• Title/Summary/Keyword: injected air temperature

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Development of Formation and Transportation Techniques for CO2-Hydrate Slurry (이산화탄소 하이드레이트 슬러리의 생성 및 수송기술개발)

  • Prah, Benedict;Yun, Rin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.7
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    • pp.341-349
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    • 2017
  • Formation and transportation of $CO_2$-hydrate slurry was conducted by circulating saturated water with $CO_2$ through a double-tube type heat exchanger which was cooled down by brine. The inner diameter and circulation length of the heat exchanger were 1 inch and 20 m, respectively. Water in tank was supersaturated by injected $CO_2$ and the operation pressure was maintained at 3,000 to 4,000 kPa with fluid-temperature of less than $9^{\circ}C$. $CO_2$ hydrate mass fraction was calculated based on density of $CO_2$-hydrate slurry mixture. Results showed that the $CO_2$-hydrate slurry could be circulated without blockage for 1 hr. Circulation status of the $CO_2$-hydrate slurry was also visualized.

Behavior of a Diesel Spray Impinged on a Wall (벽면에 충돌하는 디젤분무의 거동)

  • Cho, I.Y.;Oh, J.H.
    • Journal of ILASS-Korea
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    • v.2 no.4
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    • pp.1-6
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    • 1997
  • In the case of analyzing the combustion phenomena in a small high speed DI diesel engine, one demands the experimental results of the impinging spray on the wall as a basic characteristics. In the experiments presented here, diesel fuel oil was injected into a high pressure chamber in which compressed air at room temperature was charged. The single spray was impinged on a flat wall. The growth of the spray was photographed with transmitted light or scattered light. The effect of the spray axis angle to the wall on the impinging spray was revealed. Finally, the experimental results was presented, that is, the radius and height of the impinging spray was influenced by above mentioned variable.

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The effect of gas density on the drop trajectory and drop size distribution in high speed gas stream (고속기류에 분사된 액적궤적 및 입경분포에 미치는 주위 기체밀도의 영향)

  • Lee, C.H.
    • Journal of ILASS-Korea
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    • v.5 no.3
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    • pp.37-44
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    • 2000
  • High velocity, gas-assisted liquid drop trajectories were investigated under well-controlled experimental conditions at elevated gas densities and room temperature. A monodisperse stream of drops which are generated by a vibrating-orifice drop generator were injected into a transverse high velocity gas stream. The gas density and air jet velocity were adjusted independently to keep the Weber numbers constant. The Weber numbers studied were 72, 148, 270, 532. The range of experimental conditions included studied the three drop breakup regimes previously referred as bag, stretching/thinning and catastrophic breakup regimes. High-magnification photography and conventional spray field photographs were taken to study the microscopic breakup mechanisms and the drop trajectories in high velocity gas flow fields, respectively. The parent drop trajectories were affected by the gas density and the gas jet velocities and do not show similarity with respect to the either Weber or the Reynolds number, as expected.

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Optimum Conditions of Super-critical Water Oxidation Process for Treatment of Slurry Piggery Wastewater (슬러리형 돈사분뇨처리를 위한 초임계수 산화공정의 최적 조건)

  • Kim, Ean-Ho;Seo, Jeoung-Yoon
    • Journal of Environmental Health Sciences
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    • v.34 no.4
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    • pp.333-341
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    • 2008
  • In this study, the possibility and the optimal conditions for treating slurry type piggery wastewater using supercritical water oxidation were tested in the laboratory. The results could be summarized as follows; The slurry type piggery wastewater, which was diluted 50 times, was treated most effectively at the pressure of 300 bar, the temperature of $550^{\circ}C$ and the residence time of 10 minutes. The air saturated water was injected, as an oxidizing agent, and the removal efficiencies of $COD_{Cr}$, T-N, $NH_4^+$-N and T-Pattheoptimal conditions were 92, 40, 59 and 100%, respectively. Therefore, analte rnativemea suremu stbetaken to improve theremo valefficiency of the nitrogen compounds.

A Study on the Droplet Size Distribution of Ultra High Pressure Diesel Spray on Electronic Hydraulic Fuel Injection System (전자유압식 분사계에 의한 초고압 디젤분무의 입경분포에 관한 연구)

  • Jang, S.H.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.2 no.1
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    • pp.25-30
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    • 1998
  • In order to investigate the droplet size distribution and Sauter Mean Diameter in a ultra high pressure diesel spray, fuel was injected with ultra high pressure into the environments of high pressure and room temperature by an Electronic Hydraulic Fuel Injection System. Droplet size was measured with the immersion liquid sampling technique. The immersion liquid was used a mixture of water-methycellulose solution and ethanol. The Sauter Mean Diameter decreased with increasing injection pressure, with a decrease environmental pressure (back pressure) and nozzle diameter. Increasing the injection pressure makes the fuel density distribution of the spray more homogeneous. An empirical correlation was developed among injection pressure, air density, nozzle diameter and the Sauter Mean Diameter of spray droplets.

