• Title/Summary/Keyword: Peak Flame Temperature

Search Result 57, Processing Time 0.022 seconds

An Experimental Studies on Flame and NOx Emission Characteristics of Rapid Mix Combustor (초 저 NOx 선단 예혼합 연소기의 화염 및 NOx 배출 특성 연구)

  • Mun, Min-Uk;Kim, Se-Won;Shin, Myung-Chul;Kim, Yong-Mo
    • 한국연소학회:학술대회논문집
    • /
    • 2006.10a
    • /
    • pp.122-127
    • /
    • 2006
  • The objective of this research is to determine generally applicable design principles for the development of Rapid mix burner. Details operating RMB(Rapid mix burner) is designed that thermal NOx and prompt NOx formation be reduced through control of low peak flame temperature, and nearly uniform flame temperature by rapid mixing at the ignition point. Results from RMB(Rapid mix burner) achieving lower than 43 ppm NOx emissions and nearly flame temperature uniform

  • PDF

Soot Size and Concentration Measurements in a Laminar Diffusion Flame Using a Lignt Scattering/Extinction Technique (광산란 소멸법을 이용한 층류확산화염내에 매연입자의 크기 및 농도 측정)

  • 하영철;김상수
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.16 no.9
    • /
    • pp.1796-1804
    • /
    • 1992
  • Profiles of soot volume fraction, average diameter and particle number density have been measured using a light scattering and extinction technique in a coannular propane diffusion flame at atmosperic pressure. Temperature profiles were also obtained using a thermocouple technique. Measurements show that soot is first observed to form low in the flame in an annular region inside the main reaction zone. At higher locations this annular region widen until entire flame is observed to contain particles. Soot volume fraction and particle diameter profiles peak some 1mm on the fuel side of peak temperature and increase with height to oxidation region. Number density of the flame core drop steeply from formation region to growth region and relatively invariant to some height and decay out at flame tip.

SiC filament Pyrometry in Near Extinction Diffusion Flame (SiC 필라멘트를 이용한 소염 직전의 확산화염 온도 계측)

  • Shim, Sung-Hoon;Shin, Hyun-Dong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.11
    • /
    • pp.1481-1487
    • /
    • 2002
  • The thin SiC filament technique has been employed to identify the possibility of measuring flame temperature, and especially unstable near-extinction flame temperature in an oxidizer deficient ambience, by comparing the relative visible (non-IR) luminosities of SiC filaments with thermocouple measured temperature in co-flowing, laminar propane/air diffusion flames. The results show good agreement between the digitized relative visible luminosity profiles of the SiC filaments and temperature profiles measured using a thermocouple at temperatures above $700^{\circ}C$, although, a non-linear calibration is probably required far the whole temperature range. The highest radial peak temperature exists near to the nozzle exit. and the centerline temperatures were virtually unchanged with increasing flame height in an oxidizer deficient near-extinction flame.

A Numerical Study on Methane-Air Counterflow Diffusion Flames Part 2. Global Strain Rate

  • Park, Woe Chul
    • International Journal of Safety
    • /
    • v.2 no.1
    • /
    • pp.12-16
    • /
    • 2003
  • In Part 1, the flame structure of the counterflow nonpremixed flames computed by using Fire Dynamics Simulator was compared with that of OPPDIF for different concentrations of methane in the fuel stream. In this study, comparisons were made for the global strain rate that is an important parameter for diffusion flames for further evaluation of FDS. At each of the three fuel concentrations, $20% CH_4+ 80% N_2, 50% CH_4 + 50% N_2, 90% CH_4 + 10% N_2$ in the fuel stream, the temperature and axial velocity profiles were investigated for the global strain rate in the range from 20 to $100s^{-1}$. Changes in flame thickness and radius were also compared with OPPDIF. There was good agreement in the temperature and axial velocity profiles between the axisymmetric simulations and the one-dimensional computations except for the regions where the flame temperature reach its peak and the axial velocity rapidly changes. The simulations of the axisymmetric flames with FDS showed that the flame thickness decreases and the flame radius increases with increasing global strain rate.

