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In-cylinder combustion and emission characteristics of a 3L compression ignition engine using pure biodiesel fuel blended with 5% ethanol
(2026-04-01)
Suteerapongpun, Teerapat
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Huynh, Trung An
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Aung, Sonekhar Jarring
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Thin, Myat Hsu
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Thaeviriyakul, Poonnut
This study investigates the combustion performance, efficiency, and emission characteristics of four fuel blends—B7 (7% biodiesel), B100 (pure biodiesel), B100E5 (95% biodiesel + 5% ethanol), and B100E10 (90% biodiesel + 10% ethanol)—in a light-duty diesel engine. Experiments were conducted on an engine dynamometer under varying loads (84, 112, and 140 Nm) and speeds (1600, 1800, and 2000 rpm) to assess in-cylinder pressure, temperature, engine efficiencies, and emissions. The results demonstrate that the oxygenated B100Es blend achieves superior combustion performance, exhibiting higher peak in-cylinder pressures and temperatures than conventional B7, attributable to enhanced oxygen availability, which promotes more complete fuel oxidation. This translates to an improvement in indicated thermal efficiency despite its lower calorific value relative to B7. B100 demonstrates distinct advantages in mechanical efficiency at higher engine speeds, attributed to its superior lubricity. The study provides quantitative evidence that a strategic blend of biodiesel with ethanol can effectively balance the often-competing objectives of combustion efficiency and emission reduction in modern diesel engines. The average brake thermal efficiencies of B7, B100, B100E5, and B100E10 are approximately 35.8, 36.4, 37.7, and 37.2%, respectively. Additionally, the average smoke intensities of B7, B100, B100E5, and B100E10 are approximately 0.211, 0.075, 0.042, and 0.038%/kW, respectively.
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Seawater submersion for cylindrical lithium-ion batteries thermal runaway prevention
(2024-10-10)
Meelapchotipong, Pongkorn
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Charoenphonphanich, Chinda
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Masomtob, Manop
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Kunanusont, Nattanai
Lithium-ion batteries (LIBs) are currently used in various electric vehicles, including electric boats. To assess the risk of fire due to thermal runaway of the LIB during the operation of ferries, seawater can be used as a cooling fluid for the LIB to prevent thermal runaway as it is abundant. However, the seawater could corrode the electrodes of the battery, which would lead to toxic wastewater. Prevention of thermal runaway of lithium-ion batteries by submersion in seawater needs to be investigated to clarify the corrosion that could lead to toxic wastewater. In this study, fully charged, pristine 18650 NMC Li-ion cells were submerged in synthetic seawater (SSW) to investigate the corrosion effect compared to deionized (DI) water. The results showed that SSW induced rapid voltage discharge, leading to corrosion on the electrodes and toxic effluents, while DI water maintained the stability of the cells and did not cause any corrosion effect. In addition, the prevention of thermal runaway was investigated by exposing fully charged LIB to extreme overheating conditions. The liquid submersion system was activated by rapid voltage drop monitoring to evaluate its effectiveness in preventing thermal runaway (TR). The investigation of TR prevention by SSW submersion showed that the TR process can be effectively prevented. In addition, no corrosion effect was observed during submersion in SSW as the battery voltage was not applied. This study shows that seawater can be used to prevent TR in LIB and does not cause environmental problems comparable to water.
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Effect of a retrofitted metallic microfiber partial flow diesel particulate filter on a light duty diesel vehicle particle emission characteristics
(2024-02-01)
Mon Phyo, Mi Zwe
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Phairote, Watanyoo
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Srilomsak, Mek
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Charoenphonphanich, Chinda
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Masomtob, Manop
This study was conducted two distinct experiments, using a light-duty diesel vehicle at various engine speeds and loads as well as the new European driving cycle (NEDC) comparing commercial diesel fuel (B7) and pure biodiesel (B100). The NEDC involves a combination of urban and extra urban driving conditions. It aims to study a diesel vehicle's thermal efficiency as well as its gaseous and particulate matter (PM) emissions. This involves comparing results with and with no diesel oxidative catalyst (DOC) and a partial flow diesel particulate filter (PDPF) system. The surface morphology, micro- and nanostructure of a diesel vehicle's PM were also examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) to determine nanostructural and dimensional changes after mounting a DOC-PDPF system. Comparison of B7 and B100 combustion showed that B100 had around 1 % increase in brake thermal efficiency (BTE) at 1500 and 2000 rpm compared to B7 since B100 is a more oxygenated biofuel. At 2500 rpm, similar BTE values were observed. Introduction of a DOC-PDPF system resulted in an approximately 1 % BTE reduction for both fuels. This was due to greater friction losses caused by backpressure from the DOC-PDPF system. Increased exhaust backpressure was progressive, ranging from 1 kPa at idle speed to 6 kPa at high engine speeds for both tested fuels. The DOC-PDPF system respectively minimized PM emissions and particle numbers (PNs) by more than 50 % and 35 % for B7 and 71 % and 31 % for B100. These results are average values under the various phases of NEDC testing. A 30 % decrease in PM and a 44 % reduction in PNs under the overall test cycle were found when B100 was tested compared to B7. The soot primary particle size was reduced from 34.69 to 29.08 nm and the carbon fringe length diminished from 1.25 to 0.949 nm at different pre- and post-DOC-PDPF locations. This was due to partial oxidation on the surfaces of the PDPF metallic microstructure. PM undergoes simultaneous partial oxidation after passing through the DOC-PDPF system, as confirmed by TGA analysis.
