Steam wetness measurement using CCD imaging methods in low-pressure turbine

The steam flow in low-pressure turbine contained abundant water droplets, which will decrease the work efficiency and pose potential threaten to operation safety, so measurement of steam wetness has brought great interest in electricity generation industry. In this paper, a new measuring method using CCD (Charge Coupled Device) imaging technique was proposed to determine the wetness in steam turbine based on the forward small angle light scattering theory. A simulated steam turbine facility was designed to generate the wet steam, and light scattering experiments were carried out at various working conditions in this device. The steam wetness parameters and droplet size distribution were obtained by means of numerical inversion of the light intensity distribution based on Mie scattering theory. The results demonstrate that the obtained data from the present analysis is in good agreement with the results of the theory analysis and previous study, and the proposed method is proved to be suitable for steam wetness measuring and monitoring by further development.