Analisis Creep Pada Superheater Tube Elbow : Integrasi Metode LMP Dengan Simulasi ANSYS Untuk Memprediksi Umur Material

Jamil, Fadhil Muhammad (2026) Analisis Creep Pada Superheater Tube Elbow : Integrasi Metode LMP Dengan Simulasi ANSYS Untuk Memprediksi Umur Material. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Elbow tube superheater rentan mengalami kerusakan creep akibat temperatur tinggi, tekanan internal, serta distribusi panas dan tegangan yang tidak merata akibat geometri pipa. Penelitian ini mengevaluasi pengaruh ketebalan oksida, koefisien konveksi, dan temperatur flue gas terhadap distribusi temperatur, distribusi tegangan, serta umur creep pada elbow superheater SA-213 T91 menggunakan integrasi simulasi termal–struktural ANSYS dan metode Larson–Miller Parameter (LMP). Data input meliputi geometri pipa, kondisi operasi superheater, sifat mekanik dan termal material pipa ASTM A213 T91 dan lapisan oksida, serta sifat termal fluida kerja (steam dan flue gas). Simulasi termal menghasilkan distribusi temperatur dan heat flux, sedangkan simulasi struktural menghasilkan distribusi tegangan meliputi hoop stress, longitudinal stress, equivalent stress, dan deformasi total. Temperatur rata-rata logam (Tave,m) dan hoop stress digunakan sebagai input untuk prediksi umur creep. Hasil menunjukkan distribusi temperatur dan tegangan yang tidak seragam akibat geometri elbow. Pada ketebalan oksida 0,1 mm, temperatur maksimum mencapai 605,4 °C di area ekstrados, sedangkan temperatur minimum sebesar 594,87 °C terjadi di area intrados. Sebaliknya, hoop stress tertinggi terlokalisasi di area intrados sebesar 78,07 MPa, lebih tinggi dibandingkan ekstrados sebesar 51,53 MPa. Analisis sembilan kasus simulasi pada area intrados menunjukkan bahwa peningkatan ketebalan oksida, temperatur flue gas, dan efek konveksi meningkatkan Tave,m dari 591,62 menjadi 605,82 °C, sehingga menurunkan umur creep dari 16,68 menjadi 4,33 tahun. Pada kondisi mendekati operasi aktual, umur creep terprediksi sebesar 102.133 jam dengan error sekitar ±2% dibandingkan umur operasi aktual. Hasil ini membuktikan bahwa pendekatan integrasi ANSYS–LMP efektif untuk evaluasi umur pakai dan perencanaan inspeksi komponen superheater.
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Superheater elbow tubes are prone to creep damage due to high temperature, internal pressure, and non-uniform heat and stress distributions caused by their geometry. This study evaluates the influence of oxide thickness, convection coefficient, and flue gas temperature on temperature distribution, stress distribution, and creep life of an SA-213 T91 superheater elbow using integrated thermal–structural ANSYS simulations and the Larson–Miller Parameter (LMP) method. Input data include pipe geometry, superheater operating conditions, mechanical and thermal properties of ASTM A213 T91 and the oxide layer, as well as thermal properties of steam and flue gas. Thermal simulations provide temperature and heat flux distributions, while structural simulations yield hoop stress, longitudinal stress, equivalent stress, and total deformation. The average metal temperature (Tave,m) and hoop stress are used for creep life prediction. The results show non-uniform temperature and stress distributions due to elbow geometry. For an oxide thickness of 0.1 mm, the maximum temperature reaches 605.4 °C at the extrados, while the minimum temperature of 594.87 °C occurs at the intrados. In contrast, the highest hoop stress is concentrated at the intrados (78.07 MPa), exceeding that at the extrados (51.53 MPa). Analysis of nine simulation cases at the intrados indicates that increased oxide thickness, flue gas temperature, and convection effects raise Tave,m from 591.62 to 605.82 °C, reducing creep life from 16.68 to 4.33 years. Under near-operating conditions, the predicted creep life is 102,133 hours, with an error of approximately ±2% compared to the actual service life. These results demonstrate that the ANSYS–LMP approach is effective for creep life assessment and inspection planning of superheater components.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	ANSYS, Creep, Elbow Tube, LMP, Superheater
Subjects:	T Technology > T Technology (General) > T57.62 Simulation T Technology > TA Engineering (General). Civil engineering (General) > TA169.5 Failure analysis T Technology > TA Engineering (General). Civil engineering (General) > TA347 Finite Element Method T Technology > TJ Mechanical engineering and machinery > TJ263.5 Boilers (general)
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Fadhil Muhammad Jamil
Date Deposited:	03 Feb 2026 09:35
Last Modified:	03 Feb 2026 09:35
URI:	http://repository.its.ac.id/id/eprint/131868

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