There are several elements that affect on the integrity of steam generator tubes. One of the elements is loose parts located on outside of the tubes. It causes erosion which is possible to lead fatal defect like crack...There are several elements that affect on the integrity of steam generator tubes. One of the elements is loose parts located on outside of the tubes. It causes erosion which is possible to lead fatal defect like crack on the outside surface of the tubes. In this study, artificial loose parts on Inconel 690 tube are demonstrated and eddy current testing data of the region is acquired using rotating probe. Ferromagnetic and nonmagnetic foreign materials were used to demonstrate artificial loose parts. Eddy current channel of 100 KHz frequency shows definite signals of those foreign materials but stainless steel was not clearly detected. This result can be explained based on the electrical conductivity of the materials and it can be confirmed with lissajous window and C-scan. In addition, no indication was detected when the distance of the gap between the foreign materials and the tube is increased to more than 3 mm under this test condition. Based on these experimental inspections, we were able to find suitable methods for analyzing the signals obtained under various conditions that could occur when conducting steam generator eddy current test in NPP.展开更多
As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the ...As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the gas-steam and conventional blocks,the structure of the basic components of the blocks are changed,e.g.by reducing the diameter of the boiler,the thickness of its wall is also reduced.The attempts were also made to revise the currently binding TRD 301 regulations,replacing them by the EN 12952-3 European Standard,to reduce the allowable heating and cooling rates of thick walled boiler components.The basic assumption,on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based,was the quasi- steady state of the temperature field in the simple shaped component,such as a slab,cylindrical or spherical wall.展开更多
文摘There are several elements that affect on the integrity of steam generator tubes. One of the elements is loose parts located on outside of the tubes. It causes erosion which is possible to lead fatal defect like crack on the outside surface of the tubes. In this study, artificial loose parts on Inconel 690 tube are demonstrated and eddy current testing data of the region is acquired using rotating probe. Ferromagnetic and nonmagnetic foreign materials were used to demonstrate artificial loose parts. Eddy current channel of 100 KHz frequency shows definite signals of those foreign materials but stainless steel was not clearly detected. This result can be explained based on the electrical conductivity of the materials and it can be confirmed with lissajous window and C-scan. In addition, no indication was detected when the distance of the gap between the foreign materials and the tube is increased to more than 3 mm under this test condition. Based on these experimental inspections, we were able to find suitable methods for analyzing the signals obtained under various conditions that could occur when conducting steam generator eddy current test in NPP.
文摘As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the gas-steam and conventional blocks,the structure of the basic components of the blocks are changed,e.g.by reducing the diameter of the boiler,the thickness of its wall is also reduced.The attempts were also made to revise the currently binding TRD 301 regulations,replacing them by the EN 12952-3 European Standard,to reduce the allowable heating and cooling rates of thick walled boiler components.The basic assumption,on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based,was the quasi- steady state of the temperature field in the simple shaped component,such as a slab,cylindrical or spherical wall.
