Numerical Study Of Variation Effects Of Air Combusiton Ratio To Fluidization On Circulating Fluidized Bed Boiler 110 Mw Components (Nagan Raya Power Plant Case Study)

Wirahadi, Ari (2018) Numerical Study Of Variation Effects Of Air Combusiton Ratio To Fluidization On Circulating Fluidized Bed Boiler 110 Mw Components (Nagan Raya Power Plant Case Study). Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Rata-rata PLTU (Pembangkit Listrik Tenaga Uap) memproses uap yang dihasilkan dari pemanasan di dalam boiler menggunakan bahan bakar batu bara. Salah satu tipe boiler dengan bahan bakar batubara adalah boiler jenis Circulating Fluidized Bed (CFB). CFB memiliki keunggulan dalam penggunaan batubara low rank sehingga lebih cost efficient tetapi beresiko mengalami kerusakan lebih cepat akibat penggunaan material pasir di dalam prosesnya sehingga penting memahami proses didalamnya untuk mereduksi kerusakan terjadi. Salah satu parameter operasi yang mempengaruhi proses fluidisasi adalah udara pembakaran yaitu rasio primary air dan secondary air. Pemahaman proses didalamnya yang melingkupi parameter-parameter operasi lebih detail akan jauh lebih mudah dan mendapatkan gambaran seutuhnya jika dilakukan dengan simulasi numerik atau yang disebut CFD (Computational Fluid Dynamics). Penelitian ini merupakan studi kasus boiler CFB PLTU Nagan Raya yang memiliki kapasitas terpasang 110 MW. Pengaruh perubahan rasio udara PAF (Primary Air fan) dan SAF (Secondary Air Fan) pada area terjadinya kecepatan kritikal penting untuk dipahami lebih baik sehingga kehandalan operasi boiler tetap terjaga dan tidak terjadi high cost akibat kerusakan. Metoda yang digunakan dalam penelitian adalah menggunakan simulasi numerik CFD (Computational Fluid Dynamics). Simulasi itu dilakukan pada titik operasi 63% load dan 100% load menggunakan data operasi pada boiler kemudian dilakukan simulasi terhadap pengoperasian 110% dan masing-masing akan dilakukan perubahan rasio Primary Air dan Secondary Air pada 50%:50% dan 55%:45%. Pemodelan yang digunakan adalah multiphase Eulerian, model turbulensi k-ε standard, dengan model boiler skala rasio 1:1 pada kondisi Isothermal. Hasil dari simulasi menunjukkan bahwa rasio primary air dan secondary air berpengaruh pada karakteristik fluidisasi CFB. Pada parameter fluidisasi dengan meningkatnya persentase primary air dan kenaikan beban akan mengurangi pressure drop sepanjang ketinggian furnace, meningkatkan kecepatan pasir yang masuk ke cyclone dan konsentrasi pasir pada area tersebut. Sehingga potensi abrasi akan meningkat pada area tersebut sangat tinggi. ========================================================= The common Steam Power Plant that produces steam where is generated by boiling water in the boiler is using coal as fuel. One of the type of boiler is Circulating Fluidized Bed (CFB). CFB has advantages when uses low rank coal so it will be cost efficient but it has higher risk in degradation because of sand material inside the process. It is really important to understand the process inside of it to reduce degradation. One of operation parameter that influence fluidization process is the ratio of primary air and secondary air. Study about the process of boiler encompasses detail operation parameters will simpler and more comprehensive if it uses numerical simulation or Computation Fluid Dynamics. This research is case study of CFB Boiler of Steam Power Plant of Nagan Raya where it has capacity 110 MW with low rank coal. Effects of variation of flow rate of Primary Air Fan and Secondary Air Fan in combustion and the changes of areas where the critical velocity is happened are important to understand so reliability of boiler is maintained with low cost. Method that is used in this research is using CFD (Computation Fluid Dynamics) simulation. Simulation is applied in 63% load and 100% load using operational data of boiler then it was simulated for 110% capacity. Both of loads will be varied with rasio of Primary Air and Secondary Air in 50:50 dan 55:45. Modeling used Eulerian Multiphase, k- ε standard with boiler model scale rasio 1:1 and isothermal condition This simulation showed that ratio of primary air and secondary air are really affected to fluidization CFB characteristic. In fluidization parameter, when primary air and load is increased then pressure drop along height of furnace is decreased, sands velocity towards inlet cyclone and sand concentration increased. Based on that condition, level of potential abrasion around that area is high.

Item Type: Thesis (Masters)
Additional Information: RTM 621.194 Wir s
Uncontrolled Keywords: CFB, CFD, air combustion, fluidization
Subjects: T Technology > TJ Mechanical engineering and machinery > TJ935 Pipe--Fluid dynamics.
Divisions: Faculty of Industrial Technology > Mechanical Engineering
Depositing User: Ari Wirahadi
Date Deposited: 01 Oct 2020 06:28
Last Modified: 01 Oct 2020 06:28
URI: http://repository.its.ac.id/id/eprint/59649

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