• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.187-197
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• 2010

Carbon dioxide Capture and Storage(CCS) is regarded as one of the most promising options to response climate change. CCS is a three-stage process consisting of the capture of carbon dioxide($CO_2$), the transport of $CO_2$ to a storage location, and the long term isolation of $CO_2$ from the atmosphere for the purpose of carbon emission mitigation. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the $CO_2$ mixture captured from the power plants and steel making plants contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_2$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification, transport and injection processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to analyze the impact of these impurities on the whole CCS process at initial design stage. The purpose of the present paper is to compare and analyse the relevant physical property models including BWRS, PR, PRBM, RKS and SRK equations of state, and NRTL-RK model which are crucial numerical process simulation tools. To evaluate the predictive accuracy of the equation of the state for $CO_2-SO_2$ mixture, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $SO_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable physical property model with optimized binary parameter in designing the $CO_2-SO_2$ mixture marine geological storage process.

• Proceedings of the Korea Water Resources Association Conference
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• 1989.07a
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• pp.113-114
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• 1989

원자력, 화력발전소, 제철소 등의 다양한 임해 공업시설로부터 방출되는 냉각용 온배수는 연안일대 해수의 열균형을 파괴시켜 생태계의 보존 및 환경관리에 좋지 못한 영향을 야기케 된다. 이러한 영향은 해안 또는 만내의 수중온도를 전반적으로 높일뿐 아니라 가동중단시 갑자기 수온을 떨어뜨려 해양생물상에 피해를 줄수도 있다. 또한 온배수에 의하여 온도가 상승된 해수가 취수구를 통하여 재순환되어 냉각기능의 부진을 초래하게되면 발전효율 또는 기계가동율을 저하시키게 된다. 이러한 측면에서 온배수의 확산에 대한 정성, 정량적인 예측은 환경영향평가, 취.배수구 설계조건의 산정 등에 매우 중요한 문제라 하겠다. 본 연구는 정지수역으로 유입하는 3차원 정상류 표면온배수 해석모형의 개발로서 개발된 모형의 수치실험을 통하여 온배수 확산의 물리적 특성을 규명한다. 지배방정식에 나타나는 Reynolds 응력항($)과 온도유동 프럭스항($)의 해석에서 필요한 난류모델은 k-$\varepsilon$ 모형에 난류 평균자승 온도유동($) 및 그 감쇄방정식을 추가한 4-방정식 모델로서 구성하였다. 아울러 3차원 정상류 모형에서 야기되는 타원형 방정식을 포물형 방정식의 형태로 전환하여 효과적으로 해석할 수 있도록 모델의 특성을 정리하였다. 본 모델의 검증을 위하여 Lal 및 Rajaratnam(1977)의 물리적 실험값과 비교해본 결과 온배수 거동의 물리적현상이 잘 일치하였다. 또한 McGuirk 및 Rodi(1979)에 의해 개발된 2-방정식 k-$\varepsilon$ 난류모형의 해석결과에 대하여 비교분석을 실시하였다.

• Ocean and Polar Research
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• v.38 no.4
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• pp.315-324
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• 2016

In this study, we investigated changes in the macrobenthic community in Sihwa tidal flat before and after the operation of a Tidal Power Plant (TPP). In order to investigate changes in the macrobenthic community structure, field surveys were conducted at eighteen stations in 4 transect lines every September from 2011 to 2015. Mean density of macrobenthos decreased to $116ind./m^2$ in 2015 from $1,602ind./m^2$ in 2011. While the mean density of macrobenthos has decreased, species richness and biomass have gradually increased. The species diversity and SEP (Shannon-wiener Evenness Proportion) have also gradually increased over time since the operation of the TPP. The macrobenthic community in Sihwa tidal flat was divided into 4 groups on a yearly base. Before the operation of TPP, opportunistic species such as Neanthes succina and Polydora cornuta largely contributed to the structure of the macrobenthic community, while equilibrium species such as Periserrula leucophryna and Scopimera globosa contributed after the operation. With the operation of TPP, the macrobenthic community has rapidly recovered and this might be related to improvement in the quality of water and sedimentary environments as a result of an increase in water mass volume exchanged through the TPP gate.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.231-236
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• 1997

