Development of Low-NOx DME Multi-Port Burner

Abstract

This study focuses on the fundamental characteristics of DME (Dimethyl Ether) combustion, aiming at the development of low-NOx multi-port burner suitable for the tube-nested combustor. In the tube-nested combustion, the water tubes are moved into the furnace closely to the burner to cool the burning flame directly in the field of burning reaction leading to NOx reduction. To prevent the unburned combustibles emission, the diffusion burner used in the tube-nested combustor needs a high performance of the fuel-air mixing. Multi-port burner consists of a fuel-port and surrounding multi-air-ports, which induce a strong re-circulation flow. Thus the fuel-air mixing is enhanced so that the thermal NOx and CO emissions are significantly reduced. The NOx emission of the DME from the co-axial diffusion burner was over 130ppm at 0% O₂. On the other hand, NOx emission of DME from the multi-port burner was reduced to 60ppm at 0% O₂. With the help of the tube-nested combustion, NOx emission of DME was further reduced to 20ppm at 0% O₂.