Oxidation Kinetics of Soot on Acicular Mullite Membrane Filter Using Electron Microscopy and Thermogravimetric Analysis

Saenkhumvong Eakkawut,Karin Preechar,Charoenphonphanich Chinda,Vittayakorn Naratip,Hanamura Katsunori 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.6

This paper investigates the oxidation kinetics of carbon black on acicular mullite using thermogravimetric (TGA) and mullite microstructures by scanning electron microscopy (SEM) for the development of diesel particulate filters (DPFs). It is observed that the amount of each chemical composition strongly affects the structure of mullite. The addition of AlF3 and V2O5 to mullite promotes the growth of needle-shaped mullite crystals. Thermogravimetric analysis was used to investigate and characterize chemical kinetics of soot oxidation for better understanding of designs and configurations of diesel particulate filters. The mass conversion of soot on the acicular mullite (ACM) is oxidized faster than that on the mullite (ML) membrane at all temperatures examined. The calculation of apparent activation energy (Ea) of soot oxidation with isothermal methods on mullite was presented. The results showed that activation energy of soot oxidation is enhanced with ACM than with ML at all temperatures examined. The average calculated apparent activation energy of soot oxidation on ACM and ML are 146.4 kJ/mole and 155.3 kJ/mole, respectively.

Optical study on combustion characteristics of hydrotreated vegetable oil and blends under simulated CI engine conditions and various EGR

Vo Tan Chau,Charoenphonphanich Chinda,Karin Preechar,Susumu Sato,Hidenori Kosaka 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.9

Soot and NO x emissions are the inherent combustion characteristics of diesel engines. The modification of fuel property makes for an interesting study of methods for elimination of soot and NO x emissions. HVO and blends of 20 %, 50 %, 80 % by mass of HVO with commercial diesel fuel (mixed 7 % FAME), in combination with various EGR conditions were carried out to evaluate soot and NO xformation, as well as combustion characteristics of HVO blends in RCEM. The obtained results revealed that ignition delay, flame temperature, NO x and soot concentration decreased as HVO percentage increased. Mixing ratios of HVO with diesel showed a similar flame profile at baseline condition, higher flame temperature and darker soot density-KL regions were distributed on the upstream of spray flame. HVO displayed a slightly lower in-flame temperature and KL density, which led to a decrease of 33 % and 15.9 % of NO x and soot concentration, respectively, compared to diesel. By applying higher EGR levels, a reduction of heat release rate, flame temperature and NO x emissions were recorded. Also observed was an increase in ignition delay and soot concentration. Notably, soot at 10 % O 2concentration was lower than that of 15 % O 2 concentration.

INJECTION CHARACTERISTICS OF PALM METHYL ESTER BLENDED WITH DIESEL USING ZUECH’S CHAMBER

Prathan Srichai,Pop-Paul Ewphun,Chinda Charoenphonphanich,Preechar Karin,Manida Tongroon,Nuwong Chollacoop 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.3

This research attempts to characterize the injection of palm biodiesel blended with diesel in a Zuech’s chamber. Thailand conventional diesel (mandated blend of biodiesel at 5 % or B5), palm biodiesel (B100) and four other biodiesel blends ratios (B20, B40, B60 and B80) were investigated with single hole injector of 140 and 200 μm diameters, injection pressure of 40 MPa to 160 MPa, constant back pressure of 4.5 MPa and energize time of 2.5 ms. The results show that increasing biodiesel blending ratios leads to longer injection delay, larger injection pressure drop, smaller injection quantity discharge coefficient (Cd) and shorter injection duration. With increasing biodiesel blending ratio, high Cavitation number from biodiesel viscosity decreases Reynolds number. Increasing injector diameter from 140 μm to 200 μm has reduced injection delay, increased fuel injection quantity, discharge coefficient and remaining injection duration. The increasing of injection pressure were improve, injection delay, injection duration, injection quantity and discharge coefficient until injection pressure 120 MPa. In addition at injection pressure over 120 MPa are decrease injection quantity and discharge coefficient, it effect form the cavitation phenomena. Increasing of viscosity, density, Bulk modulus and sound velocity were effect to increase injection delay, with reduce injection quantity, injection duration and pressure drop during injection process.

COMBUSTION CHARACTERISTICS OF HYDROTREATED VEGETABLE OIL-DIESEL BLENDS UNDER EGR AND LOW TEMPERATURE COMBUSTION CONDITIONS

Sombat Marasri,Pop-Paul Ewphun,Prathan Srichai,Chinda Charoenphonphanich,Preechar Karin,Manida Tongroon,Hidenori Kosaka 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.3

This paper investigates the effects of Hydrotreated vegetable oil (HVO)-diesel blends on combustion characteristics under various ambient oxygen concentrations and ambient temperatures in a constant volume combustion chamber (CVCC). Combustion characteristics were presented in terms of heat release rate, ignition delay and integral heat release. The shadowgraph images of spray combustion were presented for spray development and combustion progress. The experiment was carried out on CVCC under constant injection pressure and energizing time. The synthetic gas with varied oxygen concentrations between three discrete values from 21, 15 and 10 % to simulate EGR on engine conditions. The ambient temperatures were varied at 1100, 900 and 700 K to study the effects of ambient temperatures. Four different fuels were tested: commercial diesel, commercial diesel-HVO blends and HVO with the single-hole injector. The results showed that decreasing ambient oxygen concentration to 10 % resulted in 13.42 % lower heat release rate and 13.89 % lower integral heat release. This also extended ignition delay. Decreasing ambient temperature resulted in longer ignition delay with higher peak heat release rate. Increasing HVO showed 6.43 % shorter ignition delay compare to diesel due to higher cetane number. The shadowgraph images showed that HVO has better evaporation 0.7 to 0.9 ms after injection due to its lower density, viscosity and distillation temperature at T90.

EFFECT OF SOOT PARTICLE SIZE ON FOUR BALL METALLIC WEAR USING ELECTRON MICROSCOPY IMAGE ANALYSIS

Preechar Karin,Warawut Amornprapa,Park Watanawongskorn,Eakkawut Saenkhumvong,Chinda Charoenphonphanich,Katsunori Hanamura 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.3

The impact of soot primary nanoparticles affecting metal wear was investigated. The commercial Carbon Black (CB) with different primary particle sizes were mixed with the engine oil for simulating soot contamination. The physical properties of carbon black including density and hardness were calculated using Transmission Electron Microscopy (TEM) image analysis. The metallic wear test was evaluated by using a Four-ball wear tester. After the tests, the ball surfaces were inspected by utilizing High-Resolution Optical Microscope (OM), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX) analysis. Based on a Four-ball wear test, the 1 % by weight of carbon black contamination shows a bit higher average wear scar diameter (WSD), but the surface roughness is reduced. SEM micrograph of metallic wear scar for the engine oil without soot shows the area of grooves, plastic deformation and subsurface crack. On the other hand, when carbon black is added to the oil, it can be seen that there are many deep grooves along with the sliding direction. The relationship of calculated oil film thickness, primary nanoparticle size distribution, carbon atom density of soot and hardness is clearly explained metallic wear mechanisms.

COMBUSTION CHARACTERISTICS OF HYDROTREATED VEGETABLE OIL – DIESEL BLEND UNDER EGR AND SUPERCHARGED CONDITIONS

Pop-Paul Ewphun,Chau Tan Vo,Prathan Srichai,Chinda Charoenphonphanich,Susumu Sato,Hidenori Kosaka 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.4

This paper investigates the effects of Hydrotreated vegetable oil-diesel blend to combustion characteristics under various ambient oxygen concentrations and ambient pressure. Combustion characteristics were investigated using heat release rate analysis, two color method, soot concentration measurement and NOx concentration measurement. The experiments were carried out on a rapid compression expansion machine to simulate the ambient condition of a CI engine at TDC. Synthetic gas with oxygen concentrations of 21 %, 15 % and 10 % were used to simulate EGR conditions. A single hole injector was used with five different fuels: commercial diesel, HVO-commercial diesel blends and HVO. The results showed that increasing HVO blending percentages decreased ignition delay, flame temperature, soot concentration and NOx concentration. Heat release at oxygen concentration of 10 % dramatically dropped due to a shortened ignition delay, which resulted in less combustion. A decreased oxygen concentration from applied EGR conditions not only increased ignition delay, heat release, flame temperature and NOx concentration, but also increased soot concentration. A combination of EGR and supercharged conditions by increasing ambient pressure and decreasing oxygen concentrations resulted in increased heat release, decreased flame temperature, ignition delay and soot concentration, compared to EGR conditions.