• 제목/요약/키워드: Heat amount

검색결과 2,374건 처리시간 0.033초

유체마찰에너지를 이용한 풍력열발생조의 성능 분석 (Performance Analysis of the Wind Power Heat Generation Drum Using Fluid Frictional Energy)

  • Kim, Yeong-Jung;Yu, Yeong-Seon;Gang, Geum-Chun;Baek, Lee;Yun, Jin-Ha;Lee, Geon-Jung
    • Journal of Biosystems Engineering
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    • 제26권3호
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    • pp.263-270
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    • 2001
  • This study was conducted in order to develop wind-water heating system where frictional heat is creased between the rotor and working fluid when they are rotating in the cylindrical heat generator. The wind-water heating system is composed of rotor, stator, working fluid, motor, inverter and heat generation tank. Instead of wind turbine, we have used an electrical motor of 30㎾ to rotate the rotor in this system. Two working fluids and six levels of rotor rpm were tested to quantify heat amounts generated by the system. Generally, as motor rpm goes up heat amount increases that we have expected. At the same rpm, viscous fluid showed up better performance than the water, generating more heat by 10$\^{C}$ difference. The greatest heat amount of 31,500kJ/h was obtained when the system constantly drained out the hot water of at the flow rate of 500ℓ/h. Power consumption rate of the motor was measured by thee phase electric power meter where the largest power consumption rate was 14㎾ when motor rpm was 600 and gained heat was 31,500kJ/h, that indicated total thermal efficiency of the wind power water heating system was 62%.

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동시냉난방 히트펌프의 냉매 충전량과 운전모드 변화에 따른 성능특성에 관한 연구 (The Performance of a Simultaneous Heat and Cooling Heat Pump at Various Charging Conditions)

  • 송인식;최종민;주영주;정현준;강훈;김용찬
    • 설비공학논문집
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    • 제20권7호
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    • pp.492-499
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    • 2008
  • The cooling load in winter is significant in many commercial buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. The development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a multi-heat pump with 3-piping system was investigated as a function of refrigerant charge and its performance was analyzed in cooling mode, heating mode, and heat recovery mode. COP in the heating or cooling mode showed little dependence on refrigerant charge at overcharge conditions, while those were strongly dependent on refrigerant charge at undercharge conditions and outdoor inlet temperature. In the heat recovery mode, the performance of the system was very sensitive to charge amount at all conditions. Optimum charge amount in the heat recovery mode was 14% lower than that in the cooling mode at the standard condition because the refrigerant only passed the indoor units. It is required to store the excessive refrigerant charge in a storage tank to optimize the system performance at operating modes.

직렬 제습방식 열펌프 시스템의 성능특성에 관한 연구 (Study on the performance of a heat pump system with serial dehumidification function)

  • 고원빈;고지운;박윤철
    • Journal of Advanced Marine Engineering and Technology
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    • 제38권6호
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    • pp.609-614
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    • 2014
  • 화산지형인 제주도의 지열에너지를 사용하기 위하여 지하공기를 측정하였을 때 지중 온도는 $15{\sim}18^{\circ}C$이며, 상대습도는 70~80%로 타 지역에 비하여 매우 높은 경향을 나타내고 있다. 본 연구는 제습기능 및 난방기능을 구비한 다단 제습 가열 열펌프 시스템의 개발에 관한 연구로써, 개발된 열펌프의 성능실험을 수행한 결과 흡입공기의 상태가 최저 $15^{\circ}C$, 60%인 경우 총제습량이 1.797(kg/h)로 나타났으며, 최고 $20^{\circ}C$, 80%인 경우 총제습량이 45% 증가한 3.269(kg/h)로 증가하여 충분한 제습이 이루어짐을 알 수 있다. 또한, 난방능력은 흡입온도 $17^{\circ}C$ 상대습도 70% 일 때 1.91로 가장 높은 효율을 얻을 수 있다.

