Analisa Pengaruh Perubahan Waktu Injeksi Diesel Fuel Dan Penggunaan Internal EGR Terhadap Performa dan Emisi Gas Buang Pada Mesin Diesel Dual Fuel Diesel Methanol

Yudhana, Samadhi Padma (2025) Analisa Pengaruh Perubahan Waktu Injeksi Diesel Fuel Dan Penggunaan Internal EGR Terhadap Performa dan Emisi Gas Buang Pada Mesin Diesel Dual Fuel Diesel Methanol. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penelitian ini bertujuan untuk menganalisis secara menyeluruh pengaruh variasi waktu injeksi bahan bakar (Start of Injection/SOI) dan penerapan sistem Exhaust Gas Recirculation (EGR) internal terhadap kinerja dan emisi gas buang pada mesin diesel dengan sistem dual fuel menggunakan campuran 20% metanol. Pengujian dilakukan pada mesin diesel satu silinder Yanmar TF-85 dengan variasi waktu injeksi antara 16° hingga 20° sebelum titik mati atas (BTDC), pada berbagai tingkat putaran dan beban mesin. Parameter yang diamati meliputi daya, torsi, konsumsi energi spesifik (SFC), serta emisi CO₂, NOx, smoke value, dan methane slip. Hasil pengujian menunjukkan bahwa variasi waktu injeksi memberikan pengaruh signifikan terhadap efisiensi dan emisi. Waktu injeksi pada 19° BTDC menghasilkan efisiensi konversi energi tertinggi pada mode dual fuel, dengan penurunan konsumsi energi dari 12,543 MJ/kWh (mode single fuel) menjadi 11,03 MJ/kWh pada 1800 RPM, menunjukkan peningkatan efisiensi sekitar 12,14%. Daya maksimum tercatat sebesar 4,85 kW pada SOI 19° pada 2200 RPM, sedangkan torsi tertinggi sebesar 22,58 Nm juga terjadi pada SOI 19° pada 2000 RPM. Emisi CO₂ pada mode dual fuel dengan SOI 19° menunjukkan nilai yang lebih tinggi dibandingkan SOI 18° (misalnya, 2,97% vol pada daya tertinggi dibandingkan 2,26% vol pada SOI 18°), mengindikasikan pembakaran yang lebih efektif. Emisi NOₓ pada SOI 19° sedikit lebih tinggi dibandingkan SOI 18° pada beban rendah hingga menengah, namun tetap jauh di bawah mode single fuel (penurunan lebih dari 70%). Penggunaan EGR internal terbukti efektif dalam menurunkan emisi NOₓ hingga 30–40% dibandingkan tanpa EGR, terutama pada beban tinggi. Kombinasi dual fuel dan EGR dengan SOI 19° menghasilkan daya tertinggi 4,81 kW pada 2200 RPM dan torsi tertinggi 22,44 Nm pada 2000 RPM. Emisi methane slip terdeteksi dalam jumlah kecil (1,58–2,47 ppm), dengan tren penurunan pada beban tinggi (1,30–1,48 ppm), menunjukkan penurunan sekitar 20-30% dibandingkan beban rendah. Secara keseluruhan, pengaturan waktu injeksi yang tepat serta penerapan sistem EGR internal secara bersamaan terbukti mampu meningkatkan efisiensi energi dan menurunkan emisi gas buang. Konfigurasi SOI 19° BTDC direkomendasikan sebagai titik operasi optimal untuk keseimbangan antara performa dan emisi, meskipun untuk pengurangan emisi NOx dan smoke value yang maksimal, SOI 16° atau 17° BTDC mungkin lebih sesuai.
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This study aims to thoroughly analyze the effect of variations in fuel injection time (Start of Injection/SOI) and the application of an internal Exhaust Gas Recirculation (EGR) system on the performance and exhaust emissions of a diesel engine with a dual fuel system using a 20% methanol blend. Tests were conducted on a Yanmar TF-85 single-cylinder diesel engine with variations in injection timing between 16° to 20° before top dead center (BTDC), at various levels of engine speed and load. Parameters observed included power, torque, specific energy consumption (SFC), as well as CO₂, NOx, smoke value, and methane slip emissions. The test results showed that injection timing variations had a significant effect on efficiency and emissions. Injection timing at 19° BTDC resulted in the highest energy conversion efficiency in dual fuel mode, with a decrease in energy consumption from 12.543 MJ/kWh (single fuel mode) to 11.03 MJ/kWh at 1800 RPM, indicating an increase in efficiency of approximately 12.14%. Maximum power was recorded at 4.85 kW at SOI 19° at 2200 RPM, while the highest torque of 22.58 Nm also occurred at SOI 19° at 2000 RPM. CO₂ emissions in dual fuel mode with SOI 19° showed higher values compared to SOI 18° (e.g., 2.97% vol at highest power compared to 2.26% vol at SOI 18°), indicating more effective combustion. NOₓ emissions at SOI 19° were slightly higher than SOI 18° at low to medium loads, but remained well below the single fuel mode (more than 70% reduction). The use of internal EGR proved effective in reducing NOₓ emissions by 30-40% compared to no EGR, especially at high loads. The combination of dual fuel and EGR with 19° SOI produced the highest power of 4.81 kW at 2200 RPM and the highest torque of 22.44 Nm at 2000 RPM. Slip methane emissions were detected in small amounts (1.58-2.47 ppm), with a decreasing trend at high load (1.30-1.48 ppm), showing a decrease of about 20-30% compared to low load. Overall, proper injection timing and simultaneous application of the internal EGR system were shown to improve energy efficiency and reduce exhaust emissions. An SOI configuration of 19° BTDC is recommended as the optimal operating point for a balance between performance and emissions, although for maximum NOx and smoke value emission reduction, an SOI of 16° or 17° BTDC may be more suitable.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	dual fuel; emisi; internal EGR; metanol; performa; waktu injeksi;dual fuel; emissions; injection timing; internal EGR; methanol; performance.
Subjects:	V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering > VM731 Marine Engines
Divisions:	Faculty of Marine Technology (MARTECH) > Marine Engineering > 36202-(S1) Undergraduate Thesis
Depositing User:	Samadhi Padma Yudhana
Date Deposited:	05 Aug 2025 12:30
Last Modified:	05 Aug 2025 12:30
URI:	http://repository.its.ac.id/id/eprint/125635

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