• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.1
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• pp.76-82
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• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressureswirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates raging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2,\;NOx,\;S0_2,$ flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$ concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.47-58
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• 2000

The relationship among the flame radiation, NOx emissions, residence time, and global strain rate are examined for turbulent non-premixed jet flames with wide variations in coaxial air conditions. Measurements of NOx emission, flame geometry and flame radiation were made to explain the NOx emission scaling based on global parameters such as flame residence time, global strain rate, and radiant fraction. The overall 1/2-power scaling is observed in coaxial air flames, irrespective of coaxial air conditions, but the degree of deviation from the l/2-slope curve in each case differs from one another. From the comparison between the results of pure hydrogen flames and those of helium diluted hydrogen flames, it is observed that flame radiation plays a significant role in pure hydrogen flames with coaxial air and the deviation from 1/2-power scaling may be explained in two reasons: the difference in the flame radiation and the difference in jet similarity in coaxial air flames. From the radiation measurements, more detailed explanations on these deviations were suggested.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.41-44
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• 2010

Hazardous air pollutants such as benzo[a]pyrene (BaP), benzene, formaldehyde have been concerned about the adverse health effect of long-term exposure. Contour map is useful for finding high-concentration region, emission source, and distributions of HAPs in the ambient air. To make a contour map, we have developed simple analytical method for selected HAPs; polycyclic aromatic hydrocarbons such as BaP, benzene and its derivatives such as toluene and xylene, and aldehydes and ketones. We have applied these methods to investigate air pollution by HAPs in some cities in Japan. The results show that these methods reveal actual emission sources if the PRTR emission report was not submitted.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2186-2191
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• 2008

An experimental study was performed to investigate the effect of swirl condition and secondary air rate on the Ion voltage and CO emission characteristics. In this study, the combustion characteristics were investigated with the variation of swirler diameter, vane angle, suction air rate. The result of this study, the Ion voltage increase with increasing the diameter of the swirler. Additionally with increasing the suction air rate, the Ion voltage is the same. The CO concentration depends on suction air rate. In the other hand, it is almost unaffected by swirler's diameter. The flame length and Ion voltage decease with decreasing O2 percentage of surrounding air.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.269-271
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• 2012

To investigate emission characteristics of laminar premixed CH4/air flame, combustion experiments were conducted at three flow rates (5.3L/min, 10.6L/min, 15.5L/min) with changing the combustor pressure(-30Kpa-30Kpa). It was found that with increasing flow rate, NOx emission increased in high pressure condition, while decreased in low pressure condition; and the emission of CO decreased with increasing flow rate. For the influence of pressure, emission of NOx increased with increasing pressure regardless of flow rates, while CO emission decreased on the contrary.

• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.75-81
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• 2003

In this paper, the study of effects of flow variables on flame structure and NOx emission concentration was performed in co-axial laminar partially premixed methane/air flames. the objectives are to reveal its effect as parameters were varied and to understand the correlation between flame structure and NOx emission characteristics in the reaction zone. equivalence ratio(${\Phi}$), fuel split degree(${\sigma}$), and mixing distance(x/D) were defined as a premixing degree and varied within $1.36{\sim}3.17$(equivalence ratio), $50{\sim}100$(fuel split degree), and $5{\sim}20$(mixing distance). the image of $OH{\ast}$ and $CH{\ast}$, and NOx concentration were obtained with an ICCD camera and a NOx analyzer. additionally the maximum intensity location of $OH{\ast}$ chemiluminescence and $CH{\ast}$ chemiluminescence were measured to compare each flame structures. In conclusion flame structure and NOx emission characteristics were changed from diffused to premixed flame when mixing degree was on the increase. the main effect on flame structure and NOx production was at first equivalence ratio(${\Phi}$), and next fuel split degree(${\sigma}$), and finally mixing distance(x/D).

