• Title/Summary/Keyword: Water and Heat Transport

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An effective emergency care of a person from water submersion (익수사고자에 대한 효과적인 응급처치 방법)

  • Oh, Yong-Gyo;Park, Hyoung-Sun
    • The Korean Journal of Emergency Medical Services
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    • v.2 no.1
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    • pp.26-35
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    • 1998
  • This study was to exhibit the effective emergency care method for the drowning and non-drowning who are reached two-thousand peoples every year in our country. For investigate the effective emergency care, this study was discussed as follows ; Pathophysiology of the water submersion, Fresh-water & sea-water drowning, Factors affecting survival, and Prehospital management. The conclusions from this study were summarized as follows; 1. Remove the patient from the water. If you suspect neck or spinal injuries, Always support the head and neck level with the back and, begin rescue breathing. 2. Maintain the airway and support ventilation in the water use the jaw-thrust technique to avoid farther injury to the neck or spine. We might encounter more resistance to ventilations than you expect because of water in the airway. Once you have determined that there are no foreign objects in the airway, apply ventilations with more force; adjust ventilations until you see the patient's chest rise and fall but not until you see gastric distention. Do not attempt to remove water from the patient's lungs or stomach. 3. If there is no pulse, begin CPR. 4. Administer high-flow supplemental oxygen; suction as needed. 5. Once the patient is breathing and has a pulse, assess for hemorrhage; control any serious bleeding that you find. 6. Cover the patient to conserve body heat, Handle the patient very gently, and, Transport the patient as quickly as possible to Emergency Department, Continuing resuscitative measures during transport. If the patient have the hypothermia, follow hypothermia management.

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An Experimental Study on the Convection Heat Transfer of Al-Mg/water Micro Fluid in a Circular Tube with Swirl

  • Chang, Tae-Hyun;Kim, Chiwon;Kil, Sang-Cheol;Lee, Chang-Hoan
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.7
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    • pp.869-875
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    • 2012
  • In the past decades, extensive studies on convection heat transfer on internal flow have been conducted by using high specific surface area, by increasing heat transfer coefficient and swirl flow, and by improving the transport properties. In this study, we applied a tangential slot swirl generator to improve heat transfer in a horizontal circular copper tube. The Al-Mg particles (approximately $100{\mu}m$ to $130{\mu}m$) were employed for this experimental work. The copper tube was heated uniformly by winding a heating coil with a resistance of 9 ohm per meter for heat transfer. Using Al-Mg particles, experiments were performed in the Reynolds number range of 5,000 to 13,130, with and without swirl. Experimental data transfers or comparisons between Nusselt numbers with and without swirl along the test tube and Reynolds numbers are presented. The Nusselt number is improved by increasing Reynolds numbers or swirl intensities along the test tube.

Study on the Design and the Prototype Manufacture of Cooling systems of the Propulsion System for the EMU (동력분산형 고속전철의 추진시스템용 냉각장치 설계 및 시제품 제작 연구)

  • Ryoo, Seong-Ryoul;Kim, Sung-Dae;Ki, Jae-Hyung;Yim, Kwang-Bin;Kim, Chul-Ju
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.422-429
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    • 2008
  • The objective of the present study is to develope a propultion unit cooling system for the next-generation High-speed EMU. The propulsion power control unit consists of some IGBT semiconductors. In general, those power semiconductors are very sensitive to temperatures and need a cooling system to keep them at a proper operational conditions in the range of $50{\sim}100^{\circ}C$. In this first year of study, we tried to focuss on the understanding of fundamental technologies for each of the two different cooling systems and collecting basic data for design and manufacturing for both cases. For the water cooling system, a heat sink with multi channels of liquid flow was considered and a model unit was designed and performance test was conducted. For the heat pipe cooling system, a Loop Heat Pipe(LHP) was considered as an element to transport heat from IGBT to environment air flow and a model unit was designed and performance test was conducted. The analysis using SINDA/FLUINT showed that those design parameters are good enough for the LHP to properly operate under a heat load up to around 360W.

