Ally, Achmad Aric Pratama (2025) Numerical Study On The Effects Of Primary Air Flow Rate Variations With Constant Coal Flow Rate On Particle Behavior, Flow Characteristics, And Wear Concentration In The Top Housing Of A Pulverizer Using CFD. Other thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Pulverizer batubara memiliki peran penting dalam pembangkit listrik tenaga uap berbahan bakar batubara dengan menghaluskan batubara menjadi partikel halus guna memastikan proses pembakaran berlangsung secara efisien. Namun, tantangan operasional seperti erosi dan keausan, khususnya pada bagian top housing, kerap terjadi akibat perilaku aliran udara yang kompleks dan tumbukan partikel dengan dinding. Studi ini menyajikan investigasi numerik untuk menganalisis pengaruh variasi laju alir massa udara primer terhadap karakteristik aliran internal, pelacakan partikel, dan potensi konsentrasi keausan pada top housing pulverizer, dengan laju alir massa batubara dijaga konstan. Model tiga dimensi pulverizer dikembangkan dan disimulasikan dengan pendekatan steady-state, menggunakan model turbulensi standar k–ε dan metode pelacakan partikel Eulerian–Lagrangian. Lima variasi laju alir massa udara primer dianalisis, dengan laju massa batubara tetap. Hasil menunjukkan bahwa peningkatan laju alir udara primer memberikan pengaruh signifikan terhadap perilaku pergerakan partikel. Variasi 30,670 kg/s menghasilkan performa paling optimal dengan persentase partikel lolos tertinggi sebesar 56,77%, massa partikel tertahan terendah sebesar 8,86 kg, serta waktu tinggal rata-rata yang stabil sebesar 5,35 detik. Pada area top housing, kondisi ini menunjukkan pola aliran yang simetris dan mengarah ke atas dengan tingkat turbulensi yang minimal. Penurunan tekanan juga tercatat paling rendah sebesar 3245,30 Pa, menunjukkan aliran yang efisien dengan hambatan rendah. Kondisi ini membantu mengurangi stagnasi dan membatasi tumbukan partikel dengan dinding. Sebaliknya, variasi 38,870 kg/s menunjukkan kontrol aliran yang buruk, dengan partikel lolos hanya sebesar 14,78% dan massa tertahan tertinggi sebesar 17,47 kg akibat pusaran tidak stabil dan pola resirkulasi. Meskipun variasi 42,970 dan 47,070 kg/s memperpendek waktu tinggal partikel, keduanya menghasilkan turbulensi tinggi dan ketidakseimbangan aliran lateral yang meningkatkan risiko keausan. Sementara itu, variasi 34,770 kg/s menunjukkan performa sedang namun masih kurang stabil dibandingkan kondisi laju udara terendah. Secara keseluruhan, laju alir 30,670 kg/s diidentifikasi sebagai kondisi paling seimbang dalam mendukung transportasi partikel yang efisien dan meminimalkan risiko erosi pada top housing pulverizer.
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The coal pulverizer plays a vital role in coal-fired steam power plants by grinding coal into fine particles to ensure efficient combustion. However, operational challenges such as erosion and wear particularly in the top housing frequently occur due to complex airflow behavior and repeated particle-wall impacts. This study presents a numerical investigation to analyze the influence of primary air mass flow rate variations on internal flow characteristics, particle tracking, and potential wear concentration in the top housing of the pulverizer, while maintaining a constant coal mass flow rate. A three-dimensional pulverizer model was developed and simulated using a steady-state approach, applying the standard k–ε turbulence model and Eulerian–Lagrangian particle tracking method. Five variations of primary air mass flow rate were evaluated. The results indicate that increasing the primary air flow significantly influences particle motion behavior. Among all variations, the airflow rate of 30.670 kg/s demonstrated the most optimal performance, with the highest particle escape percentage 56.77%, the lowest retained particle mass 8.86 kg, and a stable average residence time of 5.35 seconds. In the top housing region, this variation exhibited upward and symmetrical flow with minimal turbulence intensity. Additionally, it recorded the lowest pressure drop (3245.30 Pa), indicating efficient flow with reduced resistance. These conditions contribute to minimizing stagnation and limiting particle-wall collisions. Conversely, the variation with 38.870 kg/s showed poor flow control due to unstable swirling and recirculation, resulting in a low escape percentage of 14.78% and the highest retained mass of 17.47 kg. Although the 42.970 and 47.070 kg/s variations reduced particle residence time, they induced higher turbulence and lateral flow asymmetry, thereby increasing erosion risk. Meanwhile, the 34.770 kg/s variation showed moderate performance but remained less stable compared to the lowest airflow condition. Overall, the primary air mass flow rate of 30.670 kg/s is identified as the most balanced condition for promoting efficient particle transport and minimizing erosion potential in the top housing of the pulverizer.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | CFD; Erosi Keausan; Pelacakan Partikel; Top Housing Pulverizer; CFD; Erosion Wear; Particle Tracking; Pulverizer Top Housing |
| Subjects: | T Technology > TJ Mechanical engineering and machinery > TJ164 Power plants--Design and construction |
| Divisions: | Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis |
| Depositing User: | Achmad Aric Pratama Ally |
| Date Deposited: | 01 Aug 2025 07:25 |
| Last Modified: | 01 Aug 2025 07:25 |
| URI: | http://repository.its.ac.id/id/eprint/125485 |
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