Investigation effects of different calorific values and operating conditions on biogas flame: a CFD study

ABSTRACT

This study investigates different biogas fuels’ and operating conditions’ effects on flame temperatures and emissions (CO, CO₂, NOx, and soot). Different calorific values (15.580, 17.880, 20.430, 23.080, and 26.230 MJ/kg) were obtained by changing methane content. Furthermore, various gas pressure (0.5, 1, 2, and 3 atm), excess air coefficient (1.4, 1.8, 2.5, and 4), and oxygen values (21, 23, 25, and 27%) were simulated for 8.6 kW thermal capacity furnace. Increasing the calorific value of biogas fuels, CO, NO_x, and soot emissions and flame length tend to increase, while CO₂ decreases. Increasing gas pressure, flame temperature, and CO₂, CO, and NO_x decrease, while soot emissions tend to increase. As a result of the decrease in the air excess coefficient from 4.0 to 1.4, there is a increase in the flame temperature, flame length, and soot, CO, CO₂, and NO_x emissions. On the other hand, oxygen content from 21% to 27% oppositely affected these parameters, excluding flame length.

KEYWORDS:

• Oxygen-enrichment
• excess air
• soot
• biogas flame
• calorific value

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author is grateful for using the computing resources provided by the National Center for High-Performance Computing of Turkey (UHEM, UYBHM) under grant number [1010322021].

Notes on contributors

Mehmet Salih Cellek

Mehmet Salih Cellek joined the Institute for Automotive Engineering Department at University of Alabama. He received his BE (2010) and MSc (2013) from Sakarya University and PhD (2017) from Yildiz Technical University. His doctoral research was on the investigation of combustion emissions in industrial burner-boiler systems. He has interest in combustion, alternative fuels, and combustion modelling using CFD.

Usame Demir

Usame Demir joined the Mechanical Engineering Department at Bilecik Şeyh Edebali University. He received his BE (2010), MSc (2013) and PhD (2017) from Sakarya University. His doctoral research was in Electromechanic variable valve timing for internal combustion engine modelling usingcomputational fluid dynamics (CFD). He has interest in the following research areas are internal combustion engines, HCCI engine, alternative fuels, combustion modelling using SRM and CFD simulation tools.

Gokhan Coskun

Gokhan Coskun is associate professor in the Department of Mechanical Engineering at Sakarya University. He received his BEng (2008), MSc (2010) and PhD (2014) from Sakarya University. He was a visitor researcher in the Internal Combustion Engine Division, Lund University, Sweden. He is working on combustion simulations, fuels and combustion studies in transport.