Study on Measurement System of Cement Cooler Clinker's Temperature Field
A system of measuring temperature field is introduced in this. It is CCD colorimetric method, which achieves non-intrusive measurement of temperature field. This article describes the principle and the structure of measuring system in detail, analyses selection principles of system parameters. Experiments are carried out, and measurement results show that this method can measure clinker temperature distribution, the system can meet the measurement requirement of cement cooler for clinker temperature field. Such doing provides credible assurance for automatic control of cement cooler
Simultaneous optical measurement of soot volume fraction and temperature in premixed flames
The performance of a three-wavelength optical probe technique for measuring soot volume fraction and temperature was assessed by conducting experiments in the homogeneous environment of a premixed flame. Using a premixed ethylene/air flame, the temperatures and soot volume fractions (fva, based on absorption measurements at 633 nm and fve, based on emission measurements at 900 nm and 1000 nm) were compared with previously reported results. Although the temperatures and mean soot volume fractions compared favorably, the discrepancy between fva and fve prompted new measurements to evaluate the importance of source wavelength on the fva measurements, scattering by soot particles, light absorption by “large” molecules and the use of different indices of refraction reported in the literature. The experiments on the degree of soot scattering and light absorption by “large” molecules indicated that these effects cannot reconcile the observed discrepancy in the soot volume fractions. The measured soot volume fractions were, however, sensitive to the absorption constant and therefore varied significantly when different sets of refractive indices were used. Furthermore, the agreement between fva and fve was improved when extinction measurements were performed with longer wavelength light sources. Isokinetic soot sampling experiments were also performed to compare with the optically-measured soot volume fractions. This technique does not rely on the refractive indices of soot and therefore provides an independent measure of the soot volume fraction. The soot volume fractions measured using this technique compared favorably with the optically measured values (calculated using various indices of refraction).
Transient scalar properties of strongly radiating jet flames
Abstract An experimental and a theorietical study of transient radiation properties of strongly radiating turbulent diffusion flames is described. Simultaneous transient measurements of temperatures and volume fractions of soot obtained using a three wavelength emission-absorption probe are reported. Soot volume fractions inferred from absorption measurements are significantly higher than those inferred from emission data suggesting the presence oflarge quantities of relatively cold soot within the flames. The results show effects of progressive radiative cooling with distance from the injector exit. Reasonably good predictions of monochromatic intensities were obtained using a new bivariate stochastic analysis.