TEMPERATURE MEASUREMENT IN A LPG LAMINAR JET FLAME USING A TWO-THERMOCOUPLES TECHNIQUE FOR RADIATION CORRECTION

Rafael Salvagni¹; Rafael Polacinski Wolanin¹; Felipe Roman Centeno¹

¹ UNISINOS

doi:10.20906/CPS/COB-2015-2436

Resumo

This project presents the experimental analysis of the temperature of a laminar diffusive GLP flame in a burner, using thermocouples in a lab simulation. The analysis is based in the method of adjustment and comparison of the temperatures in the flame using two thermocouples with distinct sizes, but with the same material, to demonstrate the greatest precision of its measurements in comparison with other methods. It was possible to determine the actual value of the flame temperature Tg by calculating the correction factor given by the RRE. The RRE parameter varied from its value between 2,0 and 3,4. This implies a correction in the temperature read by the instruments, since the correction for radiation losses makes the temperature to be corrected is always more than the temperatures read individually by each thermocouple in the flame. Analysis with a flame 38 mm high, and with a volumetric flow rate of the order of 1,67 m³ x 10-5 s-1, and used thermocouples with diameters of 1,4 and 2,6 mm were made, thus giving a size ratio of approximately 1,86. Moreover, the practical results of the analysis as well as the benefits of using that technique are presented. This way will be demonstrated maximum measurement accuracy and the deviation of the measured values. With the calculation of measurement uncertainties was found that the values of the errors generated by the instruments in the measurement process may represent variations in the house of 17%, considering a reliance interval of 95%.

Palavras-chave: laminar diffusive flame; temperature; thermocouple; measurement