A Study on the Flame Structure and Combustion Charactexistics of a Premixed Flame Stabilized by a Streamline Step( $\Pi$) (유선형 스텝에 의해 안정화된 예혼합화염의 구조와 연소특성에 관한 연구 ($\Pi$))

  • 이재득;최병륜
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.6
    • /
    • pp.1661-1668
    • /
    • 1990
  • In a turbulent premixed flame stabilized by the streamline step, and dominated by a coherent eddy, a flame micro-structure was investigated with analyzing the signals of temperature, the ion current, and schieren phtographs simultaneously. Generally the contours of large scale coherent eddies of schlieren photographs was considered as the flame front, however, the main reaction can be occurred within the eddy as a structure of fine flamelets scale. The surrounding burned gas of flamelets could not propagate to a unburned mixture, obstructing flamelets from propagating to a unburned mixture. Consequently, it could restrain flashback. The main reaction region was found to be located at higher temperature of the burned gas rather than at maximum rms of fluctuating temperature. The peak probability of higher temperature was 6 times greater than that of lower temperature. As it was difficult to infer a flame structure from PDF distribution of the fluctuating temperature in form of bimodal shape, it should be taken into consideration with other informations related to the sensitive flame front, for instance, ion current.

Axisymmetric Simulation of Nonpremixed Counterflow Flames - Effects of Fuel Concentration on Flame Structure - (비예혼합 대향류 화염의 축대칭 모사 - 연료농도가 화염구조에 미치는 영향 -)

  • Park Woe-Chul
    • Journal of the Korean Institute of Gas
    • /
    • v.7 no.3 s.20
    • /
    • pp.44-50
    • /
    • 2003
  • The axisymmetric methane-air counterflow flame was simulated to investigate changes in the flame structure due to the fuel concentration and to evaluate the numerical method. The global strain rates $a_g=20,\;60,\;90\;s^{-1}$ and the mole fractions of methane $x_m=20,\;50,\;80\%$ in the fuel stream were taken to be numerical parameters. The axisymmetric simulation was conducted by using the Fire Dynamics Simulator (FDS) which employed a mixture fraction combustion model, and the results were compared with those of OPPDIF, which is an one-dimensional flamelet code and includes detail chemical reactions. In all the cases tested, there was good agreement in the temperature and axial velocity profiles between the axisymmetric and one-dimensional simulations. It was shown that the flame thickness and peak flame temperature increase and the flame radius decreases as the fuel concentration increases.

  • PDF

Fabrication and Characteristics of Flame Retardant Fabric Developed by using Bicomponent Filament (복합사를 이용한 난연 직물의 제조와 특성)

  • Lee, Shin-Hee
    • Textile Coloration and Finishing
    • /
    • v.25 no.2
    • /
    • pp.110-117
    • /
    • 2013
  • The purpose of this study is to fabricate the flame retardant polyester fabric by thermal bonding with low melting component of flame retardant bicomponent filament(LMFRPC) and to describe the characteristics of thermal bonded fabrics. The fabrics were prepared with flame retardant polyester filaments(FRP) as warp and blended filaments of FRP and LMFRPC as weft. The LMFRPC have a sheath and a core wherein the core comprises a flame retardant polyester and the sheath comprises a thermoplastic polyester of low-melting point. In this study, we investigated the physical properties, melting behavior of filament, the effect of the component of FRP and LMFRPC on the thermal bonding, mechanical properties. Melting peak of LMFRPC showed the double melting peak. The thermal bonding of the fabric formed at lower melting peak temperature of bicomponent filament of LMFRPC. The optimum thermal bonding conditions for fabrics was applied at about $170^{\circ}C$ for 60 seconds by pin tenter. On the other hand, the tensile strength, elongation, and LOI of the fabric increased with an increasing component of FRP of weft.

