Study on vibration alternating stress of pressure tapping pipe of high-pressure bypass pipeline of the steam turbine

During the operation of a thermal power unit’s high-pressure bypass (HPB) system, excessive vibration caused the breakage of the attached pressure-tapping tube. After the vibration reduction modification, it is required to analyze the vibration alternating stress level of the pressure-tapping tube a...

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Bibliographic Details
Main Authors: ZHANG Weiyong, ZHOU Shuai, CHEN Haixin, HE Shi, LIU Haoyuan, XU Decheng, LIU Yinli
Format: Article
Language:zho
Published: zhejiang electric power 2023-01-01
Series:Zhejiang dianli
Subjects:
Online Access:https://zjdl.cbpt.cnki.net/WKE3/WebPublication/paperDigest.aspx?paperID=e2b24e9f-1515-43ff-b8cc-c71770467dcb
Description
Summary:During the operation of a thermal power unit’s high-pressure bypass (HPB) system, excessive vibration caused the breakage of the attached pressure-tapping tube. After the vibration reduction modification, it is required to analyze the vibration alternating stress level of the pressure-tapping tube and assess its safety. To this end, the vibration alternating stress level at the cracked location of the pressure-tapping tube is measured by the strain test method under the change of differential pressure and opening degree before and after the high-pressure bypass valve. The relationship between the vibration alternating stress magnitude of the pressure-tapping tube and the differential pressure before and after the high-pressure bypass valve and its opening degree is analyzed. The critical operating parameters for the potential fatigue fracture of the pressure-tapping pipelines are given: when the opening degree of the high-pressure bypass valve is 35%, and its differential pressure exceeds 3.70 MPa, the fatigue fracture of the pressure-tapping tube may occur. Finally, it is concluded through analysis that the high-pressure bypass vibration mainly comprises high-frequency vibration due to the high-frequency acoustic energy, which excites and amplifies the high-frequency vibration on the pipeline wall.
ISSN:1007-1881