• 제목/요약/키워드: wind-heat

검색결과 835건 처리시간 0.027초

An Experimental Study on a Windheat Generation System with a Savonius Wind Turbine

  • Kim, Young-Jung;Ryou, Young-Sun;Kang, Geum-Choon;Paek, Yee;Yun, Jin-Ha;Kang, Youn-Ku
    • Agricultural and Biosystems Engineering
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    • 제6권2호
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    • pp.65-69
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    • 2005
  • A windheat generation system with a Savonius windturbine was developed and the performance was evaluated through field tests. The system consisted of a heat generation drum, heat exchanger, water storage tank, and two circulation pumps. Frictional heat is created by rotation of a rotor inside the drum containing thermo oil, and was used to heat water. In order to estimate the capacity of this windheat generation system, weather data was collected for one year at the site near the windheat generation system. Wind Power from the savonius wind turbine mill was transmitted to the heat generation system with an one-to-three gear system. Starting force to rotate the savonius wind turbine and the whole system including the windheat generation system were 1.0 and 2.5 kg, respectively. Under the outdoor wind condition, maximum speed of the rotor in the drum was 75rpm at wind speed 6.5 m/sec, which was not fast enough to produce heat for greenhouse heating. Annual cumulative hours for wind speeds greater than 5 m/sec at height of 10, 20, 30 m were 190, 300 and 1020 hrs, respectively. A $5^{\circ}C$ increase in water temperature was achieved by the windheat generation system under the tested wind environment.

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Heat Transfer Analysis for Asphalt Mixture Temperature Variation due to Wind Speed (풍속에 따른 포설 아스팔트 혼합물의 온도변화에 대한 열전달 해석)

  • Yun, Tae Young;Yoo, Pyeong Jun
    • International Journal of Highway Engineering
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    • 제17권4호
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    • pp.33-40
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    • 2015
  • PURPOSES: Evaluation of the wind speed effect on the temperature drop of an asphalt mixture during construction, by using the transient heat transfer theory and dominant convective heat transfer coefficient model. METHODS: Finite difference method (FDM) is used to solve the transient heat transfer difference equation numerically for various wind speeds and initial temperature conditions. The Blasius convective heat transfer coefficient model is adapted to account for the effect of wind speed in the temperature predictions of the asphalt mixture, and the Beaufort number is used to select a reasonable wind speed for the analysis. As a function of time and depth, the temperature of the pavement structure is predicted and analyzed for the given initial conditions. RESULTS : The effect of wind speed on the temperature drop of asphalt mixture is found to be significant. It seems that wind speed is another parameter to be accounted for in the construction specifications for obtaining a better quality of the asphalt mixture. CONCLUSIONS: It is concluded that wind speed has a significant effect on the temperature drop of the asphalt layer. Although additional field observations have to be made to reflect the effect of wind speed on the construction specifications, it appears that wind speed is a dominant variable to be considered, in addition to the atmospheric temperature.

A Study on a Novel Flow Control Valve for Wind Power Heat Generation Hydraulic Systems (풍력 열발생 유압 시스템을 위한 새로운 유량제어밸브에 관한 연구)

  • Choi, Sae Ryung;Lee, Ill Yeong;Han, Bong Jun
    • Journal of Drive and Control
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    • 제14권1호
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    • pp.23-28
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    • 2017
  • A wind power heat generation system that converts wind power directly to heat instead of electric power is considered in this study. The system consists of a wind turbine part and a heat generation part. The heat generation part is materialized by a hydraulic system including a hydraulic pump, a flow control valve, a hydraulic oil tank, etc. The flow control valve primarily converts hydraulic energy generated in the pump to heat energy. It should have a function of overspeed protection under excessive wind speeds. In this study, a novel flow control valve design is proposed for excellent flow control characteristics under excessive pump driving torque (excessive wind speed). The performance of the suggested valve is analyzed using numerical simulation.

Experimental Study on Heat Flow According to the Wind Velocity in an Underground Life Space (지하생활공간 화재시 풍속에 따른 열유동 특성 연구)

  • Kim, Young-No;Suk, Chang-Mok;Kim, Wha-Jung
    • Fire Science and Engineering
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    • 제21권3호
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    • pp.61-68
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    • 2007
  • The purpose of this study analyzes heat flows and fire behavior through a reduced-scale model experiments about change of wind velocity in underground life space. When the wind velocity is increased the temperature rise time of the fire room was risen fast. And temperature of fire room was increased. And increase of wind velocity displayed maximum temperature at an opening of the fire room. Heat flows by fire spread increase size of smoke occurrence and flame, and displayed high temperature distribution in passageway than inside of neighborhood department promoting eddy flow spread as wind velocity increases. Finally, heat flows are decided by wind and wind velocity at fire of underground life space, and Wind velocity increases, temperature increase and decrease could confirm that is gone fast.

