Natural gas burners for domestic and industrial appliances

Abstract

This contribution presents some examples of the application of the particle image velocimetry (PIV) technique to domestic appliances and small-scale burners, with the aim of discussing relevant results together with problems encountered. Combustion efficiency and pollutant emissions of gas burners are strongly influenced by the fluid dynamics of the mixture in both premixed and nonpremixed flames. For these reasons the Combustion Laboratory of Politecnico di Milano started using laser diagnostic techniques (LDV and PIV) many years ago. The first PIV application was on a premixed V-flame attached over a burner plate with rectangular twin slots, developed for domestic appliances. The autocorrelation of a double-exposed photograph was used to define the 2-D velocity flow field and high spatial resolution was obtained with a 1 : 1 magnification and a zoom Nikkor objective. More recently, a crosscorrelation CCD camera with a double-pulse Nd:YAG laser was used to characterize high-swirl flows under both nonreacting and reacting conditions. In the following, special emphasis will be given to the discussion of the most relevant results and the main problems encountered with PIV applications to the investigated cases. © 2008 Springer-Verlag Berlin/Heidelberg.