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Kebakaran gambut relatif sulit dipadamkan karena karakter kebakaran gambut yang membara di bawah permukaan tanah. Penelitian ini bertujuan untuk menganalisis perambatan api yang membara pada gambut yang sering terbakar dengan berbagai kadar air. Variabel yang diukur adalah perubahan suhu terhadap waktu, laju propagasi, dan laju kehilangan massa. Kadar air dari daerah yang sering terbakar yang dikeringkan selama 16 dan 24 jam adalah 272,00% dan 494,00%. Kadar air pada penelitian sebelumnya yang dilakukan terhadap sampel gambut yang dikeringkan selama 16 dan 14 jam adalah 577,52% dan 713,24%. Analisis pada kedua sampel menunjukkan bahwa sampel gambut yang dibakar pada tahun 1997/1998 memiliki suhu yang lebih tinggi daripada sampel gambut yang sering dibakar. Perambatan panas pada sampel gambut yang terbakar sekali pada tahun 1997/1998 berlangsung lebih lama (9-10 jam) dibandingkan dengan gambut yang sering terbakar (6-7 jam). Laju perambatan vertikal pada gambut yang sering terbakar lebih lambat (6-30 cm/jam) dibandingkan dengan sampel gambut yang terbakar tahun 1997/1998 (9-41 cm/jam), tetapi laju perambatan horizontal pada gambut yang sering terbakar terjadi lebih cepat (5-35 cm /jam) dibandingkan gambut yang terbakar sekali pada tahun 1997/1998 (11-21 cm/jam). Laju kehilangan massa pada gambut yang sering terbakar adalah lebih rendah (9-22 gram/jam) dibandingkan dengan contoh gambut yang terbakar sekali pada tahun 1997/1998 (25-32 gram/jam). Kata kunci: gambut, kadar air, pembakaran

Kadar air gambut adalah salah satu faktor yang memengaruhi terjadinya kebakaran gambut. Penelitian ini bertujuan untuk mengetahui pengaruh kadar air gambut terhadap proses perambatan pembakaran, serta pola perambatan pembakaran gambut pada skala uji laboratorium, menggunakan reaktor panas berukuran 10x10x10 cm3 dengan 3x3 thermocouple Penelitian ini menunjukan bahwa proses pembakaran terjadi pada seluruh sampel gambut pada kadar air yang hilang (350.91%, 577.52%, dan 713.24%). Pola perambatan pembakaran yang terjadi relatif sama pada semua tingkat kadar air yang hilang, dengan termokopel 8 paling lama bertahan dengan suhu yang tinggi dibandingkan dengan termokopel lainnya. Perambatan pembakaran pada gambut yang diteliti berbeda. Nilai perambatan arah vertikal pada gambut perlakuan oven 16, 24, dan 48 jam secara berurutan yaitu 9,62 cm/jam, 24,99 cm/jam, dan 41,72 cm/jam, sedangkan nilai perambatan arah horizontal secara berurutan yaitu 11,74 cm/jam, 17,31 cm/jam, dan 21,42 cm/jam. Kata kunci: gambut, kadar air, pembakaran

Smouldering is a slow-burning, low-temperature, flameless combustion, and frequently happens in peatland fires. The smouldering spread occurs because of the parameter achievement in oxygen supply, generated heat, and heat released to the environment. The condition of porous and fibrous peat soils makes oxygen supply easily happens. The difficulty of getting to the location of the burning peatland is one of the problems to extinguish the fire. This study aims to observe with thermal imaging study the effect of peat permeability on smouldering behaviour of a tropical peat sample. Mechanical compaction was applied to reduce permeability and pore value in the central of the peat soil. Then, peat soil is ignited to create the smouldering propagation through the compacted peat area. The combustion process that occurs on the surface is observed by a visual camera and an Infrared FLIR Thermal Camera. The initial results showed a reduction in the smouldering spread rate on the compacted soil region as compared to the undisturbed peat smouldering region. Nevertheless, smouldering combustion of peat still occurred in all regions of the reactor, once the smouldering front could penetrate the compacted region.

