Application of fast inversion algorithm in measurement of steam humidity of steam turbine
-
摘要: 为了解决汽轮机通流部分蒸汽湿度的在线测量问题，提出了一种基于散射相函数的半经验公式快速反演散射光强分布的计算方法。该算法采用MATLAB自带的cftool进行相函数的双高斯拟合，拟合误差低，且拟合函数可以快速得到Mie散射理论的近似解析解，即从散射光强分布到水滴质量中间半径的快速反演。结果表明，在约束水滴粒径范围内，得到了颗粒大小与散射比之间的半经验模型，对比实验测得散射比，吻合良好，且由半经验模型反演得到水滴质量中间半径为1.1μm。在一定条件下，可以有效解决蒸汽湿度的在线测量问题。Abstract: In order to solve the problem confronted with the online steam humidity measurement of turbine flow pass, a semi-empirical formula of phase function computing method was proposed to improve the inversion algorithm on scattering light distribution. Phase function of double Gaussian fitting by using MATLAB with cftool was adopted in this algorithm. The fitting result shows that the relative error is in small, and the approximate analytic solution of the Mie scattering theory could be got by the fitting function, which means that a rapid inversion from the scattering light intensity distribution to water quality radius. According to the results, with the restriction of the range of the droplet size, the approximation of the theory between the droplet size and scattering ratio was got. Contrast experiment showed the measured scattering ratio was similar with the simulated scattering ratio. Based on the semi-empirical model, the water quality of middle radius was 1.1μm.The fast inversion algorithm can well resolve the online measurement of steam humidity.
-
Keywords:
- scattering /
- water quality middle radius /
- double Gaussian fitting /
- turbine
-
-
[1] KADONO T, ARAKAWA M, KOUCHIC A.Size distributions of chondrules and dispersed droplets caused by liquid breakup:An application to shock wave conditions in the solar nebula [J].Icarus, 2008,197(2):621-626.
[2] SIGEL R.Light scattering near and from interfaces using evanescent wave and ellipsometric light scattering[J].Colloid & Interface Science, 2009,14(6):426-437.
[3] GOGOI A, BURAGOHAIN A K, CHOUDHURY A, et al. Laboratory measurements of light scattering by tropical fresh water diatoms[J].Journal of Quantitative Spectroscopy & Radiative Transfer, 2009,110(14/16):1566-1578.
[4] SHCHERBAKOV A A, TISHCHENKO A V. Light scattering in plane dielectric layers: modeling in the 2-D reciprocal space[J].Journal of Quantitative Spectroscopy & Radiative Transfer,2012,113(18):2424-2430.
[5] WU W, QIN Sh Q, HUANG Zh Q.A fast inversion method for water droplet size determination in scattering light measurement[J].Journal of Optics, 2011,31(7):1-5(in Chinese).
[6] HUANG Zh Q, YANG J M, SUN Ch Sh. Application of the laser scattering theory for monitoring steam wetness and droplet size in steam turbines[J].Journal of Power Engineering,2006,26(2):241-244(in Chinese).
[7] CAI W W, ZHAO Y,MA L. Direct recursion of the ratio of Bessel functions with applications to Mie scattering calculations[J].Journal of Quantitative Spectroscopy & Radiative Transfer,2008,109(16):2673-2678.
[8] HUANG Zh Q,QIN Sh Q. Investigation of exhaust wetness measurement method in steam turbine based on mie scattering of laser[D].Changsha: Graduate School of National University of Defense Technology,2010:1-118(in Chinese).
[9] ZHANG H Y, ZHAO W J, REN D M, et al. Improved algorithm of Mie scattering parameter based on MATLAB[J].Journal of Light Scattering,2008,20(2):102-110(in Chinese).
[10] GODDEERIS C, CUPPO F, REYNAERS H, et al. Light scattering measurements on microemulsions:estimation of droplet sizes[J].International Journal of Pharmaceutics, 2006,312(1/2):187-195.
[11] HUANG Zh Q, CAO X L, YANG J M, et al. Application of CCD in measuring steam moisture and droplet size [J].Opto-Electronic Engineering, 2010, 37(4):39-43(in Chinese).
计量
- 文章访问数: 2
- HTML全文浏览量: 0
- PDF下载量: 7
下载: