• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.12
• /
• pp.1359-1365
• /
• 2011

The purpose of this study is to investigate the effect of ethanol content on the emission of nanosized particles from a diesel-ethanol blended fuel engine. The engine combustion and exhaust emission characteristics of a singlecylinder diesel engine were analyzed using an emission analyzer and an SMPS(scanning mobility particle sizer). The analysis revealed that soot emission increased with the ignition delay. When the ignition delay was fixed, an increase in the ethanol content caused a decrease in the soot emission. With an increase in the ethanol blending ratio, the number concentration and mass distribution of nanosized particles generally decreased. However, for 30% ethanol blending, large particles were observed because of the agglomeration of soot particles, and consequently, the particle mass increased.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.4
• /
• pp.11-17
• /
• 2011

In order to see flame behavior in the annular reverse gas turbine combustor, sector combustion test was performed. Ignition test by using torch ignition system was carried out at various combustor inlet velocity and air fuel ratio. Also, flame blow out limit was measured by changing fuel flow rate with constant air mass flow rate. In test results, stable ignition is possible at air excess ratio of 6 and this limit is gradually increased with combustor inlet velocity. The minimum blow out limit is about 4 at 40 m/s of combustor inlet velocity. This blow out limit is also increased up to about 10 with increasing combustor inlet velocity. Test result shows that lean blow out limits are increased with air velocity. The highest blow out limit was found at the combustor inlet velocity of 65 m/s.

• Resources Recycling
• /
• v.16 no.6
• /
• pp.46-51
• /
• 2007

This study aimed at developing high-efficiency RDF(refuse derived fuels) fuel in order to use RDF energy rationally and to recycle industrial product. As most studies in this area are concentrated in large combustion apparatuses such as kilns, but this study was focused on the small-sized heating systems, applying them directly to grate type boiler which has a heating capacity of $66{\sim}132m^2$. The different kinds of fuel are experimented including RDF. Coke and Waste Tire. First, for this, we experimented and analyzed RDF to see the change in its mass and heating value. Also, four kinds of exhaust gas are sampled by gas analyzer including CO, $CO_2$, NO and $NO_2$ at different temperature. As a result, the levels of CO concentration of RDF are higher than these of coke and waste tire. But, the levels of NO, $CO_2$ and $SO_2$ concentration of RDF and coke were lower then the levels when waste tire is burned.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.153-159
• /
• 2010

In order to see the flame behavior in the annular reverse gas turbine combustor, sector combustion test was performed. Ignition test by using torch ignition system was carried out at the various combustor inlet velocity and air fuel ratio. Also, flame blow out limit was measured by changing fuel flow rate with constant air mass flow rate. In the test results, stable ignition is possible at air excess ratio of 6 and this limit is gradually increased with combustor inlet velocity. The minimum blow out limit is about 4 at 40 m/s of combustor inlet velocity. This blow out limit is also increased up to about 10 with increasing combustor inlet velocity. Test result shows that lean blow out limits are increased with air velocity. The highest blow out limit was found at the combustor inlet velocity of 65m/s.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.7
• /
• pp.737-744
• /
• 2012

A mobile emission laboratory (MEL) was designed to measure the amount of traffic pollutants, with high temporal and spatial resolution under real conditions. Equipment for the gas-phase measurements of CO, NOx, $CO_2$, and THC and for the measurement of the number, concentration, and size distribution of fine and ultra-fine particles by an FMPS and CPC was placed in a minivan. The exhausts of different types of vehicles can be sampled by an MEL. This paper describes the technical details of the MEL and presents data from the experiment in which a car chases passenger vehicles fuelled by diesel and gasoline. The particle number concentration in the exhaust of the diesel vehicle was higher than that of the gasoline vehicle. However, the diesel vehicle with a DPF emitted fewer particles than the vehicle equipped with a gasoline direct injection engine, with particle diameters over 50 nm.

• Journal of Bio-Environment Control
• /
• v.19 no.4
• /
• pp.177-183
• /
• 2010

Bum-type $CO_2$ generators are widely used in greenhouses for the purpose of $CO_2$ supply for photosynthesis and greenhouse heating. However harmful gases included in the air might give severe effects on the plant growth. For investigating the possible emission of harmful gases from commercial bum-type $CO_2$ generators, we carried out the analysis of the harmful by-products (NO, NOx, $NO_2$, CO, and VOCs) and $CO_2$ caused by using a bum-type $CO_2$ generator in greenhouses. And the harmful by-products from different type of fuels such as kerosene, LPG, and LNG were quantified. In order to minimize the uncertainties from a $CO_2$ generator, 4 different $CO_2$ generators were utilized in four plastic greenhouses and a glasshouse located at different places during the experimental works. The results showed that the concentration of NOx is proportional to $CO_2$ concentration. Levels of harmful gases in the most of greenhouses, where the new bum-type $CO_2$ generators were installed, were lower than 1.0 ppm when $CO_2$ concentration was set at 1,000 ppm. In case of LNG combustion, the concentration of CO reached out up to 300 ppm and pre-treatment for CO reduction, such as the adsorption process, would be inevitable to abate the adverse effects on plant growth.

