Mechanism and effect assessment of sub-atmospheric pressure and co-flow air to suppress the flicker of buoyancy-driven methane laminar diffusion flame

Yang, Xiao; Ma, Shijiu; Gao, Jianmin; Du, Qian; Dong, Heming; Wu, Shaohua; Qin, Yukun

doi:10.1016/j.fuproc.2022.107649

Cited by 6 publications

(3 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ance to the flame as noted previously [9,11,21,[24][25][26]. On the one hand, the reduced sure leads to an increase in the mass diffusion coefficient of combustible gases, w makes it more easily diffusible and results in an increase in the combustion radius.…”

Section: Flame Appearancesupporting

confidence: 52%

“…The width of flame is defined as the maximum radial width of flame envelope. As the pressure decreases, the flame width increases, providing an overall shrinking appearance to the flame as noted previously [9,11,21,[24][25][26]. On the one hand, the reduced pressure leads to an increase in the mass diffusion coefficient of combustible gases, which makes it more easily diffusible and results in an increase the combustion radius.…”

Section: Flame Appearancementioning

confidence: 63%

“…The schematic of the overall combustion system and its external devices are shown in Figure 1. In this work, the sub-atmospheric pressure combustion environment within the furnace was achieved by three oil-free diaphragm vacuum pumps with capacities of 10 L•min −1 , 15 L•min −1 , and 20 L•min −1 , which was proven to be scientifically sound and feasible in many previous studies [20,21]. The low air chamber has a minimum working pressure of 50 kPa with an accuracy of ±50 Pa, a cylindrical quartz tube, an internal height of 1000 mm, and an internal diameter of 116 mm.…”

Section: Experimental Methodologymentioning

confidence: 99%

See 2 more Smart Citations

An Experimental Study on the Combustion Characteristics of a Methane Diffusion Flame within a Confined Space under Sub-Atmospheric Pressure

Zhang,

Du,

Zong

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

Gas-fired boilers, gas stoves, and wall-mounted gas boilers are the main consumers of gas fuel, but they generally encounter problems when operating at high altitudes, such as reduced thermal efficiency and increased pollutant emissions. Previous studies on gas combustion characteristics under sub-atmospheric pressure were mostly carried out in a large space, which is quite different from chamber combustion equipment. Therefore, it is insufficient to guide the design and operation optimization of plateau gas equipment. In this paper, experimentations were carried out to explore the characteristics of a methane diffusion flame under sub-atmospheric pressures. The mass flow rates of methane and air remain consistent under different pressure conditions. The centerline temperature (Tc) distribution, flame appearance, smoke point, CO emission, and NOx emission under different pressures (ranging from 61.66 to 97.75 kPa) were examined under both fuel rich and lean conditions. The results show that Tc at the rear and front of furnace variation with pressure is opposite under fuel-lean and -rich combustion. The Tc at the front of furnace decreases with decreasing pressure, whereas Tc at the rear of furnace increases with decreasing pressure. With decreasing pressure, flame length decreases under lean combustion, but increases under rich combustion. The smoke point fuel flow rate, flame length, and residence time increases with decreasing pressure, following the law of negative exponent. The CO emission decreases with decreasing pressure, which indicates that the reduced pressure makes methane combustion more complete. For NO emission, the reduced pressure results in an opposite tendency under fuel-lean and -rich combustion. With decreasing pressure, the NO emission decreases under fuel-lean combustion but increases under fuel-rich combustion.

show abstract