several operating conditions of a compact desiccant rotor. This problem is of particular interest in the design of a desiccant type of dehumidifier. Room temperature, room humidity, regeneration temperature, revolution speed and frontal air velocity of desiccant rotor are varied as operating conditions. The results obtained indicate that dehumidification rate is increased with an increase in the room humidity while dehumidification effectiveness is not changed much. It is also found that the optimal rotor speed and optimal regeneration temperature exist for maximum dehumidification rate and dehumidification effectiveness.

제습냉방시스템에서 요소성능이 시스템성능에 미치는 영향 (Effects of Individual Components on the System Performance in a Desiccant Cooling System)

  • 장영수;이대영
    • 설비공학논문집
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    • 제19권10호
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    • pp.687-694
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    • 2007
  • Cycle simulation is peformed for two types of the desiccant cooling system incorporating a regenerative evaporative cooler. The cooling capacity and COP are evaluated at various effectiveness values of the regenerative evaporative cooler, the desiccant rotor and the sensible heat exchanger. As either of the effectiveness of the regenerative evaporative cooler or the humidity effectiveness of the desiccant rotor increases, both the cooling capacity and COP increase, but the enthalpy leak ratio gives the opposite effect on the system performance. It is found that COP of cycle A mainly depends on the humidity effectiveness of the desiccant rotor, while for cycle B enthalpy leak ratio of desiccant rotor has the major impact on COP. The effect of the sensible heat exchanger on the cooling capacity is small about 1/10 compared with those of other components.

제습로터 성능지료 제안 (A Proposal for New Definition of Performance Indices of a Desiccant Rotor)

  • 이대영;이길봉;김민수
    • 설비공학논문집
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    • 제19권7호
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    • pp.537-544
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    • 2007
  • To facilitate comparative analysis on the effects of numerous parameters concerning design and operation of a desiccant rotor, it is firstly required to represent the dehumidification performance as numerical indices. In this work is proposed two performance indices of a desiccant rotor: the humidity effectiveness and the enthalpy-leak ratio. The humidity effectiveness represents the actual dehumidification as compared with the dehumidification in an ideal case, while the enthalpy-leak ratio represents the enthalpy transfer from the regeneration side to the dehumidification side. In an ideal case, the two indices approach one and zero, respectively. The effects of numerous parameters on the dehumidification performance of a desiccant rotor are investigated through numerical simulation and represented with the two indices. The results show that the performance indices are mainly determined by three nondimensional parameters each representing the thermal capacity, the sorption capacity, and the transfer capacity of a desiccant rotor.

Effectiveness of Ventilation Control in a Dry Room with a Heat and Moisture Source

  • Lee, Kwan-Soo;Lim, Kwang-Ok;Ahn, Kang-Ho;Jung, Young-Sick
    • International Journal of Air-Conditioning and Refrigeration
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    • 제9권4호
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    • pp.1-9
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    • 2001
  • The temperature and moisture distributions in a dry room with a heat and moisture source -i.e., workers- are studied numerically by using a standard $k-\varepsilon$ turbulence model. In order to evaluate the effectiveness of heat and moisture ventilation inside the room, the heat removal capacity and the moisture exhaust efficiency are introduced. The effectiveness of ventilation control is analyzed by evaluating the temperature and humidity distributions in the room quantitatively. It is found that the mean absolute humidity inside the room is almost constant regardless of the models and the heat generation rates in this study range. This results from the fact that the moisture generation by the workers was relatively small. Through the modification of the design, 40% improvement in critical decay time was achieved.

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외기 온·습도 변화에 따른 종이재질 전열교환 엘리먼트 성능에 관한 연구 (Thermal Performance of an Enthalpy Exchanger Made of Paper at Different Outdoor Temperatures and Humidities)

  • 김내현;이을종;송길섭;오왕규
    • 대한기계학회논문집B
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    • 제34권7호
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    • pp.697-702
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    • 2010
  • 전열교환 엘리먼트는 열회수형 환기유닛의 핵심부품으로, 외기와 실내공기의 열 및 수분교환이 이루어진다. 본 연구에서는 현재 국내에서 사용되고 있는 전열교환 엘리먼트에 대하여 외기의 온 습도 변화가 전열교환 엘리먼트의 성능에 미치는 영향을 실험적으로 연구하였다. 전열교환 엘리먼트를 통과 하는 공기 유량, 입 출구의 건 습구 온도를 정밀하게 측정할 수 있는 실험장치를 특별히 제작하였고, 항온항습실내에서 외기의 상대습도 또는 절대습도를 변화시키며 실험을 수행하였다. 실험결과는 현열전달 유용도과 잠열전달 유용도으로 평가되는데 잠열 전달 유용도는 외기의 상대습도의 증가에 따라 증가하였으나 절대습도의 변화에는 거의 무관하게 냐타났다. 한편 현열 교환 유용도는 외기의 온도 및 습도 변화에 무관하게 일정하였다.

