Influence of Dielectric Deposition on the Steam Wetness Measurement

Abstract:

When steam wetness measuring, water film and salt will deposite on the resonant cavitys inner surface. The effect of the deposited dielectric on the resonant frequency is analyzed, and its influence on the steam wetness measurement is analyzed. Results show that the effect on measurement is less with thinner film, but greater with thicker film. The influence of wet steam pressure (temperature) on resonant frequency is small with the same water film thickness, the impact of the water film on measurement decreased slightly with the increase of wet steam pressure (temperature). The effect of deposited water film on measurement is greater than deposited salt. In case the turbines exhaust wetness measurement, the thickness of water film deposited on the resonators inner surface less than 35μm, and the deviation of wetness measurement no more than 1.262%.

• Periodical: Applied Mechanics and Materials (Volume 339)
• Pages: 503-509
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.339.503
• Online since: July 2013
• Authors: Jiang Bo Qian, Heng Fan Li, Zhong He Han, Wei Ming Wu, Di Yuan
• Keywords: Deposited Salt, Resonant Cavity, Water Film, Wetness Measurement

References

[1] M.J. Moore, C. Sieverding. Two-phase steam flow in turbines and separators: theory, instrumentation, engineering. Hemisphere Publishing Corp, Washington, DC, 1976.

[2] M.J. Moore, C. Sieverding, Aerothermodynamics of low pressure steam turbines and condensers. Hemisphere Publishing, New York, 1986.

[3] E. Perrell, W. Erickson, G. Candler. Numerical simulation of nonequilibrium condensation in a hypersonic wind tunnel. Journal of thermophysics and heat transfer, 10 (1996) 277-283.

DOI: 10.2514/3.784

[4] Z. Di. The study on liquid-droplet motion, droplet solid impaction and liquid-corrosion fatigue of wet steam turbine-blades. Xi'an Jiaotong University, Xi'an, 2001.

[5] Y. Maozheng, H. Yue. Deposition of water law and dewetting method in end class divisions of turbine. Turbine Technology, 27 (1988) 44-46.

[6] C. Yinian. Steam turbine. Xi'an JIaotong University Press, Xi'an, 1988.

[7] H. Zhonghe, Y. Kun. Reviews on wetness measurement methods of wet steam in turbine. Journal of North China Electric Power University, 29 (2002) 44-47.

[8] C. Xiaoshu, N. Fengxian, N. Yanbao, e. al. Measurement of Wet Steam in a 300MW Direct Air-cooling Low Pressure Turbine. Proceedings of the CSEE, 29 (2009) 1-7.

[9] H. Zhonghe, Z. Shue, T. Songfeng. Study on a method of wetness measurement based on resonant cavity perturbation for steam turbine exhaust. Proceedings of the CSEE, 23 (2003) 199-202.

[10] C. Zhenguo. Microwave technology base and Application. Beijing University of Posts and Telecommunications Press, Beijing, 1996.

[11] H. Zhonghe, Q. Jiangbo, Y. kun, L. Yachuan, S. Li. Key Problems of Steam Turbine Exhaust Wetness Measurements by the Resonant Cavity Perturbation Method. Power Engineering, 25 (2005) 387-391.

[12] Q. Jiangbo, H. Zhonghe. Theoretical Analysis of Cavity Perturbation Techniques for Measuring Wet Steam Tow-phase Flow. Proceedings of the CSEE, 32 (2012) 79-85.

[13] Q. Jiangbo, H. Zhonghe, Z. Meifeng. Study on Dielectric Properties of Wet Steam in Turbine. Proceedings of the CSEE, 31 (2011) 100-106.

[14] I. Kirillov, R. Yablonik. The flow of wet steam in a turbine. Proc. Instn mech. Engrs, 68 (1967) 61.