燃气轮机内部冷却瞬态液晶技术的误差分析  

Uncertainties of the Transient Thermochromic Liquid Crystal Method in Gas Turbine Internal Cooling Measurements

作　　者：阚瑞[1] 任静[1] 蒋洪德[1] 

机构地区：[1]清华大学,北京100084

出　　处：《工程热物理学报》2013年第8期1444-1448,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51076076)

摘　　要：瞬态液晶技术广泛应用于燃气轮机内部冷却的表面传热系数测量,获得其误差特性十分重要。本文针对典型的90°肋片内部冷却通道,采用单一液晶和混合液晶,对热敏液晶测温和瞬态液晶技术的测传热系数的误差进行了理论分析和实验研究。结果表明,采用色调标定曲线时液晶测温的误差最小,不超过0.2℃;混合液晶的温度-颜色特性与混合前的单一窄带液晶不同,因此必须对混合液晶进行独立的标定;瞬态液晶测量表面传热系数误差的理论分析和实验结果趋势一致,该误差在13%左右,且选取较高的主流参考温度可以减小误差。The transient measurements using thermochromic liquid crystal （TLC） have been widely used to obtain the distribution of heat transfer coefficients inside gas turbine internal cooling channels. Understanding the error of this experimental method is important. In the current study, a square channel with 90 degree ribs, which is one of the typical internal cooling channels, was investigated. Single narrow band liquid crystal and a mixture of two liquid crystals were used to analyze the error of liquid crystal itself and the uncertainties of the transient method. Results showed that the error of temperature measurements is the smallest（less than 0.2~C） when using the hue of liquid crystal for the calibration curve. A specific calibration is needed for the mixed liquid crystal, as its calibration curve is not the same as that before the mixing process. Both the theoretical analysis and the experimental study showed that the uncertainty of heat coefficients from the transient liquid crystal method is around 13%. Using a higher mainstream reference temperature can reduce this error.

关 键 词：燃气轮机内部冷却 热敏液晶 主流参考温度 测量误差 

分 类 号：TK474.7[动力工程及工程热物理—动力机械及工程]