상대습도조건에 따른 골심지의 압축강도 변화에 관한 연구 (Effects of Relative humidity Conditions on the Compressive Strength Changes of Corrugating Mediums)

  • 이준호;김수일;하영선
    • 한국식품저장유통학회지
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    • 제7권1호
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    • pp.63-67
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    • 2000
  • Changes in the compressive strength of four typical corrugating mediums (K$_2$A, AS and S) as affected by relative humidity conditions were compared and their relative cost effectiveness was analysed. All mediums lost their compressive strength as relative humidity increased. at the relative humidity of 93% , As medium lost 58% of its initial strength while S medium did about 40%. Calculations of compress factor and compress factor by price indicated that $K_2$ medium was the most cost effective and maintained the highest compressive strength among the mediums tested. It was recommended that $K_2$ medium could be effectively used to make corrugated fiberboard especially for fresh agricultural product packaging .

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더운환경에서의 냉각조끼의 착용효과에 관한 연구 (Effectiveness of Cooling Vest in Hot Environment)

  • 최정화;황경숙
    • 한국의류학회지
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    • 제25권1호
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    • pp.83-90
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    • 2001
  • Cooling garments are being considered for reducing heat strain in hot environment. We evaluated the effectiveness of ice gel-based cooling vest in hot environment both resting and exercising. Four male subjects were exposed to heat(4$0^{\circ}C$, 50%RH) with vest or without it. The results were as follows; In case of the trial wearing ice gel-based cooling vest, total body weight loss, and local sweat volume were less than those without it. Mean skin temperature, rectal temperature, pulse, energy expenditure, temperature of inside clothes, and humidity of inside also were lower than those without cooling vest. By subjective thermal sensation, subjective humidity sensation, and thermal comfort sensation, it was proved that non-wearing vest decreased comfort than wearing that. These results suggested that wearing ice gel-based cooling vest reduced human heat strain in hot environment both resting and exercising.

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빙축열 시스템의 지능형 냉방부하예측에 관한 연구 (The Study on Intelligent Cooling Load Forecast of Ice-storage System)

  • 고택범
    • 전기학회논문지
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    • 제57권11호
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    • pp.2061-2065
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    • 2008
  • In the conventional operation of ice-storage system based on operator's experience and judgement, the failure in forecast of cooling load occurs frequently due to operator's misjudgement and unskilled operation. This study presents the method of constructing self-organizing fuzzy models which forecast tomorrow temperature, humidity and cooling load periodically for economic and efficient operation of ice-storage system. To check the effectiveness and feasibility of the suggested algorithm, the actual example for forecasting temperature, humidity and cooling load of ice- storage system in KEPCO training institute, Sokcho, is examined. The computer simulation results show that the accuracy of temperature, humidity, cooling load forecast of the suggested algorithm is higher than that of the conventional methods.

활선애자점검기의 개발 및 154kV 선로에의 적용 - 제2부 : 진단 알고리즘 개발 (Development of Live-line Insulator Tester and Its Application to 154kV Power Lines - Part 2 : Inspection Algorithm Development)

  • 박준영;이재경;조병학;오기용
    • 전기학회논문지P
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    • 제59권1호
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    • pp.89-95
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    • 2010
  • A new live-line insulator tester was developed to detect faulty insulators in 154kV power transmission lines. This paper is the second part of the two-part paper and deals with its inspection algorithm development. Unlike normal condition with low pollution and low humidity, the inspection data measured in the field under high pollution or high humidity showed that the voltage distribution of an insulator string has offsets in comparison with those of others and its insulation resistances are greatly decreased, which leads to wrong results of the existing inspection algorithms under such conditions. To solve this problem, we propose new diagnosis algorithms that can exactly detect faulty insulators from measured data regardless of environmental conditions. Its effectiveness was validated by live-line field tests in actual power lines.

습공기사이클 냉동시스템의 성능해석 (Performance Analysis of a Wet Air-Cycle Refrigeration System)

  • 원성필
    • 설비공학논문집
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    • 제26권11호
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    • pp.504-511
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    • 2014
  • The objective of this study is to theoretically analyze the performance of an open wet air-cycle refrigeration system, which nowadays is increasingly generating environmental concern. The temperature and relative humidity of the outside air are selected as the most important parameters. As the temperature and relative humidity of the outside air increase, the pressure ratio of the ACM compressor is determined to be nearly constant, the air temperature at the exit of the system increases, and the amount of condensed water, the cooling capacity, the COP, and the total entropy production rate increase overall. The effects of the effectiveness of the heat exchanger and the efficiency of the turbine on the performance are greater than that of the efficiency of the ACM compressor. Also, the performance of the wet air-cycle refrigeration system with two heat exchangers is enhanced, with a high COP and low total entropy production rate, compared to the system with a single heat exchanger.