Abstract
Quenching experiments using a slot burner and surface analysis were conducted to analyze the effects of two materials (ZrO2 and 13.5 wt%Y2O3-doped ZrO2 (13.5YSZ)) deposited on stainless steel 304 (STS304) substrate on the flame stability of premixed methane/air mixtures of varying equivalence ratio and flow velocity at a wall temperature range of 373 K to 773 K. Results showed that these two types of coatings are beneficial for decreasing the quenching distance and extending the flame stability limit. Moreover, doping 13.5 wt%Y2O3 into ZrO2 coating was more conducive to reduce quenching data and broaden lower flammability limits in the fuel-lean side. Surface analyses reflected that the superior mobility of lattice oxygen for 13.5YSZ coating plays a crucial role in improving the quenching characteristics due to the formation of extrinsic active oxygen vacancies. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) verified that the methane oxidation process can be accelerated over the two coating surfaces due to the high catalytic performance. Finally, one migration route of oxygen ions consisting of the dynamic oxygen diffusion and replenishment pathways was proposed to discuss the underlying mechanism of flame stability improvement when using yttrium-stabilized zirconia composite coatings in a narrow channel.
Published Version
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 call