Studi Variasi Triangle Anti-Wear Grill Pada CFB Boiler

Maulana, Ahmad (2026) Studi Variasi Triangle Anti-Wear Grill Pada CFB Boiler. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Erosi pada waterwall tube akibat particle wall-flow merupakan salah satu permasalahan reliabilitas utama pada boiler circulating fluidized bed (CFB) yang sering menyebabkan kebocoran tube selama operasi. Penggunaan anti wear device pada waterwall telah banyak diterapkan sebagai metode mitigasi untuk menurunkan laju erosi akibat tumbukan partikel. Namun demikian, pengaruh konfigurasi multi-level anti wear grill, khususnya variasi sudut grill dan jarak antar grill (interspacing), terhadap distribusi erosi pada waterwall masih belum dipahami secara komprehensif. Oleh karena itu, penelitian ini bertujuan untuk menentukan konfigurasi anti wear grill yang memberikan laju erosi minimum pada waterwall boiler CFB. Penelitian dilakukan menggunakan metode simulasi numerik berbasis Computational Fluid Dynamics (CFD) pada boiler CFB 110 MW dengan memvariasikan sembilan konfigurasi anti wear grill berbentuk segitiga yang terdiri atas tiga variasi sudut grill (30°, 45°, dan 60°) serta tiga variasi interspacing (0,6 m; 0,8 m; dan 1,0 m). Laju erosi dihitung menggunakan persamaan Tabakoff sesuai pendekatan yang digunakan oleh Li, et al (2023), sedangkan fenomena aliran dianalisis melalui distribusi kecepatan partikel pasir dan udara pada area sekitar waterwall dan anti wear grill untuk mengevaluasi mekanisme flow recovery, particle re-impact, dan pola pembentukan kembali wall flow. Hasil penelitian menunjukkan bahwa penggunaan anti wear grill efektif menurunkan laju erosi dengan cara mendisrupsi wall flow, membelokkan partikel menuju area tengah furnace, serta mengurangi intensitas tumbukan partikel terhadap waterwall. Variasi sudut grill menunjukkan bahwa konfigurasi 60° menghasilkan performa terbaik dengan rata-rata laju erosi gabungan paling rendah sebesar 44 × 10⁻¹⁴ g/mg dan nilai erosi maksimum paling kecil sebesar 272 × 10⁻¹⁴ g/mg akibat berkurangnya fenomena particle re-impact. Selain itu, variasi interspacing menunjukkan bahwa konfigurasi 1,0 m lebih efektif dalam menunda proses flow recovery menuju waterwall dibandingkan konfigurasi 0,8 m dan 0,6 m, sehingga menghasilkan laju erosi paling rendah pada area recovery dan direkomendasikan sebagai konfigurasi optimum untuk meminimalkan erosi pada waterwall boiler CFB yang diteliti.
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Waterwall tube erosion induced by particle wall-flow is one of the major reliability problems in circulating fluidized bed (CFB) boilers and frequently causes tube leakage during operation. The installation of anti-wear devices on the waterwall has been widely applied as an effective method to reduce particle-induced erosion. In this work, multi-level triangular anti-wear grill configurations were numerically investigated by comparing the erosion behavior of local waterwall regions in a 110 MW CFB boiler using Computational Fluid Dynamics (CFD). Nine grill configurations were evaluated by varying grill inclination angle and inter-grill spacing. The results show that grill installation effectively reduces erosion by interrupting the descending near-wall particle flow and redirecting particles toward the furnace core, thereby reducing direct particle impingement on the waterwall. The grill inclination angle significantly affects erosion distribution, where the 60° configuration provides lower combined average erosion and lower peak erosion than the 45o and 30° configuration due to reduced particle rebound and more stable flow redirection. The inter-grill spacing also influences downstream erosion recovery, where the 1.0 m spacing delays gas–solid flow reattachment to the wall and reduces erosion in the near- to mid-recovery regions compared with the 0.8 m and 0.6 m spacing. Based on the combined erosion performance, the triangular anti-wear grill with a 60° inclination angle and 1.0 m interspacing is recommended as the optimum configuration for minimizing waterwall erosion in the investigated CFB boiler.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Erosi tube boiler, CFB boiler, Anti-wear device,CFB boiler, Waterwall erosion , Anti-wear grill, Computational Fluid Dynamics (CFD), Erosion mitigation
Subjects:	T Technology > TJ Mechanical engineering and machinery > TJ230 Machine design T Technology > TJ Mechanical engineering and machinery > TJ263.5 Boilers (general)
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	Ahmad Maulana
Date Deposited:	03 Aug 2026 06:36
Last Modified:	03 Aug 2026 06:36
URI:	http://repository.its.ac.id/id/eprint/142330

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