Two-Dimensional Spectroscopic Observation of Nonluminous Flames in a Regenerative Industrial Furnace Using Coal Gas

2004 ◽  
Vol 126 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Y. Hino ◽  
S. Sugiyama ◽  
Y. Suzukawa ◽  
I. Mori ◽  
N. Konishi ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Emission Intensity ◽  
Premixed Flame ◽  
Band Pass Filter ◽  
Two Dimensional ◽  
Gas Temperature ◽  
Pass Filter ◽  
Soot Particles ◽  
Coal Gas

Thermal and chemical characteristics of the flames obtained from an industrial size regenerative combustion furnace have been obtained spectroscopically. The combustion characteristics of diffusion or premixed flames in the regenerative high-temperature air combustion facility have been examined using coal gas as the fuel. The fuel gas composition consisted of H2, hydrocarbon, CO, and N2. Monochromatic images of the flames have been observed in the emission mode using a CCD camera fitted with an optical band pass filter at the desired wavelength. The two-dimensional temperature distribution in the furnace has been determined using the two-line method by utilizing the Swan emission bands from within the flame. The emission intensity profiles of NO, as well as OH and CH radicals have also been observed spectroscopically. The results showed quite uniform two-dimensional temperature distribution and emission intensity of OH and CH radical species for the diffusion flame case as compared to the premixed case using high-temperature combustion air. The premixed flame case showed high local values and large fluctuations in the combustion zone for both emission intensity and temperature distribution. The temperature distribution of soot particles in the premixed flame was also determined using the two-color optical method. The results showed high local value of temperature, similar to that found for the gas temperature using signatures for C2 species at two different wavelengths. In contrast the distribution of temperature for soot particles was different. The location of the maximum soot temperature shifted to downstream positions of the flame as compared to the maximum gas temperature regions measured from the C2 species. The experimental results are discussed in conjunction with those obtained from the heat simulation analyses.

Fine-structure of energy spectra of velocity fluctuations in the transition region of a two-dimensional wake

1975 ◽  
Vol 67 (3) ◽  
pp. 539-559 ◽  
Author(s):  
Hiroshi Sato ◽  
Hironosuke Saito
Keyword(s):  
Fine Structure ◽  
Transition Region ◽  
Nonlinear Interaction ◽  
Spectral Component ◽  
Random Fluctuation ◽  
Band Pass Filter ◽  
Two Dimensional ◽  
Pass Filter ◽  
Velocity Fluctuations ◽  
Random Components

Measurements of the fine-structure of the energy spectrum of the velocity fluctuations were made in the transition region of a two-dimensional wake. Line and continuous spectra were determined separately with a high-selectivity band-pass filter. The transition was initiated by an external sinusoidal sound. The sound-induced periodic fluctuation and the natural random fluctuation in the wake were added and a system of line and continuous spectra was formed. Higher harmonics of the periodic component were produced by the nonlinear interaction. As a result of the interaction between discrete and continuous components, a continuous spectrum was generated at low wavenumbers. A simple model for the interaction is proposed. The evolution of the spectrum is explained by three fundamental rules concerning the nonlinear interaction between spectral components: (i) the growth of a spectral component is suppressed by the presence of another strong component, (ii) mutual interaction is more effective when the amplitudes of interacting components are closer, and (iii) a stronger interaction takes place between components of closer wavenumbers. The randomization of the regular fluctuation is properly expressed as the growth of the ‘randomness factor’, the ratio of the energy of the random components to the total fluctuation energy.

Design and Development of a 14-Pole High-Temperature Superconducting Filter at 127.5MHz

2013 ◽  
Vol 392 ◽  
pp. 672-675 ◽  
Author(s):  
Jian Chang Du ◽  
Lai Yun Ji ◽  
Li Juan He
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Return Loss ◽  
Band Pass Filter ◽  
Pass Filter ◽  
High Temperature Superconducting ◽  
Hts Filter ◽  
Band Pass ◽  
Temperature Test ◽  
Better Than

A high-temperature superconducting (HTS) band-pass filter centered frequency at 127.5MHz was successfully designed and developed. The HTS filter is 14-pole, adopting compact symmetrical dual-spiral resonators. The filter was fabricated on a 3-inch-diameter 0.5-mm-thick LaAlO3 wafer with double-sided DyBa2Cu3O7 thin films. Through the low temperature test, the insertion loss of the HTS filter is under 0.1dB, the bandwidth is 20 MHz, the return loss is better than-22dB and the out-of-band rejection is greater than 80dB. The filters measurements agree well with the simulation.

A compact high-temperature superconducting band-pass filter with wide upper stopband

2019 ◽  
Vol 557 ◽  
pp. 1-6 ◽  
Author(s):  
Hongwei Yue ◽  
Hanxue Tang ◽  
Chaofei Wu ◽  
Qinglian Xie ◽  
Cheng Li
Keyword(s):  
High Temperature ◽  
Band Pass Filter ◽  
Pass Filter ◽  
High Temperature Superconducting ◽  
Band Pass

Numerical simulation of combustor temperature performance of a high-temperature high-speed heat-airflow simulation system

2016 ◽  
Vol 13 (5) ◽  
pp. 422-431 ◽  
Author(s):  
Chaozhi Cai ◽  
Leyao Fan ◽  
Bingsheng Wu
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
High Speed ◽  
Simulation System ◽  
Outlet Temperature ◽  
Gas Temperature ◽  
Fuel Gas ◽  
Content Type ◽  
Gas Ratio ◽  
Airflow Simulation

Purpose This paper aims to understand the outlet temperature distribution of the combustor of a high-temperature, high-speed heat-airflow simulation system. Design/methodology/approach The paper uses numerical simulation to study the temperature distribution of the combustor of a high-temperature, high-speed heat-airflow simulation system. First, the geometrical model of the combustor and the combustion model of the fuel are established. Then, the combustion of fuel in the combustor is simulated by using FLUENT under various conditions. Finally, the results are obtained. Findings The paper found three conclusions: when the actual fuel–gas ratio is equal to the theoretical fuel–gas ratio, the temperature in the combustor of the high-temperature, high-speed heat-airflow simulation system (HTSAS) can reach its highest and the distribution is the most uniform. Although increases in the total temperature of the inlet air can increase the highest temperature in the combustor of the HTSAS, the average temperature of the combustor outlet will decrease. At the same time, it will lead to an uneven temperature distribution of the combustor outlet. When the spray angle of the kerosene droplet is at 30 degrees, the outlet temperature field of the combustor is more uniform. Originality/value The paper presents a method to analyze the combustion performance of fuel and the gas temperature distribution in the combustor. The results will lay the foundation for the gas temperature control of a combustor.

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