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The impact of a metallic partial-flow particulate filter on diesel engine combustion and emission characteristics using palm oil biodiesel blends
(2024-02-01)
Thin, Myat Hsu
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Liu, Hai
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Thaeviriyakul, Poonnut
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Wai, Phyo
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Oh, Ban Seok
Reducing particulate emissions from diesel engines pose a significant challenge in developing countries due to increasingly stringent regulations for both new and older vehicles. While employing wall-flow filters have proven effective for new vehicles, older vehicles necessitate alternative approaches to particulate filtration without complex modifications. Partial flow filters exhibit advantages in such scenarios, characterized by their lack of external components, simplified design, minimal maintenance demands, and resilience to misfuelling. The present study mainly focuses on the evaluation of a partial flow diesel particulate filter (P-DPF) installed on a diesel direct injection compression ignition engine, operating on commercial biodiesel blends, specifically B10 and B20. According to the combustion analyses, the combustion pressure, temperature, and the heat release rate increased with the kinetic energy inside the residual gas molecules due to installation of the P-DPF system. This also resulted in higher indicated power as well as indicated thermal efficiency. However, brake-specific fuel consumption and brake-specific energy consumption, exhibited only a marginal increase, while brake thermal efficiency experienced a slight decrease of 0.65% in the case of B10 and 0.74% for B20 after the installation of the P-DPF system due to the friction loss by the filter backpressure. Furthermore, an incremental increase in exhaust backpressure was observed, ranging from 0.2 kPa at 1000 rpm and 56 Nm to 2.25 kPa at 2000 rpm and 140 Nm. An analysis of emissions limits showed a notable 65% reduction in soot emissions. Comparative analyses were conducted to assess the impact of P-DPF installation on a diesel engine without any manual changes. Ultimately, the partial flow filter (P-DPF) emerges as an effective initial measure in mitigating particulate matter emissions, particularly when employed in a retrofit exhaust after-treatment system.
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Effect of ambient temperature and density on the transition of hot temperature combustion to low temperature combustion of commercial diesel and waste plastic diesel in an optical access machine
(2023-12-01)
Aung, Zin Thu
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Charoenphonphanich, Chinda
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Ewphun, Pop Paul
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Kosaka, Hidenori
Alternative diesel production from mixed waste plastic pyrolysis is an effective method for the management of waste plastic and its related costs. The low temperature combustion (LTC) of diesel enables the reduction of nitrogen oxides and soot simultaneously. However, because of the high quantity of unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions, LTC has a low combustion efficiency. This paper investigated the combined effect of low ambient temperature and high density (LATHD) on the transition from hot temperature combustion (HTC) to LTC by using commercial diesel (CD) and waste plastic diesel (WPD) without exhaust gas recirculation (EGR) and low cetane fuels. The results showed that NOx and soot concentrations were decreased and integral heat release was increased. For a given unit heat release, the NOx emissions of CD and WPD decreased 60% and 38%, respectively, by decreasing the ambient temperature from 1050 K to 750 K. Furthermore, integral heat release is a more influential parameter on NOx than heat release rate. After that, soot concentrations of CD and WPD were significantly decreased by 85% and 81% with a reduction in ambient temperature from 1050 K to 750 K. At the same ambient temperature, the NOx and soot concentrations of WPD were higher than that of CD for all cases. With the same ignition delay, however, the NOx and soot concentrations of WPD/high cetane fuel decreased dramatically compared to CD. This information will be useful for determining compression ratio and combustion phasing when considering engine designs.
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Experimental investigation of metallic partial-flow particulate filter on a diesel engine's combustion pressure and particle emission
(2023-09-01)
Mon Phyo, Mi Zwe
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Wai, Phyo
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Thin, Myat Hsu
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Oh, Ban Seok
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Phairote, Watanyoo
The study aims to present the combustion and exhaust behaviors of a 3 L, four-cylinder common rail diesel engine with three different kinds of conventional B7 diesel fuels with and without a platinum diesel oxidation catalyst (DOC) system and non-catalytic partial flow through a diesel particulate filter (P-DPF). Testing is performed under the three different operating conditions, idle to medium engine loading at 1000, 1500, and 2000 engine revolutions per minute with four different engine torques of 84, 112, 140 and 160 Nm. The surface morphology and agglomerate size of particulate matter (PM), single primary particle analysis as well as the fringe length of the carbon crystallite structure were also examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS) to achieve a better understanding through image processing. The P-DPF system does not have a significant effect on an engine's in-cylinder combustion characteristics and brake thermal efficiency. The diesel engine's particle emissions are reduced by trapping them on the metallic micro-fibers of a P-DPF. CO<inf>2</inf>, NO, and O<inf>2</inf> levels show that the carbonaceous particle emissions on the micro-structure of the P-DPF passively react with NO<inf>2</inf> and O<inf>2</inf>. Consequently, diesel engine particle emissions can be reduced by around 50% using a P-DPF system under the experimental conditions of the current study.
