Return to search

The Evaluation of the Material Deterioration of the Boiler Tubes.

This research aims to develop a method to evaluate the deterioration of the tube material within a boiler, in order to reduce the failure of it. In this thesis, natural frequency measurement method and ultrasonic attenuation method are mainly applied, and it has reached to a conclusion that the ultrasonic attenuation method is more reliable.
Traditionally, the inspectors used the ultrasonic thickness measurement machine to evaluate the thickness and track the condition of a boiler. However, besides the thickness, the inspectors could not have clear understanding of the material and situation within a boiler. To improve the inspection effectiveness, the researcher measures the natural frequencies of the tube material in the new and old boilers by using natural frequency measurement. They found that the used tube material has been altered due to the difference between the natural frequencies.
The ultrasonic attenuation conditions of the tubes are also evaluated in this thesis. The echoes of the ultrasound propagating through the thickness of the tube can be analyzed by relative comparison and absolute comparison, respectively. The relative comparison compares the echoes of the multiple back reflections of the ultrasound between the tubes of old and new boilers. In addition, the absolute comparison analyzes the amplitude of the echoes of the ultrasonic multiple back reflection to calculate the ultrasonic attenuation of the tube. Besides the two major techniques, the material analysis, metallurgical analysis, internally scale analysis and mechanical property evaluation are also applied in this thesis to help developing a method to evaluate the deterioration of the tube material within a boiler.
This research demonstrates that the ultrasonic attenuation measuring methods can offer reliable results to evaluate the quality of the boiler.

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0809105-163616
Date09 August 2005
CreatorsWang, Ping-Chih
ContributorsShao-Yi Hsia, Yi-Cheng Huang, Jin-Jhy Jeng, Shiuh-Kuang Yang
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0809105-163616
Rightsnot_available, Copyright information available at source archive

Page generated in 0.0021 seconds