• 제목/요약/키워드: Charge of cold

검색결과 48건 처리시간 0.034초

빙축열시스템의 실질적인 최대 축열 가능량 예측 (Prediction of practically chargeable cold energy in an ice storage system)

  • 이대영;강병하;김민수
    • 설비공학논문집
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    • 제11권1호
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    • pp.133-146
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    • 1999
  • The charge operation of an ice storage system has been analyzed in this paper. The thermal characteristics of major components of the ice storage system. i.e., the refrigerator and the ice storage tank are evaluated from performance tests on an existing ice storage system. Based on the measured data for thermal characteristics, a simulation is carried out for the charge operation and the effect of the refrigerator size on the system performance is investigated. The results indicate that the larger the refrigerator size for a given storage capacity, the lower the inlet temperature of the ice storage tank so that the lower the efficiency of charge operation. It is also found that there exists an optimal size of the refrigerator with which the ice storage at the end of the charge operation is maximized, but the complete charge is not possible even with the optimally sized refrigerator. This leads to the result that the design capacity of the storage tank should be larger than the required amount of cold energy for the daytime cooling considering the practically chargeable amount of cold energy during the nighttime. Where the cooling load sharing of the storage is 40%, the nominal capacity of an ice storage tank needs to be larger than the required storage amount by 30%.

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Removal of Static Electricity on Polyimide Film Surface by $O_2$ or Ar Cold Plasma Etching

  • Lee, Jae-Ho;Jeong, Hee-Cheon
    • Fibers and Polymers
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    • 제5권2호
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    • pp.151-155
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    • 2004
  • Cold plasma of $O_2$ or Ar was irradiated on hydrophobic Kapton surface to attenuate or remove the electrostatic potential. A measurement on charge dissipation speed clarifies the obscure effect of plasma. These consequences reveal that $O_2$ plasma etching is more effective than Ar plasma. After 30 days, the dissipation speed of accumulated charge on initially etched sample has not changed under summer season.

수중 하베스트형 빙축열 시스템의 축방냉 특성 (Experiment of Characteristic on the Charge and Discharge of Cold for In-Water Harvest-Type Ice Storage System)

  • 장용식;최인수;문춘근;천석현;김재돌;윤정인
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.268-273
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    • 2001
  • A fundamental study on the harvest-type ice storage system applied ice making method in-water and its temperature characteristics in ice storage system was performed experimentally of the charge and discharge of cold. This paper is concerned with the development of a new method for making and separating ice and saving floated ice by installing an evaporation plate at in-water within a storage tank. In a conventional harvest-type ice storage system, a tank saves ice by separating a formed ice from an installed evaporation plate, which is located above an ice storage tank as an ice storage system. A new harvest-type method shows very good heat transfer efficiency than a convectional method. It is because the evaporation panel is directly contacted with water in a storage tank. Also, at a conventional system a circulating pump, a circulating water distributor and a piping are installed, but these components are not necessary in a new method. In this study two kinds of ice storage systems are experimentally investigated to study the thermal characteristics of ice storage tanks.

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Highly Efficient Cold Sputtered Iridium Oxide Films for Polyimide based Neural Stimulation Electrodes

  • Kim, Shin-Ae;Kim, Eui-Tae;Kim, Sung-June
    • 대한의용생체공학회:의공학회지
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    • 제30권3호
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    • pp.199-204
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    • 2009
  • Iridium oxide films (IROFs) have been extensively studied as a material for electrical stimulation of neurons, as iridium oxide has higher charge storage capacity than other metal films. More recently, sputtered iridium oxide film (SIROF) has been studied, because it can be made more conveniently than activated iridium oxide film (AIROF). Typically, the SIROFs are grown at temperatures from 400 to 600 $^{\circ}C$. However, such high temperatures cannot be used when the iridium oxide (IrOx) film is to be deposited on a flexible polymer material, such as polyimide. In this paper, we show that we can still obtain excellent characteristics in SIROFs grown without heating (cold SIROF), by optimizing the growth conditions. We show that the oxygen flow rate is a critical parameter for controlling the surface properties of a cold SIROF. At an oxygen flow rate of 12 seem, the cold SIROF exhibited a charge storage capacity (CSC) of 60 mC/cm$^2$, which is comparable to or better than other published values for iridium oxide films including heated SIROFs. The film produced under these conditions also had the minimum impedance value of all cold SIROFs deposited for this study. A stability test and biocompatibility test also demonstrated the superiority of the optimized cold SIROF.

수중 빙 제조방식을 적용한 빙축열시스템의 축방냉 특성 실험 (Experiment of Characteristic on the Charge and Discharge of Cold in Ice Storage System Applied Ice Making Method In-Water)

  • 최인수;김재돌;윤정인
    • 설비공학논문집
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    • 제14권1호
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    • pp.31-37
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    • 2002
  • This paper is concerned with the development of a new method for making and separating ice and saving floated ice by installing an evaporation plate at in-water within a storage tank. In a conventional harvest-type ice storage system, a tank saves ice by separating a formed ice from an installed evaporation plate, which is located above an ice storage tank as an ice storage system. A new harvest-type method shows very good heat transfer efficiency than a convectional method. It is because the evaporation panel is directly contacted with water in a storage tank. Also, at a conventional system a circulating pump, a circulating water distributor and a piping are installed, but these components are not necessary in a new method. In this study two kinds of ice storage systems are experimentally investigated to study the thermal characteristics of ice storage tanks. The results showed discharge of cold capacity of new type indicated the high values about 30~40% based on five time of drive, the temperature difference of inlet/outlet occurred the big range about $1.3^{\circ}C$. So, the new type which makes ice in water showed superiorly.

