后向散射法测量蒸汽参数的CCD相机接收角优化

为了揭示汽轮机内湿蒸汽的具体参数和实现汽轮机湿蒸汽参数的有效测量,对基于后向散射法及联合CCD相机成像的湿蒸汽参数测量模型,提出了新的CCD相机接收角度,分析了不同散射角度对散射比的影响。结果表明,当散射光接收角度为后向7°时,可获取到最佳的散射比,此时信噪比最强,为最合适的接收角度。通过对后向7°角的散射光强在不同尺度分布参数K、水滴群的质量中间半径r-0.5、水滴数密度N下所呈现的变化规律进行分析验证,结果表明后向7°角的散射光强变化趋势与理论变化相吻合,从而为后向散射法测量湿蒸汽参数的研究提供依据。

Optimization of CCD camera receiving-angle for backscatter measurement of steam humidity

In order to reveal the specific parameters and achieve the effective measurement of the wet steam parameters in steam turbines,a new receiving-angle of CCD camera is put forward for the measurement model of wet steam parameters based on the backscatter method and CCD camera imaging.The influence of different scattering angles on the scattering ratio is analyzed.The results show that the optimal scattering ratio and the maximum SNR can be obtained when the receiving-angle of scattered light is backward 7°,which means a most suitable receiving-angle.By analyzing and verifying the change law of the scattered light intensity at the backward angle of 7° along with different scale distribution parameters K,mass intermediate radius r-0.5 of water droplets group and number density N of water droplets,the trend of the scattered light intensity at the backward angle of 7° is consistent with the theoretical change trend,which may provide a basis for study on wet steam parameters measured by backscatter method.