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Effect of Metallic Microfiber Flow Through Diesel Particulate Filter System on Diesel Engine’s Particle Emission Physicochemical Characteristics
(2023-03-01)
Oh, Ban seok
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Thaeviriyakul, Poonnut
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Phairote, Watanyoo
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Srilomsak, Mek
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Charoenphonphanich, Chinda
It is well known that particulate matter (PM) from diesel compression ignition engines is harmful to the environment and to human health. To reduce engine PM emissions, exhaust after-treatment systems are utilized. A basic high-performance system can be composed of a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). This study used a system composed of a DOC and a partial flow DPF. Partial flow refers to how only a portion of the exhaust gas is filtered using metal fibrous filters instead of the full flow using ceramic filters. The PM deposited on the side wall of the stages of the system was investigated with respect to elemental composition, morphology, and nanostructure. This was to determine the effect of each component on the PM. The elemental composition analysis found traces of the engine lubricant oil in the PM collected before entering the DOC. This was then eliminated by the DOC and the remaining PM was not significantly impacted by the exhaust after-treatment system. The morphology and nanostructure show an interesting relationship where the size of the single primary particles increased while the graphitic nature of the carbon in the PM seemed to decrease. This can be explained by the simultaneous nature of partial trapping and partial oxidation that occurs in the partial-flow DPF. The emission measurements of opacity, temperature, CO<inf>2</inf>, NO, and O<inf>2</inf> from each position also support this.
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Influence of Pulse Discharging on Lithium-Ion Battery
(2023-01-01)
Naing, Hsu Myat
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Charoenphonphanich, Chinda
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Yamakita, Masaki
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Tanateerapong, Pera
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Kerdsup, Burin
This paper aims to investigate the impact of switching frequencies in pulse discharging of batteries by testing with Lithium-ion cells. Applying lithium-ion batteries in high power applications is needed to be managed according to the demand of load power and current profile. The pulse current discharging technique with different frequencies is expected to improve the charging/ discharging capacity and energy of lithium-ion batteries. In this paper, lithium-ion cells were tested with pulse current at various switching frequencies with 75% duty cycle during discharging. The results of pulse discharging with different switching frequencies were compared with constant current discharging method by evaluating capacity and energy. From this research, the results indicated that pulse discharging at low frequencies generated high discharging capacity than constant current discharging.
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Fuel Characterization of Waste Plastic Diesel from Mixed Waste Plastic Catalytic Pyrolysis
(2023-01-01)
Aung, Zin Thu
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Charoenphonphanich, Chinda
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Kosaka, Hidenori
Plastics are an essential part of the human life and the global economy. However, the use of plastics has been associated with significant environmental problems due to their accumulation in landfills, as plastic waste does not degrade or degrades at very low pace. Nowadays, fast pyrolysis of waste plastic into valuable fuels is main platform method in minimizing not only the waste disposal but also could be used as an alternative fuel for internal combustion engines. The purpose of this study was to identify, quantify and compare the composition of waste plastic diesel (WPD) with the commercial diesel (CD) of Thailand. Simulated distillation (GC-FID) and n-d-M method were used to find the composition of both fuels. Results indicated that the content of naphtha, kerosene, diesel, and long residue were determined quantitatively and also identified the paraffin, naphthenes, and aromatic contents for both fuels. Naphtha and heavy oil contents of WPD were 9.2 and 8.9wt% higher than that of CD but kerosene and diesel contents were 0.7and 17.4wt% less than that of commercial diesel. After that, paraffin, naphthenes and aromatic contents of WPD from PNA analysis were 80.42, 14.54 and 5.04wt% and these hydrocarbon contents of CD were 60.61, 25.91 and 13.48wt% respectively. By knowing them, the appropriate method can be determined for fuel upgrading and interpret correctly of combustion and emissions results.
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Influence of ethanol-biodiesel blends on diesel engines combustion behavior and particulate matter physicochemical characteristics
(2022-12-01)
Karin, Preechar
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Tripatara, Aphichai
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Wai, Phyo
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Oh, Ban Seok
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Charoenphonphanich, Chinda
Ethanol-blended biodiesel fuel can reduce smoke emissions by over 50% on both a single-cylinder engine and a four-cylinder engine. The average single primary particle size of biodiesel blended diesel, biodiesel, and ethanol blended biodiesel soot are approximately 30, 27, and 29 nm, respectively. The maximum graphene fringe length of biodiesel blended diesel, biodiesel, and ethanol blended biodiesel CI engine's soot are approximately 5.2, 4.6, and 4.5 nm. The carbon atom density of soot particles emitted from the diesel, biodiesel, and ethanol blended biodiesel CI engines are approximately 102, 91, and 88 atoms/nm3.

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