가솔린 직분식 인젝터의 분무 및 연소특성에 관한 연구 (A Study on the Spray and Combustion Characteristics of Gasoline Direct Injector)

  • 신민규;박종호;유철호;이내현;최규훈
    • 한국자동차공학회논문집
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    • 제5권5호
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    • pp.114-122
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    • 1997
  • Nowadays, gasoline direct injection engines are being commercialized by virtue of improvement in control technology of spray, flow, air fuel ratio. The stratified charge type has the advantage of improving lean limit. The homogeneous type has the advantage of reducing engine-out hydrocabon emissions in the first 30 seconds after a cold start, in addition, improving transient air fuel ratio control. The vaporization and mixing if injected fuel with air has to e completed in a short time and the fuel film in cylinder and on piston has to be minimized. So, the flow and injection should be well controlled. This paper surveyed the spray characteristics of gasoline direct injection by using laser equipment and the combustion characteristics of the single cylinder engine using homogeneousas-mixture type gasoline direct injection.

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냉시동시 압축착화 조건의 상관관계에 관한 수소 HCCI 기관의 실험적 연구 (An Experimental Study on Correlation of Compression Ignition Condition at Cold Start with Hydrogen HCCI Engine)

  • 이광주;이종구;안병호;이종태
    • 한국수소및신에너지학회논문집
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    • 제23권6호
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    • pp.628-633
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    • 2012
  • It was found that the pure hydrogen-air pre-mixture was self-ignited at a high compression ratio without any assisting method in room temperature, thus refuting the preconception that compression ignition of hydrogen engine was impossible. Therefore, in order to analyze the correlation of compression ignition condition at cold start with hydrogen HCCI engine clearly, the possibility of compression igniting compression ratio is investigated with the change of equivalence ratio and engine speed, experimentally. As the results, it is confirmed that the possibility of compression-igniting compression ratio at cold start was decreased by increasing equivalence ratio due to decreasing auto-ignition temperature. In addition, it is grasped that the possibility of compression-igniting compression ratio at cold start is decreased around 14.9% by increasing engine speed at same supply energy.

Cold Restart를 이용한 웨어러블 디바이스의 초저전력 핵심 기술 (Core Technology for Ultra Low Power Using Cold Restart in Wearable Devices)

  • 김선태;박형준;박호준;우덕균
    • 전자공학회논문지
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    • 제54권4호
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    • pp.44-49
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    • 2017
  • 헬스케어 및 의료분야를 위한 배터리 기반 웨어러블 디바이스가 많이 제품화되고 있으나, 효과적인 전력 관리 미흡으로 자주 충전해야 하는 사용자의 불편함이 존재한다. 본 연구에서는 HW에서 제공하는 전력 관리 회로도를 효과적으로 활용할 수 있는 Tickless 기반 운영체제 및 전력 관리 알고리즘을 제시하고, 보드 레벨에서 최소 전력을 소모하는 Cold Restart 기법을 제안한다. 제안된 기법의 운영체제는 기존 운영체제에 비해 웨어러블 디바이스의 응용을 모델링한 4가지 시나리오에서 2배에서 최대 33배의 전력 소모 절감을 가져왔다.

스테인리스 304 슬라브의 HCR 조건시 열적/기계적 거동 (Thermo-Mechanical Behavior of Type 304 Stainless Slab in Hot Charge Rolling Condition)

  • C.G. Sun;S.M. Hwang
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 추계학술대회논문집
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    • pp.183-186
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    • 2003
  • A finite element-based, integrated process model is presented for a three dimensional, coupled analysis of the thermal and mechanical behavior of type 304 stainless slab during hot charge rolling (HCR) and cold charge rolling (CCR) processes. The validity of the proposed model is examined through comparison with measurements. The susceptibility on micro-crack initiation or propagation due to the thermal stress in these two different process conditions was examined. The model's capability of revealing the effect of diverse process parameters is demonstrated through a series of process simulation.

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장석순의 간에 대한 천발과 임상응용 (The Jang suk-sun's explanation and clinical application about liver)

  • 김진옥;김용진
    • 대한한의학회지
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    • 제25권1호
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    • pp.85-95
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    • 2004
  • The theory of liver by Jang suk-sun[張錫純] is that first, although liver exists at right side of body and spleen at left anatomically, function of liver presents at left side of body and function of spleen at right based on principle of 'interdependence between eum and yang' and 'join strength with elasticity', and in the relation between liver and spleen, if gi of spleen ascends, gi of liver also ascends, and if gi of stomach descents, gi of gall bladder also descents. So. care of spleen and stomach becomes main point in treating disease of liver. The meaning of 'the liver being in charge of the evaporation'[肝主氣化] is that first, it raises the primordial gi and forms the 'great g' for it's circulation of whole body. Second., it excretes the functional activity of gi and connects heart with kidney and guides the evaporation of the whole body by connecting innate nature with acquired nature. Third, 'the liver being in charge of the evaporation' is realized by the help of spleen and stomach. And he said that this functional activity of gi is one of distinctive features that distinguish Oriental medicine from Western medicine. He discoursed upon physiology of 'the liver being in charge of the evaporation' and 'the Body belonged to yin and the Use belonged to yang' after seeing an evil of abusing drugs that calm the liver and check hyperfunction of liver by contemporary doctors. And he established a treat of 'warming and recuperating the gi of liver' [溫補肝氣法] and used it for symptoms of 'deficiency of liver-gi'[肝氣虛], 'exhaution of liver-gi'[肝氣脫], and 'the liver-cold'[肝寒證].

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