• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1885-1889
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• 2006

제주지역은 대륙과 해양을 연결하는 요충지로서 한라산을 중심으로 동서사면은 $3{\sim}5^{\circ}$의 완만한 경사를 이루고 있다. 연평균 강우량은 1,975mm로서 국내 최다우 지역이나 제주도의 지질 특성상 도내 대부분의 지역이 투수성이 높은 다공질 현무암으로 구성되어 있는 관계로 지표수의 발달이 미약한 반면 지하수가 풍부하게 부존되어 있으며 기저지하수, 준 기저지하수, 상위지하수, 기반암지하수로 이루어져 있다. 최근 우리나라의 교토의정서 비준으로 인한 온실가스 감축이 불가피함에 따라 대체 재생가능한 에너지를 이용한 풍력발전시대가 도래하고 있으며, 제주 행원풍력발전단지에 설치된 총 15기 발전장치의 현실성과 경제성 입증을 통해 제주지역의 풍력에너지를 이용한 지하수 취수시스템을 제안하였다. 본 연구는 제주, 고산, 서귀포, 성산포지역에 대한 제주지방기상청 연평균 풍속자료$(2004{\sim}2005)$를 통하여 대상지역내 적용 가능한 로터(Roter), 나셀(Nacelle), 타워(Tower), 발전기를 포함한 발전장치를 선정하였으며, 공기역학적(Aerodynamic)특성에서 전기에너지로 변환한 풍력에너지를 지하수 취수시스템으로 적용하기까지의 전력공급절차를 도출하였다. 또한 생산되어진 풍력에너지 용량에 적용 가능한 수중.육상모터펌프를 산정하여 '제주도 지하수개발.이용시설 설치 및 관리기준(2004)'에서 제시한 구조도를 바탕으로 대상지역내 지하수위를 고려한 지하수 취수시스템을 도시하였다. 제주도는 지형 및 지질적인 특성상 수자원을 지하수에 의존할 수밖에 없는 특수한 지역이므로 2002년말 통계를 살펴보면 생활용, 공업용, 농업용으로 각각 57만$m^2$, 11만$m^2$, 56만$m^2$를 포함한 1일 최대 124만$m^2$의 지하수를 사용하고 있다. 따라서 풍력에너지를 이용한 지하수 취수시스템을 도입하여 재생가능한 에너지이용 효과와 세계인이 공감하는 청정한 관광자원으로 활용 가능할 것이라 판단된다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.55-56
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• 2018

In order to construct an efficient monitoring system for major port cities in Korea, the first step to build and manage related laws and institutional infrastructure with strengthen the cooperation of the relevant agencies, regional port authorities, and port corporations. Second, for the management of air pollutants emitted by ports, a management system should be established through systematic inventory source inventory and real-time monitoring system. Third, active countermeasures should be established to reduce the emission of air pollutants by sources such as ships, harbor equipment, and trucks. This will improve the air quality of major port cities and move them to clean port cities.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.2
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• pp.175-184
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• 2024

This study focuses on investigating the importance of managing greenhouse gas emissions from global energy consumption, specifically examining domestic targets for clean hydrogen production. Using life cycle assessment, we evaluated reductions in global warming potential and assessed the carbon neutrality contribution of the domestic hydrogen sector. Transitioning from brown or grey hydrogen to blue or green hydrogen can significantly reduce emissions, potentially lowering CO₂ equivalent levels by 2030 and 2050. These research findings underscore the effectiveness of clean hydrogen as an energy management strategy and offer valuable insights for technology development.

• Clean Technology
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• v.25 no.1
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• pp.74-80
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• 2019

Thermochemical treatment of sewage sludge is an energy-intensive process due to its high moisture content. To save the energy consumed during the process, the hydrothermal carbonization process for sewage sludge can be used to convert sewage sludge into clean solid fuel without pre-drying. This study is aimed to investigate co-firing characteristics of the hydrothermally carbonated sewage sludge (HCS) to a pulverized coal combustion system. The purpose of the measurement is to measure the pollutants produced during co-firing and combustion efficiency. The combustion system used in this study is a furnace with a down-firing swirl burner of a $80kW_{th}$ thermal input. Two sub-bituminous coals were used as a main fuel, and co-firing ratio of the sewage sludge was varied from 0% to 10% in a thermal basis. Experimental results show that $NO_x$ is 400 ~ 600 ppm, $SO_x$ is 600 ~ 700 ppm, and CO is less than 100 ppm. Experimental results show that stable combustion was achieved for high co-firing ratio of the HCS. Emission of $NO_x$ and $SO_x$ was decreased for higher co-firing ratio in spite of the higher nitrogen contents in the HCS. In addition, it was found that the pollutant emission is affected significantly by composition of the main fuel, regardless of the co-firing ratios.