Spontaneous combustion of coal has been well-known as a problem faced by coal industries, especially in storing and trans-shipping processes. The negative impacts of this phenomenon have led to several hazardous incidents and degrading product quality. Several methods have been researched to minimize the impacts; one of the proposed ways is immersing heat exchangers inside the coal stockpile. An experiment was conducted to analyze the cooling effect of an immersed simple heat exchanger made of a copper coil. By varying the number of windings, the experiment showed a significant decrease in pile temperature due to the immersed heat exchanger. This work continues exploring the possibility of applying the method by observing and analyzing the simulation model. COMSOL Multiphysics was used to model the physics phenomena that occur within the coal reactor. The effect of the heat exchanger surface area was studied from the model to observe the heat propagation within the coal reactor. The vast reach of heat propagation from the heat exchanger through the coal pile on the simulation was promisingly showing that this method was useful to limit the occurrence of spontaneous fire in coal piles.

Indonesia’s increasing energy dependence on fossil fuels amid the country’s declining petroleum reserves requires the development of an effective solution in the form of renewable fuels such as fuel-grade bioethanol. This study investigated a potential way of reducing dependence on fossil fuels for motorcycle engines by using fuel-grade bioethanol blended with gasoline to produce a novel marketable fuel type. The present paper focuses on the effect of various fuel blends >40% ethanol on the performance of a spark ignition (SI) engine. This study used a standard, off-the-shelf, 150cc SI engine as the test engine, running on RON 92 gasoline with varying mixtures of bioethanol (40% (E40); 50% (E50); and 60% (E60)), connected to a dynamometer to obtain performance data (torque, power, and specific fuel consumption) and emission data (hydrocarbon, carbon monoxide, and carbon dioxide). The results showed that E60 represented the optimum mixture as it produced the highest torque, power and specific fuel consumption optimum used E50.

Peatland fire releases a huge amount of carbon emissions to the atmosphere causing air pollution and soil damage. The total emission released to the air could be calculated through the amount of peat that burned downor known as depth of the burn. In this research, a device was developed to detectthe smouldering spread of peat both laterally and vertically through the subsidence. The device was operated using a microcontroller and a laser ranging module. This paper presents a preliminary result on the device capability on measuring several objects such as flat surface and semi-spherical objects.

This study investigates the possibility of substituting liquid petroleum gas (LPG) with dimethyl ether (DME) by considering the procedures of burner design in terms of working region, flame stability, and flame height. An experiment was designed using a cylindrical burner worked in atmospheric pressure by means of diffusion combustion. Comparisons of the working region, flame stability, and flame height were made between LPG, DME, and DME-mixed LPG with DME compositions of 10%, 20%, 30%, 40%, and 50% w/w. The results show that, based on flame stability in terms of lift off (LO) and blow out (BO), the uf working region for DME is 67.8% lower than that of LPG, while the burning load (BL) working region for DME is 79.7% lower than LPG. Using the obtained uf working region, the average FH of DME is 31.4% lower than LPG. Blends of LPG and DME improve the working region and FH of DME.

Smouldering spread of peat fires has been studied by numerous researchers. This study focus on the development of an adjustable reactor for studying the horizontal spread rate of tropical peat. Experimental work was performed to study the impact of peat layer thickness on horizontal smouldering spread behaviour. The thickness of the peat layer was varied 2 cm, 3 cm, and 4 cm peat thickness. A 3 cm-long coil heater was placed in the centre of the base. For ignition protocol, the coil heater was powered with 100 W of electricity for the first 60 minutes. Smouldering behaviour was observed by the temperature data, that measured using thermocouples and a thermal camera. The thickness of the peat layer and bulk density play important roles in the horizontal spread probability, as it changes the heat balance between the heat generation at the reaction zone and heat loss to the environment. Higher peak temperature was observed for peat 4 cm depth and then decreased by the thickness. The smouldering spread rate increases by peat thickness from 2.21 cm/h to 2.91 cm/h and then reach an asymptotic level. Extinction corresponds to a negative energy balance observed in thickness 2 cm of peat. A self-sustained smouldering front could not be maintained after the igniter was turned off. The detail of the adjustable reactor design and more data analysis will be presented in the full paper.

This study aimed to evaluate the pressure difference distribution across the escape stair in a 24-story stairwell. A large eddy simulation (LES) method was used to model the pressure in a stairwell model with a set of simulation parameters using FDS (Fire Dynamic Simulator) software. Two configurations of fans involved single injection, and multiple fan injection is observed. A Single-injection fan is located on the highest point of the stair. The double injection system consists of two fans and is separated at 45 m at each other. When the fire alarm is activated, the pressurization fan automatically runs and delivered outdoor air to the stairwell. It is commonly acknowledged that the pressure would start to built-up in the stairwell before the occupants entering the stair by open the door. Besides, when the pressure is significantly high, the door is unable to be open from outside by occupants as a consequence. In order to overcome this issue, a pressure relief damper was then installed on the top of the stair. The numerical study shows possible pressure difference in the stairwell is about 50 and 95 Pa. However, a multi injection system has the advantages of proper pressure distribution along the stairwell. Performance-based design by using numerical computation is a valuable tool to predict the engineering system and presents a better understanding of how the system would perform in design.

