• Coupled systems mechanics
• /
• 제1권3호
• /
• pp.285-295
• /
• 2012

In this paper, two types of porous burners with radial and axial flow have been modeled numerically and compared. For this purpose, governing equations were solved one-dimensionally for methane-air premix gas. The mechanism used in simulating combustion phenomenon was 15 stage reduced mechanism based on GRI3.0. In order to compare the two burners, the inlet flow rate and fuel-air ratio have been assumed equal for the two burners. The results of the study indicated that reduction in speed and increase in cross-section area in the direction of flow have a considerable influence on the behavior of radial burner in comparison to axial burner. Regarding temperature distribution inside the burner, it was observed that the two above mentioned factors can be influential in temperature of flame propagation region. Also, regarding distribution of CO and NO emission, the results indicate that the porous radial burner has lower emissions in comparison to the axial once. The output radiative heat transfer efficiency of the two burners was also compared and in this case also even the radial porous burner was found to be preferable.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
• /
• pp.295-296
• /
• 2015

We presented the methods calculating the reduction efficiency of nitrogen oxide for the low $NO_x$ burner as the pollution prevention facilities. The standard $NO_x$ concentration was used on the emission factor of LNG, $3.7g/m^3$. The $NO_x$ reduction efficiency based on the $NO_x$ concentration was presented and the relationships between the $NO_x$ concentration and the emission factor or the specific heat emission factor were derived. These results could be accurately reflected on calculating the amount of the nitrogen oxide emissions. In addition, according to the arrangement of the low $NO_x$ burners the methods of applying their $NO_x$ reduction efficiency were proposed. The $NO_x$ reduction efficiency for the facilities consisting of the low $NO_x$ burners and the non-low $NO_x$ burners could be estimated with information about the reduction efficiency of each low $NO_x$ burners, the fuel consumption rate, and the heating value of fuel.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2009년 춘계학술대회논문집
• /
• pp.335-340
• /
• 2009

Operating medium or large scale industrial boilers in partial load condition, the burner should undergo the off-design points resulting in poor exhaust gas characteristics. To obtain the stable turn down performance, two or more burners can be used for the industrial boiler. In case multiple burners are adopted, the heat transfer can be enhanced by arranging the burners properly. In the present study, numerical simulations have been conducted for the combustion chamber of a 2 t/h class industrial boiler in order to clarify the heat transfer characteristics at the combustion chamber.

• Journal of Mechanical Science and Technology
• /
• 제19권9호
• /
• pp.1811-1820
• /
• 2005

Thermo-acoustic instability of methane/ air flames in an industrial gas-turbine combustor is numerically investigated adopting CFD analysis. The combustor has 37 EV burners through which methane and air are mixed and then injected into the chamber. First, steady fuel! air mixing and flow characteristics established by the burner are investigated by numerical analysis with single burner. And then, based on information on the flow data, the burners are modeled numerically via equivalent swirlers, which facilitates the numerical analysis with the whole combustion system including the chamber and numerous burners. Finally, reactive flow fields within the chamber are investigated numerically by unsteady analysis and thereby, spontaneous instability is simulated. Based on the numerical results, scaling analysis is conducted to find out the instability mechanism in the combustor and the passive control method to suppress the instability is proposed and verified numerically.

• 한국전산유체공학회지
• /
• 제14권2호
• /
• pp.77-83
• /
• 2009

Operating medium or large scale industrial boilers in partial load condition, the burner should undergo the off-design points resulting in poor exhaust gas characteristics. To obtain the stable turn down performance, two or more burners can be used for the industrial boiler. In case multiple burners are adopted, the heat transfer can be enhanced by arranging the burners properly. In the present study, numerical simulations have been conducted for the combustion chamber of a 2 t/h class industrial boiler in order to clarify the heat transfer characteristics at the combustion chamber.

• 대한기계학회논문집
• /
• 제19권1호
• /
• pp.277-283
• /
• 1995

For the development of low NO$_{x}$ gas burners aimed for absorption chiller/heater unit, three proto type burners of different capacity (265000, 498000, and 664000 kcal/h) have been manufactured through a combustion method of step-by-step air injection. In order to characterize the overall features of the flame and the properties of the emission gas, the temperature of the flame and the concentration of NO$_{x}$ and CO were determined. The main factors in the design of burners (the area of primary air injection, the diameter of secondary air injection hole, fuel nozzle diameter) were observed to increase linearly with the scale-up of burner capacity. The flame temperature profiles of the burners were observed to be almost similar, irrespective of their capacity. However, as their capacity increased, the flame temperature slightly increased and the hot region of the flames moved to ward the flame tip along with the expansion to the direction of radius. From the proto type units, the amount of their NO$_{x}$ emission was determined to be around 25 - 30 vppm(3% )$_{2}$) and the CO emission was less than 19 vppm (3% $O_{2}$).TEX>).

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
• /
• pp.7-8
• /
• 2006

As a new type of flame, tubular flame has attracted much attention from a fundamental viewpoint and many experimental and theoretical studies have been made on its characteristics. Recently, it is also recognized that the tubular flame has great potentials as practical combustor because its stability range is very wide in fuel concentration and also in injection velocity. Thus, tubular flame burners have been developed for various kinds of fuels. They are gaseous fuels of methane, propane, hydrogen, and by-product fuels gases in steel making processes including BFG (Blast Furnace Gas), LDG (LD Converter Gas), and COG (Cokes-Oven Gas), liquid fuels of kerosene, A-type and C-type heavy oils, and a solid fuel of biomass powder. In this paper, recent developments of the tubular flame burners have been briefly introduced.

• 대한기계학회논문집B
• /
• 제23권3호
• /
• pp.330-341
• /
• 1999

An experimental study for the two types of burners used in the non-oxidizing direct fired furnaces of the heat treatment process for the cold rolled plate has been carried out to investigate the combustion characteristics and the oxidization of the surface of steel plate. A steep temperature gradient and entrainment of residual oxygen were found near the heating surface in the flame of the nozzle mixing burner which has strong swirl velocity component. It was concluded that the elimination of the residual oxygen and the increase of the temperature of combustion gas on the heating surface are needed to enhance the performance of the burners for application to the non-oxidizing direct fired furnaces.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
• /
• pp.13-18
• /
• 2006

Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. High radiation efficiency is one of the most important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

• 한국연소학회지
• /
• 제11권1호
• /
• pp.27-33
• /
• 2006

Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. Radiation efficiency is one of the important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.