COMPARACIóN DEL MUESTREO DE ESPECIES QUíMICAS EN ZONAS REACTIVAS MEDIANTE EL USO DE SONDA CON Y SIN CUELLO SóNICO

the analysis of combustion products inside flames reaction zones and combustion chambers requires special equipment and methods of sampling compared to measurements made in chimneys. for example, non-intrusive experimental devices, such as laser techniques, or intrusive ones, such as sampling probes, should be used in zones where a flame is present. the use of the first ones means high costs, while the second ones must guarantee that the combustion reactions do not continue inside the sample probe; otherwise significant errors occur in the species measurements. to identify whether there are thermal and chemical kinetic effects that produce differences in the major species measurement, this paper presents a comparison of sampling results inside the reaction zone of a partially premixed flame when two types of sample probes are used: one with a sonic neck and a convective cooling of the sample, and another made just of a straight stainless steel tube. the results show that when using a straight tube there are errors in co2 and co measurements up to 7.0%, and errors in o2 measurements above 14%.