• The KSFM Journal of Fluid Machinery
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• v.8 no.1 s.28
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• pp.30-36
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• 2005

A sludge treatment system for introducing the waste water mixture with paint sludge from the water bath of paint booth and for recycling cleaned water to paint booth after sludge separation is developed. Floated sludge is introduced from the water surface in the bath by using floating-skimmer, and is conveyed by pump to the centrifugal separator where sludge and cleaned water are separated. From the operation results of the present sludge treatment systems applied in actual paint booths, paint sludge can be separated automatically and effectively from water bath with its water content of $60-70\%$, and sludge-free clean water is returned to paint booth.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.259-266
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• 2004

Developed is a sludge treatment system for introducing the waste water mixture with paint sludge from the water bath of paint booth and for recycling cleaned water to paint booth after sludge separation. Floated sludge is introduced from the water surface in the bath by using floating skimmer, and is conveyed by pump to the centrifugal separator where sludge and cleaned water are separated. From the operation results of the present sludge treatment systems applied in actual paint booths, paint sludge can be separated automatically and effectively from water bath with its water content of $60-70\%$, and sludge-free clean water is returned to paint booth.

• Clean Technology
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• v.17 no.1
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• pp.69-77
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• 2011

The intrinsic $CO_2$ separation and hydrogen production system is a novel concept using oxidation and reduction reactions of oxygen carrier for both $CO_2$ capture and high purity hydrogen production. The process consists of a fuel reactor (FR), a steam reactor (SR) and an air reactor (AR). The natural gas ($CH_4$) is oxidized to $CO_2$ and steam by the oxygen carrier in FR, whereas the steam is reduced to hydrogen by oxidation of the reduced oxygen carrier in SR. The oxygen carrier is fully oxidized by air in AR. In the present study, the chemical looping moving bed reactor having 200 L/h hydrogen production capacity is designed and the hydrodynamic properties were determined. Compared with other reactors, two moving bed reactors (FR, SR) were used to obtain high conversion and selectivity of the oxygen carrier. The desirable solid circulation rates are calculated to be in the range of $20{\sim}100kg/m^2s$ from the conceptual design. The solid circulation rate can be controlled by aeration in a loop-seal. To maintain the gas velocity in the moving beds (FR, SR) at the minimum fluidization velocity is found to be suitable for the stable operation. The solid holdup in moving beds decrease with increasing gas velocity and solid circulation rate.

• Journal of the Speleological Society of Korea
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• no.90
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• pp.35-56
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• 2009

The purpose of this paper is to analyze the implementation of the karst infrastructure systems for the u-cave. IT based u-cave represents spatial information derived fields, such as geographical distribution of the cave boundaries, physical configuration of the cave locations and formation characteristics of the karst history. These three aspects relate to karst infrastructure systems, cave monitoring center and spatial database implementation. In terms of the IT based u-cave infrastructure implementation systems, the u-cave depends on IT contents and spatial features. uIT contents are strongly related to IT839 strategy due to the national agenda is "u-Korea". Cave should contribute to u-cave construction through the spatial analyses methods including USN, RFID, LiDAR, ELD, and GIS technologies. For these methods various cave functions will guide to u-cave's distribution, location, and characteristics of karst. The infrastructure consists of landforms and speleothem facilities, underground related facilities, environmental protection systems, and cave planning. These six units of the cave infrastructures have spatial databases that consist of spatial configuration, such as 4-D in order to draw the spatial distribution of the limestone and lava caves. IT based u-cave system infrastructure implementation should deal with IT convergence to generate fusion affects.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.175-182
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• 2014

The use of solar energy among renewable energy tends to increase because of infinity and cleanness of resources. Even though the consumption rate of solar energy in our country is still low, however, in recent years, the research for solar energy have been widely conducted due to policy support of government. This study was performed to make the system of performance test for solar collector and to investigate thermal efficiency for solar collector with thermosyphon tube-type. As a result, in case of indoors measurement using halogen lamp, thermal efficiency for solar collector with thermosyphon tube-type was increased about 15~22% after 120 minutes compared with that of solar collector with double evacuated tube-type. In addition, in case of outdoors measurement, thermal efficiency of thermosyphon tube-type was showed maximum about 46% higher than double evacuated tube-type.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.407-414
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• 2007

Using the MPI (Moldflow Plastics Insight) software from Moldflow Co., the optimum conditions for producing the upper part of the automobile air cleaner were obtained for 20% talc filled polypropylene (PP). The analysis was carried out to solve the cracking problem between upper and lower parts and the improved process was proposed using the flow balance. The comparative results between the conventional process, CASE-1, with one-pin gate and the new process (CASE-2) comprising two-pin gate system are the followings. In the case of CASE-2, the shorter filling time and reduced cycle time induced an improved production and processibility. In addition, the orientation and volumetric shrinkage are similar to those observed in the lower part, but the assembly, deformation, and physical characteristics are enhanced. The problem induced by the CASE-1 did not originate from the residual stress, but from the difference in the size of the upper part air cleaner after shrinkage. Thus, the orientation problem was expected to improve by optimizing the gate structure.