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A collection of slides from the author's conference presentation is given. The presentation introduces the infrared-optical characterization of thermal barrier coatings and the development of LWIR pyrometer for measuring temperature in an operating gas turbine. The test facility for evaluating the LWIR pyrometer is also presented. This presentation includes the experimental setup for LWIR calibration and measurement.
The intercomparison of radiation temperature scales between PTB and NMIJ was carried out in September 2001. PTB sent their radiation thermometer LP3 to Japan and NMIJ made the comparison between the LP3 and NMIJ’s Topcon radiation thermometers with a comparison blackbody from 1000 C to 2500 C. Both scales agreed within±0.8 C in the whole range.
Mittels der planaren laserinduzierten Fluoreszenz (PLIF) können im Brennraum eines Transparentmotors Messungen durchgeführt werden, die den Gemischbildungsprozess beim Wasserstoffmotor zweidimensional qualitativ darstellen. Auch quantitative Messungen und damit Aussagen über das Kraftstoff-Luft-Verhältnis im Brennraum sind möglich. Für diese Messungen wird ein Gasgemisch ans Helium und einer Tracersubstanz verwendet, und der Motor wird geschleppt. Bei Betrieb des Motors in der Teillast sind auch Messungen im gefeuerten Betrieb, d.h. mit Wasserstoff und zugesetzter Tracersubstanz, möglich. Durch direkte Messung des Kraftstoff-Luft-Verhältnisses und der Wasserstoffkonzentration am befeuerten Aggregat mit Hilfe der Raman-Spektroskopie konnte nachgewiesen werden, daß mittels PLIF der Einströmvorgang qualitativ und das Kraftstoff-Luft-Verhältnis quantitativ grundsätzlich richtig erfaßt werden. Qualitative und quantitative PLIF-Messungen sind prinzipiell nicht nur bei Wasserstoffmotoren, sondern auch bei Gasmotoren mit anderen Brenngasen denkbar. Allerdings sind noch weitere Arbeiten erforderlich, um den Quantifizierungsfehler deutlich abzusenken. Zukünftiges Verbesserungspotential für diese Meßtechnik besteht in verschiedenen Punkten. Dazu gehört die Optimierung und Anpassung der Mischstrecke zur Erzeugung des Gas-Luft-Gemisches mit definiertem Kraftstoff-Luft-Verhältnis an die jeweiligen Meßaufgaben, um den relativen Fehler des Lambda-Wertes noch weiter zu reduzieren. Eine Verringerung der Tracerkonzentration erscheint problemlos möglich. Um das Problem der Hintergrundfluoreszenz zu lösen, sind verschiedene Möglichkeiten denkbar, die noch genauer zu untersuchen sind.
Planar laser-induced fluorescence (PLIF) has been successfully used for the investigation of the mixture formation process in hydrogen engines for passenger cars. Detailed information has been obtained about process development (qualitative measurement) and on fuel/air-ratio (quantitative measurement) inside the combustion chamber. These results can be used for further optimization of mixture formation and combustion process concerning emissions and fuel consumption. The measurement technique used is not only limited to hydrogen or to passenger car engines, but can also be applied to other fuel gases like natural gas or to other engine sizes like bus engines. The main topic of this paper is the experimental verification of the procedure which was executed by simultaneous PLIF and Raman scattering measurements. By Raman scattering the fuel/air-ratio can directly be determined from direct concentration measurements of the different gas species. The fuel/air-ratios determined by PLIF and Raman measurements are in good agreement indicating that a quantitative fuel/air-ratio measurement during the mixture formation process of gas and hydrogen engines is possible by PLIF. This fact is also confirmed by other measurements, e.g., global fuel/air-ratio calculated from measured intake air and fuel gas flow.
The temperature of high voltage equipment is often the limiting factor when transmitting electrical energy because the electrical insulation can get severely aged when the temperature is exceeding a certain limit. Hence, cooling has to be improved or heat generation must be reduced to avoid damage of the insulation. In this paper a new method was examined by investigating electrically insulating phase change materials which are able to store latent heat during a phase change from the solid to liquid state in times of high energy demand. To verify the electrically insulating properties of paraffins, one class of phase change materials, a special test cell was designed allowing the determination of breakdown voltage of phase change materials. The measurements on one paraffin sample proved the promising electrical insulating properties and it was shown that the breakdown voltage in the liquid state is comparable …