• 제목/요약/키워드: propane

검색결과 779건 처리시간 0.034초

탄화수소 냉매의 수평 원관내 응축열전달 특성 (Condensing heat transfer characteristics of hydrocarbon refrigerants in a horizontal tube)

  • 장영수;김민수;노승탁
    • 대한기계학회논문집B
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    • 제21권12호
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    • pp.1656-1667
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    • 1997
  • Condensing heat transfer characteristics of hydrocarbon refrigerants are experimentally investigated. Single component hydrocarbon refrigerants (propane, isobutane, butane and propylene) and binary mixtures of propane/isobutane and propane/butane are considered as test fluids. Local condensing heat transfer coefficients of selected refrigerants are obtained from overall conductance measurement. Average heat transfer coefficients at different mass fluxes and heat transfer rates are shown and compared with those of R22. Pure hydrocarbon refrigerants have higher values of heat transfer coefficient than R22. It is also found that there is a heat transfer degradation for hydrocarbon mixtures due to composition variation during condensation. Measured condensing heat transfer coefficients are compared with predicted values by available correlations. An empirical correlation for pure and mixed hydrocarbon is developed, and it shows good agreement with experimental data.

프로판과 R227ea 혼합냉매의 기상-액상 평형 실험 (An Experimental Study on the Vapor-Liquid Equilibria of Propane and R227ea Mixtures)

  • 강대경;김주혁;김민수;김영일
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.245-249
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    • 2003
  • Vapor-liquid equilibrium data were obtained for system of propane + R227ea (Heptafluoropropane) over the temperature range from 253.15 K to 323.15 K at 10 K intervals. Experiments were performed in a circulation type apparatus by injecting vapor through liquid pool using a magnetic pump. This system forms azeotrope in the temperature range of this study. The experimental results were correlated with the Peng-Robinson (PR) equation of state and Redlich-Kwong-Soave (RKS) equation of state using the van der Walls one-fluid mixing rule and were compared with each other.

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Twin-Jet 대향류에서 메탄 비예혼합화염의 소염 특성 (Extinction of Non-premixed methane Flame in Twin-Jet Counterflow)

  • 노태곤;양승연;류승관;정석호
    • 한국연소학회:학술대회논문집
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    • 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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    • pp.195-200
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    • 2003
  • A two-dimensional "twin-jet counterflow" burner has been designed for the better understanding of the stability of turbulent flames. This flow system enables one to systematically investigate various effects on non-premixed flames, including the effects of curvature, negative strain, and non-premixed flame interactions. The objective of this study is comparing characteristics of extinction of non-premixed methane flames with that of non-premixed propane flames investigated previously. The extinction limit of non-premixed methane and propane flames can be extended compare to that for the conventional counterflow non-premixed flame because of the existence of petal shaped flame and have same structure. The hysteresis in transition between the petal shaped flame and the curved two-wing flames could be observed. We could find differences between non-premixed methane flame and non-premixe propane flame such as the position of one wing extinction and the regime of one wing extinction.

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압력조건에서 공기로 희석된 프로판 확산화염의 매연 생성과 산화 특성 (Soot Formation and Oxidation in Air-Diluted Propane Diffusion Flames under Elevated Pressures)

  • 배승만;남연우;이원남
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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    • pp.267-268
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    • 2012
  • Soot formation and oxidation characteristics of air-diluted propane diffusion flames have been experimentally investigated under the elevated pressure conditions. PAH concentrations showed more pressure sensitive behavior comparing to soot volume fractions. The flame/soot temperatures in soot oxidation region were obtained using the MOLLIP technique. Under the complete soot oxidation environment, the flame/soot temperature is increased with pressure. The increased temperature could accelerate the soot oxidation process and then exothermic oxidation reaction, in turn, could further raise the flame/soot temperature, which would result in the enhancement of soot oxidation process.

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

  • 이상신;김정수;이도형
    • 한국가시화정보학회지
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    • 제11권1호
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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.

Modified Gas Tracer Method 를 이용한 하천 재폭기계수의 산정 (Determination of Stream Reaeration Coefficient Using Modified Gas Tracer Method)

  • 조영준
    • 한국농공학회지
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    • 제41권4호
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    • pp.57-65
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    • 1999
  • A modified gas tracer method was used to obtain reaeration coefficient from an artificial channel and a reach of Bokha stream, Ichon city. Propane was used as the tracer gas and Rhodamine-B dye as a dispersion and dulution tracer. Concentrations of propane in water sample were measured using a gas chromatograph and concentrationsof dye using UV-Spectrophotometer. To compare measured values with predicted values,commonly used 14 equations were selected . Results of this study suggested that the modified gas tracer method is a potentially useful procedure for th edetermination of reaeration cofficients. However, estimated reaeration coefficients from predictive equations were significantly different from that of this study. Therefore, when using predictive equations, careful selection of equation with consideration for hydraulic characteristics such as flow depth and average velocity, or use of newly derived predictive equation which is adequate for questioned stream would be needed.