Smoke from peatland wildfires contributes significantly to global greenhouse gas (GHG) emissions, while reactive gases and particulates cause transboundary haze episodes. Haze is the large-scale accumulation of smoke at low altitudes, especially frequent in Southeast Asia during dry periods. Understanding emissions from peatland fires plays a vital role in calculating GHG budgets, forecasting haze events and modelling future climate change. However, only a handful of field studies or laboratory experiments on tropical peat fire smoke have been undertaken to date. Of the few studies that have investigated tropical peatland fire emissions, there exists substantial inter-study variabilities of emission factors (EFs) with some gas emission factors varying by a factor of 10 between studies. Explaining the nature of such variability remains a challenge. In August/September 2018 in Riau, Indonesia, we carried out the first field-scale experimental burn on a tropical peatland (the GAMBUT Workshop), aiming to understand how fires ignite, how they spread, and how emissions vary across the life-cycle of a peatland fire. Our site was a heavily degraded tropical peatland subjected to long-term drainage, logging, and agricultural conversion. Here we present the field measurements of gas emissions from the fire experiment. Open-path Fourier transform infrared spectroscopy (OP-FTIR) was used to retrieve mole fractions of 13 gas species. EFs from 40 measurement sessions over two weeks of burning during different fire stages (e.g., slash and burn ignition, smouldering spread or suppression) and weather events (e.g., wind or rainfall) were calculated and reported. We present field evidence to indicate that EFs vary significantly among fire stages and weather events. Heterogenous physicochemical properties of our peatland site (e.g. moisture content, inorganic content and bulk density) were also found to affect the EFs. We discuss the implications for air quality forecasting, suggesting the necessity for more complex mapping of peatland heterogeneity/land-use for emissions inventories and temporally variable emissions factors, depending on the time since the initiation of a fire event.

Indonesia has the largest peatland area in the tropical region, situated mainly in Sumatra, Kalimantan and Papua. Peat is an organic substance which is highly combustible in dry conditions; dried peat can burn easily and spread vertically and laterally along peat layers. In Indonesia, peat fires have often occurred in recent decades. Besides being influenced by the amount of organic content, smoldering peat fires are also effected by the drying rate, pyrolysis, and heterogeneous oxidation on the peat surfaces. In contrast to flaming combustion, which have been widely studied, smoldering peat fires remain little understood. To date, the major peat fire-related publications concern the pyrolysis and combustion stages. The contribution of the drying kinetics of peat in the peat fire phenomenon is important, as this could provide complete understanding of the peat fire process. The objective of this paper is to make an isothermal drying kinetics analysis of peat. Peat samples were taken from various locations in Indonesia with the largest peat distribution, namely South Sumatra, Central Kalimantan and Papua. An isothermal test was conducted using a Shimadzu MOC63u Moisture Balance. At certain interval times, the weight of the specimen was measured, until it reached a constant weight of less than a 0.05% change in moisture content. Isothermal analysis was conducted for each peat sample at temperatures of 60, 70, 80, 90, 100, and 110oC. The results show that the activation energies from the isothermal measurement test were 24.97, 25.08, and 30.11 kJ/mole for Papuan, South Sumatran and Central Kalimantan peat, respectively.

Peatland fires remain a major contributor of environmental problems in Indonesia. Several studies on peat fire suppression have been conducted with multiple methods, such as quarrying, water spray, artificial rain, and foam spray. This research is focused on laboratory scaled experiments of Indonesian peat smoldering fire behaviour and suppression by a water mist system. The peat used in this work was obtained from two different locations, namely Papua and South Sumatra, Indonesia. During the suppression tests, the intensity of the water mist spray was varied by changing the distance between the nozzle and the peat surface. Meanwhile, the time periods of spray were 15 min (short period of suppression) and approximately 2 h for full suppression until the peat fire was extinguished. The peat temperature and the total mass lost during the smoldering reaction were recorded to get the burning rate ratio for each sample. The spread rate of the smoldering process was identified by the changes in the local temperatures of the peat bed. The results show that the spread rate of the smoldering combustion front was affected by particle size and permeability of peat material. The short duration of water suppression failed to extinguish the peat fires. A re-ignition phenomenon was identified due to the persistence of stored heat in the core of the peat. In addition, the total water required to fully suppress both peat fires is about 6 L/kg peat.

