碩士 / 國立彰化師範大學 / 工業教育學系 / 90 / The objective of this study is to analyze the occurrence of failure of grid bars of condensers' ball-collection strainers for thermal power plant. The first part of this study is to employ the scanning element microscope (SEM) to investigate the possibility of failure at broken section from the view of micro-structural. In addition, in order to obtain practical dynamic situations, measurements of the strain of strainers was performed. The finite element program ANSYS then was employed to obtain analytical results, according to the data obtained from water flow field. The result were compared with the results from measurements.
The result also shows that the crack of grid bars occurs from the outside boundary and then propagate into the inside hole. Thereafter, in the form of beach mark, it propagates to the both side of hole. This, of course, cause the broken of grid bars. It is caused by unexpected high speed of water flow field. The phenomenon is a kind of fatigue fracture. This is, perhaps, due to the excessive forces acting on the grid bars which implies that it produce more internal stresses than the limit of fatigue strength of SUS 316L.
| Identifer | oai:union.ndltd.org:TW/090NCUE0037022 |
| Date | January 2002 |
| Creators | Chan Kuo Chien, 詹國強 |
| Contributors | Meng - Jiun Wu, Shun-Fa Hwang, 王宜明, 黃順發 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 68 |
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