• Title/Summary/Keyword: 수소 혼입

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Measures to Secure Safety according to Gas pipe Hydrogen Mixing(Carbon Neutral) (가스배관 수소혼입(탄소중립)에 따른 안전확보 방안)

  • Kwak, Che-Sik;Sin, Dong-Il
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2022.10a
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    • pp.290-291
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    • 2022
  • 본 논문에서는 우리나라 2030년 국가 온실가스 감축목표(NDC*, 291백만톤 감축)달성 및 2050년 탄소중립 목표 달성을 위해 필연적으로 수반되는 천연가스 내 수소 혼입에 따른 안전성확보 방안과 수소혼입에 따른 국민 불안감 해소 및 수용성 제고를 위한 대안을 제시하고, 해외 사례를 연구 하였다. 탄소중립은 온실가스(이산화탄소 등)의 배출량을 최대한 줄이고, 남은 온실가스를 흡수, 제거해서 실질적인 배출량이 "0"이 되는 것을 의미하고, 수소혼입은 도시가스의 주성분인 메탄 연소시 발생하는 CO2를 최소화하기 위해 수소(H2)를 도시가스에 일정비율 혼합하는 것을 말한다. 본 연구에서는 수소 혼입 시 우려되는 수소취성 및 배관내구성 문제와 수소 특성인 작은 입자로 인한 누출 위험성, 고층에서 메탄과 수소가 분리되는 현상 등에 따른 문제를 도출하고 이에 대한 안전관리 방안도 함께 제시하였다. 또한, 도시가스 배관에 수소 혼입시 천연가스 대체를 통한 온실가스 감축 및 기존 배관망 사용을 통한 경제성 분석결과와 국가 온실가스 감축에 어느 정도 기영할 수 있는지도 함께 기술하였다.

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Prediction of Damage Area due to Explosion of LNG-Hydrogen Mixed Gas (도시가스-수소 혼합가스의 누출사고 영향범위 분석)

  • Chan-sik, Yoon;Jin-du, Yang;Gil-soo, Na;Sung-Hyun, Im;Ki-young, Kim;Eun-ki, Choi
    • Explosives and Blasting
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    • v.40 no.4
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    • pp.27-34
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    • 2022
  • The government is promoting various policies to reduce greenhouse gas emissions for carbon neutrality, one of the key tasks is to revitalize the hydrogen economy. As one of these policies the government has formulated a plan to incorporate hydrogen into existing city gas pipes, and aims to commercialize 20% hydrogen mixing by 2026. In preparation for the commercialization of city gas and hydrogen mixture, this study quantitatively predicts the scale of damage and the range of impact in the event of leakage of these two gas mixtures. The quantitative damage prediction method is to calculate the damage conversion distance through the calculation of the TNT equivalent by setting the leakage amount of the gas mixture in the event of an accident under a virtual scenario.

Investigation on the Physical Properties of the Lightweight Mortar Made with Hydrogen Peroxide (과산화수소를 혼입한 경량기포 모르타르의 물리적 특성에 관한 연구)

  • Lee, Soo-Yong;Kim, Ji-Hyun;Lee, Jae-Yong;Chung, Chul-Woo
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.2
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    • pp.117-123
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    • 2018
  • The increase in energy efficiency has became a significantly important issue for building construction and maintenance. The energy efficiency is known to be achieved by using a material with lower thermal conductivity, and the best method is to increase the internal porosity of the material. Typical ways to increase internal porosity within cementitious composite are to use foaming agents or to use reactive powder such as aluminum. However, in this work, hydrogen peroxide was chosen as an alternative material to make lightweight cement mortar. The volume expansion of fresh cement mortar and unit weight, compressive strength and thermal conductivity of 28 day old cement mortar were measured. According to the experimental results, the incorporation of hydrogen peroxide increased internal porosity, and thereby reducing the compressive strength and thermal conductivities of cement mortar. It was found that hydrogen peroxide can be successfully used to produce lightweight mortar for thermal insulation purposes of buildings.

Properties of LightWeight Foamed Concrete According to Mixing Ratio of Admixtures. (혼화재 혼입에 따른 경량기포콘크리트의 특성)

  • Kim, Jae-Kyung;Ahn, Jung-Hyun;Lee, Sang-An;Kim, Wha-Jung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.297-298
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    • 2010
  • This study was investigates to the lightweight foamed concrete are uses by foamed agent to hydrogen peroxide($H_2O_2$). and then, lightweight foamed to improve the physical characteristics were mixed. mixes to type of admixture/level by changes/character to investigates, It is a purpose to look up admixture and mix proportion to be suitable in order to improve lightweight foamed concrete.