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.

In the Fire Safety Engineering subject, one of the basic phenomena is fire spread on around an object that close to heat source because of the heat transfer process. At high temperature, radiation thermal have a significant effect on an exposed object. There are 3 kinds of characteristic of radiation, which are reflection, absorption, and transmission. Their characteristics are more convenient to learn if there are experiment tools or learning facilities that used radiation to be the main process. Therefore, this research has the objective of designing and built experimental tools used that process and it refers to radiometer. The radiometer is used to study the radiative heat transfer phenomenon in which heat flux emitted from a heat source is measured by using a heat flux sensor as the measurement instruments. Compared to existing radiometer apparatus, the design of this radiometer has some advantages like multi-axis features, user-friendly, portable, and low-cost manufacture. There are some additional features in radiometer likes variation of measurement range in x, y, and z-axis, measurement of view factor, measurement of tilt plane to acknowledge convection effect to heat transfer process, and using flat radiant heater. In this paper, the outcome is the design of a radiometer that can measure heat flux of thermal radiation and suits the study literature.

Coal transport by sea transportation method including inter-islands barge system remains important means of bulk material transportation method. Depend upon the distance between the coal mine sites to the power plant sited, the coal transportation could take days or weeks. Prolonged transportation time could lead to self-heating leading to spontaneous combustion of lower rank coal. To prevent this, a heat exchanger submersion method is proposed to reduce the potentials of self-heating problem by means increasing the heat loss from the coal piles. This experiment work was conducted to determine the effect of cooling water flow rate on decreasing temperature of coal. Laboratory-scale experiments were performed using a stainless steel cylinder that opens at the top and insulated by rockwool to reduce heat loss. The heat source comes from the bottom which is heated by a hot plate heater. A U-shaped heat exchanger of laboratory-scale experiments was prepared. In this experiment, subbituminous coal was used. The effect of flow rate on the prevention of spontaneous combustion was studied by providing variations of the flow rates, thus the amount of heat taken from the heated coal bed. In this experiment the greater flow rate is accompanied by a higher decrease in coal temperature. Therefore, this heat exchanger effective for taking heat from the coal bed.

Smoldering is the dominant mechanism of combustion in peat fires. It is represented by a slow burning, low temperature, and flameless types of combustion. The rate of spread of smoldering peat is generally considered as the main feature in relation to a rating of fire hazards. It is determined by the oxygen supply, the amount of heat generated and the amount of heat loss that is released into the environment. Since the heat balance of a smoldering combustion process is affected by the amount of heat generation and heat loss to the environment, therefore the size of the peat layer plays a great role. This study aims to observe the impact of the layer thickness on the smoldering spread of peat samples from Papua, Indonesia. The experimental works were carried out in an adjustable reactor equipped with insulation board to minimize the heat loss to the environment, a set of thermocouples spread evenly throughout the reactor, a data acquisition system, and a FLIR One infrared camera. The dry peat samples (MC 3-5 % wet base) was ignited using an electric coil heater which was powered by 100 watts of electricity, and the spread of the heat is observed using a thermocouple circuit and the infrared camera. Experiments were carried on thin peat layers of 3 cm and 4 cm. The results show that the average smoldering spread for 3 cm and 4 cm depth are 4.10 cm/h and 5.01 cm/h respectively. Higher peak temperature was observed for 4 cm depth than the 3 cm depth.

Indonesia has abundant natural resources spread throughout the islands. The utilization of these natural potentials has not been fully played and developed to meet daily needs such as for cooking. The purpose of this study is to explore the potential of leaf litter as a domestic source of energy for cooking. In particular, a set of laboratory scaled experiment was conducted by using leaf litter of the species Artocarpus champaden, L., Nephelium lappaceum, L., and Mangifera indica, L. In Indonesia these species are known as Cempedak, Rambutan, and Mangga trees which produce fallen leaf throughout the years. A way of reducing the leaf litter problems by local people is by collecting it from the garden and roof, then burn it to reduce the volume. The experimental work was carried out through some steps. The leaf litter was transformed to biomass briquettes fuel in order to increase energy content for combustion by adding Canola Oil and Starch as a binder. The briquettes were produced manually with minimum mechanical works. Thermal analysis, including calorific value, proximate and ultimate analysis, was performed by standard method and equipment. The experiment was carried out by using a biomass stove with a fuel chamber volume of approximately 660 cm3. A fan was attached to the stove to supply an updraft forced vortex flow of air. Water Boiling Test method was performed to measure the burning characteristic and stove efficiency. It was found that the briquettes (100 grams) from all leaf type tested can boil the water of 1000 ml within 7 minutes. In general, the burning performance of the briquettes were related to proximate and ultimate analysis of the samples. Nevertheless, by comparing the performance using Water Boiling Test suggested that the discrepancies of the performance using different types of leaf litter were not significant. This work showed that leaf litter has the potential as a reliable energy source for cooking in household at rural areas.