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Numerical Investigation on Natural Circulation in a Simplified Passive Containment Cooling System (단순화된 피동 원자로건물 냉각계통 내 자연순환에 관한 수치적 연구)

  • Suh, Jungsoo
    • Journal of the Korean Society of Safety
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    • v.33 no.3
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    • pp.92-98
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    • 2018
  • The flow of cooling water in a passive containment cooling system (PCCS), used to remove heat released in design basis accidents from a concrete containment of light water nuclear power plant, was conducted in order to investigate the thermo-fluid equilibrium among many parallel tubes of PCCS. Numerical simulations of the subcooled boiling flow within a coolant loop of a PCCS, which will be installed in innovative pressurized-water reactor (PWR), were conducted using the commercially available computational fluid dynamics (CFD) software ANSYS-CFX. Shear stress transport (SST) and the RPI model were used for turbulence closure and subcooled flow boiling, respectively. As the first step, the simplified geometry of PCCS with 36 tubes was modeled in order to reduce computational resource. Even and uneven thermal loading conditions were applied at the outer walls of parallel tubes for the simulation of the coolant flow in the PCCS at the initial phase of accident. It was observed that the natural circulation maintained in single-phase for all even and uneven thermal loading cases. For uneven thermal loading cases, coolant velocity in each tube were increased according to the applied heat flux. However, the flows were mixed well in the header and natural circulation of the whole cooling loop was not affected by uneven thermal loading significantly.

An Experimental Study on the Convection heat Transfer of Al-Mg/water Micro Fluid in a Circular Tube with Swirl (선회유동장에서 Al-Mg/물 마이크로 유동의 대류 열전달에 대한 실험적 연구)

  • Chang, Tae-Hyun;Kim, Chi-Woon;Kil, Sang-Cheol;Lee, Chang-Hoan
    • Journal of the Korean Society of Visualization
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    • v.10 no.3
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    • pp.16-20
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    • 2012
  • In the past decades, extensive studies on convection heat transfer on internal flow have been conducted by using high specific surface area, by increasing heat transfer coefficient and swirl flow, and by improving the transport properties. In this study, we applied a tangential slot swirl generator to improve heat transfer in a horizontal circular copper tube. The Al-Mg particles (approximately $100{\mu}m$ to $130{\mu}m$) were employed for this experimental work. The copper tube was heated uniformly by winding a heating coil with a resistance of 9ohm per meter for heat transfer. Using Al-Mg particles, experiments were performed in the Reynolds number range of 5,000 to 13,130, with and without swirl. Experimental data transfers or comparisons between Nusselt numbers with and without swirl along the test tube and Reynolds numbers are presented. The Nusselt number is improved by increasing Reynolds numbers or swirl intensities along the test tube.

Entropy analysis in a cilia transport of nanofluid under the influence of magnetic field

  • Abrar, Muhammad N.;Haq, Rizwan Ul;Awais, Muhammad;Rashid, Irfan
    • Nuclear Engineering and Technology
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    • v.49 no.8
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    • pp.1680-1688
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    • 2017
  • In this study, analysis is performed on entropy generation during cilia transport of water based titanium dioxide nanoparticles in the presence of viscous dissipation. Moreover, thermal heat flux is considered at the surface of a channel with ciliated walls. Mathematical formulation is constructed in the form of nonlinear partial differential equations. Making use of suitable variables, the set of partial differential equations is reduced to coupled nonlinear ordinary differential equations. Closed form exact solutions are obtained for velocity, temperature, and pressure gradient. Graphical illustrations for emerging flow parameters, such as Hartmann number (Ha), Brinkmann number (Br), radiation parameter (Rn), and flow rate, have been prepared in order to capture the physical behavior of these parameters. The main goal (i.e., the minimizing of entropy generation) of the second law of thermodynamics can be achieved by decreasing the magnitude of Br, Ha and ${\Lambda}$ parameters.

Parametric Study of an Integrated Steam Methane Reformer with Top-Fired Combustor (통합 수증기 개질 시스템의 작동 조건에 대한 수치적 연구)

  • Noh, Jung-Hun;Jung, Hye-Mi;Kim, Donghee;Um, Sukkee
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.156.1-156.1
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    • 2011
  • It is of great importance to predict operating parameter characteristics of an integrated fuel processor by the increased life-time and system performance. In this study, computational analysis is performed to gain fundamental insights on transport phenomena and chemical reactions in reformer which consists of preheating, steam reforming, and water gas shift reaction beds. Also, a top-fired burner locates inside of the reforming system. The combustor is providing thermal energy necessary for the steam reforming bed which is a endothermic catalytic reactor. Two-dimensional numerical model of the integrated fuel processing system is introduced for the analysis of heat and mass transport phenomena as well as surface kinetics and catalytic process. A kinetic model was developed and then computational results were compared with the experimental data available in the literature. Subsequently, parameter study using the validated steam methane reforming model was conducted by considering operating parameters, i.e. steam to carbon ratio and temperature.

