| The wind power in China is developing rapidly,but it is abandoned due to the instability of wind power and the insufficient capacity of the power grid,resulting in a waste of resources.However,thermal power units in the three north regions in winter use heat to set power,which further reduces the proportion of wind power connected to the grid.High voltage electrode boiler in thermal power plant can combine thermoelectric decoupling of thermal power plant with new energy consumption and effectively alleviate this contradiction.As a large capacity electric heating energy conversion equipment,high voltage electrode boiler has attracted extensive attention in recent years due to its advantages such as fast start and stop speed,high production efficiency,small installation space and green environmental protection.As the core component of electrode boiler system,high voltage electrode material and its corresponding heat production performance are the focus of research at home and abroad.However,the research on electrode boiler in China started late,and the technology is not mature enough to realize the localization of high voltage electrode and other core components of electrode boiler.Based on the above problems,this paper intends to study the influence of electrode material,voltage,furnace water concentration and other parameters on the corrosion performance of the electrode,in order to explore the corrosion characteristics of the electrode in the furnace water,to provide a theoretical basis for the localization of the electrode boiler.In this paper,according to the working condition of the high voltage electrode,firstly,the electrode corrosion platform was designed and built,and the corrosion test of different electrode materials(titanium,304 stainless steel,graphite,20# steel,copper and aluminum)was carried out for a long time to explore the corrosion process.Then,the corrosion properties of four materials(Titanium,304 stainless steel,graphite and 20#steel)with good performance were studied.The long-term corrosion experiments were carried out in different concentrations(0,0.003%,0.006%,0.009% and 0.015%)of trisosodium phosphate solution in furnace water,and the mass loss and surface morphology of the electrode were recorded.Then corrosion tests were carried out on the electrode materials under different AC voltage(100/200/300/400V)to further observe the surface morphology,so as to further explore the key influencing factors of corrosion under AC voltage,and to provide a basis for material selection and structure improvement of the high voltage electrode.The results show that copper and aluminum electrodes have no ac corrosion resistance,304 stainless steel electrode and graphite electrode have good corrosion resistance,20# steel electrode can effectively resist AC corrosion even after forming a certain thickness of rust layer,and titanium electrode has the lowest corrosion rate.At400 V,the corrosion rate of 304 stainless steel increases with the increase of the concentration,and the corrosion rate of 20# steel reaches the maximum at0.003%.Corrosion resistance: titanium > 304 stainless steel > graphite > 20# steel.The conductivity of different materials electrodes in solution: graphite > titanium > 304 stainless steel > copper > iron ≈ aluminum.The 304 stainless steel electrode and copper electrode have obvious pitting tendency,the pitting pits are shallow,and the number of pitting pits increases with the increase of current density.20# steel electrode corrosion surface products have cracks,can not prevent oxygen into the internal;There is almost no corrosion on the surface of titanium electrode.In the design of electrode boiler,suitable materials are selected according to the working conditions,and the electric field is distributed as evenly as possible,which can effectively improve the life of electrode. |