• Fire Science and Engineering
• /
• v.22 no.3
• /
• pp.258-264
• /
• 2008

This study proposes the experimental methods which shows various guidelines for systematic study of surface forest fuels. The thermal characteristics of surface fire fuels such as Quercus Variabilis and Pinus Densiflora fallen leaves are measured using TGA and Oxygen Bomb Calorimeter. Both of them are common species of Korean forest. Also the combustion characteristics of surface fire fuels are analysed according to the methods which are commonly used in Pool Fire analysis. The measured parameters are gas velocity, temperature, flame height, heat release rate and mass loss rate. A system is designed to simulate the surface fire. Methods and results are shown for the application of forest fire study.

• Resources Recycling
• /
• v.15 no.1 s.69
• /
• pp.46-57
• /
• 2006

For the development of combustion technology of RDF(refuse derived fuel), combustion characteristics are examined in bubbling fluidized bed, circulating fluidized bed, continuos combustor and batch type combustor. The characteristics of combustion and exhaust gas has been compared and analyzed in many type of combustion facilities, which has been utilized as basic data for the advanced research of specified RDF combustion facility. Stable combustion has been observed in bubbling and circulating fluidized bed from controled operating condition like the proper feeding rate and superficial gas velocity. In circulating fluidized bed, concentration of NOx has been increased with the operating condition by the fuel-NO and oxygen reaction and $SO_2$ can be considered not to be produced in RDF fluidized bed from very low concentration in flue gas. HCl concentration is 36.4 ppm as average value and lower than standard emission value, but the counter plan is needed. Shaped RDF and fluff RDF have been compared in continuos combustor and batch type combustor and shaped RDF shows benefit for the stable heat recovery and gas emission shows similar value and characteristics.

• Analytical Science and Technology
• /
• v.23 no.1
• /
• pp.45-53
• /
• 2010

For the determination of chlorine in uranium compound, analytical methods by using a steam distillation and a pyrohydrolysis have been developed. The steam distillation apparatus was composed of steam generator, distilling flask and condenser etc. The samples were prepared with an aliquot of LiCl standard solution and a simulated spent nuclear fuel. A sample aliquot was mixed with a solution containing 0.2 M ferrous ammonium sulfate-0.5 M sulfamic acid 3 mL, phosphoric acid 6 mL and sulfuric acid 15 mL. The chloride was then distilled by steam at the temperature of $140^{\circ}C$ until a volume of $90{\pm}5\;mL$ is collected. The pyrohydrolysis equipment was composed of air introduction system, water supply, quartz reaction tube, combustion tube furnace, combustion boat and absorption vessel. The chloride was separated from powdered sample which is added with $U_3O_8$ accelerator, by pyrohydrolysis at the temperature of $950^{\circ}C$ for 1 hour in a quartz tube with a stream of air of 1 mL/min supplied from the water reservoir at $80^{\circ}C$. The chlorides collected in each absorption solution by two methods was diluted to 100 mL and measured with ion chromatography to determine the recovery yield. For the ion chromatographic determination of chlorine in molten salt retained in a metal ingot, the chlorine was separated by means of pyrohydrolysis after air and dry oxidation, and grinding for the sample.

• Fire Science and Engineering
• /
• v.22 no.1
• /
• pp.99-104
• /
• 2008

It is important to understand thermal characteristic as a method to estimate the new materials, because spontaneous ignition characterized by causing combustion in the low temperature without ignition source. If can not find out the thermal characteristics of materials, it is frequent that causes of fires could not be found. The danger level of spontaneous ignition material should be estimated and by closely studying its thermal characteristic. However, RPF(Refuse Paper & Plastic Fuel) is a solid matter and getting increasesa year by year because it is an economy profit as alternative energy for limited fossil fuels. Some time RPF occur a fire in the cases of its production process and conservation. Therefore study for thermal stability and critical ignition temperature of RPF was so imperative that the experiment by means of Bombe Calorimeter, TG-DTA, MS80, SIT-II, and Wire Basket Test was implemented. As a result, RPF had a caloric value 26.4-28.3 MJ/kg, and its initial pyrolysis temperature was $192^{\circ}C$ at heating rate 2 K/min. With the result of analysis by MS 80 which is an instrument measuring microscopic calory, pure RPF not containing water has higher caloric value than RPF containing 20% water. Also, SIT-II which is an instrument of insulated auto-ignition was ignited by $118.5^{\circ}C$. This temperature is lower than that of Wire Basket Test. The critical ignition temperature was calculated by Frank-Kamenetskii equation can cause ignition at $80^{\circ}C$ when conserved in the height of 10 m by the standard of infinity slab.