Studi Numerik Dan Analisis Kelayakan Ekonomi Penggantian Rigid Seal Menjadi Soft Seal Pada Tri-Sector Air Preheater: Studi Kasus PLTU Paiton Unit 9

Yusra, Hafied (2026) Studi Numerik Dan Analisis Kelayakan Ekonomi Penggantian Rigid Seal Menjadi Soft Seal Pada Tri-Sector Air Preheater: Studi Kasus PLTU Paiton Unit 9. Masters thesis, Institut Teknologi Sepuluh Nopember.

Text 6007241036-Master_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (4MB) | Request a copy

Abstract

Kebocoran udara pada rotary air preheater (APH) dapat meningkatkan laju aliran gas buang, menambah kehilangan panas, dan menurunkan kinerja pembangkit. Penelitian ini bertujuan menganalisis pengaruh penggantian seal terhadap pola aliran, air leakage, kinerja termal, manfaat operasional, penurunan emisi CO₂, dan kelayakan investasi pada APH PLTU Paiton Unit 9. Analisis dilakukan menggunakan simulasi CFD tiga dimensi pada kondisi tunak. Heating element dimodelkan sebagai porous medium dengan pendekatan local thermal non-equilibrium, sedangkan putaran rotor direpresentasikan menggunakan multiple reference frame. Kondisi rigid seal dimodelkan dengan plenum gap sebesar 21 mm pada sisi hot end dan cold end, sedangkan kondisi setelah penggantian seal dimodelkan tanpa plenum gap. Model divalidasi menggunakan data performance test pada beban 642 MW dan menghasilkan kesalahan sebesar 0,10–5,16%.
Hasil simulasi menunjukkan bahwa penutupan plenum gap menurunkan kecepatan lokal dari 44 m/s menjadi 2 m/s. Laju aliran massa outlet flue gas menurun dari 479,26 kg/s menjadi 465 kg/s, sedangkan air leakage turun dari 8,61% menjadi 5,38% atau berkurang sebesar 37,51%. Temperatur outlet primary air, secondary air, dan flue gas masing-masing menurun sebesar 2,66°C, 1,24°C, dan 1,20°C, sementara gas-side efficiency meningkat dari 65,11% menjadi 66,52%. Pengurangan panas sensibel outlet flue gas mencapai 2,28 MW dan menghasilkan potensi penghematan batubara sebesar 3.437,07 ton/tahun serta penurunan emisi sebesar 5.416,28 ton CO₂/tahun. Pada skenario finansial dasar, investasi menghasilkan NPV sebesar Rp2,6 miliar, IRR sebesar 348%, dan payback period 2,68 bulan. Dengan demikian, penggantian rigid seal menjadi soft seal efektif mengurangi kebocoran udara dan layak diterapkan secara teknis, operasional, lingkungan, dan finansial.
==================================================================================================================================
Air leakage in a rotary air preheater (APH) can increase the flue-gas flow rate, increase heat loss, and reduce power plant performance. This study aims to analyze the effects of seal replacement on flow patterns, air leakage, thermal performance, operational benefits, CO₂ emission reduction, and investment feasibility in the APH of Paiton Unit 9 Coal-Fired Power Plant. The analysis was conducted using a three-dimensional steady-state CFD simulation. The heating elements were modeled as porous media using the local thermal non-equilibrium approach, while rotor rotation was represented using the multiple reference frame method. The rigid-seal condition was modeled with a 21 mm plenum gap at the hot and cold ends, whereas the post-replacement condition was modeled without a plenum gap. The model was validated using performance-test data at a unit load of 642 MW and produced errors ranging from 0.10% to 5.16%.
The simulation results show that closing the plenum gap reduced the local velocity from 44 m/s to 2 m/s. The flue-gas outlet mass flow rate decreased from 479.26 kg/s to 465.00 kg/s, while air leakage decreased from 8.61% to 5.38%, corresponding to a relative reduction of 37.51%. The outlet temperatures of the primary air, secondary air, and flue gas decreased by 2.66°C, 1.24°C, and 1.20°C, respectively, while the gas-side efficiency increased from 65.11% to 66.52%. The reduction in sensible heat carried by the flue-gas outlet reached 2.28 MW, resulting in potential coal savings of 3,437.07 tonnes per year and a CO₂ emission reduction of 5,416.28 tonnes per year. Under the base financial scenario, the investment generated a net present value of IDR 2.6 billion, an internal rate of return of 348%, and a payback period of 2.68 months. Therefore, replacing the rigid seal with a soft seal is effective in reducing air leakage and is technically, operationally, environmentally, and financially feasible.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	air leakage, rotary air preheater, CFD, soft-seal, kelayakan investasi, air leakage, rotary air preheater, computational fluid dynamics, soft seal, investment feasibility
Subjects:	T Technology > TJ Mechanical engineering and machinery > TJ164 Power plants--Design and construction T Technology > TJ Mechanical engineering and machinery > TJ263 Heat exchangers
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	Hafied Yusra
Date Deposited:	30 Jul 2026 01:31
Last Modified:	30 Jul 2026 01:31
URI:	http://repository.its.ac.id/id/eprint/140265

Actions (login required)

View Item