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Synthesis of Dibenzoylmethanes as Intermediates for Flavone Synthesis by a Modified Baker-Venkataraman Rearrangement

  • Song, Gyu-Yong;Ahn, Byung-Zun
    • Archives of Pharmacal Research
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    • 제17권6호
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    • pp.434-437
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    • 1994
  • 1-Polyoxyphenyl-3-(2, 6-dioxyphenyl)propane-1, 3-diones have been synthesized as intermediates for flavone synthesis by condensation of 2-(2, 6-dioxybenzoyloxy)polyoxyacetophenone in the presence of phae transfer catalyst. The average yields of 1-polyoxyphenyl-3-phenylpropane-1, 3-diones, 1-polyoxyphenyl-3(2-benzyloxyphenyl)propane-1, 3-diones and 1-polyoxy-3-(2, 6-dibenzyloxyphenyl)propane-1, 3-dions were 79%, 74% and 71% respectively. The bulkiness of the benzyloxy groups or methyoxy gorups exerted steric hindrance and reduced the yield. Nevertheless, the yield were higher than the previously reported ones.

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프로판/이소부탄 혼합냉매를 적용한 가정용 소형 멀티 냉동시스템의 성능특성에 관한 연구 (Evaluation of the Performance Characteristics of Propane/isobutene Refrigerant Mixtures in a Small multi-refrigeration System)

  • 이무연;최석재;김상욱
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1945-1950
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    • 2004
  • In this paper, The performance of Kim-Chi refrigerator with three evaporator and one compressor was investigated in employing 55% propane and 45% isobutane (R290/R600a) refrigerant mixture as an alternative refrigerant of R134a. The drop in test was performed by varying both refrigerant charge amount and capillary tube length in order to find both the performance and reliability of a small multi-refrigeration system. As a result, Both the power consumption and COP is increased by about 15% and 10%, respectively as compared to the baseline R134a system. In addition, the propane/isobutene refrigerant mixture system took advantage of the minimization of modification and redesigning of system components because of similar thermodynamic properties with R134a such as saturation pressure, temperature, normal boiling point(NBP) characteristics

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HFC125+Propane 혼합냉매의 기-액 평형에 관한 실험적 연구 (An Experimental Study of Vapor-Liquid Equilibrium for HFC12S+Propane Refrigerant Mixtures)

  • 강준원;박영무;유재석;이종화
    • 설비공학논문집
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    • 제15권7호
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    • pp.563-571
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    • 2003
  • The forty vapor-liquid equilibrium data of the binary system, HFC125+Propane, were measured between 273.15 and 313.15 K at 10 K interval and the composition range 0.2∼0.75, respectively. Experiments were performed in a circulation type apparatus in which the vapor phase was forced through the liquid phase. The composition at equilibrium were mea-sured by gas chromatography, and its response was calibrated using gravimetrically prepared mixtures. Vapor-liquid equilibrium data were calculated by using CSD equation of state and compared with the experimental data.

혼합 액체 프로판 표준가스 개발 (Development of Primary Reference Gas Mixtures for Liquid Propane)

  • 정윤성;김진석;배현길;강지환;이승호;김용두
    • 한국가스학회지
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    • 제25권4호
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    • pp.49-56
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    • 2021
  • 액화석유가스(Liquefied Petroleum Gas)는 Propane(C3H8)과 Butane(C4H10)을 주성분으로 한 가스를 액화한 것으로 구분된다. LPG는 혼합 성분에 따라 품질의 차이가 커 성분 함량을 정확하게 측정하는 것이 중요하다. 이와 같은 물질은 혼합물의 성분별로 상온에서는 액체와 기체가 같이 공존해 정확한 측정이 까다롭다. 따라서 탄화수소의 성분별 농도의 측정 불확도가 높아 실제 함량 기준과 많은 차이가 발생하는 문제점을 안고 있다. 그러므로 탄화수소 물질의 조성과 정확한 농도 측정을 위해 혼합 액체 프로판 표준가스의 개발이 필요하였다. 혼합 액체 프로판 표준가스는 ISO-6142(2015)의 중량법으로 벨로즈형 정압실린더에 제조되었다. 제조한 4병의 표준가스에서 균질성이 GC-FID로 확인되었다. 제조 상대확장불확도는 0.01 % - 0.30 %, 균질성은 0.03 % - 0.25 %이었다. 이 혼합 액체 프로판 표준가스에서 중량법, 제조 일치성, 실린더 흡착 여부 및 장기 안정성에 대한 상대확장불확도는 0.26 % - 1.39 %(신뢰도 약 95 %, k=2)이내로 개발되었다.