Analysis of Recirculation Zone and Ignition Position of Non-Premixed Bluff-Body for Biogas MILD Combustion

Abstract

Combustion ignition study is important due to the combustion process becoming more lean and efficient. This paper studied the recirculation zone and ignition location for the bluff-body non-premixed MILD burner with biogas used as fuel. The location of the ignition was critical to ensure that the spark energy supply during the ignition process can successfully ignite the mixture of air and fuel. The numerical calculations were done using the commercial code ANSYS-Fluent to simulate the furnace with a bluffbody burner to determine the recirculation zone. The turbulence model used was the realizable k-ε model. The inner recirculation zone between the air and fuel nozzle is the best location for the ignition point, since the low velocity of air and fuel mixing will assist the ignition process. This is because the ignition energy will have time to ignite the mixture in the low speed turbulent swirl flow. The most suitable location with the highest possibility of ignition is the center of the recirculation zone.

Design and Development of MILD Combustion Burner

“…Moreover, computational simulation frequently provides information on physical quantities that are difficult to measure. CFD is increasingly being used for the optimization of gas burners (Scharler & Obernberger, 2000) and industrial gas furnaces (Dally, Riesmeier, & Peters, 2004;Noor et al, 2013a;Riahi, Mergheni, Sautet, & Nasrallah, 2012) or coal combustion (Calchetti, Nardo, Mongibello, & Mongiello, 2007). In this study, the CFD was used to model MILD combustion in the mode of non-premixed combustion.…”

“…Nakamura, Smart, and Van de Kamp (1993) and (Weber, Orsino, Lallemant, & Verlann, 2000;Weber, Smart, & Kamp, 2005) experimentally studied pilot-scale furnaces equipped with heat exchangers and demonstrated that heat transfer was affected by the port locations and angles. After finalizing the pre-design, the simulation was done on the final model (Figure 2) for the ignition location study (Noor et al, 2013a), air fuel ratio study (Noor et al, 2012b) and other parametric studies (Noor et al, 2012c) on the MILD combustion using biogas as a fuel. Different combinations of air and fuel compositions injected into the chamber gave different results.…”

“…Due to the energy needs and pollution emissions, combustion researchers are focusing on the improvement of the combustion efficiency, new combustion technology and combustion modeling (Merci, Naud, & Roekaerts, 2007;Noor, Wandel, & Yusaf, 2012a;Smith & Fox, 2007). MILD combustion is a new combustion technology that produces lower pollution emissions and increases thermal efficiency (Cavaliere & de Joannon, 2004;Dally, Karpetis, & Barlow, 2002;Noor, Wandel, & Yusaf, 2013a). This combustion is also called flameless oxidation or FLOX (Mancini, Schwoppe, Weber, & Orsino, 2007;Wünning, 1991), low NOx (Orsino, Weber, & Bollettini, 2001) and high-temperature air combustion (HiTAC) (Katsuki & Hasegawa, 1998;Tsuji, Gupta, & Hasegawa, 2003).…”

Single-zone zero-dimensional model study for diesel-fuelled homogeneous charge compression ignition (HCCI) engines using Cantera

“…Homogeneous charge compression ignition (HCCI) engines have received increasing attention recently because of their advantages in reducing emissions levels, such as NOx [1][2][3][4][5][6]. An attempt by regulatory bodies, such as those in Europe, the United States (US) and Japan, to reduce emissions levels from conventional engines [7][8][9] has made the HCCI engines a viable alternative for low emissions engines.…”

Effect of Air-Fuel Ratio on Temperature Distribution and Pollutants for Biogas Mild Combustion

“…A new combustion process is able to contribute to the increase of combustion thermal efficiency and reduce of the emissions. MILD combustion produces higher thermal efficiency due to re-cycling of Exhaust Gas by using exhaust gas recirculation (EGR) [7,[9][10][11][12]. Others call it flameless oxidation (FLOX) [13,14], High-Temperature Air Combustion (HiTAC) [15,16] and Colourless Distributed Combustion (CDC) [17,18].…”