Phosphor thermometry for high temperature gas turbine applications
Phosphor thermometry for high temperature gas turbine applications
复制标题
用于高温燃气轮机应用的荧光测温
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
B. Su
中科院分区：
文献类型：
--
作者：
J. Feist;A. Heyes;Kwang;B. Su
本文介绍了应用热像荧光粉测量燃气轮机燃烧室表面温度和热流密度的研究进展和初步实验。当用紫外光(通常来自脉冲激光)照射时，这些材料显示出磷光，这是由于不同发射线的相对强度的变化或一旦激发停止后发生的指数发射衰减的时间常数的变化而与温度有关的。用一系列的荧光粉研究了这两种模式的灵敏度，包括：YAG：Tb，YAG：Dy和Y/sub2/O/sub3/：Eu。在这些材料中，已证明最适合在燃烧室中进行测量。它对300到1500 K的温度很敏感，在光谱的蓝绿色区域发光，那里的黑体辐射相对较弱，并表现出两种模式的敏感性。此外，还介绍了在金属衬底上涂覆荧光粉的几种技术，并对两种技术进行了实验研究。第一种是使用类似于热涂料中使用的化学粘结剂，第二种是由帝国理工学院材料系开发的一种新的低成本涂层技术，称为静电辅助燃烧化学气相沉积(EACVD)。后者允许在不需要化学粘结剂的情况下铺设薄层荧光粉，并严格控制涂层成分和厚度。为了演示这一技术，在尼姆金衬底上铺设了2/splµ/m厚的Y/sub2/O/sub3/：Eu层，并与使用替代化学粘结剂技术铺设的类似涂层的性能进行了比较。EACVD涂层已被证明比那些用化学粘结剂铺设的涂层更坚固，而涂层表现出类似的温度敏感性。
In the paper developments and some preliminary experiments concerning the application of thermographic phosphors for surface temperature and heat flux measurements in gas turbine combustion chambers are presented. When illuminated with UV light (typically from a pulsed laser) these material exhibits phosphorescence, which is temperature dependent by virtue of variations in the relative intensity of distinct emission lines or of variations in the time constant of the exponential emission decay which occurs once excitation has ceased. Both modes of sensitivity have been investigated with a range of phosphors including are YAG:Tb, YAG:Dy and Y/sub 2/O/sub 3/:Eu. Of these YAG:Dy has been shown to be best suited to measurements in combustion chambers. It is sensitive to temperatures in the range 300 to 1500 K, emits light in the blue green region of the spectrum where blackbody radiation is relatively weak and exhibits both modes of sensitivity. In addition a number of techniques for laying down phosphor coatings on metal substrates are reviewed and an experimental investigation of two techniques is presented Firstly, the use of chemical binders similar to those used in thermal paints and, secondly, a new cost effective coating technique referred to as Electrostatic assisted Combustion Chemical Vapour Deposition (EACVD) which has been developed in the Materials Department at Imperial College. The latter allows thin layers of phosphors to be laid down without the need for a chemical binder and with close control of coating composition and thickness. To demonstrate the technique a 2 /spl mu/m thick layer of Y/sub 2/O/sub 3/:Eu has been laid down on a nimonic substrate and a performance comparison made with a similar coating laid down using the alternative chemical binder technique. The EACVD coating has been shown to be more robust than those laid down with chemical binders whilst the coating shows similar temperature sensitivity.