발화온도 산출 프로그램 개발 및 적용 (Development of Program for Ignition Temperature and Its Applications)

  • 박원희;조영민;권태순
    • 예술인문사회 융합 멀티미디어 논문지
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    • 제7권4호
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    • pp.243-250
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    • 2017
  • 목재와 같은 고체에서 불이 붙는 화재현상은 고체가 외부로부터 열을 받아 재료가 열분해 과정을 통하여 생성된 가스가 연소되는 현상을 포함한다. 이러한 고체의 열분해 현상은 외부로부터 유입되는 에너지의 양, 고체재료의 열이 확산되는 정도, 고체표면과 인접하여 있는 공기와의 열전달 정도를 포함한 고체재료와 주변과의 열전달 및 고체의 표면방사율 및 주변의 공기 중 산소의 분율 등 매우 여러 인자와 복잡하게 연결되어 있다. 본 논문에서는 화재현상을 가장 간단히 모사하기 위하여 필요한 발화온도를 산출하였다. 콘칼로리미타를 이용하여 다양한 목재시편을 이용하여 목재시편에 유입되는 열유속을 다양하게 제어하여 발화시간을 측정하였으며 이를 이용하여 발화온도를 산출하였다. 이를 위하여 사용자가 쉽게 사용할 수 있는 발화온도 산출 프로그램을 개발하였다. 고려된 목재는 5종류로 저밀도 MDF, 고밀도 MDF, 합판, 방부목, PB 등이며 다양한 두께에 대하여 고려하였다. 본 논문에서 제시된 발화온도는 고체의 화재 전파현상을 해석하는데 활용될 수 있다.

EPR의 열화에 의한 충.방전 전류 특성에 관한 연구 (A Study on Properties of Charge & Discharge Current by Degrade in EPR)

  • 이성일
    • 한국전기전자재료학회논문지
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    • 제21권7호
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    • pp.679-685
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    • 2008
  • This paper describes the degraded properties of between the charge and discharge current for ${\gamma}$-ray irradiated in electric power cable rubbers using in nuclear power generating station. The charge and discharge current of degradation in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0.033 Mrad/h, have been measured in order to investigate the influence of the atmosphere(in amount of reinforcing agent, moisture absorption and heat treatment) on electrical properties. When ${\gamma}$-ray were irradiated on the EPR with more reinforcing agent from 4 to 40 Phr, charge and discharge currents was increase due to the amount of reinforcing agent. It was verified that the discharging and charging currents irradiated by ${\gamma}$-ray were higher than those that was not irradiated. The amount of the degraded current was more after moisture absorption than before moisture absorption. The charge and discharge current after heat treatment was similar to that of before heat treatment and it was decreased with the time elapsed. As these properties related with ${\gamma}$-ray irradiation dose, it is suggested that these properties can be utilized as a index of irradiation degradation.

질소-프로판-공기분위기에서 저탄소 합금강의 침탄시 내부산화 특성에 미치는 가스조성의 영향 (Effects of the Gas Composition on Internal Oxidation Characteristics of Low Carbon Alloy Steel during Carburizing in Nitrogen-Propane-Air Atmospheres)

  • 노용식;김성만;김영희;김한군;이상윤
    • 열처리공학회지
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    • 제4권4호
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    • pp.53-60
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    • 1991
  • This study has been performed to investigate into the internal oxidation characteristics of low carbon steel with respect to the added amount of air in nitrogen-propane atmosphere after gas carburizing for various times at $930^{\circ}C$. The results obtained from the experiment are as follows ; (1) Optical micrographs have shown that the internal oxidation is unlikely to occur in the gas atmosphere without air and that oxidized zone in the outer surface layer is formed in the gas atmosphere with air revealing that the depth of oxidized zone increases with increasing the added amount of air. (2) The formation of internally oxidized zone in the outer surface layer has been found to be inhibited as Ni content increases, i. e, the amount of alloying element increases. (3) The depth of oxidation has been measured to increase with almost parabolically gas carburizing time of up to 6 hours.

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우육(牛肉)의 불고기 조리시 과산화지질의 변화에 관한 연구 (Study on the Change of Lipid Peroxides Amount While Beef Bulgogi Cocking)

  • 신덕규
    • 한국응용과학기술학회지
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    • 제6권2호
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    • pp.75-87
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    • 1989
  • Study to report this result that state of lipid peroxides while beef Bulgogi Coocking of general-seasoning, sale-seasoning, each flavour's characteries. Raw meat show high lipid peroxides amount and high increasing in heat and antioxidative effected by flavour about lipid peroxidies change existence by beef Bulgogi seasoning. Change of lipid peroxides are significant increased in meat cold storage and cold storage and cold storage heat meat after while 30 minute after seasoned and reduced 9 hour - 33 hour cold storage raw meat, that change of lipid peroxides by cooking time. every condition by adding soften were revealed lipid peroxides, reduce. Lipid peroxide change are very high while no-sugar in raw meat and not a stone look in 9-hour raw-meat after seasone about antioxidative effect by each flavour characteristic TBA showed very high not take parched seasone seeds item about 30-minute cold storage beat raw-meat and high lipid peroxides revealed increase in not take wine item, not take a pear item, in 9 hour cold storage heat-meal and it showed little amount not-sugar item, no opepper item. According to high lipid peroxides change reduced high after seasoned cold storage stage in Korea traditional Bulgogi Cooking and thought high that action of antioxidative lipid peroxides wine and a pear in flavour.