Indonesia is the country with the largest source of coal in the world, one of the region in Tarahan, Sumatera. Many power plants in Indonesia use coal as its main source, one of them in Suralaya. Coal is used as the main source of power generation because it has a heat value and considerable power compared to other generating sources. In addition, the price is relatively cheap to be one consideration of usage. Coal distribution process from Tarahan to Suralaya using barge. The use of barges is still widely used because it can bring considerable capacity and cheap shipping prices compared with other transportation During the shipping process, there is often a fire on coal in barges that greatly affects the safety and quality of coal itself. There have been cases of coal barge fires due to the heat energy incurred by the coal itself. Spontaneous combustion often occur as a result of a pile of coal in barges that are directly exposed by the environment causing spontaneous fires in coal. Environmental factors such as air, temperature, weather, and humidity are very influential. This method to prevent the spontaneous combustion of coal in barges is using the U-tube heat exchanger that is installed on the barge sideboards. The purpose of this research is to have preliminary design and calculate pump capacity of the heat exchanger system in the barge with the consideration of the loading and unloading process of coal so as not to interfere with the work process. Ratio of thermal transfer influence occurring in coal to heat exchanger placement distance to determinate the placement of the heat exchanger. The heat exchanger dimension value uses the pipeline surface area ratio to the coal surface area directly exposed by the environment. The preliminary design drawings of the heat exchanger in the barge are provided. The test results showed the necessary heat exchanger pipe design and placement on the barge to prevent spontaneous combustion.

The phenomenon of wildland fires in the tropical area does not only occur on dry land, but also in wetlands such as peatlands, especially in the dry season which caused the wetlands to dry up then become more flammable. This peat fires are dominated by smoldering combustion that is the most persistent type of combustion. Previous researchers have studied about smoldering combustion behavior and gain some information that the combustion process on peatfires is a function of the moisture content, organic content and density of material, The literature review based on previous research was being an initial guidelines and observations were held by seeing the data that had been taken from laboratory-scale experiments of natural peat soil from Kampar, Indonesia with two types of inorganic modified content are 1:12 and 1:6. This experiment prove that modifying the inorganic content of a sample can affect the ability of peat to smoldering. From observations Natural Peat, Modified Peat 1 and Modified Peat 2 have the value of average smoldering spread rate ∼1.08 cm/h, ∼0.80 cm/h but the Modified Peat 2 was failed to smoldering because the heat generation was not enough to propagate the next deeper layer. The results of this research can provide new knowledge about effect of adding inorganic content and can be one of the basic references for further research related to the prevention of the widespread peatfires which is a serious problem for the environment.

Smoke is the real threat in a fire in an enclosed, underground parking garage. A model of the smoke movement in a basement was simulated using Fire Dynamics Simulator (FDS) 6.0 software. In this paper, the study used a basement model of 60 m (length) × 30 m (width) × 13 m (height) and has three typical floors. Smoke ventilation shafts were provided for the basement. The required ventilation was based on the air changing ten times per hour. Smoke modeling was investigated under different fire scenarios. Well-controlled liquid pool fire with a heat release rate (HRR) of 5, 10, 15, and 20 MW was used as an input parameter. The following parameters were varied: the location of the fire, the presence or absence of sprinklers, the presence or absence of a smoke extraction system, the variation of the quantity of makeup air to be introduced to basement, and the presence or absence of a jet fan and ducting. Simulation shows that the provision of sprinklers is very important to reduce the heat release rate. The ventilation strategy through a mechanical exhaust fans and makeup air fans can be applied to make the time for smoke removal faster. When makeup air is less, the heat release rates from the design fire more than 5 MW cause high temperature in the fire compartment which may cause fatal injury when exposed to human skin. Combination of ventilation fan and jet fan shows good performance to make smoke removal time shorter.

