Application of Noncircular Primary-Air Inlet Geometries in the Inshot Burners of Residential Gas Furnaces

摘要

Experiments with an inshot burner used in residential natural gas furnaces are presented. The concentrations of NO_x, NO, and CO in the combustion products of partially aerated natural gas flames were measured in a laboratory combustion chamber. When the conventional circular venturi inlet of the inshot burner was replaced by elliptic venturi inlets, an increase of up to 30 percent in the primary-air entrainment and a decrease of up to 20 percent in the NO_x emission index were observed. Temperature field measurements in the flames were in conformity with the emission index measurements.