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.3-8
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• 2005

Building parts of Multi-Family Houses are consisted of several building material assembly. Therefore, after selecting building materials with test result of emission intensity and their feature, composed building materials are made equally with actual construction methods, and experimented emission intensity. 7 days after experiment, formaldehyde emission intensity appeared low in an order of Tile Wall, Wood Flooring, Wallpaper, Reum Flooring, Silk Wallpaper, and 20 days after experiment, TVOC emission intensity appeared low in an order of Tile Wall, Reum Flooring, Silk Wallpaper, Wood Flooring, Wallpaper. There was a clear difference in TVOC emission intensity according to kind of building materials. Composed building materials that weight per unit area is big and omission intensity is high, they effect continuously to indoor air because decrement is small.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.441-445
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• 2000

Considering international status of our country as world class ship builder and geographical characteristics encircled by sea in three facets, controlling of air pollutants emission from marine engines becomes more and more important issue in recent days. Implementation of immediate pollutants emission control regulation and standardization of test and certification procedure are required to reduce air pollution from marine engines. But cost increments due to additional equipment of emission control device and development and certification test expenses as well as depreciation of fuel economy should be considered. To satisfy those air pollution reduction and economic requirements, we should make our own interpretation of IMO standard and implementation schedule depending on our country's status. For this purpose we measured NOx emission from small and middle class marine engines to calculate emission factor and total pollutant emission in our country. With the comparison and analysis of other countries emission control regulation we proposed basic data of total emission from marine engine and future emission control standard in our country. According to our estimation, 62% of total NOx emission of marine engines comes from fishing boat and 38% from commercial vessels. The portion of NOx emission from marine engine is 18.6% of whole country NOx emission. Due to the voyage characteristics of middle and large vessel and necessity of international harmonization of marine engine pollutants emission control standard, it is inevitable to adopt IMO standard for middle and large marine engines. But considering technological and cost effect of fishing boat operating in near sea, it is resonable to set a standard within 80% of measured value at the moment and gradually implement the same IMO standard in near future.

• Journal of Korea Water Resources Association
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• v.52 no.4
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• pp.235-243
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• 2019

Recently, urban inundation was frequently occurred due to the intensive rainfall exceeding marginal capacity of the flood control facility. Furthermore, needs for the underground storage facilities to mitigate urban flood are increasing according to rapidly accelerating urbanization. Thus, in this study, drainage efficiency in drain tunnel connecting to underground storage was investigated from the air-core measurements in the drop shaft against two types of inlet structure. In case of the spiral inlet, the multi-stage structure is introduced at the bottom of the inlet to improve the vortex induction effect at low inflow discharge (multi-stage spiral inlet). The average cross-sectional area of the air-core in the multi-stage spiral inlet is 10% larger than the tangential inlet, and show the highly air emission effect and the highly inflow efficiency at the high inflow discharge. In case of the tangential inlets, the air emission effect decreased after exceeding the maximum inflow discharge, which is required to maintain the inherent performance of the tangential inlet. From the measurements, the empirical formula for the cross-sectional area of the air-core according to locations inside the drop shaft was proposed in order to provide the experimental data available for the inlet model used in experiments.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.31-39
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• 2010

Although driving patterns strongly influence greenhouse gas and air pollutant emission rate from light duty vehicles, emission measurements have been mainly based on chassis dynamometer testing with one standard driving pattern. And there has been limited work on quantifying the independent effect of driving parameters on emission rate because of multidimensional nature of real-world driving pattern. The objective of this study is to obtain the quantitative effect of relative positive acceleration (RPA) on vehicle emission rate. RPA has been used to define the occurrence of acceleration demanding large amounts of power in certain driving distance and shown to be a significant affecting parameter for real-world emission rate. 40 driving patterns have been developed with fixed driving parameters to investigate independent effect of RPA. For the same values of average vehicle speed and power, the trend in carbon dioxide emission rate and fuel consumption with respect to RPA is very clear. Emission rate of nitrogen oxide and particulate matter also increase with respect to RPA, but the trend is less clear. Carbon dioxide emission from diesel vehicle appear to be more affected by high accelerations compared to that from gasoline vehicle because of high intake air restriction during acceleration caused by turbocharger and intercooler. The results have implications for the possible reduction of environmental effects through better traffic planning and management, driver education and car design.