Jurnal Teknologi dan Riset Terapan (JATRA)

Analisis Efisiensi Gas Turbine Unit 2 Sebelum dan Sesudah Overhaul di PLTGU Tanjung Uncang

Jhon Hericson Purba — 2024-06-30

An overhaul was conducted for maintenance on Gas Turbine unit 2, type SGT 800 at PLTGU Tanjung Uncang, with the purpose of preventive maintenance. The operating hours of the gas turbine exceeded the maintenance schedule, reaching around 36,000 working hours, whereas maintenance should have occurred between 20,000 to 30,000 working hours. The discrepancy between the actual working hours and the standard maintenance schedule for the gas turbine was due to the Tanjung Uncang power plant operating on a base load system, requiring the turbine to run continuously for 24 hours. This study aims to analyze the thermal efficiency, heat rate, and specific fuel consumption before and after the overhaul. The method used in this study is the thermodynamic analysis calculation of the Brayton cycle. By performing thermodynamic analysis to determine the gas turbine's efficiency and calculating specific fuel consumption, heat rate, and thermal efficiency under load, the comparison of the gas turbine's efficiency values can be determined. The thermal efficiency after the overhaul increased by 5.17%. The heat rate after the overhaul decreased by 1867.806 kJ/kWh. The specific fuel consumption after the overhaul decreased by 0.037 kg/kWh. The overhaul impacted the maximum load that could be produced by gas turbine unit 2. Before the overhaul, the maximum load was 36 MW. After the overhaul, the maximum load increased to 45 MW. This increase in load is influenced by temperature, fuel flow rate, and pressure.

Studi Keausan Mata Pahat Pada Proses Pembubutan Material ST 37

Meilani Mandhalena Manurung — 2024-06-30

Penelitian ini bertujuan untuk membandingkan tingkat keausan pada tiga jenis pahat insert bubut, yaitu CNMG120408-NM4 WPP20, CNMG432-MS3, dan CNMG 150604r-k 4325, dalam kondisi pemotongan yang identik. Variabel kedalaman potongan dan kecepatan spindle ditetapkan pada 1,0 mm dan 560 rpm, dengan material yang digunakan adalah besi ST 37. Hasil menunjukkan bahwa CNMG 150604r-k 4325 mengalami kehilangan massa paling besar, sedangkan CNMG120408-NM4 WPP20 menunjukkan keausan paling rendah. Faktor-faktor yang mempengaruhi keausan ini meliputi gesekan, temperatur tinggi, kecepatan potong, material yang diproses, dan kondisi pemotongan. Penelitian ini memberikan highlight tentang faktor-faktor yang mempengaruhi keausan pada pahat insert bubut sehingga dapat dijadikan referensi untuk pemilihan pahat yang tepat untuk meningkatkan efisiensi proses permesinan

Studi Simulasi Statis Struktur Desain Cradle Penopang Kokpit BAC 111

Windy Stefani — 2024-06-30

Cradle, a lifting device used to move the Cockpit head and other aircraft parts. The aim of this research is to obtain maximum data on the cradle structure through static simulation using SolidWorks 2020 software. The research was carried out by simulation using SolidWorks 2020 software with analysis of stress, strain and safety factor calculations for the cradle structure in supporting a static load of 1400 kg. The cradle design process was made using SolidWorks software, with the cradle size being 338 cm long, 145 cm wide at the top and 297 cm at the bottom, and using ASTM A36 type channel iron material with dimensions of 150 mm x 75 mm x 6.5 mm with loading. static of 1400 kg. The simulation results show that the maximum pressure value applied to the cradle with ASTM A36 steel material is 50.206 Mpa, below the yield strength value of 250 Mpa. The maximum displacement recorded was 1,169 mm, indicating that the deformation that occurred in the cradle structure was very minimal. With a maximum cradle capacity weighing 6.97 tons and a maximum wheel load capacity of 2.7 tons

Perbandingan Ketangguhan Material S355G7+M Pada Pengelasan SAW (Original) dan SMAW (Repair) Dengan Metode Impact Charpy V-Notch

Roza Puspita — 2024-07-31

Proses pengelasan SAW menggunakan fluks yang berbentuk seperti pasir yang berfungsi melindungi logam pengisi yang mencair saat proses pengelasan agar tidak terjadinya kontaminasi dengan udara luar sehingga didapatkan hasil pengelasan yang cukup baik. Sedangkan elektroda SMAW (Shielded Metal Arc Welding) diselaputi atau dilindungi oleh fluks dengan proses pengerjaan secara manual. Penelitian ini bertujuan untuk menganalisa perbandingan hasil pengelasan dengan menggunakan metode standar WPS PS-03 (Original) dan WPS PS-03R (Repair), dengan menggunakan pengujian impact untuk mengetahui ketangguhan pada spesimen S355G7+M. Pengujian ini bertujuan untuk mengetahui ketangguhan impact pada bagian hasil pengelasan pada WPS PS-03 (Original) dan WPS PS-03R (Repair). Spesimen WPS PS-03R memiliki nilai lebih besar di bandingkan dengan spesimen WPS PS-03. Apabila nilai kekuatan spesimen semakin besar, maka semakin kuat dan tangguh pula pada spesimen tersebut. Temperatur pada spesimen sangat berpengaruh terhadap keuletan atau kegetasan suatu logam. Semakin tinggi temperaturnya maka semakin ulet logam tersebut begitupun sebaliknya.

Pengaruh Engine Bleed Trip Terhadap Tingkat Kebutuhan Pergantian Komponen Pada Pesawat B737-800

Muhammad Andi Nova — 2024-06-30

An engine bleed trip is an indication that there is a failure in the engine bleed system in regulating the temperature and pressure of the bleed air. This can affect the work of other systems that rely on the output of the engine bleed system, one of which is the cabin pressure system. The aim of this research is to find out the percentage level of the need for main components in the engine bleed system to be replaced in handling engine bleed trip cases. This research is an ex post-facto comparative research with primary data collection methods sourced from aircraft maintenance databases and interviews. The research results showed that from a total of 52 bleed trip cases that occurred during 17 months, the percentage of main components that needed to be replaced were the 390F thermostat sensor (42.3%), precooler control valve (19.2%), pressure regulating shuttle valve (11 .5%), bleed air regulator (7.7%), and the rest are other components.