Serious consideration of fire phenomena has become mandatory as many strict requirements in fire safety have been implemented in design, construction, management of building, and firefighting strategy. One of the most important features of building nowadays is basement which in fire condition imposes severe threat as smoke and heat movement tend to move upside going through means of egress. Aside from threat to the tenant and building structure, fire – induced smoke is also extremely dangerous to the firefighter during fire fighting operation involving enclosure conditions such as a building fire or even a basement fire situations. One way to study smoke movement and design effective measures in mitigating fire hazard is to conduct experimental fire test by using smaller geometry represent actual real building. This paper study fire – induced smoke movement in 1:8 scale of basement structure represent actual basement facility used for firefighter training. By assuming that smoke movement and temperature distribution is mainly caused by buoyant force from combustion of fire source, Froude number is maintained in the non – dimensional analysis for scaling purpose to hold temperature constant while leaving Reynold number differs from the real scale phenomena. This approach is considered sufficient and acceptable as long as the flow in the small scale model is turbulent enough. Further, result from the fire test in this study was compared with result from fire simulation built using Fire Dynamic Simulator (FDS) of NIST. Thus, aside from assessing fire phenomena by using Froude modeling and planning effective firefighting strategy in basement fire, this study can also be used as validation study of FDS which is widely used by fire safety engineering community.

Smoldering combustion is a phenomenon that is quite unique, because it is a flameless combustion. This smoldering phenomenon can be a hazard, because of it's characteristics. The characteristic of smoldering combustion is slow, low-temperature, flameless and sustained combustion. This phenomenon can occur on cellulose material both organic and non-organic. Smoldering combustion in organics material can cause a wildland fires, both in surface and inside the soil. This phenomenon in organics material was studied using tobacco material and found that ignition temperatures of 380-620 o C were observed. This reaserch was conducted in small scale, vertically oriented smoldering cylindrical apparatus, with varied air flow and from-up ignition (downward propagation). The oxidizer which contacted with the bottom surface of tobacco, was forced in certain volumetric flow rate. A constant power to igniter is applied until the temperature of tobacco 10 mm from the igniter reached 500 o C. The main observation of this research is temperature distribution, mass loss rate and optical density from the resulting smoke. The temperature records in this research were measured by six type-K thermocouples. The mass loss rate of the tobacco in this research were masured by digital scale in real time. The optical density from the released smoke in this research were measured by opacity meter, which transmitted intensity value, converted into optical density value. Air flow variations used in this research were 1, 3, 5, 7, and 9 liter per minute (LPM). The result of this research showed that air flow is an important factor in the process of smoldering combustion. The ignition position and direction of air flow affect direction of propagation. In this research the propagation occured in two direction. In the first process, the propagation of smoldering front was in downward direction. Nevertheless, after the smoldering front reached the bottom surface of tobacco, heat released by ember were accumulated. The air flow from the bottom of the tube forced the combustible mixture to move upwards and then followed by the upward propagation of smoldering front.

Shophouse (Rumah Toko) is a type of building that provides a combined functions for residential and business purposes. Fire risk of shophouse building depends upon the type and volume of the materials stored in the premises. Fire safety improvement for shophouses can be achieved by providing fast response and effective fire supression system such as water mist system. Water mist is a fire supression system that minimizes the risk of material damage by cooling the surface of fuel material. Wood, cellulose material, is one of the most common materials that can be found in shophouse building, thus it is used as fuel material in this experiment. The experimental work was performed in laboratory scale using a single full cone spray with various water pressures of 3, 5 and 7 bar and various fuel placement ((1) center of the room; (2) one corner of the room; (3) all 4 corners of the room). Comparison with numerical simulation using Fire Dynamics Simulator version 6.0 in 1:1 scale with the real test experiment was also performed. Wood crib of 12 cm x 12 cm x 27 cm sizes with an estimated heat release rate of 126 kW/m 2 was applied in this work. The water mist nozzle was placed at 2.5 m height above the floor. The water was supplied by a stand alone pump. The results showed that water mist spray can extinguish the fire effectively under 5 minutes, with 7 bar system pressure as the fastest. Droplet coverage area measured from discharge nozzle, increased in accordance with the increase of water pressure. At higher water pressure, water mist can cover larger fuel surface and perform cooling action, to prevent fuel vapor from reacting with oxygen. Water usage calculated for water mist (NFPA 750) for each system pressure of 3, 5 and 7 bar was 0.15, 0.19, and 0.23 LPM/m 3 ,respectively. It shows that water mist system requires far less water consumption than the calculated water requirements for sprinkler system (NFPA 13) of 0.79 LPM/m 3 which uses the nozzle's K factor.

