• 한국가스학회지
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• 제26권2호
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• pp.1-8
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• 2022

본 연구에서는 탄산염암 저류층에서 활용 가능한 GPTMS((3-Glycidoxypropyl)trimethoxysilane)-SiO₂ 나노유체를 제조하고 주입 효과를 분석하였다. 표면개질에 따른 나노입자의 구조적 변화를 확인하기 위해 푸리에변환적외선분광(Fourier transform infrared spectroscopy, FTIR) 분석을 수행했으며, 0.5 mmol/g 이상의 GPTMS 농도에서 실리카 입자의 표면개질을 의미하는 2,950 cm^-1의 C-H 신축 진동(C-H stretching vibration)을 확인하였다. 또한, 친유성 상태로 에이징된 석회석과 백운석을 대상으로 나노입자의 농도와 주입률에 따른 GPTMS-SiO₂ 나노유체의 코어유동 실험을 수행하였다. 나노유체 주입에 따라 최대 18.9%의 오일이 추가로 회수되었으며, 암석의 접촉각과 투과도 변화를 확인할 수 있었다. 이는 나노입자가 탄산염암 표면에 흡착됨에 따라 습윤도를 개선함과 동시에 공극에 영향을 준다는 것을 의미한다. 따라서, 제조된 나노유체는 탄산염암 저류층을 대상으로 한 석유회수증진의 주입유체로 사용될 수 있으며 습윤도, 투과도 변화와 같은 유체 유동물성 개선에 활용될 것으로 기대된다.

• Nuclear Engineering and Technology
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• 제41권9호
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• pp.1157-1170
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• 2009

A variety of Generation III/III+ reactor designs featuring enhanced safety and improved economics are being proposed by nuclear power industries around the world to solve the future energy supply shortfall. Nanofluid coolants showing an improved thermal performance are being considered as a new key technology to secure nuclear safety and economics. However, it should be noted that there is a lack of comprehensible design works to apply nanofluids to Generation III+ reactor designs. In this work, the review of accident scenarios that consider expected nanofluid mechanisms is carried out to seek detailed application spots. The Axiomatic Design (AD) theory is then applied to systemize the design of nanofluid-engineered nuclear safety systems such as Emergency Core Cooling System (ECCS) and External Reactor Vessel Cooling System (ERVCS). The various couplings between Gen-III/III+ nuclear safety features and nanofluids are investigated and they try to be reduced from the perspective of the AD in terms of prevention/mitigation of severe accidents. This study contributes to the establishment of a standard communication protocol in the design of nanofluid-engineered nuclear safety systems.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1845-1850
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• 2022

In-vessel corium retention (IVR) during external reactor vessel cooling (ERVC) is a key severe accident management strategy adopted in advanced nuclear power plants. The injection of nanofluids has been regarded as a means of enhancing CHF when using the IVR-ERVC strategy to safeguard high-power nuclear reactors. However, a critical practical concern is that various types of debris flowing from the contaminant sump during operation of an ERVC system might degrade CHF enhancement by nanofluids. Our objective here was to experimentally assess the viability of nanofluid use to enhance CHF in practical ERVC contexts (e.g., when fluids contain various types of debris). The types and characteristics of debris expected during IVR-ERVC were examined. We performed pool boiling CHF experiments using nanofluids containing these types of debris. Notably, we found that debris did not cause any degradation of the CHF enhancement characteristics of nanofluids. The nanoparticles are approximately 1000-fold smaller than the debris particles; the number of nanoparticles in the same volume fraction is 1 billion-fold greater. Nanofluids increase CHF via porous deposition of nanosized particles on the boiling surface; this is not hindered by extremely large debris particles.

• 한국가스학회지
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• 제27권1호
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• pp.23-32
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• 2023

본 연구에서는 고갈된 가스전의 사암 저류층 또는 심부 대염수층 내 이산화탄소(CO₂) 주입효율 및 저장용량 증진을 위한 주입 첨가제로써 Al₂O₃ 나노유체를 합성하였다. 기반 유체로 탈이온수(deionized water, DIW)와 API Brine의 조성을 참고하여 제조한 염수를 사용하였으며, 양이온성 계면활성제인 CTAB (cetyltrimethyl-ammonium bromide)을 첨가한 Al₂O₃ 나노유체를 이용하여 유체를 합성하였다. 육안관찰, 동적광산란광도계(dynamic light scattering, DLS), 전자투과현미경(transmission electron microscope, TEM), 혼화성 시험(miscibility test)의 방법을 활용한 유체의 분산 안정성 평가 결과, 나노입자 농도가 0.05 wt% 이하 조건에서 70,000 ppm의 염수와 반응 후에도 응집 및 침전되지 않는 안정한 유체를 합성할 수 있음을 확인하였다.