Observation for hot water spread has been carried out by such activites as sampling of water with ship, etc, until now It was required further to have new probe methodologies in such issues as simultaneity, great-spheric nature, and economics due to many hindering ele- ments such as spread speed of hot waste water, weather conditions, cost and expenses, scope and location determinations. However, it was believed that satellite could be utilized to monitor spread of water temperature and spread level in more quick and correct way than existing one, because it would be possible to supervise and detect marine environment within significantly short period if analyzed by means of satellite images. Therefore, this study is taken into account to flow and spread conditions of hot waste water, survey of water temperature, by means of satellite images.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.194-200
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• 2015

본 연구에서는 하천부터 하구까지의 댐 구조물 건설로 인해 해안으로의 표사 공급원이 감소하는 것을 정량적으로 검토하였다. 내륙과 해양의 전이역인 연안은 농수산업, 임해산업단지, 발전소 및 항만과 같은 산업 인프라, 관광 및 레크리에이션 등의 다양한 편익을 제공하여 높은 경제 사회 환경적 가치가 있다. 그러나 80년대 이후 무분별하게 추진되어온 각종 연안 개발은 직 간접적인 해안의 침식문제를 발생시켰다. 우리나라 서해의 경우 하천으로부터의 토사 유입 차단은 심각한 수준이다. 아직 그 영향이 해안으로 완전히 파급되지 못하여 그로 인한 장기 해안 침식이 두드러지지 않고 있으나 고파랑에 의한 빈번한 침식과 저질의 세립화 현상을 통하여 현재 진행형임을 알 수 있다. 그러나 일단 피해가 심각해지기 시작하면 돌이킬 수 없는 재앙이 될 측면도 많다. 따라서 우리나라 유역의 개발과 수리구조물 건설 현황을 살펴 이로 인한 해안 침식 결과가 얼마나 심각할 수 있는 지를 살펴본다. 본 연구에서는 수리구조물로 인한 토사량 감소 중 가장 주요한 토사 공급원 감소 원인인 댐으로 인한 토사량 감소율에 대한 연구를 진행한다. 먼저 각 댐의 건설 전, 유역면적당 토사량과 댐 건설 후, 해안 유입 토사량 사이에 감소율을 계산하고, cascade 방법에 의하여 댐군에 의한 토사감소율을 산정한다. 유입 토사량 감소율을 산정하고 토사 공급원 감소로 인한 표사 수지 분석을 통해 해안 침식 폭의 위험도 평가를 실시한다.

• Journal of the Korean institute of surface engineering
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• v.55 no.6
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• pp.433-440
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• 2022

Environmental pollution caused by power plant exhaust gas is highlighted and eco-friendly regulations are being strengthened. However, due to the abundant reserves and low prices of coal, still the most used for power generation in the world. Therefore, flexible operation of coal-fired power plants to reduce emissions has become an inevitable option. However, lowering the output increases the possibility of acid dew point corrosion as the exhaust gas temperature decreases. The dew point corrosion occurs when condensable gases such as SO₃, HCl, NO₂ and H₂O cools below the saturation temperature. SO₃ is already well known to cause severe low- temperature corrosion in coal-fired power plants. Therefore, this study aims to prevent damage that may occur during operation by analyzing the dew point and corrosion resistance with exhaust gas temperature and sulfuric acid concentration of the power plant economizer tube.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.52-68
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• 2014