An Experimental Study on Flame and $NO_x$ Emission Characteristics of Front Mixing Premix Combustor ($NO_x$ 선단 예혼합 연소기의 화염 및 $NO_x$ 배출 특성 연구)

  • Shin, Myung-Chul;Kim, Se-Won;Mun, Min-Uk
    • Journal of the Korean Society of Combustion
    • /
    • v.11 no.2
    • /
    • pp.22-27
    • /
    • 2006
  • This experimental study has been mainly motivated to obtain generally applicable design correlation for the front mixing premix combustor. The design concept of the front mixing premix combustor is to minimize thermal $NO_x$ and prompt $NO_x$ formation by maintaining low peak flame temperature, and nearly uniform flame temperature through rapid mixing process near the ignition point. The present experimental results clearly indicate that the front mixing premix combustor yields the $NO_x$ level lower than 43 ppm $NO_x$ emissions and the nearly uniform temperature distribution.

  • PDF

Characterization of $SiO_2-P_2O_5-B_2O_3$ Glass Soot fabricated by Flame Hydrolysis Deposition (화염 가수분해 증착에 의해 형성된 $SiO_2-P_2O_5-B_2O_3$ 유리 미립자의 특성)

  • 최춘기;정명영;최태구
    • Journal of the Korean Ceramic Society
    • /
    • v.34 no.8
    • /
    • pp.811-816
    • /
    • 1997
  • SiO2-P2O5-B2O3 glass soot was fabricated by flame hydrolysis deposition and their properties by SEM, XRD, TGA-DSC were investigated., The mechanism of consolidation process of a glass soot as a function of consolidation temperature was analyzed by SEM observations. In the XRD patterns, the crystalline peaks which seem to be generated from B2O3 and BPO4 were observed. When the temperature of heat treatment exceeded 105$0^{\circ}C$, the non-crystalline state of SiO2-P2O5-B2O3 glass was observed. In the TGA-DSC curves, the evaporation of water molecule by a sudden endothermic reaction was observed at 128$^{\circ}C$ and a broad endothermic peak was seen in the temperature range of 40$0^{\circ}C$-95$0^{\circ}C$, without any weight loss. Finally, this peak was began to recover its baseline at 953$^{\circ}C$. This point is equal to the temperature at which the densification begins. Furthermore, we observed that the addition of dopants such as P2O5 and B2O3 decrease the onset of consolidation temperature till 95$0^{\circ}C$.

  • PDF

A Study on the Electrical-Fire Analysis and Firing Characteristics of Power Cord by Thermal Stress (열적 피로에 의한 전원코드의 발화 특성과 전기화재 분석에 관한 연구)

  • 최충석;송길목;김향곤;김동욱;김동우
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
    • /
    • 2003.04a
    • /
    • pp.164-170
    • /
    • 2003
  • In this paper, we studied on the firing characteristics and electrical fire analysis of power cord deteriorated by thermal stress. The cross section of PVC insulating cord deteriorated by indirect flame decreased through heat convection. PVC insulating cord deteriorated by direct flame was bumpy shape. The exothermic peak of normal cord was shown at ($526.7^{\circ}C$), but the peaks or on(heat treatment temperature) ($150^{\circ}C$) cord was shown at ($299.6^{\circ}C$) and [$502.2^{\circ}C$]. The exothermic peaks according to high temperature were similar to those of amorphous carbon. In the FT-IR analysis, the absorption peak of normal cord indicated double bond of oxygen and carbon in benzene ring at 1720.0$cm^{1}$. As the HTT was high, the height of characteristic peak decreased and the peak of carbonyl group was shown at about 1625.7$cm^{-1}$. The characteristic peak of single bond(O-H) was shown at about 3479.2$cm^{-1}$. In case of the internal part of wire covering deteriorated by over current, the characteristic peak were shown at about 3417.3$cm^{-1}$ and 1600.2$cm^{-1}$. The above results show that we can distinguish the differences according to the fire pattern through the internalㆍexternal analysis of wire covering deteriorated by heat.

  • PDF