Studi Fluidisasi dan Pembakaran Batubara Polydisperse di Dalam Fluidized Bed Berbasis Simulasi CFD (Computational Fluid Dynamic)

Mochammad Agung Indra Iswara, Tantular Nurtono, Sugeng Winardi

Abstract


Penelitian ini bertujuan untuk mengetahui fenomena pembakaran batubara dimana dimensi alat, distribusi ukuran partikel, dan jenis kualitas batubara menggunakan validasi dari penelitian Wang. Penelitian ini mengarahkan pada simulasi berbasis CFD. Kondisi operasi pada saat simulasi pembakaran dilakukan pada kecepatan bubbling. Metode yang digunakan sebelum melakukan simulasi pembakaran merupakan kelanjutan dari simulasi fluidisasi dimana masih menggunakan geometri 2-D fluidized bed lalu dilakukan meshing, selanjutnya memasukkan persamaan energi. Geometri fluidized bed yang digunakan berbentuk tabung dengan panjang silinder fluidized bed 1370 mm, diameter silinder 152 mm. Bahan yang digunakan pada penelitian ini berupa pulverized coal dengan jenis batubara Bituminous dimana ukuran partikel dianggap polydisperse dengan ukuran partikel 1 mm dan 1,86mm yang masing-masing sebesar 50% fraksi massa dengan kecepatan 0,2 Kg/s dan suhu 1200 K, dan udara luar yang diinjeksikan dengan kecepatan 0,8 m/s dan suhu 300 K. Analisa pengambilan data adalah berupa kontur fase padatan, kontur temperatur pada fase-1 dan fase padatan, fraksi massa produk pembakaran, massa padatan awal dan akhir simulasi dengan time step sebesar 0,0001 detik dan number of time step sebesar 300000. Selanjutnya data tersebut diplot menjadi grafik temperatur terhadap time step dan disajikan dalam setiap 1 menit simulasi selama 5 menit simulasi.

This research aims to determine coal combustion’s phenomenon, where the device’s dimension, particle size distribution, and the quality of rank coal  which validated Wang’s reseach. This reseach leads on CFD simulation. The operation condition has did in bubbling velocity. This method is a continuation from fluidization simulation which is use 2-D Geometry and then used the meshing method, and enter the energy equation. The geometry of fluidized bed used was tubular cylinder with 1370 mm length and 152 mm. Materials used in this study was pulverized coal with Bituminous coal type which the particle size was considered as monodispers with particle size was 1.43 mm and polydispersed with particle size was 1 mm with 50% mass fraction and 1.86 mm with 50% mass fraction with flow rate 0,2 Kg/s and the temperature is 1200 K, and the outside air are injected in 0,8 m/s and 300 K. The analysis of data retrieval is solid phase contour, temperature contours in phase-1 and solid phase, mass fraction of combustion product, initial solid mass and final solid mass simulation with time step 0,0001 s and the numberof time step 300000. Then the data is plotted into a graph temperature vs time step and presented in 1 minute simulation for 5 minute simulation.


Keywords


coal; combustion; computational fluid dynamic; fluidized bed; hidrodynamic

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References


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DOI: http://dx.doi.org/10.33795/jtkl.v2i1.62

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Copyright (c) 2018 Mochammad Agung Indra Iswara, Tantular Nurtono, Sugeng Winardi

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This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.