【摘要】 高浓度水雾条件下的表面高温温场反演测量在航空航天、冶金铸造等工业领域有着重要的应用。由于水雾的弥散作用，高温表面的辐射透过水雾后，会出现强烈的衰减和散射，导致传统辐射测温方法出现很大误差。现有水雾弥散条件下的温场反演测量主要包括基于试验数据反推及实时测量水雾参数进行修正的测量方法，并基于辐射传输理论对测量结果进行误差分析和评估，测量方式多为单通道或双通道点辐射测温。基于水雾场红外光谱辐射特性的计算，提出了一种水雾强弥散条件下表面高温温场多光谱成像反演方法；根据辐射传输理论，考虑强弥散条件下的邻近效应，建立了相应的反演模型。在水雾场相关参数未知的情况下，通过三个透过水雾场后的高温目标长波红外光谱辐射图像，反演得到表面高温温场的真温分布。反演第一步是辐射温度场反演，即通过长波红外辐射图像，根据定标曲线和高温目标的光谱发射率先验数据，得到高温目标透过弥散水雾场经过发射率校正的辐射温度场；反演的第二步是根据三通道非线性反演模型，得到目标的真温温场分布。设计了一个长波红外三光谱通道反演测量装置，中心波长分别是8.8, 10.7和12.0μm,对高温目标进行三个长波红外光谱通道的同时探测成像。设计了一套验证测试装置，利用标准高温黑体源和水雾弥散设备，进行了高温目标水雾弥散条件下的辐射图像采集和目标温度的反演试验。试验结果表明8～14μm长波红外波段比短波波段对水雾弥散具有更强的抗干扰能力，在1 100和1 200℃典型温度点反演的平均误差在7%左右，大大减小了未经校正的辐射传输失真，适用于黑体和灰体高温目标，且无需水雾场的浓度和粒径分布等先验信息，基于多光谱成像信息的水雾弥散条件下温场反演方法具有一定的普适性和创新性。更多还原

【Abstract】 The surface temperature retrieval of high-temperature objects shielded by strong diffusive mist plays a critical role in aerospace, metallurgical and many other industries. Traditional radiation temperature measurements under extreme conditions usually cause substantial errors because of the strong extinction and scattering by mist during light propagation. The current infrared temperature retrieval methods often use single-channel or double-channel non-imaging temperature measurement strategies. In such methods, the temperature is corrected using either pre-measured or real-time mist parameters, and the results are analyzed and evaluated according to radiative transfer theory. Based on the calculated spectral radiation characteristics of mist, this paper proposed an infrared imaging temperature measurement method. A temperature retrieval model is also built based on radiative transfer theory while the adjacent effect is considered. The exact surface temperature distribution can be retrieved while the parameters of the diffusive mist medium remain unknown. During a typical temperature retrieval process, the radiative temperature distribution is firstly calculated according to the infrared images in three different channels calibrated by the pre-acquired calibration and emissivity data. Then the exact temperature is retrieved according to this non-linear temperature retrieval model. A three-channel infrared temperature retrieval system is designed, with its three channels centered at 8.8, 10.7, and 12.0 μm, respectively. Three identical long-wave infrared focal plane detector is applied, which can simultaneously photograph the high-temperature object. Besides, an experimental verification device is assembled to test the performance of the three-channel infrared system based on a high-temperature blackbody and a home-made mist generator. The results prove that long-wave infrared shows a higher interference resistance capacity than mid-wave infrared. This three-channel device and the temperature retrieval model reduce the image distortion caused by mist and show an average temperature retrieval error of ca. 7% at 1 000, 1 100, and 1 200 ℃ conditions. This method is suitable for both high-temperature blackbody and graybody, while the pre-acquisition of the mist parameters is not required. The temperature retrieval method based on multi-spectral infrared imaging proposed in this article shows universal applicability and considerable innovativeness.更多还原