Abstract
Lean premixed low swirl combustion is an effective way to control NOx emission. In the present work a low swirl burner fitting with vane swirler has been used to investigate the flowfield characteristics. Two swirlers (65° and 40° setting angle) have been adopted for velocity measurement by using PIV technique. The results show that the critical swirl number when recirculation zone appears scarcely changed with the swirler setting angle and central jet velocity, and the demarcation between high and low swirl flow can be set as 0.48 in this work. Compared to swirler II, a wider low speed zone and a more divergent flow emerge downstream swirler I. Dimensionless axial velocity profiles along central axis decline linearly and approximately come to zero at x/D=1.37 for swirler II and x/D=1.56 for swirler I. For two-dimensional turbulent kinetic energy profiles, two peaks downstream of the swirl mean higher burning velocity than central jet. And turbulent kinetic energy downstream swirler II is observed higher.
Highlights
Swirl provides an effective means to control flame stability as well as combustion intensity
The results show that the critical swirl number when recirculation zone appears scarcely changed with the swirler setting angle and central jet velocity, and the demarcation between high and low swirl flow can be set as 0.48 in this work
According to a steady central recirculation zone in the flowfield, swirl flow can be divided into high swirl flow and low swirl flow
Summary
Swirl provides an effective means to control flame stability as well as combustion intensity. Several effective methods (e.g., fuel staging, autofeedback loop, exhaust gas clean up, catalytic assisted combustion) have been adopted to control NOx emission. These schemes need accurate control combustion process that lead to high expense K., et al, 1992) firstly used a tangential air jet swirler to produce low swirl in methane premixed combustion. They found that recirculation zone doesn’t exist in the flow field and flame is stabilized by flow divergence. To the authors’ knowledge no investigation currently exists that provides quantitative date at various swirler setting angles in the near-field region of a low swirl burner. The demarcation between high and low swirl is discussed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