In this study, we investigated the seasonal variation of SST(Sea Surface Temperature) and thermal effluents estimated by using Landsat-7 ETM+ around the Kori Nuclear Power Plant for 10 years(2000~2010). Also, we analyzed the direction and range of thermal effluents dispersion by the tidal current and tide. The results are as follows, First, we figured out the algorithm to estimate SST through the linear regression analysis of Landsat DN(Digital Number) and NOAA SST. And then, the SST was verified by compared with the in situ measurement and NOAA SST. The determination coefficient is 0.97 and root mean square error is $1.05{\sim}1.24^{\circ}C$. Second, the SST distribution of Landsat-7 estimated by linear regression equation showed $12{\sim}13^{\circ}C$ in winter, $13{\sim}19^{\circ}C$ in spring, and $24{\sim}29^{\circ}C$ and $16{\sim}24^{\circ}C$ in summer and fall. The difference of between SST and thermal effluents temperature is $6{\sim}8^{\circ}C$ except for the summer season. The difference of SST is up to $2^{\circ}C$ in August. There is hardly any dispersion of thermal effluents in August. When it comes to the spread range of thermal effluents, the rise range of more than $1^{\circ}C$ in the sea surface temperature showed up to 7.56km from east to west and 8.43km from north to south. The maximum spread area was $11.65km^2$. It is expected that the findings of this study will be used as the foundational data for marine environment monitoring on the area around the nuclear power plant.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.982-990
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• 2019

The interest of researchers and governments in exploiting tidal energy resources is increasing. Jangjuk strait is a place with high tidal energy density potential and is therefore appropriate for the constructing of a tidal turbine farm. In this study, a numerical approach is presented to evaluate the current flow and power potential in Jangjuk strait with an ADCIRC model. Then, the tidal field characteristics are utilized as input parameters for tidal resource calculation with an in-house program. The 1 MW scale tidal energy converter devices are employed and arranged in 4 layouts to investigate the annual energy yield as well as flow deficit due to the wake ef ect at the surveyed area. The best-performed array generates an annual energy yield up to 12.96 GWh/year (without considering the wake effect); this value is reduced by 0.16 GWh/year when accounting for the energy loss caused by the flow deficit. Moreover, by altering the turbine yaw angle during the flood and ebb tides, the impacts of this factor on the energy extraction are analyzed. This indicates that the turbine array attains the maximum tidal power when the turbine yaw angle is at 346° and 164° (clockwise, to the North) for the spring and neap tide in turns.

• 한국해양학회지
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• v.1
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• pp.37-48
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• 1971

Observations of water temperature, salinity, pH and transparency of the Ko-ri sea area were made between May 1969 and April 1970. A seasonal thermocline was well defined in August, strongly isolating the warm serface water(19-22$^{\circ}C$) from the cold bottom water (14-17.5$^{\circ}C$) introducing from the open sea. In February the coldest isothermal water (11$^{\circ}C$) occurred. In the warm months(May- September), the salinity patterns show great variations with the coastal run-off During the cold months(December-April) the highest isohaline water (35 ) occurred. Annual ranges of surface and bottom pH values were 7.8-8.4(averaging 8.27) and 7.9-8.4(averaging 8.26), respectively. The transparency was greatest (6.0-7.0m) during winter and spring months and least (1.2-2.5m) during summer months.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.110-123
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• 2021

We investigated geochemical constituents of pore-water and sediment, rates of organic carbon (C_org) oxidation and sulfate reduction (SR), and benthic nutrient flux (BNF) to elucidate characteristic of C_org oxidation and its control in the coastal area near Lake Shihwa. The study sites were selected in the vicinity of Soraepogu (E0), Songdo tidalflat (E1) and Oido dock (E3) and in front of floodgate Shihwa tidal plant (E5). The C_org contents in the sediments and concentrations of ammonium and phosphate in pore water exhibited the highest value at EO, and gradually decreased toward the outer sea (E1, E3, E5). Rates of anaerobic C_org oxidation (260.6 mmol C m^-2 d^-1) and SR (91.4 mmol S m^-2 d^-1) at E0 were 4-9 and 6-54 times higher than at the site of outer sea (E1, E3, E5). Rates of SR at E3 and E5 accounted for 11-23% of anaerobic C_org oxidation, whereas it comprised 47-70% of anaerobic C_org oxidation at E0 and E1. Rates of C_org oxidation and SR showed a highly positive correlation with the concentration of dissolved organic carbon (r² = 0.795 and 0.777, respectively). The BNF at E0, E1, and E3 accounted for 120-510% and 26-178%, respectively, of the N and P required for primary production in the water column. Overall results suggest that the C_org oxidation in the sediment controlled by concentration of dissolved organic carbon in the pore water and the excessive C_org oxidation stimulates the benthic nutrient flux, which may cause a phytoplankton bloom in the water column.