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Development of Control Program for Methane-hydrogen Fuel Conversion Based on Oxygen Concentration in Exhaust Gas (배기가스 내 산소 농도 기반 메탄-수소 연료 전환 제어 프로그램 개발)

  • EUNJU SHIN;YOUNG BAE KIM
    • Transactions of the Korean hydrogen and new energy society
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    • v.34 no.1
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    • pp.38-46
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    • 2023
  • Carbon neutrality policies have been strengthened to reduce emissions, and the importance of technology road maps has been emphasized. In the global industrial boiler market, carbon neutrality is implemented through fuel diversification of methane-hydrogen mixture gas. However, various problems such as flashback and flame unstability arise. There is a limit to implementing the actual system as it remains in the early stage. Therefore, it is necessary to secure the source technology of methane-hydrogen hybrid combustion system applicable to industrial fields. In this study, control program for methane-hydrogen fuel conversion was developed to expect various parameters. After determining the hydrogen mixing ratio and the input air flow, the fuel conversion control algorithm was constructed to get the parameters that achieve the target oxygen concentration in the exhaust gas. LabVIEW program was used to derive correlations among hydrogen mixing rate, oxygen concentration in exhaust gas, input amount of air and heating value.

The Electrical Properties of Hydrogenated Diamond Thin Film, MS and MIS Diamond Diodes (수소함유 다이아몬드 박막과 MS 및 MIS 다이아몬드 다이오드의 전기적 특성)

  • 이철로;임재영;천병선
    • Journal of the Korean Vacuum Society
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    • v.3 no.1
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    • pp.103-110
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    • 1994
  • 기전력 증가에 따라 균일 두께로 4종류 다이아몬드 박막을 성장하였다. 이들에 대해 성장직후 및 진공소둔 후 전기전도도를 조사한 결과 성장 중 기전력이 증가하면 다이아몬드 결정내에 원자상 수 소의 혼입이 증가되어 높은 전기전도도를 나타낸다. 고진공소둔에 의해 탈가스를 하면 원자상수소가 제 거되어 전기저도도를 감소시킬 수 있다. 그러므로 다이아몬드 박막을 유전체 박막에 응용하기 위해서는 진공 탈가스가 필요하다. MS 및 MIS 구조 다이아몬드 다이오드를 제조하여 정류특성을 평가한 결과 저농도 MS구조는 극히 낮은 정류특성을 나타내며 고농도는 Ohimc 거동을 하였다. MIS구조에서는 저 농도 및 고농도 모두 우수한 정류특성을 나타냈다. 그러므로 다이아몬드 박막으로 MIS구조에 의한 다이 오드를 제조하므로써 고속 고출력 전자소자 및 고온 고방사, 원자료, 우주 등 열악한 환경하에서 사용될 수 있는 전자소자의 가능성이 높다고 사료된다.

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Microstructure and Properties of Mortar Containing Synthetic Resin using Image Analysis (이미지 분석을 활용한 합성수지 혼입 모르타르의 특성 및 미세구조 분석)

  • Lee, Binna;Min, Jiyoung;Lee, Jong-Suk;Lee, Jang-Hwa
    • Journal of the Korea Concrete Institute
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    • v.28 no.1
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    • pp.59-65
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    • 2016
  • Commercial synthetic resins with great amount of hydrogen atoms were investigated for neutron shielding aggregates. Total three types of resins were considered in this study: high density polyethylene (HDPE), polypropylene (PP), and ultra molecular weight polyethylene (UPE). When these resins replaced 20, 40, 60 vol% of fine aggregates, mechanical properties were first evaluated including compressive and tensile strengths, and then image/microstructure analyses such as cross-section analysis, SEM, and X-ray CT were performed. The results showed that the compressive and tensile strengths decreased with the increase of replacement ratio of HDPE and PP, which was found through image analysis that it was closely related to the distribution of resins at the failure surface of test specimens. The strength reduction of UPE was quite small compared to HDPE and PP but it abruptly increased when the replacement level exceeded 60 vol%. The results of microstructure analyses indicated that the replacement level significantly affected the amount of air void so that it is critical to determine the reasonable amount of UPE to make cementitous materials for neutron shielding.