The unconfined vapor cloud explosion (UVCE) is fire accidents that could cause severe damage and it sometimes leads to high potential of casualties. Severity caused by UVCE is due to its wide spread fire explosion and that the source mostly comes from a relatively small amount of gasoline or gas leak that has happened long enough leading to the occurrence of an explosion. Since the awareness to this situation relatively low. Research on flammability levels from various liquid and gas fuels has been conducted extensively and it has even been shown in MSDS which ease users in utilizing fuel handling and the selection of safety factors. There have been many studies completed on discovering the cause of fire occurrence especially after the incident of several UVCE-related accidents. Similarly, many dispersion models of fuel leakage and liquid followed by evaporation process have been developed at an applicable level. UVCE still leaves some questions related to the initiation of the explosion. Some research on the phenomenon of explosions on UVCE has been carried out to find out the conditions so as to enable an explosion. Moreover, there is still one question unanswered on UVCE concerning on how do high velocity of deflagration arises in the conditions of an open space explosion. From an accident evaluation so far, it can be believed that the obstacle in the flame path will make the escalated flame velocity reach the Deflagration to Detonation Transition (DDT) level. This was supported by the results of a large scale experimental study conducted by several researchers whose results were reported in line with these assumptions. In addition, some researchers believe that the explosion of UVCE is sequential, beginning with the initial fire. The flame formed will generate heat quickly through radiation heat transfer to the unburned vapor cloud section. This phenomenon is considered responsible for the occurrence of a larger explosion and covers a large area on several accidents.This paper presents preliminary results from lab scale research to characterize the deflagration velocity of vapor cloud flame which is affected by the temperature of the environment. Visual observation is processed from the camera record on deflagration in an open vertical tube with a hot plate. By using gasoline as a vapor cloud source, tests were carried out in three conditions: lean mixture, stoichiometric mixture and rich mixture. In experiments with lean mixture does not occur or it is difficult to fire. For stoichiometric mixture, deflagration occurs quickly and causes an explosion sound. In rich mixture conditions a loud explosion occurs. Especially for the 1.8 stoichiometric concentration, two fires were produced and with the loudest explosion sound. On first fire combustion occurs quickly with a large fireball, after which a second explosion is followed which depletes the rest of the unburned vapor cloud. In experiments with very rich mixture (concentrations of 2 x stoichiometric conditions) occur fire with a slow flame velocity and form soot significantly.

This paper presents a multi-objective optimization model for a long-term generation mix in Indonesia. The objective of this work is to assess the economic, environment, and adequacy of local energy sources. The model includes two competing objective functions to seek the lowest cost of generation and the lowest CO2 emissions while considering technology diffusion. The scenarios include the use of fossil reserves with or without the constraints of the reserve to production ratio and exports. The results indicate that Indonesia should develop all renewable energy and requires imported coal and natural gas. If all fossil resources were upgraded to reserves, electricity demand in 2050 could be met by domestic energy sources. The maximum share of renewable energy that can be achieved in 2050 is 33% with and 80% without technology diffusion. The least cost optimization produces lower generation costs than the least CO2 emissions, as well as the combined scenario. Total CO2 emissions in 2050 are five to six times as large as current emissions. The least CO2 emissions scenario can reduce almost half of the CO2 emissions of the least cost scenario by 2050. The proposed multi-objective optimization model leads some optimal solutions for a more sustainable electricity system.

Fire in a typical car park is capable to induce large Heat Release Rate. The heat release rate in car park can be ranged from 500 kW to 20 MW depends on the ventilation condition of the car - park and the car itself. When fire occurs in poor ventilated car, i.e. the window is closed, fire will immediately burn out. Otherwise, fire will rapidly spreads and consume adjacent car. This condition can result in wide spread of fire involving all of the available car in the parking lot considering the availability of ventilation in underground car - park which strongly affect the fire and smoke spread. In this paper, a typical large underground car - park is being considered by varying the aspect ratio of the parking lot shape with constant floor to ceiling height. The effect of horizontal ventilation system and its thrust direction on the spread of smoke, its flow pattern, and overall CO distribution will be covered. In addition, the impact of additional building structure, basement aspect ratio, and ceiling beam will be discussed by considering it effect on smoke flow pattern and extraction effectiveness. Furthermore, based on the simulation which had been carried out the dilution of smoke by the air from the horizontal ventilation system is significantly increasing the CO concentration at 2 m height as it disturbed the smoke concentration stratification.