계면활성제 첨가시 수평 냉각관 외부를 흘러내리는 LiBr수용액의 열 및 물질전달 특성에 관한 연구 (A Study on Heat and Mass Transfer Characteristics of LiBr-$H_2$O Solution with a Sufactant Flowing over a Cooled Horizontal Tube)

  • 김경희;설신수;이상용
    • 설비공학논문집
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    • 제14권4호
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    • pp.341-349
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    • 2002
  • Heat and mass transfer characteristics of a surfactant-added LiBr-$H_2O$ solution flowing over a single horizontal tube were examined experimentally. The parameters considered were surfactant (2-ethyl-1-hexanol) concentration, solution temperature at the top of the tube and absorber pressure. Even with an amount of the surfactant below the solubility limit, heat and mass transfer performances were enhanced tremendously. The Nusselt and Sherwood numbers increased by about 70% and 340%, respectively, when 10 ppm of the surfactant was added. However, an excess amount of the surfactant in the solution did not bring a further enhancement. The absorption performance deteriorated when the non-condensable gases were extracted from the system (by a vacuum pump) since the vaporized surfactant was also extracted during the process. Therefore, it is desirable to add a sufficient amount of the surfactant (more than 10 ppm) to maintain high performance of absorption.

Ion Implantation으로 Ca를 첨가된 단결정 $Al_2$O$_3$의 Crack-Like Pore의 Healing 거동-III: Stability of Crack-Like Pore (Effects of Ca Implantation on the Sintering and Crack Healing Behavior of High Purity $Al_2$O$_3$ Using Micro-Lithographic Technique-III: Stability of Crack-Like Pore)

  • 김배연
    • 한국세라믹학회지
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    • 제36권9호
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    • pp.887-892
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    • 1999
  • The inner crack-like pore with controlled amount of Ca impurity in the high purity alumina single crystal sapphire had been created by micro-fabrication technique which includes ion implanation photo-lithography Ar ion milling and hot press technique. The crack-like pores in two-hour hot pressed specimen were extremely stable even after heat treating at 1,80$0^{\circ}C$ for 5 hours almost no healing was observed. But the crack-like pores in one-hour hot pressed specimen at 1,30$0^{\circ}C$ were healed by heat treatment and the amount of healing was increased with the heat treatment time and temperature and the amount of Ca addition. The edges of crack-like pore parallel to <1100> direction in (001) basal plane were stable but the edges normal to this direction in (00101) plane <1120> direction were unstable to facetting This means that the surface energy of alumina along the <1100> direction in (0001) basal plane in much lower than <1120> direction.

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CBR의 제조(製造) 및 이를 자동차(自動車) Tyre에 활용(活用)하는데 관(關)한 연구(硏究)(제3보(第三報)) Diene rubber와 Turfdene rubber와의 blend에 관(關)하여 (Studies on it's Practical Application to Auto Pneumatic Tyre and Manufacture of CBR (cis-1,4-polytutadiene Rubber) (Part. 3) On the Blend of Diene rubber and Turfdene rubber)

  • 이현오;이영길
    • Elastomers and Composites
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    • 제7권1호
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    • pp.21-37
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    • 1972
  • We have studied the blending effects of Diene NF 35R and Turfdene 1000R at various blending ratios 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black NAF and ISAF at various compounding ratios of 55 PHR, 65PHR, 75PHR for tyre tread rubber. As the results, it was found that; 1. For tyre tread rubber, as the blending ratio, Diene NF 35R/Turfdene 1000R, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 63PHR. The compounding of ISAF made better result than that of HAF for tensile strength, tearing strength, and abrasion quantity. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved, and as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to Turfdene 1000R than to Diene NF 35R. 5. In this pysical properties, mooney viscosity, and mooney scorch time, as the compounding amount of carbon black increased, the values of mooney viscosity increased, but that of mooney scorch time dropped.

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