• Title/Summary/Keyword: 프로판/공기

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Comparison of Dynamic Characteristics of Methane/Air and Propane/Air Premixed Flames with Ultrasonic Standing Wave (정상초음파가 개재하는 메탄/공기 및 프로판/공기 예혼합화염의 동역학적 특성 비교)

  • Kim, Min Cheol;Bae, Dae Seok;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.4
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    • pp.44-51
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    • 2017
  • An experimental results on the dynamic characteristics of hydrocarbon/air premixed flames with ultrasonic standing waves are presented and compared. Images of the propagating flames were acquired by using a high-speed camera, and the flame behavior of methane/air and propane/air premixed flame were closely scrutinized through the image post-processing. At the fuel-lean conditions, the flame propagation velocity increased due to the intervention of the ultrasonic standing wave and vice versa at the fuel-rich conditions.

Study of the Dehydrogenation Characteristics of Pt-Sn Catalysts by Propane Pulse Injection (프로판 펄스 주입에 의한 백금주석촉매의 탈수소반응 특성 연구)

  • Koh, Hyoung Lim;Jung, Jae-Won;Choi, Yi-Sun
    • Korean Chemical Engineering Research
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    • v.57 no.4
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    • pp.575-583
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    • 2019
  • The results of the catalytic reaction by pulsed injection of reactants are useful for studying the initial reaction characteristics in the case of many coke invloved reactions. The dehydrogenation characteristics of alumina supported platinum tin catalysts were investigated by pulsed injection of propane. The yield of propylene was maximized when the reduction time of propane injection catalyst was $550^{\circ}C$. Raman analysis showed that the amount of coke was very small when PtSn (4.5) catalyst was used and the short contact time was simulated by propane pulse injection. n order to differentiate the degree of dispersion of platinum, PtSn (4.5) catalyst was sintered at $900^{\circ}C$ with hydrogen, and then the temperature of air - redispersion was varied and propane pulse was injected. As a result, conversione and yield were the highest when air-redispersion temperature is $600^{\circ}C$. The lower the air-redispersion temperature, the higher the selectivity. As the tin content in the platinum catalyst increased, the propane conversion was lowered, but the selectivity to propylene increased and the yield increased. From this, it can be seen that the tin-added platinum catalyst is less active than the platinum catalyst from the beginning of the reaction, which is less affected by coke. The dehydrogenation reaction by the propane pulse injection shows a higher conversion rate than the result of continuous injection due to the formation of COx, and the amount of coke is very small. Decrease in selectivity due to the formation of COx can be reduced by increasing the reduction temperature and time.

Interacting Effects of an Ultrasonic Standing-wave on the Propagation Behavior and Structural Stabilization of Propane/Air Premixed Flame (프로판/공기 예혼합화염의 전파거동 및 구조안정화에 대한 정상초음파의 간섭효과)

  • Lee, Sang Shin;Seo, Hang Seok;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.16 no.6
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    • pp.1-8
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    • 2012
  • An experimental study has been conducted to scrutinize into the influence of ultrasonic standing wave on the propagating behavior and structural stabilization of propane/air premixed flame at various equivalence ratios in half-open rectangular duct. Evolutionary features of the flame fronts are caught by high-speed images, and the variation of flame structure and local flame velocities along the propagation are analyzed. It is revealed that the propagation velocity agitated by the ultrasonic standing wave is greater than that without the agitation: the velocity enhancement diminishes as the equivalence ratio approaches the stoichiometric. Influence of standing wave on the flame overwhelms that of the buoyancy which slants the flame front towards top of the duct, and thus the standing wave contributes to the structural stabilization of propane/air premixed flame.