Stoker fired boilers have been used widely for small scale power plant in isolated region or small island in Indonesia and for industries. Nevertheless, stoker fired boilers face some operational problems related to burning low rank coal. Water cooled vibrating grate stoker has potential to minimize the problem compared to traveling grate stoker. In this study, 15 kW (th) vibrating grate stoker simulator has been developed for characterizing combustion in stoker fired boiler. Combustion characteristic such as burning out time and combustion rate can be evaluated for both fixed grate and vibrating grate types. Experimental results plotted in horizontal temperature profiles indicate important combustion steps, i.e. drying, volatile release and char burning. Peak temperature while burning sub-bituminous coal was 861 °C, higher than lignite coal of 647 °C. In vibrating grate, the combustion rate of sub-bituminous and lignite coal in vibrating grate increase 56.5% and 25.9%, respectively, compared with in fixed grate. Application of vibrating grate instead of fixed grate in boiler can minimize the furnace size room because of higher heat release rate per area.Stoker fired boilers have been used widely for small scale power plant in isolated region or small island in Indonesia and for industries. Nevertheless, stoker fired boilers face some operational problems related to burning low rank coal. Water cooled vibrating grate stoker has potential to minimize the problem compared to traveling grate stoker. In this study, 15 kW (th) vibrating grate stoker simulator has been developed for characterizing combustion in stoker fired boiler. Combustion characteristic such as burning out time and combustion rate can be evaluated for both fixed grate and vibrating grate types. Experimental results plotted in horizontal temperature profiles indicate important combustion steps, i.e. drying, volatile release and char burning. Peak temperature while burning sub-bituminous coal was 861 °C, higher than lignite coal of 647 °C. In vibrating grate, the combustion rate of sub-bituminous and lignite coal in vibrating grate increase 56.5% and 25.9%, respectively, compared with in fixe...

Probability of land and forest fire in Indonesia is quite high. Peat land is one of the highest contribute of the fire disaster. Indonesia is the country with the highest peat land in Southeast Asia, with more than 50 % of tropical peat species. Combustion of peat produced carbon emission with large quantities and affect to global warming. Characteristic of smoldering combustion of peat cause detection and extinction be difficult. Moreover, there are another impact such as high erosion potential, structural collapse and soil layer damage. Flameless on peat smoldering causes peat restoration institution build fire prevention method. Regulation of water table on peat land with rewetting method aims to maintain and restore the moisture of peat. The experiment aims to understand characteristic of smoldering combustion of rewetting peat. Sample used in the experiments was taken from Bagaiserwar village, Sarmi, Papua (01°55’14, 11”, E: 138°6’17, 35”). A set of thermocouples were used to explore horizontal spread rate at 80 mm intervals. Mass loss rate indicates derivation caused by evaporation on wet peat. Author discovered a fire risk is higher than natural combustion in experiments with rewetting peat. Spread rate of smoldering is high on rewetting peat with initial MC before rewetting is ≤ 10 %. Hydrophobic of peat cause retention of water on peat changes. This phenomenon causes evaporation process being faster and total combustion time occur rapidly, start from preheating until self extinction.

Smoldering combustion was categorized as a very dangerous combustion and considered as a main cause to haze problem during wildland fires in Sumatera, Indonesia. This study aims to determine the characterized of the spread of peat fire, so the mitigation can be done. This study was used experimental methods. In this case, peat from Riau were analyzed and the samples to be used were peat that has been dried in the oven during 24 hours at 100 °C of temperature, moisture content after interaction with air was 7.09%;. This study was resulted the maximum combustion temperature of 508.72 °C. The rate of propagation of peat fires was determine from the difference of time when the combustion temperature reaches 300°C and 365°C. The rate of smoldering propagation at temperature of 300°C of 14.3 cm/h on the vertical direction and 6.31 cm/h on horizontal direction. The rate of smoldering propagation at temperature of 365oC of 19.76 cm/h on the vertical direction and 5.17 cm/h on horizontal direction.

CFD simulations of full scale wind turbine have been carried out to predict recovery of wake that occur behind the hybrid VAWT turbine double, which states that recovery starts to occur in plane x/d = 4, verification of this result needs to be done. This study tested and measured the wind speed behind the scale model turbine in the wind tunnel. The purpose of this study was to create a prototype scale model of the VAWT hybrid, test it in the wind tunnel. Statistical methods will be used in this study to process data and determine the recovery position of wake from the VAWT double hybrid. The results show that wake recovery in wind tunnel experiment, in field x/d = 3 with 99%, compare with wake recovery occurs in simulation, shown a show the same trend, but need further investigation with similarity and Reynold number.