Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Proses pencampuran merupakan faktor penting dalam proses pembakaran untuk mencapai efisiensi termal yang lebih tinggi terutama pada wilayah premix flame, ini disebabkan homogenitas pencampuran bahan bakar dan udara mempengaruhi heat release rate. Tujuan dari penelitian ini adalah untuk meningkatkan efisiensi termal dari rotating fan mixer swirl burner dengan cara menimbulkan aliran pusar (swirling flow) dalam ruang pencampuran. Aliran pusar tersebut akan dihasilkan oleh rotating fan mixer (RFM) dan akan dihitung dengan bilangan tak berdimensi yang disebut swirl number yang merupakan perbandingan antara fluks aksial dari momentum anguler dan momentum aksial. Variasi swirl number yang digunakan pada percobaan ini antara lain 0,46; 1,79; 2,97; 3,93 and 4,66. Komposisi bahan bakar dan udara berada dibawah kondisi stoikiometri dengan menjaga laju aliran udara konstan sedangkan laju aliran LPG divariasikan 9 cc/s; 10,5 cc/s; 12 cc/s; 13,5 cc/s and 15 cc/s. Hasil dari percobaan menunjukkan bahwa efisiensi termal semakin meningkat ketika mendekati komposisi AFR stoikiometri dan peningkatan efisiensi termal untuk setiap AFR yang diujikan adalah sebagai berikut: AFR 7,53 (Δη = 1,29 %); AFR 6,45 (Δη = 1,31 % ); AFR 5,65 (Δη = 1,02%); AFR 5,02 (Δη = 1,64 %); AFR 4,52 (Δη = 3,09%). Hasil ini menunjukkan bahwa pola aliran pusar dapat meningkatkan homogenitas campuran yang mempunyai korelasi dengan heat release rate dari suatu pembakaran premix flame. ...... Mixing process is an essential factor in combustion in order to get the higher thermal efficiency especially in premix flame region, due to the homogeneity of fuel-air mixing which influenced the heat release rate. The purpose of research is to enhance thermal efficiency of Rotating Fan Mixer Swirl burner by generate swirl flow in mixing chamber. Swirl flow will be generated by rotating fan mixer (RFM) and it will be quantified by non dimensional number called swirl number which representing the comparison between axial fluxes of angular momentum and axial momentum. Swirl number used in this experimentation are 0,46; 1,79; 2,97; 3,93 and 4,66. Fuel-air mixing under stoichiometric conditions by using constant air flow rate and LPG flow rate's variation: 9 cc/s; 10,5 cc/s; 12 cc/s; 13,5 cc/s and 15 cc/s. The results of this research show that thermal efficiency increase when AFR is much closer to stoichiometric and the difference's value of increasing thermal efficiency based on the variation of AFR as follows : AFR 7,53 (Δη = 1,29 %); AFR 6,45 (Δη = 1,31 % ); AFR 5,65 (Δη = 1,02%); AFR 5,02 (Δη = 1,64 %); AFR 4,52 (Δη = 3,09%). This result show that swirling flow can enhance homogeneity and it has correlation with heat release rate of premix flame combustion.

Abstrak :
This study aimed to analyze the heat release rate from the combustion process of bioethanol from sago waste to determine the viability and feasibility of low-concentration bioethanol as an alternative fuel. The heat release rate, exhaust gas, and flame temperature were measured using a cone calorimeter, and bioethanol combustion was conducted using the pilot ignition method, with an ethanol quality range of 60–70%. The analysis that the heat release rate of 60% bioethanol combustion ranged from 20 to 140 kW/m2, while a lesser range resulted from 70% bioethanol combustion (18–45 kW/m2). The flame temperature for 60% bioethanol was found to be 440°C, while the smoke and orifice temperature was 150°C. The combustion of 70% bioethanol produced a flame temperature of 450°C and a smoke and orifice temperature of 120°C after approximately 6 min of combustion. This study contributes a solution for meeting the energy demand in rural areas, where the access to and availability of major fuel resources are limited. In addition, from the obtained results, this research concluded that bioethanol made from sago waste is suitable as a clean and alternative fuel for household applications in rural areas.

