Papers by Author: Yong Yan Zhou

Abstract: The decomposition of sulfur hexafluoride (SF6) in overheated electric equipment at different temperature in high humidity was simulated in the study. SF6 is very stable and not significantly decomposed at 200 °C, 250 °C and 300 °C. SF6 is significantly decomposed at 350 °C. SF6 is more easily to be decomposed and decomposed more rapidly at higher temperature. The concentrations of SF6 byproducts are much higher at higher temperature. SF6 will be decomposed to format HF. The concentration of HF will decrease when its concentration increases up to a certain concentration. It may be because that HF was strongly corrosive and its corrosion to inner equipment made the concentration of HF decreasing.

Abstract: A large number of high-speed soot particles would be produced after fossil fuels' (oil or coal) combustion in the boiler. These high-speed particles not only directly attack the heating surface of boiler tubes (damaging the tubes mechanically), but also condensate on the wall, causing even more serious chemical corrosion. The discussion has deeply studied the occurrence sites, reaction mechanism, influence factors as well as identification and prevention methods of oil-ash corrosion, coal-ash corrosion, so it would have a positive guiding significance for reducing (or preventing) the flue-gas side corrosion.

Abstract: Several different kinds of flue-gas side abrasions occurred in thermal power plant were discussed. And the occurring positions, characteristics, influence factors as well as identification and prevention methods were also introduced in detail. So some advice may serve a reference for efficiently identificating and preventing boiler failure caused by flue-gas side abrasion.

Abstract: According to the characteristics of silicon in water, analysis is implemented for the excess SiO₂ content in a 300MW unit boiler water. Serious excess SiO₂ content in the economizer inlet water and boiler water is caused by high-pressure heater leakage. In addition, SiO₂ content increases with the raising feedwater temperature, because colloidal silicon solubility increases with the raising feedwater temperature. Colloidal silicon in water is induced by condenser tiny leakage. High-pressure heater plugging must be handled. Improving activated charcoal filters washing and boiler blow-off frequency can be used to reduce the impact of colloidal silicon on boiler and ensure safe operation of the boiler

Abstract: This study aims at analyzing the chemical resistance of a wide range additives in air curing fluorocarbon coatings. Scanning Electron Microscope (SEM) and Immersion tests are used to detect coatings performances. The results showed that the surface state of coating does not affect the chemical resistance. While fumed SiO₂ content in the coating is lower than 5.2%, chemical resistance are enhanced as the increasing of fumed SiO₂ content, then maintained stability as content is more than 5.2%. Chemical resistance is increased gradually while the rutile TiO₂ content of coating is less than 3.1%, and essentially unchanged while greater than 3.1%. As wax powder content increases, chemical resistance of coating decreased. Coupling agent content increases, leading to enhanced chemical resistance of the coating when coupling agent content is less than 5.8% and maintained stable while greater than 5.8%. So fumed SiO₂, rutile TiO₂, and coupling agent would inhance chemical resistance for coating to a certain extent, and wax powder would weaken the chemical resistance.