Structural Design and Life Assessment of a Molten Salt Solar Receiver

1985 ◽  
Vol 107 (3) ◽  
pp. 258-263 ◽  
Author(s):  
T. V. Narayanan ◽  
M. S. M. Rao ◽  
G. Carli
Keyword(s):  
Molten Salt ◽  
Structural Integrity ◽  
Life Assessment ◽  
Fatigue Life Assessment ◽  
Life Evaluation ◽  
Creep Fatigue ◽  
Asme Code ◽  
Safety And Reliability ◽  
Solar Receiver ◽  
Commercial Size

This paper discusses the structural integrity and creep-fatigue life assessment of a commercial size molten salt solar central receiver. The life evaluation is based on criteria that are a modified version of ASME Code Case N-47. These criteria are deemed conservative enough to provide a reasonable level of safety and reliability, and yet not so conservative as to impose severe economic penalties on the receiver. The justification for these criteria and their application to the receiver are discussed in detail.

Structural Integrity Code and Regulatory Issues in the Design of High Temperature Reactors

2008 ◽  
Author(s):  
William J. O’Donnell ◽  
Amy B. Hull ◽  
Shah Malik
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Structural Integrity ◽  
Cyclic Creep ◽  
Creep Rupture ◽  
Creep Fatigue ◽  
Asme Code ◽  
High Temperature Reactors ◽  
Gen Iv ◽  
Very High

Since the 1980s, the ASME Code has made numerous improvements in elevated-temperature structural integrity technology. These advances have been incorporated into Section II, Section VIII, Code Cases, and particularly Subsection NH of Section III of the Code, “Components in Elevated Temperature Service.” The current need for designs for very high temperature and for Gen IV systems requires the extension of operating temperatures from about 1400°F (760°C) to about 1742°F (950°C) where creep effects limit structural integrity, safe allowable operating conditions, and design life. Materials that are more creep and corrosive resistant are needed for these higher operating temperatures. Material models are required for cyclic design analyses. Allowable strains, creep fatigue and creep rupture interaction evaluation methods are needed to provide assurance of structural integrity for such very high temperature applications. Current ASME Section III design criteria for lower operating temperature reactors are intended to prevent through-wall cracking and leaking and corresponding criteria are needed for high temperature reactors. Subsection NH of Section III was originally developed to provide structural design criteria and limits for elevated-temperature design of Liquid-Metal Fast Breeder Reactor (LMFBR) systems and some gas-cooled systems. The U.S. Nuclear Regulatory Commission (NRC) and its Advisory Committee for Reactor Safeguards (ACRS) reviewed the design limits and procedures in the process of reviewing the Clinch River Breeder Reactor (CRBR) for a construction permit in the late 1970s and early 1980s, and identified issues that needed resolution. In the years since then, the NRC, DOE and various contractors have evaluated the applicability of the ASME Code and Code Cases to high-temperature reactor designs such as the VHTGRs, and identified issues that need to be resolved to provide a regulatory basis for licensing. The design lifetime of Gen IV Reactors is expected to be 60 years. Additional materials including Alloy 617 and Hastelloy X need to be fully characterized. Environmental degradation effects, especially impure helium and those noted herein, need to be adequately considered. Since cyclic finite element creep analyses will be used to quantify creep rupture, creep fatigue, creep ratcheting and strain accumulations, creep behavior models and constitutive relations are needed for cyclic creep loading. Such strain- and time-hardening models must account for the interaction between the time-independent and time-dependent material response. This paper describes the evolving structural integrity evaluation approach for high temperature reactors. Evaluation methods are discussed, including simplified analysis methods, detailed analyses of localized areas, and validation needs. Regulatory issues including weldment cracking, notch weakening, creep fatigue/creep rupture damage interactions, and materials property representations for cyclic creep behavior are also covered.

scholarly journals Creep Fatigue Life Assessment of a Pipe Intersection with Dissimilar Material Joint by Linear Matching Method

2016 ◽  
Vol 853 ◽  
pp. 366-371
Author(s):  
Daniele Barbera ◽  
Hao Feng Chen ◽  
Ying Hua Liu
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Direct Method ◽  
Life Assessment ◽  
Dissimilar Material ◽  
Matching Method ◽  
Fatigue Life Assessment ◽  
Creep Fatigue ◽  
The Impact ◽  
Linear Matching Method