Abstrak :
ABSTRACT
Industri minyak bumi dan gas dihadapkan pada risiko besar (high risk) terkait dengan kecelakaan yang berhubungan dengan kebakaran dan ledakan pada fasilitas produksi, salah satunya pada tangki produksinya. Penelitian ini bertujuan untuk mengetahui potensi bahaya dan besar estimasi kebakaran yang mungkin terjadi pada tangki produksi di Stasiun Pengumpul Utama SPU-3 KSO PT Pertamina EP – PT Benakat Barat Petroleum menggunakan simulasi pyrosim fire modelling. Hasil penelitian menunjukkan tangki berisiko mengalami kebakaran dengan skenario unobstructed full liquid surface fire dengan bentuk pool fire. Laju pelepasan kalor yang dihasilkan sebesar 91.919,05 kW, dengan durasi kebakaran 48,19 jam, dan ketinggian api 13,48 meter. Radiasi terbesar adalah 20,43 kw/m2. Pemodelan pyrosim menunjukkan kisaran suhu 450o C dimana dengan kondisi tersebut hampir dipastikan terjadi kebakaran katastropik dengan 100% makhluk hidup mati dalam waktu satu menit dan cidera parah dalam waktu 10 detik.

---

ABSTRACT
Oil and gas industry faced high risk hazardous associated with accident-related fires and explosions in production facilities, such as in production tank. This study aims to determine the potential fire hazards and estimates fire accident that may occur in a production tank at Main Gatherring Station SPU-3 KSO PT Pertamina EP - PT Benakat Barat Petroleum using pyrosim fire modelling. The results showed the tank at risk of fire accident with “unobstructed full liquid surface fire” scenario with pool fire form. Fire may produce heat release rate at 91.919,05 kW, with the burning duration reached 48.19 hours, and a height of 13.48 meters fire. The biggest radiation is 20,43 kW/m2. Pyrosim fire modeling show 450o C for temperature range. In that condition is almost certainly be catastrophic fire with 100% living things die in one minute and serious injuries within 10 seconds.

Abstrak :
Kepolisian Negara Republik Indonesia (POLRI) melaporkan 5.336 kecelakaan kebakaran yang terjadi antara Mei 2018 hingga Juli 2023. Tren ini terus meningkat, dan tercatat 255 kecelakaan kebakaran terjadi pada Juni 2023. Oleh karena itu, diperlukan penilaian risiko kebakaran untuk menilai apakah sebuah rumah atau apartemen aman ketika terjadi kebakaran. Metode FLAME merupakan salah satu metode parametrik semikuantitatif untuk mengukur risiko kebakaran pada suatu gedung, dengan tujuan untuk mendapatkan metode penilaian risiko yang mudah digunakan dan dapat menjadi strategi awal untuk menilai suatu risiko kebakaran karena penilaian risiko denga sepenuhnya kuantitatif lebih rumit dan memerlukan biaya lebih besar. Pada penelitian ini metode FLAME dipadukan dengan pemodelan dalam Fire Dynamic Simulator (FDS) untuk menganalisis waktu untuk laju pelepasan panas mencapai 1 MW. Tiga variasi dibuat dengan perbedaan kepadatan properti. Pada variasi 1 dengan properti paling padat, laju pelepasan panas mencapai 1 MW hanya dalam waktu 48 detik. Sedangkan pada variasi 2, laju pelepasan panas mencapai 1 MW dalam waktu 109 detik saat tidak ada sprinkler dan 332 detik saat ada sprinkler. Pada variasi 3, laju pelepasan panas mencapai 1 MW dalam waktu 204 detik ketika tidak ada sprinkler, dan ketika ada sprinkler laju pelepasan panas tetap berada di bawah 1 MW. FLAME memiliki acceptability criteria bagi penghuni dan properti, dimana risiko penghuni dapat diterima untuk semua variasi baik dengan sprinkler atau tanpa sprinkler, dan perbaikan lebih lanjut tidak diperlukan. Acceptabilityrisiko properti berbeda-beda untuk setiap variasi, dengan skor terburuk ada pada variasi 1. Risiko properti pada variasi 1 tidak dapat diterima, dimana tindakan perlindungan mungkin tidak mampu mengatasi parahnya kebakaran. Perbaikan diperlukan agar properti tetap aman ketika terjadi kebakaran. ......The Indonesian National Police (POLRI) reported 5.336 fire accidents that happened between May 2018 and July 2023. This trend is rising, and a record of 255 fire accidents was hit in June 2023. Therefore, a fire risk assessment is needed to assess whether a house or an apartment is safe when a fire accident happens. The FLAME method is a semi-quantitative parametric method to measure the risk of fire in a building, with the goal of having a risk assessment method that is easy to use and that can be the preliminary strategy to asses a fire risk since a fully quantitative risk assessment is more complicated and costs more. In this study, the FLAME method is combined with modeling in a Fire Dynamic Simulator (FDS) to analyze the time for the heat release rate to reach 1MW. Three variations are made with the differences in the density of the property. In variation 1, with the most dense property, the heat release rate reaches 1 MW in only 48 seconds. While in variation 2, the heat release rate reaches 1 MW in 109 seconds when there are no sprinklers and in 332 seconds when there are sprinklers. In variation 3, the heat release rate reaches 1 MW in 204 seconds when there are no sprinklers, and when there are sprinklers the heat release rates are maintained below 1 MW. The FLAME has acceptability criteria for occupants and properties, where the occupant's risk is acceptable for all variations either with a sprinkler or without sprinklers, and further improvements are not required. The property’s risk acceptability varies for each variation, with the worst score is in variation 1. The property’s risk on variation 1 is nonacceptable where the protection measures may not be able to deal with the severity of the fire. The improvements are needed to so the properties will be safe when there is a fire accident.