A Study on the Properties of Foamed Concrete with Plaster Using the Experimental Design (실험계획법을 이용한 석고 혼입 기포콘크리트의 특성에 관한 연구)

  • Lee, Sang-An;Kim, Wha-Jung;Yoon, Sang-Chun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.6
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    • pp.130-137
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    • 2013
  • This research was performed through the experimental design to get the statistical analysis on foamed concrete mixed plaster with hydrogen peroxide. In this experiment, we set the ratio of each material, which part of lightweight concrete, as experimental factors and evaluated on the mechanical properties by statistical analysis for response variables obtained from experiments. Experimental factors are plaster replacement, water binder ratio, and hydrogen peroxide ratio. Response variables are dry density, compressive strength, and flexural strength. Mixing design of the foamed concrete set up a total of 15 experimental points by Box-Behnken (BB) method of the response surface analysis. Thus, the results of a study were summarized as follows. Values of the probability in experimental factors (plaster replacement, water binder ratio and hydrogen peroxide ratio) on the response variables were estimated to be significant at the 95% of confidence limit. On response surface analysis for dry density of foamed concrete, water binder ratio and hydrogen peroxide ratio were estimated to be significant (${\alpha}$ = 0.05), and the relationship between the amount of void and the water content for dry density is inverse proportional. On response surface analysis for the compressive strength of foamed concrete, water binder ratio, hydrogen peroxide ratio and (hydrogen peroxide ratio)$^2$ was estimated to be significant (${\alpha}$ = 0.05). On response surface analysis for the flexural strength of foamed concrete, water binder ratio, hydrogen peroxide ratio was estimated to be significant (${\alpha}$ = 0.05). Through multi response surface analysis, we found the optimal area that meets performance goals.

Evaluation on the Basic Properties of Phosphate Modified Portland Cement Paste for Potential Application of Geologic CO2 Sequestration (이산화탄소 지중 격리용 인산염 혼입 시멘트 페이스트에 관한 기초물성 평가)

  • Yoon, Ju-Han;Kim, Seong-Geun;Kim, Ji-Hyun;Lee, Jae-Yong;Chung, Chul-Woo
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.3
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    • pp.253-260
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    • 2017
  • As global warming became a worldwide issue, a significant effort has been made on the development of technology related to $CO_2$ capture and storage. Geologic sequestration of $CO_2$ is one of those technologies for safe disposal of $CO_2$. Geologic sequestration stores $CO_2$ in the form of supercritical fluid into the underground site surrounded by solid rock, and concrete is used for prevention of $CO_2$ leakage into the atmosphere. In such case, concrete may experience severe damage by attack of supercritical $CO_2$, and especially in contact with underground water, very aggressive form of carbonation can occur. In this work, to prevent such deterioration in concrete, calcium phosphates were added to the portland cement to produce hydroxyapatite, one of the most stable mineral in the world. Temperature rise, viscosity, set and stiffening, and strength development of cement paste incorporating three different types of calcium phosphates were investigated. According to the results, it was found that the addition of calcium phosphate increased apparent viscosity, but decreased maximum temperature rise and 28 day compressive strength. It was found that monocalcium phosphate was found to be inappropriate for portland cement based material. Applicability of dicalcium and tricalcium phosphates for portland cement needs to be evaluated with further investigation, including the long term compressive strength development.

Neutron Shielding Performance of Mortar Containing Synthetic High Polymers and Boron Carbide (합성 고분자 화합물 및 탄화붕소 혼입에 따른 모르타르의 중성자 차폐성능 분석)

  • Min, Ji-Young;Lee, Bin-Na;Lee, Jong-Suk;Lee, Jang-Hwa
    • Journal of the Korea Concrete Institute
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    • v.28 no.2
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    • pp.197-204
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    • 2016
  • Concrete walls of neutron generating facilities such as fusion reactors and fission reactors become radioactive by neutron irradiation. Both low-activation and neutron shielding are a critical concern at the dismantling stage after the shutdown of facilities with a requirement of radioactive waste management. To tackle this, two types of additives were investigated in fabricating mortar specimens: synthetic high polymers and boron carbide. It is well known that a hydrogen atom is effective in neutron shielding by an elastic scattering because its mass is almost the same as that of the neutron. And boron is an effective neutron absorber with a big neutron absorption cross section. In this study, the effect of the type, shape, and size of polymers were investigated as well as that of boron carbide. Total 16 mix designs were prepared to reveal the effect of polymers on mechanical properties and neutron shielding performance. The neutron does equivalent of polymers-based mortar for fast neutrons decreased by 36 %, and the count rate of boron carbide-based mortar with regard to thermal neutrons decreased by 90 % compared to conventional mortar. These results showed that a combination of polymers and boron carbide compounds has potential to reduce the thickness of neutron shields as well as radioactive waste from reactors.