• Title/Summary/Keyword: Cold flow

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A Study on the Cold Flow Characteristics of a Flue Gas Recirculation Burner with Both Outlets Opening (양쪽 출구가 트인 배기가스 재순환 버너의 냉간 유동 특성에 관한 연구)

  • Ha, Ji Soo
    • Journal of the Korean Institute of Gas
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    • v.22 no.3
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    • pp.7-12
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    • 2018
  • Thermal NOx is generated in a high temperature environment in a combustion facilities. Exhaust gas recirculation method is widely used among various methods for reducing nitrogen oxides in combustion devices. In the present study, the computational fluid dynamic analysis was accomplished to elucidate the cold flow characteristics in the flue gas recirculation burner with both outlets opening. Because the reciculation pipes is installed toward the tangential direction, the swirling flow is formulated in the burner and the phenomenon of the reverse flow creation is detected at the center area of circular burner. We are confirmed that this is the similar trend with the burner with one side outlet closed. From the present study, it was seen that the recirculated inflow from both recirculated burner outlets increased by about 5% compared to the burner with one side outlet opening. At the outlet located at the exhaust gas recirculation pipe inlet(gas exit 1), the inlet flow was formed in the entire region. At the opposite outlet(gas exit 2), the total flow was discharged, but the center part of the burner was observed to have a reverse flow. The flow rate at the gas exit 2 was 3 ~ 5 times larger than the flow rate at the gas exit 1.

A Study of Cold Flow Characteristics of a Flue Gas Recirculation Burner using Coanda Nozzles (코안다 노즐을 이용한 배기가스 재순환 버너의 냉간 유동 특성에 관한 연구)

  • Ha, Ji Soo;Park, Chan Hyuk;Shim, Sung Hun;Jung, Sang Hyun
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.152-158
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    • 2016
  • Nitrogen oxide is generated by the chemical reaction of oxygen and nitrogen in higher temperature environment of combustion facilities. The NOx reduction equipment is generally used in the power plant or incineration plant and it causes enormous cost for the construction and maintenance. The flue gas recirculation method is commonly adopted for the reduction of NOx formation in the combustion facilities. In the present study, the computational fluid dynamic analysis was accomplished to elucidated the cold flow characteristics in the flue gas recirculation burner with coanda nozzles in the flue gas recirculation pipe. The inlet and outlet of flue gas recirculation pipes are directed toward the tangential direction of circular burner not toward the center of burner. The swirling flow is formed in the burner and it causes the reverse flow in the burner. The ratio of flue gas recirculation flow rate with the air flow rate was about 2.5 for the case with the coanda nozzle gap, 0.5mm and it was 1.5 for the case with the gap, 1.0mm. With the same coanda nozzle gap, the flue gas recirculation flow rate ratio had a little increase when the air flow rate changes from 1.1 to 2.2 times of ideal air flow rate.

Results of Cold Flow Test and Design of Injectors for Oxidizer-rich Preburner (산화제 과잉 예연소기용 분사기 설계 및 수류 시험 결과)

  • So, YoonSeok;Woo, SeongPil;Lee, Kwang-Jin;Yu, ByungIl;Kim, Jinhyung;Cho, Hwangrae;Bang, Jeongsuk;Han, YeongMin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.1
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    • pp.52-57
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    • 2018
  • This paper presents the design and cold flow test results of oxidizer-rich preburner injectors for a 9 tonf-class staged combustion engine cycle. Three types of coaxial swirl injectors were designed, and 12 injectors were designed for each type. The diameters of the fuel tangential holes are identical. The diameters of the oxidizer tangential holes were varied to investigate the influence of combustion in the oxidizer-rich preburner according to the momentum ratio of the gas oxidizer generated from combustion in the injector chamber and liquid oxidizer through the cooling channel. It will be verified through a powerpack and combustion test using an oxidizer-rich preburner. In the cold flow test, the fuel flow rate and oxidizer tangential hole flow rate reached the target value based on the designed differential pressure.

A Study on Flow and Mixing Caracteristics according to Hot Water Extraction (온수 추출에 따른 유동 및 혼합 특성에 관한 연구)

  • 장영근;박이동;김철주;황영규
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1995.05a
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    • pp.53-59
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    • 1995
  • In a hot water extraction process, the flow pattern of upper region in a storage tank is a major reason of mixing between hot water and cold water. In this study, the temperature distribution in a storage tank was measured to predict the flow pattern of upper region, and the degree of stratification was analysed to the variables dominating a extraction process. And also, it was found that the degree of stratification improved expecially in a low flow rate in case of using modified distributor I(DMI) as a outlet port type.

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A STUDY OF THE FLAMMABILITY LIMIT OF THE BACKWARD FACING STEP FLOW COMBUSTION

  • Tae-Ho Lee
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1993.10a
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    • pp.55-61
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    • 1993
  • An experimental investigation was conducted in order to determine the flammability limit of the solid fuel ramjet using the backward facing step flow combustion of the plexiglass grain. In order to get the different step height ratio, the grain was drilled straight forward or stepwise. The Phoenics computer code was adopted in order to compare. the flow patterns of the some sample tests using a non-reacting cold turbulent flow model. The stepwise grain give some loading advantage; specially thin and long shape grain design.

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