Abstrak :
The development of a _fire calorimeter (Prototype-I) equipped with an exhaust gas installation, a fluid flow rate measurement apparatus and a gas composition analyzer has enabled combustibility tests of materials (i. e. estimation of heat release rate) by means of oxygen consumption measurements. Two wood species, prepared with across and along grain orientations were used in this work. The incident heat flux levels were varied between 5 to 17 kW/m2 . This paper examines the effects of wood species and heat flux level on the time to ignition, mass loss rate, heat release rate and the correlation established The outcomes are in good agreements with those reported in the literatures.

Abstrak :
ABSTRAK
Dewasa ini, material komposit banyak digunakan dalam berbagai aplikasi karena memiliki sifat mekanik yang lebih bagus dari pada logam, memiliki kekuatan pembentukan yang tinggi, memiliki ketahanan yang baik, memiliki kekuatan jenis dan kekakuan jenis (modulus Young) yang lebih tinggi daripada logam. Namun demikian, material komposit rentan terhadap degradasi termal pada temperatur tinggi. Oleh karena itu, penelitian dalam tesis ini bertujuan untuk meningkatkan ketahan termal dan sifat mampu bakar material komposit dengan mencampurkan zat tahan api berbasis halogen jenis brominated bisphenol A ke dalam material komposit serat karbon dengan dua variasi densitas serat, yaitu 200 dan 240 gr/m2. Penelitian yang dilakukan berbasis pada eksperimen skala laboratorium menggunakan kalorimeter kerucut. Fenomena pembakaran yang terjadi adalah piloted ignition dengan fluks kalor pembakaran dibatasi sampai dengan 25 kW/m2. Hasil penelitian menunjukkan bahwa sampel komposit serat karbon terbakar karena vaporisasi dari resinnya, sedangkan serat karbonnya sendiri hanya mengalami pengarangan (charring). Eksperimen pada fluks kalor 21,12 kW/m2, menunjukkan bahwa kebeadaan kandungan brominated bisphenol A di dalam sampel komposit serat karbon mampu menekan puncak laju produksi kalor dari sekitar 125 kW/m2 menjadi hanya sekitar 80 kW/m2. Hasil penelitian juga menunjukkan bahwa kandungan zat tahan api (fire retardant) mampu menunda waktu penyalaan api pembakaran dan memberikan ketahana termal yang lebih baik kepada material komposit

---

ABSTRACT
Nowadays, carbon fiber reinforced epoxy-acrylate composite (CFRE) is used in various applications such as in aircraft and industrial applications including pressure vessels, civil engineering/construction-related uses, ship manufacturing, and automobile. That is because of its characteristics such as lightweight and high-strength. Nevertheless CFRE is very easy to be burned after preheating in a low heat flux, moreover with the presence of an external energy source. Hence, this study aimed to find out the effects of brominated bisphenol A as fire retardant agent on fire retardancy of CFRE using cone calorimeter with a spark igniter as a trigger to represent an amount of external energy source. Carbon fibers used in this study have density of 200 gr/m2 and 240 gr/m2. The parameter studied in this research includes density of carbon fiber, time to ignition, heat release rate and density of smoke production. In this initial work, the heat flux was limited up to 25 kW/m2 with piloted ignition. The measured temperatures of CFRE’s ignition range from 450oC to 575oC at atmospheric pressure. The initial result shows that the ignition of CFRE is strongly depend on the density of carbon fiber, the existing of an external energy source and the condition of gas mixture. For the density of of 200 gr/m2, CFRE starts to ignite under heat flux of 14.2 kW/m2 with peak heat release rate of 163.4 kW/m2. While for the density of of 240 gr/m2, CFRE starts to ignite under heat flux of 16.7 kW/m2 with peak heat release rate of 98 kW/m2. Combustion mechanism of CFRE started when a spark igniter is turned on after preheating at a certain sufficient heat flux, causing a flaming condition on the surface of CFRE. Next, vaporization of its resin causing a sustain flaming condition until reaching a decay period. When it burned, the resin vapor is forced out of the fiber pores, causing the material to swell and increased its volume. The effects of brominated bisphenol A as fire retardant agent in the CFRE give a significant impact to fire retardancy of the CFRE, especially in time to ignition and heat release rate aspect.