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A Study on Ice Slurry Production by Water Spray

  • Kim, Byeong-Sun;Lee, Yoon-Pyo;Yoon, Seong-Young;Lee, Jin-Ho
    • International Journal of Air-Conditioning and Refrigeration
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    • v.6
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    • pp.45-55
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    • 1998
  • A theoretical and experimental study is performed to investigate the characteristics of ice slurry product. By diffusion-controlled evaporation model the possibility of ice slurry is theoretically anticipated. The water vapor evaporated from the surface of droplets is extracted continuously from the chamber by a vacuum pump. The droplet diameter is measured by silicon immersion method. The ice slurry is obtained by spraying droplets of ethylene glycol aqueous solution in the chamber where pressure is maintained under the triple point of water. The droplet with the diameter of 300 $\mu\textrm{m}$and the initial temperature of 2$0^{\circ}C$ was changed into ice particle within the chamber of 1.33m in height.

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A study on ice-slurry production by water spray (수분무에 의한 아이스 슬러리 생성에 관한 연구)

  • Kim, B.S.;Lee, Y.P.;Yoon, S.Y.;Lee, J.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.134-143
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    • 1997
  • A theoretical and experimental study has been performed to investigate the characteristics of ice-slurry product. By diffusion-controlled model, the possibility of ice slurry has been theoretically anticipated. The water vapor evaporated from the surface of droplets is extracted continuously from the chamber by a vacuum pump. The droplet diameter was measured by silion immersed method. The ice slurry has been obtained by spraying droplets of ethylene-glycol aqueous solution in the chamber where pressure is maintained under the triple point of water. The droplet of which the diameter is $300{\mu}m$, and the initial temperature is $20^{\circ}C$, was changed into ice particle within the chamber of which the height is 1.33m.

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Three-dimensional Numerical Prediction on the Evolution of Nocturnal Thermal High (Tropical Night) in a Basin

  • Choi, Hyo;Kim, Jeong-Woo
    • International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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    • v.25 no.1
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    • pp.57-81
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    • 1997
  • Numerical prediction of nocturnal thermal high in summer of the 1995 near Taegu city located in a basin has been carried out by a non-hydrostatic numerical model over complex terrain through one-way double nesting technique in the Z following coordinate system. Under the prevailing westerly winds, vertical turbulent fluxes of momentum and heat over mountains for daytime hours are quite strong with a large magnitude of more than $120W/\textrm{m}^2$, but a small one of $5W/\textrm{m}^2$ at the surface of the basin. Convective boundary layer (CBL) is developed with a thickness of about 600m over the ground in the lee side of Mt. Hyungje, and extends to the edge of inland at the interface of land sea in the east. Sensible heat flux near the surface of the top of the mountain is $50W/\textrm{m}^2$, but its flux in the basin is almost zero. Convergence of sensible heat flux occurs from the ground surface toward the atmosphere in the lower layer, causing the layer over the mountain to be warmed up, but no convergance of the flux over the basin results from the significant mixing of air within the CBL. As horizontal transport of sensible heat flux from the top of the mountain toward over the basin results in the continuous accumulation of heat with time, enhancing air temperature at the surface of the basin, especially Taegu city to be higher than $39.3^{\circ}C$. Since latent heat fluxes are $270W/\textrm{m}^2$ near the top of the mountain and $300W/\textrm{m}^2$ along the slope of the mountain and the basin, evaporation of water vapor from the surface of the basin is much higher than one from the mountain and then, horizontal transport of latent heat flux is from the basin toward the mountain, showing relative humidity of 65 to 75% over the mountain to be much greater than 50% to 55% in the basin. At night, sensible heat fluxes have negative values of $-120W/\textrm{m}^2$ along the slope near the top of the mountain and $-50W/\textrm{m}^2$ at the surface of the basin, which indicate gain of heat from the lower atmosphere. Nighttime radiative cooling produces a shallow nocturnal surface inversion layer with a thickness of about 100m, which is much lower than common surface inversion layer, and lifts extremely heated air masses for daytime hours, namely, a warm pool of $34^{\circ}C$ to be isolated over the ground surface in the basin. As heat transfer from the warm pool in the lower atmosphere toward the ground of the basin occurs, the air near the surface of the basin does not much cool down, resulting in the persistence of high temperature at night, called nocturnal thermal high or tropical night. High relative humidity of 75% is found at the surface of the basin under the moderate wind, while slightly low relative humidity of 60% is along the eastern slope of the high mountain, due to adiabatic heating by the srong downslope wind. Air temperature near the surface of the basin with high moisture in the evening does not get lower than that during the day and the high temperature produces nocturnal warming situation.

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