• 청정기술
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• 제17권4호
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• pp.406-411
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• 2011

포항철강산업단지에서 발생하는 폐열을 회수하기 위하여 주요 기업의 폐에너지 발생 규모에 대한 데이터베이스를 설문조사를 통해 구축하고, 가시적인 기법을 적용하여 에너지 교환망 구축방안을 고려하였다. 폐열의 온도 수준, 유효에너지 발생량, 폐에너지 발생 기업과 예상 수요 기업의 거리, 구축비용 등의 관점에서 잠재성이 높은 에너지 교환망을 제시하고 경제성을 평가하였다. 최종 제안된 4개 기업의 에너지 교환망의 투자비 회수기간은 평균 2.8년이고, 에너지 절감량은 연간 4,778 TOE로 분석되었다. 현재 사용되는 LNG를 폐열 회수로 대체하면 연간 약 11,160 $CO_2$ ton을 감축할 수 있다.

• 한국가스학회지
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• 제28권1호
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• pp.1-10
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• 2024

본 연구에서는 농업 분야 에너지 자립 시스템 기술도입의 일환으로 농산부산물 기반 SOFC 열병합발전 시스템의 공정 모사 모델을 구축하고 열교환망 최적화를 진행하였다. 0.3 ton/d급 농산부산물 반탄화 연료 가스화기 실험 결과를 기반 농산부산물 SOFC 열병합발전 시스템 모델을 구축하여 4~20 kW급 SOFC 발전 용량별 열교환망 최적화를 진행하였다. 현재 시스템상에서 8 kW급 농산부산물 기반 SOFC 열병합발전 시스템이 최적으로 도출되었으며, 본 연구 결과를 기반으로 추후 상용 설비 설계 시 기초자료로 활용이 가능할 것으로 판단된다.

• 한국수소및신에너지학회논문집
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• 제33권5호
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• pp.515-524
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• 2022

In this study, the on-site hydrogen production process for refueling stations that were not energy-optimized was improved through exergy analysis and heat exchange network synthesis. Furthermore, the process was scaled up from 30 Nm3/h to 150 Nm3/h to improve hydrogen production capacity. Exergy analysis results show that exergy destruction in the SMR reactor and the heat exchanger accounts for 58.1 and 19.8%, respectively. Thus, the process is improved by modifying the heat exchange network to reduce the exergy loss in these units. As a result of the process simulation analysis, thermal and exergy efficiency is improved from 75.7 to 78.6% and 68.1 to 70.4%, respectively. In conclusion, it is expected to improve the process efficiency when installing on-site hydrogen refueling stations.

• 한국지열·수열에너지학회논문집
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• 제18권3호
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• pp.1-6
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• 2022

Ground source heat pump (GSHP) system is highly efficient and environment-friendly and supplies heating, cooling and hot water to buildings. For an optimal design of the GSHP system, the ground thermal properties should be determined to estimate the heat exchange rate between ground and borehole heat exchangers (BHE) and the system performance during long-term operating periods. However, the process increases the initial cost and construction period, which causes the system to be hindered in distribution. On the other hand, much research has been applied to the artificial neural network (ANN) to solve problems based on data efficiently and stably. This research proposes the predictive performance model utilizing ANN considering local characteristics and weather data for the predictive performance model. The ANN model predicts the entering water temperature (EWT) from the GHEs to the heat pump for the modular GHEs, which were developed to reduce the cost and spatial disadvantages of the vertical-type GHEs. As a result, the temperature error between the data and predicted results was 3.52%. The proposed approach was validated to predict the system performance and EWT of the GSHP system.

• 제어로봇시스템학회논문지
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• 제12권12호
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• pp.1184-1190
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• 2006

Most chemical companies try to maximize their energy efficiencies due to high oil price and reinforcement of environmental regulation. An individual factory continuously has tried to reduce energy consumption or carbon dioxide discharge for high profit. Nevertheless, it is found that waste heat is disposed with forms of low or medium pressure steams. It can be improved by the aspect of entire industrial complex. Therefore, we have developed a steam network optimization method using Steam Networking Matrices(SNMs) in this research. Results from an illustrative example show that energy consumption can be reduced by optimizing steam exchange networks.