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Numerical simulation of combustor afterward sprayed in hot product stream (고온기류중에 재분사된 연소기 후류의 수치해석)

  • Kim, Tae-Han;Gwon, Hyeong-Jeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.7
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    • pp.841-848
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    • 1997
  • Combustion of gaseous fuel combustor in a high temperature vitiated air stream was studied with computer simulation. It is for application to afterburner of gas turbine engine which the exact mechanism is not yet clarified. As the jet velocity from fuel nozzle is very high and the geometry of combustor is three dimensional complex structure, many time and money are required to have good results. To consider this demerit, it is simplified to 2-dimensional and modified with the nozzle hole area to same area of annual status. As the thickness of annual is too thin, it is to divide with the many grids for reasonable results. Accordingly, new method which injected fuel mass, momentum and energy are added to source terms of each governing conservation equation as a source terms is introduced like as two phase analysis. Reaction rate is determined by taking into account the Arrhenius reaction based on a single step reaction mechanism. It is focused to temperature and product concentration distribution at each equivalence ratio of inlet hot product.

The Spray Behavior Analysis and Space Distribution of Mixture in Transient Jet Impinging on Piston Cavity (비정상 충돌 분류의 Cavity형상에 따른 공간 농도 분포 및 거동해석)

  • Lee, S.S.;Kim, K.M.;Kim, B.G.;Chang, S.S.;Ha, J.Y.
    • Journal of ILASS-Korea
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    • v.1 no.2
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    • pp.16-23
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    • 1996
  • In case of a high-speed D.I. diesel engine. the injected fuel spray is unavoidable that the impinging on the wall of piston cavity and in this case the geometry of piston cavity has a great influence on the atomization structure and air flow fields. In the field of combustion and in many other spray applications, there are clear evidence of correlation between spray structure and emission of pollutants. Ordinary, the combustion chamber of driving engine have unsteady turbulent flow be attendant on such as the change of temperature, velocity and pressure. So the analysis of spray behavior is difficult. In this study, a single spray was impinged on each cavity wall at indicated angle in a quiescent atmosphere at room temperature and pressure, as being the simplest case, and 3 types of piston cavity such as Dish, Toroidal and Re-entrant type was tested for analyzing the influence of cavity geometry. And hot wire probe was used for analyze non-steady flow characteristics of impinging spray, and to investigate the behavior of spray, the aspects of concentration c(t), standard deviation $\sigma(t)$ and variation factor (v.f.) was measured with the lapse of time.

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A Study on Atomization Characteristics of Gasoline Impinging Spray Using Glow plug (글로우플러그를 이용한 충돌분무의 미립화특성에 관한 연구)

  • 문영호;오영택
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.5
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    • pp.54-61
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    • 2001
  • It is reported that during the cold starting, especially in gasoline engine, the engine response and the effect of HC emission can be improved by prompting atomization and reducing the quantity of fuel adhered to the range of injector tip, inlet port, and inlet valve. The purposes of this study are to promote atomization of fuel before air-fuel mixture in the inlet port. In order to achieve its goal, the glow plug is to evaluate the feasibility of for the early fuel evaporator and the spray behavior characteristics of gasoline, injected on the surface of glow plug with room temperature(2$0^{\circ}C$) and high temperature(25$0^{\circ}C$) is to examine. Particle motion analysis system(PMAS) was used to measure the SMD and the dropsize distribution of impinging spray and free spray. The results of this experiment, evaporation rate of impinging spray was higher than that of free spray, and the higher evaporation rate win, the smaller peak dropsize was. Especially, during early spray SMD of impinging spray was still smaller than that of fee spray.

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An Experimental Study for the Effect of Ventilation Velocity on Performance of a High Pressure Water Mist Fire Suppression System (객차내 환기속도가 고압 미세물분무 화재제어 시스템 성능에 미치는 영향에 대한 실험적 연구)

  • Kim, Dong-Woon;Bae, Seung-Yong;Ryou, Hong-Sun
    • Journal of the Korean Society of Safety
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    • v.23 no.4
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    • pp.1-6
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    • 2008
  • This experiments are perfol1ned to investigate the effect of ventilation velocity on a high pressure water mist tire suppression in train. The experiment is conducted in half scale modeled train of a steel-welled enclosure (5.0m${\times}$2.4m${\times}$2.2m). The ventilation velocity is controlled by the ventilation duct through an inverter in the range of 0 to 3m/s. The coverage-radius and an injection angle of an high pressure water mist system are measured. The mist nozzle with 5-injection holes is operated with pressure 60bar. The heptane pool fires are used. The fire extinguishment times and the temperature are measured for the ventilation velocities. In conclusion, because the momentum of injected water mist is more dominant than that of ventilation air, the characteristics of water mist, the fire extinguishment times and the temperature are affected very little by ventilation velocity.

A Study On Heat Transfer and Flow Characteristics for Boring in Sewer by Rotating Cutter Tool (회전노즐장비 작동시 하수관내의 열전달 및 유동현상에 관한 연구)

  • Park Young-Ki;Lee Jang-Choon;Lee Dong-Joo
    • Journal of Environmental Science International
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    • v.15 no.1
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    • pp.95-100
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    • 2006
  • Heat transfer and flow characteristics in a pipe in which the rotating cutting tool for boring a underground pipe without digging were considered in this study. The amount of heat generation due to the friction between the rotating cutter and pipe wall, mixing (low of air and water injected to cool down are the two important factors to design the boring machine Computational fluid dynamics analysis using the Eulerian mixture model and the standard $\kappa-\varepsilon$ turbulence model was used to analyze the complex phenomena in a pipe during the process. Results show that pipe wall temperature decreased with increasing the cooling water inlet velocity. it is also shown that pipe wail temperature was lowered when the cutter rotation speed was increased until 600 rpm. There was no further cooling effect over 600 rpm.