Ultra-low-emission steam boiler constituted of reciprocal flow porous burner

• Published in: Experimental thermal and fluid science Vol. 35; no. 3; pp. 570 - 580
• Main Authors: Barcellos, William M., Souza, Luis Carlos E.O., Saveliev, Alexei V., Kennedy, Lawrence A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2011; Elsevier
• Subjects: Air pollution caused by fuel industries; Applied sciences; Boilers; Carbon monoxide; Combustion; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Equivalence ratio; Exact sciences and technology; Extraction; Filtration; Filtration combustion; Heat exchangers; Metering. Control; Methane; Reciprocal flow burner; Ultra-low NO x and CO emissions; Reciprocal flow burner; Filtration combustion; Ultra-low NO x and CO emissions; and CO emissions; Ultra-low NO
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2010.11.005

This experimental study examined a low-emission steam boiler in which the filtration combustion technology was employed. This new boiler concept is consisted of a reciprocal flow porous burner, in which a combustion wave propagates along the reactor length. The boiler’s burner is filled up by an inert porous material, which leads to a stable burning of ultra-lean fuel/air mixtures, operating below flammability limits of conventional burners. In reciprocal filtration combustion, the reaction zone travels back and forth along the length of the burner, maintaining a typical trapezoidal temperature distribution favorable to the energy extraction. Embedding heat exchangers into the ends of the porous bed results in an alternative low-emission high-efficiency boiler. The heat re-circulation inside the porous matrix and the low degree of thermal non-equilibrium between the gas and the solid phases result in ultra-low levels of CO and NO x . Over an equivalence ratio range from 0.20 to 1.0 and a gas flow velocity range from 0.2 to 0.6 m/s, burning the technical methane, the developed prototype has reached efficiencies superior to 90% and NO x and CO emission levels lower than 1.0 and 0.5 ppm, respectively.