As the energy demand increases the power industry has to enhance both efficiency and environmental sustainability of power plants by increasing the operating temperature. The accurate creep fatigue life assessment is important for the safe operation and design of current and future power plant stations. This paper proposes a practical creep fatigue life assessment case of study by the Linear Matching Method (LMM) framework. The LMM for extended Direct Steady Cycle Analysis (eDSCA) has been adopted to calculate the creep fatigue responses due to the cyclic loading under high temperature conditions. A pipe intersection with dissimilar material joint, subjected to high cycling temperature and constant pressure steam, is used as an example. The closed end condition is considered at both ends of main and branch pipes. The impact of the material mismatch, transitional thermal load, and creep dwell on the failure mechanism and location within the intersection is investigated. All the results demonstrate the capability of the method, and how a direct method is able to support engineers in the assessment and design of high temperature component in a complex loading scenario.

A Study on Fatigue and Creep-Fatigue Life Assessment Using Cyclic Thermal Tests With Mod.9Cr-1Mo Steel Structures

2012 ◽  
Author(s):  
Masanori Ando ◽  
Hiroshi Kanasaki ◽  
Shingo Date ◽  
Koichi Kikuchi ◽  
Kenichiro Satoh ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Temperature Distribution ◽  
Crack Initiation ◽  
Thermal Loading ◽  
Life Assessment ◽  
Estimation Methods ◽  
Short Term ◽  
Cyclic Thermal Loading ◽  
Fatigue Life Assessment ◽  
Creep Fatigue

In a component design at elevated temperature, fatigue and creep-fatigue is one of the most important failure modes, and fatigue and creep-fatigue life assessment in structural discontinuities is important issue to evaluate structural integrity of the components. Therefore, to assess the failure estimation methods, cyclic thermal loading tests with two kinds of cylindrical models with thick part were performed by using an induction heating coil and pressurized cooling air. In the tests, crack initiation and propagation processes at stress concentration area were observed by replica method. Besides those, finite element analysis (FEA) was carried out to estimate the number of cycles to failure. In the first test, a shorter life than predicted based on axisymmetric analysis. Through the 3 dimensional FEA, Vickers hardness test and deformation measurements after the test, it was suggested that inhomogeneous temperature distribution in hoop direction resulted in such precocious failure. Then, the second test was performed after improvement of temperature distribution. As a result, the crack initiation life was in a good agreement with the FEA result by considering the short term compressive holding. Through these test and FEA results, fatigue and creep-fatigue life assessment methods of Mod.9Cr-1Mo steel including evaluation of cyclic thermal loading, short term compressive holding and failure criterion, were discussed. In addition it was pointed out that the temperature condition should be carefully controlled and measured in the structural test with Mod.9Cr-1Mo steel structure.

Sensitivity of Estimated Tube Life to Material Property Variation

1983 ◽  
Vol 105 (1) ◽  
pp. 73-79 ◽  
Author(s):  
I. Berman ◽  
M. S. M. Rao
Keyword(s):  
Material Property ◽  
Failure Modes ◽  
Creep Damage ◽  
Cycle Number ◽  
Property Variation ◽  
Life Evaluation ◽  
Creep Fatigue ◽  
Incoloy 800 ◽  
Solar Receiver ◽  
Tube Life

The estimated tube life of the Incoloy 800 tubes of a solar receiver panel under nonaxisymmetric loading is compared for various material property assumptions. The basis of each life evaluation is an elastic-creep analytical study of up to 20 load cycles. The effect on tube life of a variation in the creep rate for the failure modes of creep ratcheting and creep fatigue is studied in some detail. As shown for these elastic-creep conditions, the creep damage and mean diametral strain accumulations per cycle decrease linearly over the calculated 20 cycles when plotted against cycle number on a log-log scale. The predictions of total creep damage and mean diametral strain in 10,000 cycles based on the extrapolated log-log scale curve are substantially lower than the predictions based on multiplication of the change in value of the 20th day of operation by 10,000. A limited evaluation of the effects of variations in other material parameters is also made.

scholarly journals Creep-Fatigue Life Assessment for Sn-3.0Ag-0.5Cu Solder

2009 ◽  
Vol 3 (3) ◽  
pp. 507-517 ◽  
Author(s):  
Shengde ZHANG ◽  
Shinsuke OGAWA ◽  
Masao SAKANE
Keyword(s):  
Fatigue Life ◽  
Life Assessment ◽  
Fatigue Life Assessment ◽  
Creep Fatigue
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