• 한국수소및신에너지학회논문집
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• 제29권1호
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• pp.19-24
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• 2018

Fuel cells are used to generate electricity with a reformer. In particular, methanol has various advantages among the fuels for reformer. Methanol steam reformer devices can efficiently supply hydrogen to PEM fuel cell. This study investigated the optimal operation conditions of a methanol steam reforming process. For this purpose, aspen HYSYS was used for the optimization of reforming process. The optimal operating condition could be designed by setting independent variables such as temperature, pressure and steam to carbon ratio (SCR). The optimal temperature and steam to carbon ratio were $250-270^{\circ}C$ and 1.3-1.5, respectively. It is advantageous to operate at a pressure of 15-20 barg, considering the performance of the hydrogen purifier. In addition, a heat exchange network was designed to supply heat constantly to reformer through the latent heat of steam.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.351-351
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• 2000

Since the heat exchange system, such as the boiler of power plant, gas turbine, and radiator require an application of intelligent control system for a high rate heat efficiency and the efficiency of these systems is depended on the control methods it is important for operator to understand control system of these systems and intelligent control technologies. In order to properly apply control equipment and intelligent technology to these process control systems, it is necessary to understand fuzzy, neural network, genetics, and immune as well as the basic aspects and operation principle of the process that relate control, interrelationships of the process characteristics, and the dynamics that are involved. Generally, since PID controllers are used in these systems it is difficult far engineer to understand both the complex dynamics and the intelligent control method. In this paper, we design an effective experimental system for the intelligent control education and analyze its characteristics through experimental system and each intelligent method to study how they can learn intelligent control system by experiments.

• 한국가스학회지
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• 제28권1호
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• pp.44-52
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• 2024

본 연구에서는 유기성 폐기물로부터 생산되는 바이오가스를 이산화탄소 제거 없이 직접 이용하여 바이오가스 전처리 및 정제 공정 비용을 절감하여 수소를 생산하는 공정의 모델을 구축하고 열교환망 최적화를 통해 공정비용 최소화, 수소 생산량 및 최종 배가스 온도 최대화를 목표로 공정 모사를 진행하였다. 공정 최적화 결과 열교환기 개수 제한조건을 충족하면서 최종 배가스 온도를 최대화하는 공정모델이 가장 효율적임을 확인하였다. 본 연구의 결과는 바이오가스 직접 이용 수소 생산 공정의 상용개념설계에 활용되어 바이오가스의 청정수소 에너지 전환기술 확대에 기여 가능할 것으로 판단된다.

• Korean Chemical Engineering Research
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• 제52권6호
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• pp.720-726
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• 2014

PEMFC(Proton Exchange Membrane Fuel Cell) 차량은 미래 청정수송기관으로 각광받고 있지만 수소스테이션의 인프라부족으로 현재는 수소를 공급해주는 연료개질기를 함께 장착하여 구동하여야 한다. 탄화수소연료로부터 수소를 생산하는 연료개질기를 대상으로 다양한 연구가 진행되어왔는데 기존연구에서는 열적중립 조건의 ATR(Auto-Thermal Reformer) 반응기에 대해 집중적으로 분석하거나 공정최적화부문에서 최대수소생산을 목표로 주로 열효율을 목적함수로 설정하여 평가해 왔다. 본 연구에서는 100 kW PEMFC용 연료개질기를 대상으로 간단한 소형시스템을 얻기 위해 외부 유틸리티가 필요없는 단열열교환망으로 구성된 조건에서 기존 열효율이 아닌 수소효율을 새로이 정의하여 가솔린, LPG, 디젤 각 연료에 대해 최적운전조건을 도출하였다. 가솔린의 경우 기존 비교문헌보다 9.43% 연료절감효과를 얻음으로써 제안한 목적함수의 타당성을 입증하였고, 추가적으로 수소효율 및 열교환량, 열교환면적에 대한 민감도 분석을 실시하였다. 마지막으로 제안한 시스템을 한국시장에 적용할 경우 LPG 연료를 사용하는 연료개질기가 가장 경제적임을 알 수 있었다.

• 한국자기공명학회논문지
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• 제23권1호
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• pp.26-32
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• 2019

${\alpha}B$-crystallin (${\alpha}BC$) is a member of a small heat-shock protein (sHSP) superfamily and plays a predominant role in cellular protein homeostasis network by rescuing misfolded proteins from irreversible aggregation. ${\alpha}BC$ assembles into dynamic and polydisperse high molecular weight complexes containing 12 to 48 monomers; this variable stereochemistry of ${\alpha}BC$ has been linked to quaternary subunit exchange and its chaperone activity. The chaperone activity of ${\alpha}BC$ poses great potential as therapeutic agents for various neurodegenerative diseases. In this mini-review, we briefly outline the recent advancement in structural characterization of ${\alpha}BCs$ and its potential role to inhibit protein misfolding and aggregation in various human diseases. In particular, nuclear magnetic resonance (NMR) spectroscopy and its complimentary techniques have contributed much to elucidate highly-dynamic nature of ${\alpha}BCs$, among which notable advancements are discussed in detail. We highlight the importance of resolving the structural details of various ${\alpha}BC$ oligomers, their quaternary dynamics, and structural heterogeneity.