A Structural Behavior of the Propane/Air Premixed Flame Interacting with an Ultrasonic Standing-wave (정상초음파가 개재하는 프로판/공기 예혼합화염의 구조 거동)

  • Lee, Sang-Shin;Seo, Hang-Seok;Kim, Jeong-Soo;Lee, Do-Hyung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.294-299
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    • 2012
  • An investigation into the influence of ultrasonic standing wave on the structural behavior of propane/air premixed flame has been made to get a clue to the combustion reaction acceleration and combustion instability, as well. Visualization technique utilizing the Schlieren method was employed for the observation of structural variation of the premixed flame. The flame shape and propagation velocity were measured according to the variation of equivalence ratio. It was found that the standing wave distorted the flame front and expedited a transition to the flame with turbulent nature.

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A Visualization of the Propane/Air Premixed Flame Interacting with an Ultrasonic Standing-wave by Schlieren Photography (정상초음파가 개재하는 프로판/공기 예혼합화염의 슐리렌기법에 의한 가시화)

  • Lee, Sang Shin;Kim, Jeong Soo;Lee, Do Hyong
    • Journal of the Korean Society of Visualization
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    • v.11 no.1
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    • pp.22-27
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    • 2013
  • An investigation into the influence of ultrasonic standing wave on the structural behavior of propane/air premixed flame has been made to get a clue to the combustion reaction acceleration and combustion instability. Visualization technique utilizing the Schlieren photography was employed for the observation of structural variation of the flame reaction zone. Evolutionary characteristics of the flame front were caught by the high-speed Schlieren image, through which local flame velocity of the moving front were analyzed in detail.

A Study on The Ignition Limit of Flammable Gases by Discharge Spark of Resistive Circuit (저항회로의 개폐불꽃에 의한 폭발성 가스의 점화한계에 관한 연구)

  • Lee Chun-Ha
    • Journal of the Korean Institute of Gas
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    • v.1 no.1
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    • pp.106-112
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    • 1997
  • This study measured the ignition limits of methane-air, propane-air, ethylene-air, and hydrogen-air mixture gases by discharge spark of D.C. power resistive circuit. The used experimental device is the IEC type spark ignition test apparatus, it consists of explosion chamber and supply -exhaust system of mixture gas. Mixture gases (methane-air, propane-air, ethylene-air, and hydrogen-air) were put into explosion chamber of IEC type spark ignition test apparatus, then it was confirmed whether ignition was made by 3,200 times of discharge spark between tungsten electrode and cadmium electrode. The ignition limits were found by increasing or decreasing the value of current. For the exact experiment, the ignition sensitivity was calibrated before and after the experiment in each condition. The ignition limits were found by changing the value of concentration of each gas-air mixture in D.C. 24 [V] resistive circuit. As the result of experiment, it was found that the minimum ignition limit currents exist at the value of methane-air 8.3 [$Vol\%$], propane-air 5.25[$Vol\%$], ethylene-air 7.8 [$Vol\%$], and hydrogen-air 21[$Vol\%$] mixture gases. For each the minimum ignition concentration of gases, the relationships between voltage and minimum ignition current were found. The results are as follows. - The minimum ignition limits are decreasing in the order of methane, propane, ethylene, and hydrogen. - The value of ignition current is inversely proportional to the value of source voltage. - The minimum ignition limit currents increase sharply at more than 2 [A]. The reason is caused by overheating the electrode.

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A Study on the Improved Ignition Limit with Resistor for Propan-air Mixture Gas (저항을 이용한 프로판-공기 혼합가스의 점화한계 개선에 관한 연구)

  • 이춘하;오종용;옥경재;지승욱;이광식;심광렬
    • Fire Science and Engineering
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    • v.18 no.1
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    • pp.18-23
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    • 2004
  • This paper describes the minimum ignition limits for propane-air 5.25 Vol.% mixture gases in low voltage inductive circiuts. The improved effects on the ignition limit are studied by parallel safety components(resistors) for propane-air 5.25 Vol.% mixture gas in low voltage inductive circuits. The experimental devices used in this test are the IEC type spark ignition test apparatus. The minimum ignition limits are controlled by the values of current in inductive circuit. Energy supplied from electric source is first accumulated at the inductance, it's extra energy is working as ignition source of the explosive gas. The improved effects on the ignition limit are respectively obtained as the maximum rising rate of 330% by composing parallel circuits between inductance and resistor as compared with disconnecting inductance with the safety components. The more values of inductance increase the higher improved effects of ignition limit rise. The less values of resistor the higher improved effects of ignition limit rise. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof machines which are applied equipment and detectors used in dangerous areas but also for datum for its equipment tests.

