Comparative evaluation of creep response of X20 and P91 steam piping networks in operation

Salifu, Smith; Desai, Dawood; Kok, Schalk

doi:10.1007/s00170-020-05727-7

Cited by 8 publications

(6 citation statements)

References 29 publications

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“…Furthermore, the plot shows that there was a gradual decrease in temperature across the thickness of the assembly until the minimum temperature of 42.9 ℃ was formed on the external surface of the assembly. The comparatively low temperature value recorded on the insulation jacket corroborates the fact the pyrogel is a good insulation jacket suitable for the prevention of heat loss in steam pipes [18,30,37]. The plot for the creep stress distribution after 1-hour steady-state operation in the piping network is depicted in Figure 6(a).…”

Section: Resultssupporting

confidence: 54%

“…The pipe-insulation assembly was meshed using a 50 mm hexagonal-shaped element mesh size applied through a sweep technique and advanced front algorithm [36]. Furthermore, the assembly was assigned an 8 nodal linear brick element type (DC3D8) in the heat transfer analysis while the assembly was assigned an 8 nodal linear bricks with reduced integration hourglass controlled element type (C3D8R) in the creep analysis [36,37]. In both analyses, a total of 92126 elements with 15162 nodes was obtained such that the pipe has a total of 40774 elements with 69520 nodes while the insulation jacket has 51352 elements with 85642 nodes.…”

Section: Finite Element Mesh Generationmentioning

confidence: 99%

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Numerical Simulation of Stress Relaxation and Creep Response of X20 Steam Piping under Diverse Operating Conditions

Salifu

Desai

Kok

2021

JERA

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The creep response and stress relaxation of X20 CrMoV12-1 steam piping under diverse operating conditions were simulated using finite element analysis (FEA) code, Abaqus alongside fe-safe/Turbolife software. In the study, steady-state creep and creep analysis characterized by 24 hours daily cycle consisting of a total of 6 hours peak, 4 hours transient and 14 hours off-peak period was considered. Modified hyperbolic sine creep model used in the analysis was implemented in Abaqus via a special creep user-subroutine to compute the stress relaxation and creep behaviour, while the useful service life and creep damage was estimated using fe-safe/Turbolife. The optimum creep strain, stress, damage, and worst life were found at the intrados of the piping, with the steady-state analysis having a higher useful creep life and slower creep damage accumulation. Furthermore, slower stress relaxation with faster damage accumulation was observed in the analysis involving cycles. Finally, a good agreement was obtained between the analytical calculated and simulated rates of the piping.

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Section: Resultssupporting

confidence: 54%

Section: Finite Element Mesh Generationmentioning

confidence: 99%

Numerical Simulation of Stress Relaxation and Creep Response of X20 Steam Piping under Diverse Operating Conditions

Salifu

Desai

Kok

2021

JERA

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“…As depicted in Figure 2(b), a seed size of 50 mm was discovered to be appropriate for both the heat transfer and creep analysis after conducting mesh convergence studies. "An operating temperature of 550 ℃ having 10 000 W/m 2 K convection heat transfer coefficient [31] was applied to the interior surface of the pipe while 25 ℃ temperature having 18.0 W/m 2 K convection heat transfer coefficient was applied to the exterior surface of the insulation jacket in the assembly" [28,32]. (outer) of the jacket buttresses the fact that pyrogel is indeed a good insulation jacket for high-temperature components.…”

Section: Resultsmentioning

confidence: 99%

“…"An operating temperature of 550ºC having 10 000 W/m 2 K convection heat transfer coefficient 31 was applied to the interior surface of the pipe while 25ºC temperature 18.0 W/m 2 K convection heat transfer coefficient was applied to the exterior surface of the insulation jacket in the assembly". 28,32 A steam pressure load of 18.0 MPa representing the optimal operating pressure of the piping was applied to the interior surface of the pipe in the steady-state creep analysis while the steam pressure and temperature profile representing the different sections of the daily cycle was applied to the pipe in the analysis involving cycle. Figure 3 Through curve fitting of the P92 steel creep data obtained experimentally, the constitutive creep model constants were obtained as shown in Table . 2.…”

Section: Finite Element Modelmentioning

confidence: 99%

Determination of the dominant failure mechanism of P92 steam piping subjected to daily operational cycle using finite element (FE) technique

Salifu

Desai

Kok

2021

SATNT

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In a bid to minimise the cost of electrical energy production through the reduction in the quantity of coal usage, the power generation companies resolved to operate different daily cycles characterized by peak and off-peak energy demand periods. These daily operational cycles have left the power plant components operating in a possible creep-fatigue regime. As such, earlier failure of the plant’s components such as the steam pipes due to creep, fatigue, or the combination of both failure modes became inevitable. This study employed finite element (FE) technique to determine the dominant failure mechanism and useful life of P92 power generation steam piping subjected to one of the daily operational cycles. The outcome of the study showed that the failure of the piping when subjected to the daily cycle is creep dominated, and failure due to fatigue or possible creep-fatigue interaction was impossible since the daily cycle was insufficient to induce the extensive plastic strain required for the initiation and propagation of fatigue failure. Hence, the best form of operating steam pipe/piping is steady-state, since subjecting them to daily cycles significantly reduce their useful life.

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“…To ensure the accuracy of the FEA, a mesh convergence study is required to determine the optimal mesh size [31][32][33][34][35]. Figure 2(a) displays the results of the mesh convergence study which was conducted by gradually reducing the mesh size until the desired results with a reasonable computational time was obtained.…”

Section: Mesh Convergence Study and Mesh Typementioning

confidence: 99%

Assessment of Buckling Failure in Oil Storage Tanks: Finite Element Simulation of Combined Internal and External Pressure Scenarios

Mashiyane,

Tartibu,

Salifu

2024

Sci. Eng. Technol.

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Investigating the structural behaviour and buckling susceptibility of cylindrical oil storage tanks is crucial for ensuring their safe and reliable operation. In this study, the structural behaviour and buckling susceptibility of closed roof-top cylindrical oil storage tanks under combined internal and external pressure scenarios were investigated using the finite element analysis (FEA) technique. By utilizing the FEA technique, the combined effect of wind-induced pressure of 250 Pa, applied on the outer surface of the tank and internal pressure of 0.5 MPa, applied on the outer surface of the storage was analysed. The result reveals significant stress concentrations and deformation patterns, particularly on the windward side of the tank, thus, emphasizing the susceptibility of the storage tank to buckling under the specified operating conditions for both the filled and half-filled tank; with internal pressure emerging as the primary contributor to mechanical strain and deformation experienced in the tank, while the wind load plays a secondary but significant role in the deformation of the tank. The fe-safe predicted useful life shows that under the specified operating conditions, the filled storage tank will survive 1 429 hours (2 months) while the half-filled tank will survive 3 551 hours (5 months) before failure due to buckling. Thus, the useful life estimation results show the importance of varying oil levels and operating conditions in the structural assessments of storage tanks.

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Comparative evaluation of creep response of X20 and P91 steam piping networks in operation

Cited by 8 publications

References 29 publications

Numerical Simulation of Stress Relaxation and Creep Response of X20 Steam Piping under Diverse Operating Conditions

Numerical Simulation of Stress Relaxation and Creep Response of X20 Steam Piping under Diverse Operating Conditions

Determination of the dominant failure mechanism of P92 steam piping subjected to daily operational cycle using finite element (FE) technique

Assessment of Buckling Failure in Oil Storage Tanks: Finite Element Simulation of Combined Internal and External Pressure Scenarios

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