Ryang-Gyoon Kim, Chan-Won Hwang, Chung-Hwan Jeon

•  Pressurized wire-heating reactor (PWHR) was designed for CO2 gasification kinetics coal char.

•  PWHR can provide experimental conditions up to 50 atm and 1750 K.

•  The intrinsic activation energies based on nth order reaction rate equation were determined.

•  The effectiveness factor was analyzed to determine the effects of pressure and temperature.

Jong Pil Kim, Ho Lim, Ju Hun Song, Young June Chang, Chung Hwan Jeon

• A silicon photovoltaic module converts sunlight energy into electricity applying the photovoltaic effect of the semiconductor. Simulation method to attach fins to the backside of PV module is discussed. This work shows the comparison of the thermal characteristics between a PV module with and without fins.

Yong Ki Jeong, Chung Hwan Jeon, Young June Chang

• An experimental study was performed to investigate the effects of partially premixing, varying the equivalence ratios and in laminar partially premixed flames. The signals from the electronically excited states were detected through interference filters using a photo multiplier tube, which were processed to the intensity ratios to determine a correlation with the local equivalence ratios. Furthermore, the consistency between the results of the tomographic reconstruction; Abel inversion technique, image with CCD (Couple Charged Detector) camera and the local radical intensity with PMT was investigated.

Ryang-Gyoon Kim, Dongfang Li, Chung-Hwan Jeon

• Coal ignition for different ranks and sizes is investigated under high heating rate.

• Med-, high-volatile bituminous coal in 150–200, 75–90 μm undergo homogeneous ignition.

• High volatile bituminous coal undergo homogeneous ignition at <45 μm.

• Medium volatile bituminous coal underwent heterogeneous ignition at <45 μm.

• Anthracite and lignite coals with sizes in 150–200 μm fragmented during ignition.

Byoung-Hwa Lee, Eric G. Eddings, Chung-Hwan Jeon

• The influence of coal blending methods, such as out-furnace (external or premixed) blending and in-furnace (initially nonmixed) blending, with different excess oxygen (highest, medium, and lowest stoichiometric conditions) on unburned carbon and NOx emissions of blend combustion in an entrained flow reactor has been analyzed, using experimental and numerical approaches for binary coals used. The reduction of NOx emission under the lowest conditions is more effective than those under other conditions for the two blending methods because of homogeneous and heterogeneous NOx reduction mechanisms.

Dong Sik Han, Nak Won Choi, Sung Lai Cho, Jin Saeng Yang, Kwang Suk Kim, Wan Suk Yoo, Chung Hwan Jeon

• Vehicle emissions in a representative military area.

• Gradient-sensitive driving cycle is developed for paved and unpaved roads over steep and undulating terrain.

• The driving cycle is developed by taking into account important parameters that affect fuel consumption.

Ryang-Gyoon Kim, Chung-Hwan Jeon

• A novel technique was used to measure the coal char particle temperature.

• The ignition point determined from a dT/dt minimum is a spot ignition point.

• A spot ignition model was suggested to analyze the intrinsic reaction kinetics of coal char.

• Internal conduction has to be considered in order to evaluate the intrinsic kinetics for larger particle (above 1 mm).

Byoung-hwa Lee, Seoung-gon Kim, Ju-hun Song, Young-june Chang, Chung-hwan Jeon

• The influence of coal-blending methods, such as out-furnace and in-furnace methods, on unburned carbon and NO emissions of blending coal combustion in a drop-tube furnace (DTF) has been analyzed using experimental and numerical approaches for binary coals (sub-bituminous and bituminous coals) used. Furthermore, the emission index of NO (EINO) is proportional to the SBR. In addition, the in-furnace blending method is applied using a modified DTF to improve the efficiency of unburned carbon fractions and the involvement of NO emissions. The numerical modeling strongly supports these phenomena and provides insights into the mechanisms that affect the blending methods during the combustion of coal blends.

Byoung-hwa Lee, Ju-hun Song, Young-june Chang, Chung-hwan Jeon

• One of the critical factors for controlling the rate of mixing of fuel and air is the number of injector holes in a diesel engine. This study was intended to explore the behavior of the formation of spray mixtures, combustion, and emissions as a function of the number of injector hole changes; from this work, we propose an optimal number of holes for superior emissions and engine performance in diesel engine applications. The results show that increasing the number of holes significantly influences evaporation, atomization, and combustion. However, when the number of holes exceeds a certain threshold, there is an adverse effect on combustion and emissions due to a lack of the air entrainment required for the achievement of a stoichiometric mixture.

Yu Jiang, Byoung-Hwa Lee, Dong-Hun Oh, Chung-Hwan Jeon

• Achieving combustion stability while reducing gas emissions under half-load conditions in boiler.

• Furnace suffers from asymmetrical combustion due to various burner group arrangements.

• The optimal CCOFA/SOFA ratio is 5% CCOFA and 15% SOFA.

• The influence of excess air ratio on NOx/UBC is discussed.

• Field tests are performed under optimal conditions.

Young-Joo Lee, Jong-Won Choi, Ju-Hyoung Park, Hueon Namkung, Gyu-Seob Song, Se-Joon Park, Dong-Wook Lee, Joeng-Geun Kim, Chung-Hwan Jeon, Young-Chan Choi

• Among various biomasses, the herbaceous biomass is regarded as an abundant and relatively inexpensive fuel. However, it contains high ashes (especially high levels of alkali metals), leading to operation troubles such as slagging and fouling inside a heat exchanger or deterioration in efficiency. Accordingly, we herein propose an economical method to remove the inherent ashes in the biomass using 16.6 M acetic acid pretreatment at 60 °C for 10 min. Seven different biomasses were investigated to validate the effects of method. Furthermore, the proposed wet treatment was more effective for biomass with higher surface areas.

Byoung-Hwa Lee, Lkhagvadorj Sh, Jong-Soo Bae, Young-Chan Choi, Chung-Hwan Jeon

• Combustion behavior of coals impregnated with glycerol was investigated.

• Combustion efficiency for up to 20% glycerol improved and NOx emission decreased.

• Higher addition levels than 20% glycerol was adversely affected by unstable combustion.