Removal of Benzene-Nonaqueous Phase liquid(NAPL) in Soil Tank by NAPL Swelling and Non-swelling alcohols (토양 탱크에서 흡수 알코올과 비흡수 알코올을 이용한 벤젠-비수용상액체 제거 연구)

  • Song, Chung-Hyun;Jeong, Seung-Woo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.17 no.3
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    • pp.40-47
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    • 2009
  • Coinjection of alcohol and air or alcohol flooding only were evaluated with 3-D soil tank for removal of nonaqueous phase liquid (NAPL) contaminant from soil. 70%-ethanol and 40%-isopropanol were used for non-NAPL-swelling alcohol and NAPL-swelling alcohol, respectively. 729 ml-benzene was placed in the 37 liter soil tank. Alcohols were respectively injected from the injection well placed near the bottom of the tank and mobilized free phase NAPL and aqueous phases were then recovered from the extraction well placed in the upper part of the soil tank. Approximately 50% of removed NAPLs were free-phase in all experiments. The results were completely different to the previous soil column experiment results and also implied that alcohol properties did not affect the NAPL removal efficiency in the 3-D soil tank experiment. Air was also co-injected with alcohol to evaluate co-injection effects on NAPL removal. Enhanced NAPL removal effect of co-injection of 70%-ethanol and air was also found even in the 3-D soil tank evaluation. However, co-injection effect of 40%-iso-propanol and air was less apparent. This study determined that the most important parameter governing alcohol flooding for NAPL removal would be extraction capacity to recover NAPL and aqueous phase flowing in the soil. More researches are required for improving recovery efficiency of extraction well in real soil contamination conditions.

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A Study on Fire and Explosion Characteristics of Propane Gas (프로판가스의 화재 및 폭발 특성치에 관한 연구)

  • Ha Dong-Myeong
    • Journal of the Korean Institute of Gas
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    • v.10 no.2 s.31
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    • pp.33-39
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    • 2006
  • For the safety design and operation of many gas process, it is necessary to know certain explosion limit, flash point, auto ignition temperature and minimum oxygen concentration of handling substances. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of propane, explosion limit and autoignition temperature of combustion characteristics for propane were investigated. By using the literatures data, the lower and upper explosion limits of propane recommended 2.0 vol% and 10.0 vol%, respectively. Also autoignition temperatures of propane with ignition sources recommended $450^{\circ}C$ at the electrically heated cruicible fumace(the whole surface heating) and recommended about $960^{\circ}C$ at the local hot surface. The new equations for predicting the temperature and the pressure dependence of the explosion limits of propane are proposed. The values calculated by the proposed equations were a good agreement with the literature data.

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A Numerical Study on the Propane Combustion Characteristics in a Catalytic Combustor (프로판의 촉매연소 특성에 관한 수치적 연구)

  • Lee, Youn-Hwa;Kim, Chong-Min;Kim, Man-Young;Yu, Myoung-Jong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.05a
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    • pp.247-250
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    • 2009
  • The catalytic combustor has the advantage of stable combustion under very lean conditions with low emissions of $NO_x$, CO and unburned hydrocarbon(UHC). Notwithstanding these advantages, the commercial application of the catalytic combustion has been delayed due to the complicated reaction process. For the stable operation of catalytic combustor, study on the combustion characteristics of the catalytic combustor is needed. So, in this study, numerical study on the propane combustion characteristics of the catalytic combustor with Pd-based catalyst is performed.

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