A Study on the Thermal and Flow Characteristics of Wind and Radiant Heat Shield for Offshore by using Mesh Screen (메쉬 스크린을 적용한 해양구조물용 방풍 및 복사열 차단막 열유동특성에 관한 연구)

  • Yi, Chung-Seob;Chin, Do-Hun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • 제11권3호
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    • pp.166-173
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    • 2012
  • This study is about comparison of thermal and flow characteristics on the wind & radiant heat shield with STS mesh type screen for offshore. Numerical analysis was conducted to find transmission coefficient in the mesh and then analyse the flow characteristics about wind & radiant heat shield. The experiment method of solar radiation has been used as thermal radiation source to get the performance of radiant heat shield measurement. The sensor radiation device has been used to measure the reduction of solar radiation with various size of cells and at a distance of 0.5m and 1m from the cold face of the wind & radiant heat shield.

Estimation on locations of air-supply and exhaust ports in the nacelle of wind turbine (풍력터빈 나셀 냉각시스템의 급.배기 위치 평가)

  • Woo, S.W.;Kim, H.T.;Lee, J.H.;Lee, K.H.;Park, J.P.
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.240-242
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    • 2011
  • Wind power system is generally divided into the onshore wind turbine and the offshore wind turbine according to site locations. The offshore wind turbine is manufactured as a closed nacelle cooling system including a heat exchanger to prevent corrosion, but the onshore wind turbine is manufactured as open nacelle cooling system dependent on only the outdoor air without a heat exchanger. The indoor of a nacelle which is composed of a generator, foil power converters and a gearbox with a lot of heat is very narrow and airtight. This aim of the study is to demonstrate the temperature effect depending on positions of air-supply and exhaust ports. And this study discusses the flow field and removal efficiency of heat caused by components.

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Observational Study on the Local Wind of the Dalbi-Valley Located at Ap-Mountain in Daegu (대구 앞산 달비골의 국지풍 특성에 관한 관측적 연구)

  • Koo, Hyun-Suk;Kwon, Byung-Hyuk;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • 제16권1호
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    • pp.73-79
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    • 2007
  • The purpose of this study is to clarify the effect of mountain-valley wind on heat island formed in urban area which is located around valley mouth. The meteorological observations were carried out over the Dalbi-valley under a clear summer pressure patterns, and some consideration were tried from the results. In order to make clear the climatological characteristics and air-mass modification process of the mountain-valley wind over the valley, the meteorological observations were done simultaneously at two points. The observational points were located at the breast and valley mouth parts, respectively. The results were as follows: First, it was found that the valley wind was observed through the daytime, and it was replaced by a mountain wind after sunset. Second, the heat budget is also investigated with observation data. The sensible heat flux over the breast of Dalbi-valley reached to about $200 W/m^2$ during daytime, which is a little more than one third of net radiation. On the other hand, the sensible heat flux represented negative values during nighttime. But the sensible heat flux over the valley mouth covered by asphalt showed plus value(about $20{\sim}30 W/m^2$) during the nighttime.

A Case Report on a Patient with Wind-Heat Type Urticaria Sensitive to Aspirin and NSAIDs Using Bangpoongtongsung-san Gamibang (아스피린과 NSAIDs 과민성 풍열형(風熱型) 두드러기에 대한 방풍통성산가미방(防風通聖散加味方)의 치험례)

  • Kyung-Jun Kim
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • 제36권2호
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    • pp.83-93
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    • 2023
  • Objectives : The purpose of this case study is to report the effectiveness of Bangpoongtongsung-san gamibang on a patient with wind-heat type urticaria sensitive to aspirin and NSAIDs. Methods : We treated a 48-year-old man who had aspirin and NSAIDs sensitive wind-heat type urticaria with Bangpoongtongsung-san gamibang, pharmacopuncture(Hwangnyunhaedok-tang), acupuncture(needle remaining time : 20 min) and photodynamic therapy. Results : The Urticaria Activity Score(UAS) started at 5 and ended with 0, and the Visual Analog Scale(VAS) of heating sensation on whole body started at 10 and ended with 1-3. Conclusions : This study has demonstrated that Bangpoongtongsung-san gamibang could be effective to treat aspirin and NSAIDs sensitive wind-heat type urticaria.

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

  • 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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A Bibliographic Study on the Cause of Hoarse Voice (성시(聲嘶)의 원인(原因)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Han, Dae-Gil
    • The Journal of Internal Korean Medicine
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    • 제12권1호
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    • pp.98-104
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    • 1991
  • I studied some important medical Literatures in order to examine the cause of Hoarse Voice and found out some facts of follows ; 1. The exogenous cause of disease in wind. 2. Wind-cold, Wind-fire, Wind-heat, Summer-heat, Heat. 3. The endogenous cause of disease is deficiency of Yin and dificiency of blood leads fire-evil was lung-dry stool dificiency of body fluid. 4. The non-exo-endogenous causes of disease is sing ballads and call out.

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