Assessing the Condition and Estimating the Remaining Lives of Pressure Components in a Methanol Plant Reformer: Part 1 — NDE

Author(s):  
Brian E. Shannon ◽  
Carl E. Jaske ◽  
Gustavo Miranda

Statoil Tjelbergodden operates a 2,400 ton/day methanol plant in Norway. In order to assess the condition and reliability of high temperature components within the reformer, a series of advanced non-destructive examination (NDE) technologies were applied to radiant catalyst tubes, outlet pigtails, and outlet collection headers. The inspection techniques were selected and developed to provide data that could easily be used in the engineering assessment of the high-temperature components. Special focus was given to detecting and quantifying high-temperature creep damage. This paper describes the NDE techniques that were employed and provides examples of typical data obtained by using the techniques. Catalyst tubes were inspected using the H SCAN® (Figure 1) multiple sensor technology. This technique utilizes two types of ultrasonic sensors, eddy current sensors, laser measurements, and elevation location sensors in scanning each catalyst tube. The H SCAN® P-CAT™ (Figure 2) technique is applied to outlet pigtails, while the H SCAN® H-CAT™ (Figure 3) technique is applied to outlet headers.

2003 ◽  
Vol 38 (2) ◽  
pp. 125-132 ◽  
Author(s):  
S-T Tu ◽  
X Ling

The creep damage behaviour of two-bar structures of different dimensions and materials is studied in terms of continuum damage theory. The basic model is used to interpret the effectiveness of life extension measures for complicated structures. It is found that replacement of the more damaged component prior to rupture will result in an optimized life extension efficiency, depending on the geometric or material difference between the damaged and less damaged components. This has potential to provide guidance on the effectiveness of life extension repairs in high-temperature plants.


2007 ◽  
Vol 353-358 ◽  
pp. 2391-2394 ◽  
Author(s):  
Kuniaki Akahoshi ◽  
Kazuhiro Ogawa ◽  
Hideo Miura

In order to assure the reliability of advanced gas turbine systems, it is very important to evaluate the damage of high temperature materials such as Ni-based superalloys under creep and fatigue conditions quantitatively. The refractive index of the gamma-prime phase is found to be smaller than that of the gamma phase in the Ni-based superalloy, when the wavelength of an irradiated laser beam is shorter than 500 nm. Therefore, it is possible to evaluate the creep damage of this material quantitatively and non-destructively by observing the change of the micro texture in a grain (rafting) using a scanning laser microscope.


2008 ◽  
Vol 44-46 ◽  
pp. 25-32 ◽  
Author(s):  
Shan Tung Tu

The impact of remanufacturing on the conservation of energy and resources has been well recognized during the last decade. When the relevant technologies are applied for high temperature components in power and process industries, a redesign of the component life should be required due to the time-dependent feature of high temperature failure. In order to provide some fundamentals for redesign and remanufacture of high temperature components, mechanical behavior of a two-bar structure with one bar being remanufactured is analyzed. An optimal repairing time is given. From the viewpoint of creep damage, various high temperature structures are analyzed by using damage coupled finite element method. Suggestions for life extension remanufacture are proposed for typical high temperature components.


Author(s):  
Chang Che ◽  
Gong Qian ◽  
Xisheng Yang

China has the most supercritical boilers in the world. Grade 91 steels are widely used for high temperature components of supercritical boiler. During high temperature service, microstructural evolution of Grade 91 steel may affect the mechanical properties, including creep strength. However, there are very few studies on quantitative assessment of microstructural evolution for Grade 91 steel, especially on precipitates content. In this article, microstructural evolution of Grade 91 was studied. A quantitative assessment of microstructure evolution was given during long-term creep, focusing on the precipitated phase content in Grade 91 steel. The results show, the precipitates content of Grade 91 steel has a corresponding relationship with creep damage.


1993 ◽  
Vol 46 (5) ◽  
pp. 229-231
Author(s):  
B. F. Dyson ◽  
F. A. Leckie

Power producing plant operating at high temperature are designed for finite life. This is necessary because the operating conditions are sufficiently high to cause continuous growth of material damage. Failure occurs when damage reaches a critical value. Design is based on stress levels with an appropriate factor of safety. Since life is dependent on a strongly non-linear function of stress the actual life can be many times greater than the design life. In these circumstances it is then natural to explore the possibility of extending the working life. To increase the working life it is necessary to decrease the factor of safety, but it may be possible to follow this course of action provided the growth of physical damage is carefully monitored. In this paper creep damage mechanisms are reported and growth laws are proposed.


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